Developing new equations for estimating cover-management factor in fire-affected forest lands in west north of the Guilan province
ali
akbarzadeh
Ph.D. Student of Shahrekord University
author
Shoja
Ghorbani-Dashtaki
Faculty member of Shahrekord University
author
Mehdi
Naderi-Khorasgani
Faculty member of Shahrekord University
author
Jahangard
Mohammadi
Faculty member of Shahrekord University
author
Rouhollah
Taghizadeh-Mehrjardi
Faculty member of Ardakan University
author
text
article
2017
per
Background and Objectives: The correct estimation of cover-management (C) factor for accurate evaluating of soil loss is essential. Because of spatial variations in soil erosion parameters and vegetation attributes in large areas, the possibility of applying the available tables and regression equations to estimate the C-factor to other regions is limited. Up to this time, no studies have been done to estimate the C-factor in the forests of northern Iran. The main objective of this study was to develop new equations to estimate the C-factor in some parts of forest lands of the Guilan province using remote sensing methods and field works. Materials and Methods: In parcels separated in 15 fire-affected sites and 15 original forests beside the burned (unburned) sites, in five sub land units, some vegetation attributes, soil properties and erosion rate were measured. The soil erosion was also estimated for all 30 studied parcels using the Revised Universal Soil Loss Equation (RUSLE) model. The actual C-factor were extracted for all the studied parcels (burned and unburned sites) using the measured (observed) erosion and other factors used in the RUSLE model. A split-plot in space design was performed to determine whether the differences between five sub land units (between subjects) and also within burned and control (unburned) sites (within subjects) were significant. Results: The results showed that the average of the actual C-factor in unburned and burned sites in five sub land units depending on plant density and disturbance of forest lands by fire severity and human and animal activity were between 0.05 to 0.14 and 0.13 to 0.24, respectively. In general, the estimated C-factor was more than the actual C-factor in all the studied sites. Moreover, the results of analysis of variance showed that damaging of trees by fire had significant effect on the estimated C-factor, actual C-factor, estimated erosion, measured erosion and soil erodibility factor. To develop new equations for estimating the C-factor, the correlations between the actual C-factor and some vegetation attributes and soil moisture characteristics were investigated. First of all, the relationship between the actual C-factor and the Normalized Difference Vegetation Index was derived as a new equation to estimate the C-factor in the study area. Then, the results of Multiple Linear Regression by stepwise method showed that among all the variables related to vegetation and soil moisture, the thickness of surface litter, canopy cover, diameter of trees at breast height, saturated water content and Permanent Wilting Point were the best variables to estimate the C-factor in the study area. Conclusion: The soil erosion assessment using available models to estimate the C-factor had no adequate accuracy and caused errors in soil loss estimation. The models derived in this paper can be used for accurate estimation of the C-factor in other areas having similar crop attributes.
Journal of Water and Soil Conservation
Gorgan University Of Agricultural Sciences
2322-2069
23
v.
6
no.
2017
1
25
https://jwsc.gau.ac.ir/article_3476_42ec1ddd10127ccbcb355c9acfeb19da.pdf
dx.doi.org/10.22069/jwfst.2017.10820.2521
Drought characteristics based on Reconnaissance Drought Index and its variations in different time periods and regions of Iran
Abolfazl
mosaedi
دانشگاه فردوسی مشهد- دانشکده منابع طبیعی و محیط زیست
author
samaneh
محمدی مقدم
دانشجوی دکتری گروه مرتع و آبخیزداری، دانشگاه محقق اردبیلی
author
غزاله
کواکبی
دانشجو دکتری گروه علوم و مهندسی آب دانشگاه فردوسی مشهد
author
text
article
2017
per
Background and objectives: Drought is a climatic phenomenon that occurs in all climatic zones. Drought has three characteristics of duration, severity and magnitude. Reconnaissance Drought Index (RDI) is a indicate for drought. Climate change and subsequent changes in the characteristics of the phenomenon of drought and its impact on terrestrial ecosystems caused concern among researchers in human societies. َAthough drought occurred in all climate zones, but its features may vary by region. Characteristic’s drought may changes at time during due to word warming (Climate change). Therefore, propose of this study is investigating drought characteristics (including: severity, intensity, magnitude, time interval and frequency of drought) and their statistical Characteristics based on RDI in 8 synoptic station at time period of 60 years. Materials and methods: In order to monitor droughts for 8 selected synoptic stations of Esfehan, Ahwaz, Babolsar, Tabriz, Tehran, Khoramabad, Zahedan and Mashhad from different weather's conditions. Run Theory is a common method in analysis of drought. In addition to the three above characteristics of drought (severity, intensity, magnitude), in this study, other features of droughts include time interval and number of droughts is introduced and studied. While at the same time of drought monitoring, drought characteristics and possible changes in these properties during the studied period, were investigated. For this purpose, first, the values of Reconnaissance Drought Index (RDI) for the entire period of 1951 to 2010 in three scales of annual, seasonal and monthly were calculated. Drought characteristics include severity, intensity, magnitude, time interval and frequency for the "first half and the second half" was compared together using the Mann-Whitney test at 95% level. Cut point was determined by Kolmogorov-Smirnov test. Accordingly, the whole period of 60 years was divided into two periods (the period before the cut point and the period after it) and characterization of drought in these two periods were compared with each other. Results: In all stations, cut point year in the period of 60 years is different from the middle year (1981). On an annual scale, in any of the studied stations, the characteristics of duration and drought number had no significant difference at95%. Other features of drought in annual scale have significant difference only in Tabriz and Tehran. In the seasonal scale by comparing the two periods of 1951-1980 (first half) with 1981-2010 (second half) in the city of Zahedan, in the second half period, the severity, magnitude and frequency of drought were increased while, the interval time between the droughts was reduced. Other regions show no significant change in the properties of drought. At the seasonal scale, in general it can be concluded that in spring droughts are more severe comparing with the first period. While drought in the winter did not noticeably change in most stations. For monthly scales, In general, the highest reduction of drought events was happened in November, while in many cities the number or severity of drought events were increased in May or April in the second half than the first half. This could indicate reducing of rainfall and increasing of evapotranspiration in the spring months. Conclusion: In general, time series of drought indices values in all stations have a cut point at 95% level. This reflects the heterogeneity and changes in drought conditions. In addition, some changes were occurred in the drought characteristics or in occurrence time in some stations. This changes in drought characteristics is more pronounced, especially in the spring months. Although these changes were not significant in many cases, at 95% yet. The main reason for this can be seen in relation to the issue of global warming and climate change.
Journal of Water and Soil Conservation
Gorgan University Of Agricultural Sciences
2322-2069
23
v.
6
no.
2017
27
52
https://jwsc.gau.ac.ir/article_3477_89b2428d5b2a56689fcd99d66259d323.pdf
dx.doi.org/10.22069/jwfst.2017.8878.2266
Investigation of Effect of Biochar and Natural Zeolite Application on Copper Stabilization in a Cu-Polluted Calcareous Soil
hamidreza
boostani
دانشکده کشاورزی و منابع طبیعی داراب، دانشگاه شیراز
author
مهدی
نجفی قیری
دانشکده کشاورزی و منابع طبیعی داراب، دانشگاه شیراز
author
text
article
2017
per
Background and objectives: In situ immobilization procedures concern the reduction of heavy metals bioavailability in contaminated soils using the materials which are compatible with the environment. In recent years, biochars effectively have been used to minimize the heavy metals uptake by agricultural crops in polluted sites using the immobilization process. Also, zeolite is a porous alkali alumino-silicate mineral that its application as an inorganic modifier is developing particularly in stabilizing the soil heavy metals. Accordingly, the aim of this study was to investigate the copper (Cu) stabilization as influenced by biochars (derived from different organic materials) and natural zeolite application and their interactions in a Cu-polluted calcareous soil. Materials and methods: The appropriate amount of soil from the surface horizon (0-30 cm) of a calcareous soil, was collected, air dried and passed through 2 mm sieve. Then, the amount of 500 mg kg-1 Cu supplied as CuSO4, 5 H2O was added to each soil sample (200 g). A factorial experiment in a completely randomized design was done with three replications. Factors included zeolite at three levels (0 (Z0), 3 % (Z1) and 6 % (Z2) (w/w)) and biochar at six levels (without biochar application (C), wheat straw biochar (WSB), corn straw biochar (CSB), licorice root pulp biochar (LRB), rice husk biochar (RHB) and sheep manure biochar (SMB) each at 3 % (w/w)). Contaminated soil samples were treated according to the experimental design and were kept for 90 days at room temperature (22±2 ˚C) and about field capacity moisture with distilled water. To assess the efficiency of applied amendment materials in soil for stabilization of Cu, the sequential extraction procedure, reduced partitioning index (IR) and the parameters of two-first order kinetic model using EDTA extractant (Q1, Q2 and Q3) were used. Results: Relative percentage of Cu chemical fractions in different treatments in soil were as: carbonatic (Car) > residual (Res) > organic (OM) > adsorbed (Ads) > soluble+exchangeable (WsEx). With increasing the application of zeolite levels from Z0 to Z2, the concentration of WsEx, Ads, OM and Car fractions were significantly reduced by 5.46, 7.80, 10.40 and 15.30 percent respectively while, the Res form of Cu was increased. Application of all biochars except RHB, significantly caused the decrease of WsEx fraction compared to control. Use of all biochars led to reduction of the concentration of OM and Car fractions of Cu significantly while, Res fraction was significantly increased compared to control. Also, IR value was significantly increased as affected by zeolite levels and biochars application. The SMBZ2 combined treatment had the highest IR value. Soil pH showed a significant and positive correlation with Res fraction and IR value of Cu, which it indicates the important role of pH enhancement in stabilization of Cu in tested soil as affected by applied treatments. Copper desorption by EDTA extractant in all treatments was initially rapid, then continued at a slower rate, which probably indicating the incorporation of several sites with different bond energy in Cu desorption from soil. The Q1/Q3 and Q2/Q3 ratios were significantly decreased by application of all biochars and zeolite levels. The lowest of these ratios was observed in WSBZ2 combined treatment. There was a significant and positive correlation between the Q1 and Q2 parameters with Car fraction and the Q3 parameter with Res fraction of Cu in soil. Conclusions: Application of all biochars and zeolite levels caused the transformation of Cu chemical fractions from more bioavailable and mobile forms to more stable forms. According to the results, it seems that SMBZ2 and WSBZ2 combined treatments were more effective to stabilize Cu in soil than other treatments.
