نوع مقاله : مقاله کامل علمی پژوهشی
نویسندگان
1 گروه خاکشناسی، دانشکده کشاورزی، دانشگاه شهید چمران اهواز، اهواز، ایران
2 گروه خاکشناسی، دانشکده کشاورزی، دانشگاه شهید چمران اهواز-ایران
3 مربی گروه خاکشناسی، دانشکده کشاورزی، خاک دانشگاه شهید چمران اهواز، ایران
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
Extended Abstract
Introduction
Aggregate stability is one the most important soil physical properties, which is estimated using easily accessible parameters. Remote sensing (RS) is a useful technique that has meaningful capabilities to monitor soil and water resources. Moreover, soil aggregate stability is an index of soil erodibility which can be used as a useful tool to manage and control the soil against destructive factors. Therefore, it is really important to model the effective factors on soil aggregate stability. The present study conducted because of importance of soil physical properties and land use effects on crop cover status and its modeling.
Methods and material
In this research, the relation between vegetation indices and mean weight diameter (MWD) as an index of soil aggregate stability was investigated in forest and rangeland land uses. In order to evaluate the relation between land uses and vegetation indices in Dehdez watershed located in the southeast of Khuzestan Province, Iran country; the images of Landsat 8 with pass number 164 and the row of 38 provided from the Earth Explorer website with GeoTIFF format. The radiometric correction performed using ENVI 5.1 software. The evaluated vegetation indices including, RVI, VIN, TVI, YVI, SBL, DVI, NDGI, RI, NDI, NDVI, PVI, SAVI, TSAVI, ARVI ,and MSAVI. The Pearson correlation between the above vegetation indices and organic carbon, sand, silt, clay ,and mean weight diameter evaluated for 50 soil samples collected from two land uses. In this study, two type of land use, including forest and rangeland assessed. Pearson ´s correlation analysis and multivariate adaptive regression spline (MARS) applied to investigate the relation between vegetation indices and MWD.
Results
The results illustrated that in the rangeland, MWD had a significant correlation with VIN, TVI, MSAVI, RVI, SAVI, TSAVI, NDVI, and PVI indices at the level of 0.01. However, in the forest, there was no significant relation between the studied indices. Also, MARS modeling showed that the fitted model based on vegetation indices in rangeland (Adjusted R-Sq. = 0.55, RMSE = 0.16) has much higher predictive power and accuracy than the fitted model for forest (Adjusted R-Sq. = 0.35, RMSE= 0.36).
Conclusion
In general, the results of this study revealed that the controlling factors of soil aggregate stability are different for rangeland and forest land uses. This has led to differences in correlation coefficient between vegetation indices and MWD, and consequently modeling results. Also, remote sensing can provide convenient technology for providing the sustainable management purposes of soil and water resources. To cover the sustainability purposes in the watershed scale, it is necessary to utilize different technologies such as remote sensing. Indeed application of various techniques helps to simplify the processes and finally preserve the soil and water resources against degradable factors.
کلیدواژهها [English]