Journal of Water and Soil Conservation
Gorgan University Of Agricultural Sciences
2322-2069
23
v.
6
no.
2017
53
78
https://jwsc.gau.ac.ir/article_3478_3799c5f5262dcf34d0edc509536e6868.pdf
dx.doi.org/10.22069/jwfst.2017.11632.2609
Reduction of arsenic mobilization in soil by application of hematite nanoparticles and acrylic polymers
tahereh
mansouri
دانشگاه زنجان
author
احمد
گلچین
استاد گروه خاکشناسی دانشگاه زنجان
author
محمد
بابااکبری ساری
استادیار گروه خاکشناسی دانشگاه زنجان
author
شروین
احمدی
عضو هیئت علمی پژوهشگاه پلیمر ایران
author
text
article
2017
per
Background and objectives: Arsenic (As) is one of heavy metals that because of its toxicity and carcinogenicity, attention to the environmental remediation of this element is growing. It is the forms of chemical associations of As with various soil solid phases rather than its total concentration that affects its mobility, bioavailability and toxicity to the biosphere. Chemical stabilization technique is based on reduction the mobility and availability of toxic metals by different additives (adsorbents). This study was conducted to evaluate and compare the effectiveness of hematite nanoparticles and acrylic polymers in As immobilization in soils contaminated with different levels of As and find appropriate application dosage of the adsorbents. Materials and methods: A Factorial experiment was conducted using a completely randomized design and three replications. The experimental factors were types and dosages of adsorbents (Four types of adsorbents including hematite nanoparticles, acrylamide - acrylic acid copolymer (A), Maleic anhydride- Styrene - acrylic acid copolymers (B and C) in four levels including 0, 0.05, 0.1 and 0.2 percent) and As levels (0, 6, 12, 24, 48 and 96 mg/kg). Soil samples were incubated for five months, then adsorbents were added to them and after three months the concentrations of soil available As and specifically sorbed As were determined using 0.05 M of ammonium sulfate and 0.05 M of ammonium phosphate respectively. The concentration of sum of soil available and specifically sorbed As was calculated. The effectiveness of the adsorbents in reduction the concentrations of soil As fractions were discussed. Results: SEM and TEM images showed that the average diameter of hematite nanoparticles was 32.69 nm and the morphology was spherical. The results showed that the concentrations of soil available, specifically sorbed and sum of soil available As and specifically sorbed As concentrations increased as the levels of soil As increased. Application of adsorbents decreased the concentrations of soil available, specifically sorbed and sum of soil available As and specifically sorbed As and with increasing the application dosage of adsorbents, the rate of reduction of concentrations of soil available, specifically sorbed and sum of them increased, so that the lowest concentrations of these As fractions obtained from application of 0.2 % of adsorbents. The application of hematite nanoparticles decreased the concentrations of soil As fractions more than other adsorbents, and C, A and B acrylic copolymers stand in next places respectively. At all levels of soil As, the minimum concentration of soil sorbed As was related to soil treated with 0.2% of hematite nanoparticles and the maximum concentration of it was related to control treatment (not treated with adsorbent). The rates of reduction of soil available As concentrations by application of 0.2 % of hematite nanoparticles, C, A and B acrylic copolymers were 60.80%, 56.82%, 37.87%, 26.57% respectively. At the same types and dosageof adsorbents, the rates of reduction of soil specifically sorbed As concentrations were 27.56%, 22.72%, 14.88% and 10%. Finally the rate of reduction of soil total sorbed As concentrations, at the same types and dosage of adsorbent, were 39.39%, 34.84%, 23.05%, 15.88% respectively. The nature and then number of metal chelating ligands determined polymers adsorption capacity. At higher levels of soil As, adsorbents were more effective in reducing the concentrations of soil As. Also their effectiveness in reducing the concentration of soil available As was higher than the soil specifically sorbed As. Conclusion: Hematite nanoparticles and C, A and B acrylic copolymers, especially hematite nanoparticles, can be used as effective adsorbents in reducing the concentrations of soil available As, specifically sorbed As.
Journal of Water and Soil Conservation
Gorgan University Of Agricultural Sciences
2322-2069
23
v.
6
no.
2017
79
99
https://jwsc.gau.ac.ir/article_3479_23e07cf7ef8f0ed1b9338a17e72b8c45.pdf
dx.doi.org/10.22069/jwfst.2017.10254.2473
Factors affecting the Transport of Carboxymethyl Cellulose coated Zero Valent Iron Nano-particles in Soil
محمود
فاضلی سنگانی
دانشجوی دکتری تخصصی دانشگاه فردوسی مشهد
author
Ali Reza
Astaraei
عضو هیئت علمی دانشگاه فردوسی مشهد
author
امیر
فتوت
عضو هیئت علمی دانشگاه فدوسی مشهد
author
Hojat
Emami
عضو هیئت علمی دانشگاه فردوسی مشهد
author
text
article
2017
per
Abstract Background and objectives: As versatile materials, zero valent iron nanoparticles (NZVI) have been employed for in-situ decontamination of a wide range of water and soil contaminants, including organic chlorinated compounds, pesticides, inorganic anions and heavy metals. To carry out a successful clean-up plan, it is necessary to deliver the decontaminant agent to the vicinity of pollutant. Therefore a considerable number of studies have investigated the factors which affecting transport behavior of NZVI particles in natural subsurface environments. Most of these studies have been utilized model solutions and well defined homogeneous porous media such as glass beads and pure quartz sand. As bare (unmodified) NZVI particles has been found to be immobile even in homogeneous porous media, different coating agent such as Carboxymethyl cellulose (CMC) has been used for surface modification of NZVI in order to improve their mobility in subsurface environments. So far, no investigation has been conducted on undisturbed soil columns, considering the real properties of the media in which the NPs are transported. So in this study, different soil types covering a wide range of soil properties in terrestrial systems are examined and the main characteristics associated with NZVI mobility in saturated soil media. Materials and methods: Several parameters (n=29) including physiochemical and hydraulic properties of 20 different soil types and nanoparticle characteristics in soil extract suspension were measured and the transport parameters estimated from breakthrough curves employing a two-site kinetic model of advection-dispersion equation. Principal component analysis (PCA) was then used to explore the significant factors which control CMC-NZVI transport. Multi-linear regression model was investigated between the percentage of transported CMC-NZVI through the soil and the properties of soil and nanoparticles. Results: Results showed that depending on the soil type, 10.2 to 61.9 percent of introduced CMC-NZVI mass passed through the soil columns which indicates CMC-NZVI particles are mobile in soil medium; However CMC-NZVI particles were significantly retained by soils with higher clay contents and salinity. PCA results showed that 7 selected principal components (PC) described 88.2% of the total variance of the input variables where, Solution chemistry had high loading values in PC1 among the examined parameters. A multi-linear regression model developed between two kinds of input variables including primary variables and factor scores (FSs) as secondary variables, and percentage of transported CMC-NZVI through the soil column, showed that regression model employing FSs as secondary input variables presents a better estimation of CMC-NZVI particles transportability in soil with higher R2 and lower RMSE values. Conclusion: PCA results indicate the significance of solution chemistry, clay content and hydrodynamic properties of soil in CMC-NZVI transport. Results of this study suggest CMC-NZVI particles are mobile enough to be employed for subsurface remediation when clay content and salinity of soil are not so high. However more investigations are need to explore the efficiency of these materials for removing different pollutants from natural soils and subsurface media.
Journal of Water and Soil Conservation
Gorgan University Of Agricultural Sciences
2322-2069
23
v.
6
no.
2017
101
121
https://jwsc.gau.ac.ir/article_3480_9bf5c11c61b10a0c59283029ed88eca8.pdf
dx.doi.org/10.22069/jwfst.2017.9199.2316
Modelling the daily runoff of Nazloo Chai watershed at the west side of Urmia Lake
حسین
رضایی
دانشیار و عضو هیئت علمی گروه مهندسی آب، دانشگاه ارومیه
author
Anahita
Jabbari
the PhD candidate of irrigation and drainage engineering, water engineering department, urmia university
author
Javad
Behmanesh
associte professor and the academic member of water engineering department of Urmia university
author
Behzad
Hessari
assistant professor and the academic member of Urmia lake research center
author
text
article
2017
per
Background and objectives: After 1960,s computer revolution, the hydrologic modelling took on a new form and the Stanford watershed model may be considered as one of the early successful attempts in this regard. The rainfall runoff models have always been considered as one of the most effective decision tools in watershed management. In the current study, the Tank daily rainfall runoff model was used in Nazloo Chai river watershed at the west side of Urmia Lake. The importance of the lake hydrologic fluctuations in today’s critical situation is obvious to everyone. Knowing the rainfall runoff relations in all sub catchments of the Urmia basin especially in a watershed such as Nazloo which suffers from insufficient number of measurement stations and limited information from those parts of catchment located in Turkey, is so important. As a result, the goal is building a relation between rainfall of catchment and the out let runoff, in order to predict the future amounts of runoff. Materials and methods: The Nazloo Chai river with almost 93 km length is one of the 13 rivers drops into Urmia lake. The Tank rainfall runoff model is a simple, conceptual and lumped model. The model inputs are precipitation, evaporation, and daily runoff at the outlet of watershed. Among all available gauges, 3 stations with the most acceptable overlapping covered area and longest joint statistical period, 16 years, have been selected. Due to high water withdrawals in the last sub catchment before the watershed outlet, the mentioned sub catchment has been eliminated and the total area of modeled watershed has been decreased. The monthly average of precipitation and evaporation measured data have been compared with long term amounts of these parameters in order to modify the input data and reflect the watershed processes in input data as well. The Tank model is presented along with some other famous rainfall runoff models in RRL software package which has been developed in Australia. The sum of 224 calibrations and verifications by using 7 optimization methods, 8 primary objective functions and 4 secondary objective functions have been done. The model was evaluated by considering Nash and correlation coefficients in each run. Results: Totally about 117 runs from all 224 runs have shown nice fit, and their Nash coefficients were reported between 0 and 1 which is an acceptable range. About 30 cases also had a Nash coefficient more than 0.4 and the graphical fitness between observed and estimated runoffs also confirmed the acceptable fitness. The correlation coefficient was also evaluated and totally confirmed the models which were selected based on Nash coefficient. But due to Nash coefficient advantages compared with correlation coefficient, it was used in current study. Conclusion: It was concluded that the model didn’t perfectly simulate the peak discharges and they have been lower estimated. It was determined through field research and historic data evaluation, that the peak discharges occur mostly during April and May in the region. Along with the high rainfall events the snowmelts are also constituent the large part of runoffs at that time. Insufficient number of stations especially in highlands of the region, and the lack of some nodes in model in order to exert snowmelt data, eventuate lower rainfall input data and as a result disable model to simulate peak flows. But generally the base flows were simulated well and the model performance was accepted.
Journal of Water and Soil Conservation
Gorgan University Of Agricultural Sciences
2322-2069
23
v.
6
no.
2017
123
141
https://jwsc.gau.ac.ir/article_3481_7aa3e4806e5b47f299f13908f0c50e7f.pdf
dx.doi.org/10.22069/jwfst.2017.9735.2401
Experimental study on the effects of the shapes and arrays of submerged impermeable plates on turbidity current characteristics
zahra
ghorbani
MSc student of Hydraulic structure Birjand University
author
Hossein
Khozeymehnezhad
Assistant professor Department of water Engineering University of Birjand
author
Yousef
Ramezani
Assistant professor Department of water Engineering University of Birjand
author
text
article
2017
per
Background and objectives: Nowadays, dams are one of the most important structures to store surface water. Turbidity currents are usually the reason of sediment transport and deposition in deep reservoirs. As the turbidity current is completely stopped in the middle regions of the reservoir, sediment deposition reduces near the dam wall and as a result the main tasks of the dam are not disrupted. So, it is important to study the phenomenon. Roughening up or using obstacle the bed is a technique for changing the turbidity current hydraulics or reducing of its velocity. Some researches have been studied at this field, however, it is necessary to evaluate the effect of submerged impermeable plates on turbidity currents. Materials and methods: In the present research, the head velocity and height of the turbidity current head were studied on the bed with submerged impermeable plates. For this purpose an experimental, flume with 30cm width, 10m length and 46cm height was used. The turbidity current was entered into the flume with concentration of 20 g.l-1 with 1 and 2 percent bed slopes and concentration of 40 g.l-1 with 1 and 2 percent bed slopes. Impermeable plates which came into two different areas (16 and 36 cm2) in five shapes (Square, rectangular, triangle, rhombus and trapezius) were located across the current. Also, square impermeable plates were placed as five arrays (parallel, plaid, converge, diverge and Z-shape) with an area of 16 cm2. Results: Flow velocity was measured in 6 sections with distance 50cm and the height of head in 21 sections with distance 15cm. Then, non-dimensional graphs of velocity, height, Froude number and Richardson number of turbidity current head were drawn by using the data which obtained by Buckingham dimensional analysis method. Dimensionless velocity during the installation significantly decreased due to collision turbidity current to with plates. Also, the height of turbidity current head in the along of flow path indicated that plates gradually reduced the height of head at the beginning of the route. Height of turbidity current head was increased and the current path Froude number was decreased at the end of the path. Conclusion: Results showed that the development velocity of the turbidity current reduced between 25-48 percent proportion to smooth bed in the condition of plate’s installation with different shapes and also the height of head reduced between 5.1-18.4 percent. Also, development velocity was reduced between 11.2-45.1 percent and the height of head was reduced between 0.4-18.4 percent in different arrays. Converge array in the concentration of 20 g.l-1 and Parallel array in the concentration of 40 g.l-1 were determined as the best array. By changing the area of plates from 16 to 36 cm2 between different shapes, the shape of rhombus with 22.2 percent, showed the greatest effect in reducing velocity.
Journal of Water and Soil Conservation
Gorgan University Of Agricultural Sciences
2322-2069
23
v.
6
no.
2017
143
162
https://jwsc.gau.ac.ir/article_3482_0157417d34f2cb782cc414f08a58755f.pdf
dx.doi.org/10.22069/jwfst.2017.10569.2500
Simulation of soil moisture distribution under drip irrigation pulsed and continuous in dimensional analysis method.
آرش
محمدبیگی
دانشگاه تهران
author
فرهاد
میرزایی
دانشگاه تهران
author
نگین
اشرف
دانشگاه تهران
author
text
article
2017
per
Background and Objectives: In recent decades, drip irrigation to reduce applied water, increasing yield and better distribution of fertilizer have been considered.in drip irrigation the soil around root zone of plants is moisten instead of whole soil surface which resulted in Reducing applied water. Pulse irrigation is a series of cycles, each cycle of an irrigation phase and a resting phase is formed (12). Water Alternating used in drip irrigation due to completed the wetting front with less water than a continuous stream. Pulse drip irrigation with good management, have great potential to improve the uniformity distribution of water in the soil and association with rise uptake by plant roots. Materials and methods: In this study, using a physical model to simulate the condition of drip irrigation was used on the farm. Three soil textures including heavy, medium and light, and two discharge of dripper 2.4 and 8 liter per hour (respectively Q1 and Q2) and two pulse and continuous drip irrigation method was used. In addition, by using one of the proposed method of simulation water movement in soil, means dimensional analyses and by using Buckingham π theorem to obtain Dimensionless numbers with communication between them due to get some equation which allow to estimate moisture distribution, progressive front pattern and manner of distribution in wet soil. Finally, in order to compare simulated and measured values of statistical indicators maximum error (ME) and root mean square error (RMSE) was used. Results: The results showed that the horizontal component of moisture respectively in clay, loam and sand soils are 33, 30 and 20.5 is more than in pulse method (respectively are 28, 26 and 18.6). Vertical component of moisture in discharge of dripper 2.4 L/h in pulse method (respectively for clay, loam and sand are 21.2, 27 and 50) was more than the continuous method (respectively are 19, 22 and 43) for all soils. By comparing the distribution of moisture in the horizontal direction indicates the horizontal component of moist soil for both pulsed and continuous in 8 L/h is more than 2.4 L/h. Increase moisture in the vertical and horizontal components can be argued that the use of intermittent irrigation water in drip irrigation makes up the wetting front with less water than continuous stream was completed. As well as by use of dimensional analysis for simulation water distribution around emitters for both pulse and continuous irrigation, equations was obtained. Conclusion: Assessment by statistical indices show that the proposed equations were desirable and their results are of considerable reputation.
Journal of Water and Soil Conservation
Gorgan University Of Agricultural Sciences
2322-2069
23
v.
6
no.
2017
163
180
https://jwsc.gau.ac.ir/article_3483_840bd5c96d4d4e2560064a9a3fd3f1d5.pdf
dx.doi.org/10.22069/jwfst.2017.9762.2412
Evaluation of the Combined AR-ARCH and GAR-ARCH Models in Modeling Rivers Flow Rate (Case Study: Zarineh River in West Azerbaijan)
Javad
behmanesh
دانشگاه ارومیه- گروه مهندسی آب
author
مرضیه
عباس زاده افشار
دانشگاه ارومیه
author
کیوان
خلیلی
دانشگاه ارومیه
author
text
article
2017
per
Many of processes related to water resources systems are non-linear over time. Although certain aspects of these systems may be closer than other aspects of the linear process. However, the nature of the non-linearity is not obvious for us. For this reason, it seems that by combination of linear and nonlinear models can be increased the hydrological modeling results. Using time series models is one of the applied methods to simulate and predict the hydrological data. One of the main problems in using time series models to modeling and prediction the hydrologic data is a kind of generate random data series. In this process the generated data will be changed with changing random series. In this study, the first, time series of Zarineh rood river discharge data were evaluated of initial analysis such as trend, stationary and independent and homogeneous. The results showed that the evaluated data in annual scale and in 5 percentage confidence level are without trend and the homogeneity and stationary of data were confirmed. Finally the data that were evaluated with the initial tests were investigated with the AR (Autoregressive) and GAR (Gamma Autoregressive) models and the AR(1) and GAR(1) models were selected as the best models with attention to the AICC test’s results. After the comparing the mentioned (AR & GAR) models, extracted the residual time series of these models and were fitted by ARCH (Autoregressive Conditional Heteroscedastic) models. Then combined two autoregressive and gamma autoregressive models, two AR-ARCH and GAR-ARCH models were obtained. The results of modeling the discharge of Zarineh-rood river showed that with combined two GAR-ARCH and AR-ARCH models, the model validation accurate was increased 12 percentage and 11 percentage in scale of cubic meters per second respectively and the model errors were decreased about 40 and 50 percentages in scale of cubic meters per second respectively. The results of evaluation and comparing the accuracy and amount error of two AR (Autoregressive) and GAR (Gamma autoregressive) models showed that the GAR (Gamma autoregressive) model has better results in modeling the Zarineh-rood flow discharge data. The GAR model has a lower error and upper accuracy than AR model. Also the results showed that the combined models have better results than traditional models in modeling the peak flow discharge of Zarineh-rood River in comparing the AR (Autoregressive) models. Using the nonlinear models and combine of these models with linear models greatly increases the modeling and forecasting results.
Journal of Water and Soil Conservation
Gorgan University Of Agricultural Sciences
2322-2069
23
v.
6
no.
2017
181
197
https://jwsc.gau.ac.ir/article_3484_47753cb419794eedb9f96d3f5027f849.pdf
dx.doi.org/10.22069/jwfst.2017.9666.2397
Seasonal and Spatial Variability of Airborne Dust Loading Rate over the Sistan plain cities and its Relationship with some Climatic Parameters
مهدی
دانش شهرکی
دانشجوی سابق کارشناسی ارشد گروه علوم خاک دانشگاه زابل
author
Ali
Shahriari
گروه علوم خاک، دانشگاه زابل
author
مجتبی
گنجعلی
استادیار گروه جنگل و مرتع، مرکز تحقیقات و آموزش کشاورزی و منابع طبیعی سیستان
author
ابوالفضل
بامری
مربی گروه علوم خاک دانشگاه زابل
author
text
article
2017
per
Background and Objectives: Sistan plain has a high erodibility potential because of fine grain size alluvial deposits and these fine particles can be easily moved due to 120-day wind blow in this arid region and cause numerous dust storms. Therefore, this study aimed to investigate seasonal changes of dust loading rate in Sistan plain and its relationship with some climatic parameters from March 2015 to March2016. Materials and Methods: 25 Siphon dust trap samplers were installed in the 5 cities of Sistan plain including Zabol (7), Zahak (4), Nimrouz (4), Hirmand (5) and Hamoun (5) and the dust was collected and measured seasonally. Seasonal climate data including wind speed, air temperature, relative humidity, precipitation, evapotranspiration and average soil temperature at depth of 5 cm were used from Zabol and Zahak meteorological stations. Suitable statistical analyses were used to investigate seasonal and spatial variations of dust loading rate and its relationship with climatic parameters. Results: The results showed average and total annual dust loading rate in Sistan plain were 338.85 (g/m2) and 6777.03 (g/m2), respectively. Hirmand city had the highest dust loading rate in the spring and summer and Nimrouz city had the highest rate in the autumn and winter. Hamoun city had the lowest dust loading rate in the all periods. The average of dust loading rate in the summer (566.23 g/m2) was greater than the average rates in the autumn and winter, significantly. The average dust loading rate showed significant positive correlation with wind speed, air temperature, soil temperature at a depth of 5cm and evapotranspiration and also showed a significant negative correlation with relative humidity. The correlation between precipitation and dust loading rates were negative but not significant. Conclusion: According to the results, the most important factors on spatial and temporal variations of dust loading rate in Sistan plain are the distance from source of dust origin (Hamoun wetlands), the erodible area in the direction of prevailing wind and climatic factors that directly affected on soil erosion and degradation, and hydrologic and ecologic conditions (presence of water in Hamoun wetlands and vegetation cover) in the region. Conclusion: According to the results, the most important factors on spatial and temporal variations of dust loading rate in Sistan plain are the distance from source of dust origin (Hamoun wetlands), the erodible area in the direction of prevailing wind and climatic factors that directly affected on soil erosion and degradation, and hydrologic and ecologic conditions (presence of water in Hamoun wetlands and vegetation cover) in the region.
Journal of Water and Soil Conservation
Gorgan University Of Agricultural Sciences
2322-2069
23
v.
6
no.
2017
199
215
https://jwsc.gau.ac.ir/article_3485_0bfc8138250001ac2e8f84ce82e0fa84.pdf
dx.doi.org/10.22069/jwfst.2017.11530.2595
Annual assessment of Kashafrood watershed basin climate components in future periods by using fifth report of intergovernmental panel on climate change
Amirhosein
Aghakhani Afshar
Department of Water Engineering and Hydraulic Structures- Civil Engineering College- Tabriz University
author
Yousef
Hassanzadeh
Professor Department of Civil Engineering, College of Civil Engineering, University of Tabriz, Tabriz, Iran
author
Ali Asghar
Besalatpour
Assistant Professor Department of Soil Sciences, College of Agriculture, Vali-e-Asr University of Rafsanjan, Rafsanjan, Iran
author
Mohsen
Pourreza Bilondi
Assistant Professor Department of Water Engineering, College of Agriculture, University of Birjand, Birjand, Iran
author
text
article
2017
per
Background and Objectives: Hydrology cycle of river basins and water resources availability in arid and semi-arid regions are highly affected with climate changes. So that in the recent years, increase of temperature due to increase of greenhouse gases have led to anomaly in the Earth’ climate system. At present, General Circulation Models (GCMs) are the most frequently used models for projection of different climatic change scenarios. Up to now IPCC has released 4 different versions of GCM models including: First Assessment Report models (FAR) in 1990, Second Assessment Report models (SAR) in 1996, Third Assessment Report models (TAR) in 2001 and Fourth Assessment Report models (AR4) in 2007. The purpose of this study is to survey the annual trend of the future climate components in kashafrood watershed basin (located in the northeastern part of Iran and in the khorsan razavi province) by using fifth report of Intergovernmental panel on climate change (IPCC) under new emission scenarios. Material and Methods: In this research, keeping in view the importance of precipitation and temperature parameters, fourteen models obtained from the General Circulation Models (GCMs) of the newest generation in the Coupled Model Intercomparison Project Phase 5 (CMIP5) were used to forecast the future climate changes in the study area. In historical time (1992-2005), simulated data of these models were compared with observed data using four evaluation criteria for goodness-of-fit including Nash-Sutcliffe (NS), Percent of Bias (PBIAS), coefficient of determination (R2) and the ratio of the root mean square error to the standard deviation of measured data (RSR). Results: According to performance criteria, among 14 models used in this research, four was chosen as the best namely GFDL-ESM2G, IPSL-CM5A-MR, MIROC-ESM and NorESM1-M which indicated more agreement with observed data. Furthermore, four Representative Concentration Pathways (RCPs) of new emission scenario, namely RCP2.6, RCP4.5, RCP6.0 and RCP8.5 under three future periods: near-century (2006-2037), mid-century (2037-2070) and late-century (2070-2100) were investigated and compered. Conclusion: The results of Mann-Kendall (MK) test which was applied to examine annual trend, revealed that the precipitation have a variable positive and negative trends which were statistically significant. Also mean, maximum and minimum temperature have a significant positive trend with 90, 99 and 99.9% confidence level. On the other hand, in all parts of the Kashafrood Watershed Basin (KWB), average temperature of watershed increased up to 0.56 °C - 3.3 °C and precipitation decreased up to 10.7% until the end of the 21st century in relation with the historical baseline.
Journal of Water and Soil Conservation
Gorgan University Of Agricultural Sciences
2322-2069
23
v.
6
no.
2017
217
233
https://jwsc.gau.ac.ir/article_3486_5850399c756ca9fc638d24f6baa57f52.pdf
dx.doi.org/10.22069/jwfst.2017.11186.2553
Determination irrigation time for sugarcane fields using infrared thermometer and measurement of soil moisture in root zone
شادمان
ویسی
دانشگاه شهید چمران اهواز
author
عبدعلی
ناصری
دانشگاه شهید چمران اهواز، دانشکده مهندسی علوم آب
author
سعید
حمزه
دانشگاه تهران، دانشکده جغرافیا، گروه سنجش از دور
author
text
article
2017
per
Determination irrigation time for sugarcane fields using infrared thermometer and measurement of soil moisture in root zone Shadman Veysi1, Abdali Naseri2 and Saeed hamzeh3 1PhD student of Irrigation and Drainage Engineering, Faculty of Water Sciences Engineering, Shahid Chamran University of Ahvaz, Khuzestan, Iran, 2Professor at Faculty of Water Sciences Engineering, Shahid Chamran University of Ahvaz, Khuzestan, Iran, 3Faculty of Geography, Department of Remote sensing, University of Tehran, Tehran, Iran Abstract Background and objectives: One of the important factors that reduce of sugarcane yield is short-term water stress between irrigation rounds. So that, the goal of this research is monitoring effectiveness parameters that determine water status of plant for irrigation scheduling and detection irrigation time. Materials and methods: This research monitored CWSI at sugarcane fields from May-September 2015 in Salman Farsi agro industry unit. Four different ages of sugarcane fields (plant, Ratoon1, Ratoon2, Ratoon3) at CP69-102 variety were investigated. For detection CWSI, sugarcane canopy temperature using infrared thermometer at three directions was measurement. Second step of this research in places that canopy temperature was measured, the percentage of soil moisture at two depths (0-30 cm & 30-60 cm) were measured and relationship of Soil moisture with CWSI was investigated. Each round, eight fields that have same age and various irrigation days for monitoring has been selected (totally 32 fields). With a round of measurement at different ages to calibration the relationship between soil moisture and CWSI was done. At the second round of measurement validation was conducted. Relationship between soil moisture and CWSI was assessment. Results: Lower baseline equation for CP69-1062 in all of the growth period , with R2=87% was estimated. Also upper baseline equation is horizontal line that vicinity 4°c varied. Results shown with increase of sugarcane age correlation between CWSI and Soil moisture was decreased. In other words, age of sugarcane is effectiveness parameter on absorb water to sugarcane. The results shown that the optimal amount of water stress index in all of sugarcane ages to start of irrigation is 0.5. Calibration equation shown RMSE=0.15 between observation and calculated CWSI. As so correlation between CWSI & soil moisture was low, so that the affection of irrigation water salinity is significant and salinity stress is important. Conclusion: Generally, the results have shown that CWSI that was calculated from canopy temperature is good index to varied of plant water, so that utilize it for determine irrigation time and soil moister because of irrigation water salinity is not reasonable. Keywords: water stress, Salman Farsi agro industry, Infrared thermometer, soil moisture, sugarcane
Journal of Water and Soil Conservation
Gorgan University Of Agricultural Sciences
2322-2069
23
v.
6
no.
2017
235
251
https://jwsc.gau.ac.ir/article_3487_3e9398b2a700d4446555bd3503113f29.pdf
dx.doi.org/10.22069/jwfst.2017.10747.2515
Effect of enrichment and microbial inoculation on properties of sugar beet vinasse for application in farmland
Akbar
Hassani
استادیار گروه علوم خاک دانشگاه زنجان
author
مهدی
نورزاده حداد
استادیار گروه کشاورزی دانشگاه پیام نور
author
text
article
2017
per
Background and objectives: Vinasse is a dark brown effluent of ethanol industrial process, which contains different organic and inorganic compounds and disposal of vinasse into the environment may create some problems. In recent years, different point of view at by-products and their application is taken into consideration. Application of vinasse in farmlands as a part of soil fertilization program is one of the cases. The aim of this study was to evaluate the effect of vinasse treatment with a consortium of three different bacteria and the effects on chemical and biological oxygen demand, phenol concentration and color of vinasse and also the effects of raw and treated vinasse on soil fungal and bacterial populations. Materials and methods: Vinasse was supplied from Taghtir Khorasan company. In this study, A bacterial consortium comprising of three bacterial cultures, Pseudomonas aeruginosa, Stenotrophomonas maltophila and Proteus mirabilis was used to degrade vinasse. The effects of temperature degree, inoculum concentration, presence of mineral salts, different concentrations of humic acid and various sources of carbon and nitrogen on vinasse degradation was studied. To evaluate the effect of raw and treated vinasse on soil microbial community, populations of soil bacteria and fungi as an indicator of microbial population was determined. Results: The results showed that in optimum condition with inoculum concentration of 10 percent V/V at 38⁰ C under static condition the consortium reduced chemical and biological oxygen demand 57.1% and 75.7% respectively within 5 days. Also 59.2 % decolorization and 66.6 % reduction in phenolic matters was observed. Gglucose as a simple source of carbon increased the effectiveness of the consortium and humic acid as a complex source of carbon had a positive effect on the consortium effectiveness on vinasse. The most decolorization and reduction of chemical oxygen demand and phenol was in concentration of 40 mg L-1 of humic acid. Soil bacterial populations increased 27.6% and 17.0% by adding raw and treated vinasse to soil within 33 days. This was repeated almost similar to fungi. Conclusion: The results of this study showed the application of the consortium at optimum condition could considerably reduce color, chemical oxygen demand and phenolic matter concentration in vinasse and treating the raw vinasse with the consortium to reduction the potentially harmful effects could considered in ethanol industry. Adding raw and treated vinasse to soil, increased fungal and bacterial populations which the effect of raw vinasse was some more than treated one.
Journal of Water and Soil Conservation
Gorgan University Of Agricultural Sciences
2322-2069
23
v.
6
no.
2017
253
268
https://jwsc.gau.ac.ir/article_3488_805f25da59fafe455250ab1baecca1c9.pdf
dx.doi.org/10.22069/jwfst.2017.11462.2588
Pattern recognition of soil classes across a semi-arid landscape of western Iran using knowledge-based fuzzy approach
parviz
shekaari
Faculty member, Razi University
author
Javad
Yalveh
-
author
text
article
2017
per
Background and objectives: Modeling soil variation plays an essential role in sustainable management of the resource. However, discontinuous models used for decades, do not describe soil variation enough as that required in modern agriculture, since lead to basic shortcomings in spatial predictability value of maps. To conquer the problem, new statistical algorithms known as “machine learning” tools are increasingly used to construct and improve soil maps, digitally. As a means of machine learning, SoLIM employs knowledge-based fuzzy approach to realize soil-landscape relations and predict soil pattern in a continuous way. In this work, SoLIM used to predict soil distribution pattern in a 2300 ha area of Miandarband region of Kermanshah province. Materials and methods: Maps of slope gradient and aspect, planform and profile curvature, and wetness index derived from a 10m-resolution digital elevation model (DEM), and along with geological map used in the study as most effective environmental covariates of soil diversity over the area. Based on physiographic analysis, 26 pedons were described and classified in 7 subgroups of Soil Taxonomy (ST) and 16 RSGs of WRB at second-level, respectively. To train the algorithm to recognize relations between covariates and classified soils in both systems, required fuzzy rules defined in SoLIM environment. Following inference, a fuzzy distribution map for each subgroup and RSG constructed. After combining the fuzzy outputs, a non-fuzzy map of predicted soil distribution pattern over the study area obtained for each classification system. Results: Though results confirmed good learning ability of the algorithm, outputs where different for two the classification systems. As a reflection of its hierarchical structure, map of ST great groups was more contiguous than that of WRB. However, patchy appearance of WRB map interpreted as a sign of better spatial predictability, because of its more flexible two-leveled structure. Thus, probably WRB-based inference leads to more realistic predictions. This indicates how the results are affected by logical structure of soil classification system. To evaluate model performance, results of 25 more pedons aligned in 4 transects and 5 purposive points so that capture most soil variability over the study area, compared to SoLIM predictions. Based on overall map accuracy (OA) and Kappa agreement index (K), SoLIM predictions at ST subgroup level, were correct by 78 and 64 percent, respectively. Same values for WRB were 67 and 62. Inference at family level led to poor results. However, considering transects, correct predictions were 78.3 and 65.2 percent for ST and WRB, but for the random points was 75 for both. Results confirmed good predictions by SoLIM in the study area. At lower categories of ST with hierarchical structure, the model showed a poor ability to identify various soils. Conclusion: No doubt, increasing sample points is the most effective factor on improving predictability of maps either in traditional or modern soil mapping techniques. However, such viewpoint seems unfeasible and not conforms to economic considerations of DSM. Probably, adopting some other strategies such as identifying most effective environmental covariates, increasing algorithms sensitivity, and better sampling designs to obtain optimal number and distribution of observations over the study area.
Journal of Water and Soil Conservation
Gorgan University Of Agricultural Sciences
2322-2069
23
v.
6
no.
2017
269
283
https://jwsc.gau.ac.ir/article_3489_761c7387cee8457f8a7a426d3fed29ea.pdf
dx.doi.org/10.22069/jwfst.2017.11249.2562
Water retention and wheat grain yield as affected by plough direction in a semi-arid rainfed land in west of Zanjan
علیرضا
واعظی
گروه خاکشناسی دانشکده کشاورزی دانشگاه زنجان
author
Lida
Piri
Former M.Sc. Student of Soil Science (Soil Phyiscs & Conservation) in the University of Zanjan
author
text
article
2017
per
Abstract Background and objectives: The availability of water is the most important factor controlling the soil productivity in arid and semi-arid regions. In this area, crop yield is strongly affected by precipitation and water retention in the soils. The application of soil management practices can be suitably control surface runoff and enhance water retention in soil. Tillage as the major tool of soil management practices can affect the runoff production and soil erosion and so can influence the availability of water and crop yield in the rainfed lands. Yet, in most semi-arid areas, rainfed lands are ploughed up and down slope, a practice that decline water retention by declining the opportunity of water infiltration in to soil. Although various studies have been done to determine the effect of tillage methods on water conservation and crop yield worldwide, little information is available on the role of plough direction on the water retention and crop yield in wheat rainfed lands in semi-aria areas, particularly in Iran. Therefore this study was conducted to determine the effects of two plough directions (up and down slope and contour line) on soil water content during the growth period and grain yield of wheat in a semi-arid rainfed land in Iran. Materials and Methods: The study was carried out in a rainfed lands with slope steepness of 10 % and clay loam soil in west of Zanjan, north western Iran in 2015. Winter wheat was cultivated in two directions consisted of 1) up and down slope (as conventional tillage) and 2) contour line (as conservation tillage) early October 2014. A total of twenty four plots, with 1.75 m 8 m dimensions were designed on the land after cultivation. Soil water content was determined in three core samples taken from the rhizosphere in each plot in 5-day interval during the growth period from October 2014 to Jun 2015. Grain yield and yield components of wheat were determined by collecting all crops of plot surface at the harvesting time (Jun). Analysis of variance and the Duncan’s test were conducted for data of soil water content and grain yield of wheat. Statistical analysis was conducted using SPSS 21 software. Results: Mean soil water content during the growth period in the contour plots (9.1%) was 62% more than the up and down slope plots (5.6%). This difference was statistically significant (p< 0.001). Wheat grain yield was differed significantly between two plough directions (p< 0.001). It was 67% in the contour plots more than up and down slop cultivated plots. In addition, significant differences were also found between the two plough directions in wheat yield components i.e. crop height (p< 0.01), number of grains per spike (p< 0.05), 1000 grain weight (p< 0.001), and biological yield (p < 0.01). Wheat grain yield was significantly related to soil water content (R2= 0.43, p< 0.01). With an increase in soil water content, wheat grain yield considerably increased in the plots. Conclusion: This study showed that the plough direction is the major factor controlling soil water content in rainfed wheat farms. In the plots ploughed on the contour line, the opportunity of rainwater to infiltrate into the soil is very high. This factor is the most important factor controlling wheat yield under rainfed condition. Increased wheat grain yield under the contour lines cultivation could be attributed to increase in yield components which in turn were influenced by increase soil water content. With regarding these results, application of contour line ploughing method in the rainfed lands of sloped area could be substantial strategy to decline water loss and enhance crop yield in semi-arid regions.
Journal of Water and Soil Conservation
Gorgan University Of Agricultural Sciences
2322-2069
23
v.
6
no.
2017
285
299
https://jwsc.gau.ac.ir/article_3490_6dcd673bdb90642f389002eaeb7480ee.pdf
dx.doi.org/10.22069/jwfst.2017.10163.2460
Optimization of water use in agriculture using the results of a crop growth simulation model (WOFOST)
(Case study: Mahidasht- Kuzaran, Kermanshah Province)
علی
بافکار
استادیار دانشگاه رازی - عضو هیات علمی گروه مهندسی آب
author
بهمن
فرهادی بانسوله
استادیار دانشگاه رازی - عضو هیات علمی گروه مهندسی آب
author
سعید
برومندنسب
استاد دانشگاه شهید چمران اهواز
author
text
article
2017
per
Background and objective: Iran with the average of annual precipitation about 230 mm is one of the countries in the world which is located in the semi-arid and arid regions. Improper spatial and temporal distribution of rainfall regarding to the time of required water for agriculture is another problem for agricultural sector. Using crop growth simulation models is a strategy which can be used to assess water balance, to simulate the growth process and to study different managerial scenarios. In this regard, the combination of crop growth simulation models with geographic information system (GIS) and optimization models is also necessary. Calibration of crop parameters is one of the limiting factors of the use of crop growth simulation models. Results of previous researches have shown that the use of simulation models out of range, often leading to disappointing results. Some of these parameters are crop (variety) specific, so to use of these models, they must first be calibrated according to the local varieties. In the past decades several models have been developed for agricultural land use planning in different scales. The aim of the present study was to determine the cropping area of major agricultural crops based on the combined results of the Crop growth simulation model and is linear programming in the Mahidasht plain, Kermanshah province. In this study, WOFOST model is used to simulate crop growth and GAMS software is used for linear programming. Material and methods: Field experiments was carried out in the cropping year 2010-2011 for calibration and validation of crop parameters of WOFOST model for major crops (wheat, barley and maize) under deficit irrigation managements. Experiments were implemented as randomized complete block design with three irrigation regimes (Full irrigation, 20 and 40 percent deficit irrigation) and four replications. Agricultural lands in the plain were classified into 440 equal units according to soil characteristics and administrative divisions. Maximization of farmers' income was considered as the objective function in the linear programming model. The constraints of monthly water, seasonal water, labor, land and agricultural machinery were considered at the study area. Considering the available water in the study area the best cropping pattern in 8 studied scenarios of water supply and irrigation system were determined using developed model. Results: The value of most sensitive parameters of WOFOST model for major crops in the Mahidasht plain was determined by model calibration. Yield and water requirement of mentioned crops in the potential and water-limited situations were estimated in the region regarding to long-term average climatic parameters. Analysis of the scenarios showed that the scenario 6 (doubled water price and sprinkler irrigation system) with the total farmers' income of 140 billion IRR has the highest income among studied scenarios. The area under cultivation in this scenario would be 75,262 hectares which shows increasing compared to the base scenario. Conclusion: The combination of crop growth simulation models and linear programming can be used for determination of the appropriate cropping patterns under different conditions of water resources. The maximum farmers' income in this study would be occurred in the scenario 6 which water price will be doubled and irrigation system is sprinkler.
Journal of Water and Soil Conservation
Gorgan University Of Agricultural Sciences
2322-2069
23
v.
6
no.
2017
301
315
https://jwsc.gau.ac.ir/article_3491_864de500def5eb2dfe4671282acc1540.pdf
dx.doi.org/10.22069/jwfst.2017.9634.2388
Estimation of longitudinal dispersion coefficient of suspended sediments through the large porous Medias
Jafar
Chabokpour
University of Maragheh
author
Ebrahim
Amiri Tokaldany
Irrigation and reclamation department of University of Tehran
author
Mohammad
Sedghi Asl
University of Yasouj
author
text
article
2017
per
Abstract Background and objectives: Applicability of rockfill dams which has been made from large rock materials for purpose of flood detention reduces over the time because of siltation of pore system with sediment contained basin outflow. Since some of structures which were built with large rock materials should convey suspended sediment contained flows therefore routing process of these type flows have been investigated. The investigation around advection and dispersion of sediments particles through the large porous media usually is being done with breakthrough curve. This investigation is usually common for pollutants in rivers, sewer system and fine porous media. Previous researchers used from various techniques like numerical solving, parameter estimation and exact solution for solving of above mentioned problems. But unfortunately any general inquiry about suspended sediments was not accomplished yet. The exit breakthrough curves in many cases are asymmetrical and have Skewness in their falling limbs. Therefore some researchers after collecting the series of field data have discovered it and have presented a new model named transient storage model. Some investigators by considering Asymmetry in exit breakthrough curve have joined first order mass transfer equation with ADE equations and have extracted exact solutions with various primary and boundary conditions. The important criterion in this regard is to use them in similar primary and boundary conditions. Therefore in many cases the investigators are using from temporal and spatial moment technique according to experimental data series. By emphasis to above mentioned criteria and as regards to this fact that any coherent research in the investigation of behavior of suspended sediments through the large porous media were not accomplished yet therefore in this research tried to focus on it. Materials and Methods: In this research by creating a laboratory model of large porous media and employing suspended sediment particles, tried to acquire an experimental data series in order to investigate longitudinal convection and dispersion phenomenon of suspended sediments through the large porous media. In this investigation by application of 2 media diameters, 4 inflow discharges and different hydraulic gradients over the media, the breakthrough curves of suspended sediments were extracted. The BC curves were extracted with water sampling from media end and then the samples have been passed from filter paper and dried. The concentration-time graphs were extracted after weighting of dried sediment particles. Also by using of parameter estimation technique for classical advection dispersion equation and temporal moments method, the longitudinal dispersion coefficients were extracted. Results: The results showed that due to the inherent properties of exit breakthrough curve, the temporal moments method has a better estimation accuracy rather than classical advection dispersion equation. Additionally by dimensional analysis method a relationship has been acquired for estimation of longitudinal dispersion coefficient with average relative error of 30% which is reliable in sediment transport studies. Furthermore, the results of analysis of BC curves exhibited that the curve has an Asymmetric limbs in rising and falling stages which this observation is because of temporary storage of sediments and gradual release of them through the downstream flow.
Journal of Water and Soil Conservation
Gorgan University Of Agricultural Sciences
2322-2069
23
v.
6
no.
2017
317
332
https://jwsc.gau.ac.ir/article_3492_92268077e1a896beb0b68844ffd81555.pdf
dx.doi.org/10.22069/jwfst.2017.9347.2337
Investigation of the hydrologic response of river flow to climate change (Case study: Dez Dam Basin)
Roya Sadat
Mousavi
دانشجوی دکتری مهندسی منابع آب/دانشگاه بوعلی سینا، همدان
author
صفر
معروفی
گروه آب دانشگاه بو علی سینا همدان
author
text
article
2017
per
Background and objectives: In the recent years due to observing evidences of climate change in meteorological and hydrological variables, concerns arisen regarding variations of renewable water resources and future water availability under climate change condition. Due to the importance of possible effects of climate change on surface water resources and flow regime, the present study investigates river flow variations during last decades as well as projections of future discharge of Dez dam basin. Materials and methods: Nonparametric Mann-Kendal trend test and two shift change point detection tests of Pettit and Buishand were applied to the discharge time-series at the outlet of Tire, Marbore, Sazar and Bakhtiari sub-basins to identify monotonic and abrupt changes. Also to project the discharge in 21st century considering the impact of climate change the outputs of two Global Circulation Models of CCSM3 and ECHAM5-OM for three pessimistic (A2), average (A1B) and optimistic (B1) scenarios, were used. To downscale the outputs of GCMs to the study area LARS Weather Generator were applied and the downscaled data fed to the HBV hydrological model to simulate the future flow. Results: The Mann-Kendall test showed significant negative (decreasing) trend of the flow in three sub-basins of Tire, Marbore and Sazar but no significant trend were detected for Bakhtiari. Also shift change point detection tests identified occurrence of downward shifts in the three aforementioned sub-basins; while upward shift were detected for Bakhtiari sub-basin. The magnitude of these changes is noticeable and ranges between 14.7% in Bakhtiarin to 43.3% in Marbore sub-basin. Also based on the results of the hydrological model by using the precipitation and temperature obtained for future time horizons of 2020, 2050 and 2080 as input, the annual flows show significant reductions in all sub-basins. Also, seasonal flows of Tire, Marbore and Sazar decreases in spring, autumn and winters but increases in summers. Seasonal flows of Bakhtiari basin also decreases in all seasons except for autumns. Generally, future simulation of the flow under the given climate change scenarios in the Dez Dam Basin shows drastic decrease (more than 1 billion cubic meters) of the annual potential discharge of the basin. Conclusion: Investigation of the flow of Dez Dam Basin in the past decades shows significant monotonic and abrupt changes which is mostly toward decreasing the basin’s potential runoff. Additionally, assessment of future flow by different scenarios show reduction of flow due to impact of climate change. Considering these evidences it is likely that the basin face with discharge reduction in future and results emphasize on modification of water resources management strategies to adapt with climate change.
Journal of Water and Soil Conservation
Gorgan University Of Agricultural Sciences
2322-2069
23
v.
6
no.
2017
333
348
https://jwsc.gau.ac.ir/article_3493_f764078ea80c3cbcec0fc48518186970.pdf
dx.doi.org/10.22069/jwfst.2017.12000.2653
The effect of Piggyback line on local scour below horizontal pipe lines
sobhan
moradi
دانشجوی کارشناسی ارشد سازه های آبی دانشگاه فردوسی مشهد
author
kazem
esmaili
هیات علمی دانشگاه فردوسی مشهد
author
mohammadreza
akbarzadeh
هیات علمی دانشگاه فردوسی
author
سعیدرضا
خداشناس
هیات علمی دانشگاه فردوسی
author
kazem
esmaili
Head of department
author
text
article
2017
per
Background and Objectives: Waste water or fuel pipelines transmission from the erosion bed of sea and river causes an interaction between water and erosion bed which results some changes in hydrodynamic flow around the tube which caused some scour under the pipeline. As a result, it may leads to instability, bending and even breaking the pipe. To protect the pipelines in counter with potential risks, understanding of amount and scouring pattern around the pipe is necessary. Materials and Methods: The present study has investigated the scour below the horizontal pipeline in a laboratory flume with three different pipe diameters (2, 3.2, 3.8 cm), located on the erosion bed with two medium-size of sediment (0.3, 1.18 mm) and three different shape of Piggyback line (blade, circle, triangle), under the steady, resistant and a unidirectional in lucid water conditions (V⁄V_C ≈0.9). First of all, using Pi-Bukingham method all the dimensional parameters affecting on local scour under the pipeline analyzed. Then by various experiments some important and dimensionless parameters such as diameter of the pipe, Froude number of flow, depth of flow, average grain size of the sediment of bed and the shape of Piggyback line have been surveyed on maximum depth scour. Results demonstrated that the surface area of barrier opposite of flow effects on final mount of scour and it increases by accretion of pipe diameter, depth of maximum scour and consuming time up to balanced final sour. Results: According to Experimental results, the surface area of the barrier affect the flow path in the final scour and by increasing diameter of the pipe, a maximum depth of scour and time reaching to the final balance of scour increase. In this research, by increasing in Froude number in a constant diameter of pipe and soil grading size, maximum depth of scour obtained in Froude number of 3.0. The depth of flow effects on depth of scour at y_n⁄D≤3.5 was almost negligible. In this regard, in small amount of this ratio, depth of scour is independent of depth of flow. On the other hand, average grain size of the sediment doesn’t have a considerable impact on maximum depth of scour. But, because the standard deviation of grain size of the sediment with an average size in 1.18mm, was less than 1.4 (high uniformity), it can be conclude that the standard deviation has a significant effect in amount and location of maximum scour depth and can change the scour profiles significantly. By using different forms of Piggyback line in equal height, length of hole scour became equal approximately and it just depended on length of obstacle opposite of flow. The observation showed that the wave length of the leading sediment and scour is affected by Piggyback line. It was in blade Piggyback line form 2.42, triangle Piggyback line form 2.25 and circle Piggyback line form established on main pipe 1.19 times more than single pipe on the detrital bed. Different depth in maximum sour between blade and triangle Piggyback line was less but in accordance with circle ones it was more. Conclusion: our results demonstrate that any change in stabilized Piggyback line on main pipe can affect scour pattern of under horizontal pipe line. To increase in the maximum depth of scour and transmission of electricity, telephone cables and water-sewer duct along the main pipe, triangle Piggyback line is the better option to replace the spoilers which have been used these days.
Journal of Water and Soil Conservation
Gorgan University Of Agricultural Sciences
2322-2069
23
v.
6
no.
2017
349
363
https://jwsc.gau.ac.ir/article_3494_63a8a420b0b17183654d351b52b030d1.pdf
dx.doi.org/10.22069/jwfst.2017.10326.2477
Numerical solution of lateral distribution of suspended sediment in river bends
حسین
شریفان
عضو هیئت علمی دانشگاه علوم کشاورزی و منابع طبیعی گرگان
author
Abdolreza
Zahiri
عضو هیئت علمی دانشگاه علوم کشاورزی و منابع طبیعی گرگان
author
بهروز
دهانزاده
عضو هیئت علمی دانشگاه آزاد اسلامی واحد شوشتر
author
هرمز
شیار بهادری
کارشناس ارشد اداره منابع طبیعی بهبهان
author
text
article
2017
per
Background and Objectives: Distribution of lateral velocity and especially suspended sediment concentration in river bends are extremely non-uniform. For better management of hydraulic structures located on river bends, the lateral variation of sediment concentration has high importance. Several two-dimensional and quasi two-dimensional mathematical models have been developed by many researchers which in most of them, the river has been assumed as a straight reach. Also, sediment concentration variations across the river and especially in the case of river bends have been simulated just by complicated two and three dimensional mathematical models. Due to the essence of simplicity for applied studies in flow and sediment transport hydraulics, the simple quasi two-dimensional models have attracted much attention, recently. The aim of this paper is to investigate the quasi-two dimensional modeling of lateral flow velocity and suspended sediment concentration in river bends. Material and Methods: for lateral distribution of flow velocity and sediment transport at the river bends, the Shiono and Knight method has been numerically solved in this paper using the finite difference method. For calibration of Manning roughness coefficient in this model, the field data of lateral velocity distribution at the one of bends in Karoun river at the vicinity of Ahwas hydrometric station have been used. Furthermore, by selecting three empirical sediment transport equations of Ackers-White, Engelund-Hansen and Yang, the sediment transport module of this model has been calibrated with field data of lateral distribution of sediment concentration at the bend Results: The results of numerical solution of Shiono and Knight model showed that the among the selected sediment transport equations, the Yang equation has very well agreement with the measured lateral suspended sediment concentration, in comparison to the Ackers-White and Engelund-Hanssen equations. The former two equations predict the sediment transport very larger than the measured value. Due to this fact that the unit stream power is the basis of Yang equation derivation and in this theory, the transport of each sediment particle mainly depends to its flow velocity, hence the Yang sediment transport equation has higher accuracy. With lateral integration of sediment concentration across the river bend, the total load has been computed as 16000 tons per day against the measured value of 26500 tons per day which shows nearly 40 percent error. These errors for Ackers-White and Engelund-Hansen equations are 265 and 325 percent, respectively, which are very high predictions comared with the actual value. Conclusion: according to the results obtained in this paper, the sediment concentration distribution in any flow discharge and especially in flood conditions may be computed and used for designing lateral intakes on outer bank of the river bend.
Journal of Water and Soil Conservation
Gorgan University Of Agricultural Sciences
2322-2069
23
v.
6
no.
2017
365
373
https://jwsc.gau.ac.ir/article_3495_731d0f383d0e562f6f81637b8a748106.pdf
dx.doi.org/10.22069/jwfst.2017.8898.2265
Evaluation of spatial variation of soil saturated hydraulicconductivity using spatial statistic (Case study: Laghar plain)
changiz
saadipour
Student of Master of shahed university
author
Mohsen
Roodpeyma
Faculty member of Shahed University
author
Alidad
Karami
Faculty member of Agriculture and Natural Resources Research Institut of Fars
author
Naser
Davatgar
Assistant professor, Soil and Water Research Institute of Iran
author
Maryam
Salahedin
Student of Master of Shahed university
author
text
article
2017
per
Background and Objectives :Soil saturated hydraulic conductivity is an important parameter for all activities related to water flow in soil, controlling soil water infiltration and superficial runoff, pesticide leaching from farms and transferring pollutants from polluted area to underground water. The spatial distribution of physical and hydraulic properties is effective on the behavior of hydrological, water transfer and sediment to surface and subsurface water therefore the variations of these characteristics is effective on land management. In a study with the aim of analysis of the spatial variability of soil hydraulic conductivity using Geostatistics methods of simple kriging, ordinary kriging and public kriging by Barani et al (2013) in Zydon plain of Khuzestan has been done, the number of 200 Regular grid point with 1 × 1 kilometers Distance the hydraulic conductivity measured by methods well and inverse well, the results showed that between the studied methods, simple kriging had higher estimation accuracy in the study plain and between the variogram models, spherical model is selected (2). This research aims were to study spatial variation of soil hydrauic conductivity and effective factors on it with geostatistic method and selecting the most appropriate on method in the Laaghar plain. Materials and Methods: Laaghar plain with approximately area of 12986 hectares is located in Khonj city the functions of Fars province that located in geographic range of 28˚ 1ʹ 2ʺ to 28˚ 12ʹ 54ʺ Northern and 53˚ 4ʹ 44ʺ to 53˚ 21ʹ 50ʺ Eastern. For this purpose spatial variation of soil saturated hydraulic conductivity and some other soil parameters like soil particle size percentage (sand, silt and clay), gypsum (CaSo4) and calcium carbonate (CaCo3) percentage were studied using spatial statistics. Interpolating and zoning of these properties were done with IDW, kriging and co-kriging methods, and these estimators accuracy were compared with each other. Results: Results showed that the parameters of sand, gypsum (CaSO4) and calcium carbonate (CaCO3) percentage with a Nugget variance ratio to threshold by 0.001, 0.246, 0.217 have strong spatial structure, and saturated hydraulic conductivity, silt and clay percentage having Nugget variance ratio to threshold by 0.499 had a moderate spatial structure. Fitnessing theory model on experimental variograms show that the Gaussian model for the sand, silt and clay, gypsum percentage properties, and spherical model for saturated hydraulic conductivity parameter and calcium carbonate percentage having the highest R2 and lowest RSS are best fitness on experimental variograms. Hydraulic conductivity was measured in the field with well and inverse well method. The results showed that the studied parameters had suitable spatial structure, and each one of them had specific spatial pattern. Conclusion: Kriging estimator had better results and less error for interpolating saturated hydraulic conductivity, gypsum and calcium carbonate percentage parameters compare to IDW method, but the IDW method showed better results in interpolating sand, silt and clay percentage parameters. The cokriging interpolating method were not used to interpolate properties because of the lack correlation between major variable (saturated hydraulic conductivity) and other parameters (as the accessory variable) to interpolate the properties.
Journal of Water and Soil Conservation
Gorgan University Of Agricultural Sciences
2322-2069
23
v.
6
no.
2017
375
382
https://jwsc.gau.ac.ir/article_3496_60687616083d62f12c7118324c448191.pdf
dx.doi.org/10.22069/jwfst.2017.10141.2458