تحلیل طوفان های گردوغبار سیستان با استفاده از شاخص های DDI و DSI و پارامترهای سرعت باد، دید افقی و غلظت PM10

نوع مقاله : مقاله کامل علمی پژوهشی

نویسنده

گروه مرتع و آبخیزداری، دانشکده آب و خاک، دانشگاه زابل

چکیده

سابقه و هدف: در طی دهه های اخیر طوفان های گردوغبار به یکی از مخاطرات جدی طبیعی در دنیا تبدیل شده اند. اگر چه این پدیده از جنبه های مختلف مورد مطالعه قرار گرفته است، تغییرات لحظه ای پارامترهای مرتبط با این پدیده و همچنین تغییرات فراوانی ماهانه و سالانه این پدیده در مناطق تحت تاثیر نیاز به بررسی دارد. از اینرو در این تحقیق تغییرات لحظه ای سرعت باد و دید افقی در طی شبانه روز، ماه های مختلف سال و همچنین تغییرات فراوانی ماهانه و سالانه طوفان های گردوغبار در منطقه سیستان مورد مطالعه قرار گرفت.
مواد و روش ها: منطقه سیستان در جنوب شرق ایران به عنوان منطقه مورد مطالعه در نظر گرفته شد. این منطقه دارای اقلیم گرم و خشک، متوسط بارندگی سالانه کم (59 میلیمتر) درجه حرارت بالا (میانگین سالانه 22 درجه سانتیگراد) و بادهای 120 روزه می باشد. جهت بررسی تغییرات لحظه ای سرعت باد و دید افقی داده های ثبت شده در مقیاس زمانی سه ساعته در ایستگاه سینوپتیک زابل از سازمان هواشناسی کشور برای بازه زمانی 1370-1397 دریافت گردید. همچنین جهت بررسی تغییرات فراوانی طوفان های گردوغبار وغبارناکی منطقه مورد مطالعه از دو شاخص DDI (روزهایی که سرعت باد بیشتر از 15 متر بر ثانیه و دید افقی کمتر از 1000 متر می باشد) و DSI (شاخص غبارناکی) استفاده شد. تغییرات روزانه، ماهانه و سالانه PM10 (ذرات معلق در هوا با قطر کمتر از 10 میکرون) نیز در بازه زمانی 1392-1397 مورد بررسی قرار گرفت.
یافته ها: الگوی تغییرات لحظه ای باد و دید افقی و همچنین غلظت PM10 در طی شبانه روز در تمامی ماه های سال و در بازه زمانی مورد برسی یکسان بوده و حداکثر غلظت PM10 و حداقل دید افقی در ساعت 10:30 صبح منطبق با حداکثر سرعت باد رخ می دهد. همچنین در ساعت 7:30 بعدازظهر منطبق با به حداقل رسیدن سرعت باد و غلظت PM10 میزان دید افقی به حداکثر میرسد. فراوانی ماهانه شاخص های DDI و DSI و همچنین غلظت PM10 نشان داد که ماه تیر بالاترین مقادیر این شاخص ها یعنی 8DDI = روز، 15 DSI = روز و662 PM10 = میکروگرم در مترمکعب را دارا می باشد. در طول دوره مورد بررسی سال 1380 با 31860 دقیقه (531 ساعت) زمان طوفانی و دارا بودن شاخص 74DDI = روز از بالاترین فراوانی این پدیده برخوردار بوده است. بطور کلی بازه زمانی 1378-1383 از شرایط غبارکی شدیدتری نسبت به بازه های زمانی 1370-1377 و 1384-1397 برخوردار می باشد. در این بازه های زمانی شاخص DSI بترتیب 14، 174 و 66 روز برآورد گردیده است. ارتباط معنی دار بین تغییرات سرعت باد و دید افقی، بین سرعت باد و غلظت مواد معلق در هوا و بین دید افقی و غلظت مواد معلق در هوا نشان داد که میزان دید افقی و غلظت مواد معلق در هوا کاملا به سرعت باد وابسته می باشد. همچنین ارتباط معنی داری بین غلظت مواد معلق در هوا (PM10) با شاخص های DDI و DSI نیز برقرار گردید. با برقراری ارتبط بین شاخص های DDI، DSI، PM10 و متوسط سالانه سرعت باد مشخص گردید که تغییرات این پارمترها نیز کاملا وابسته به تغییرات سرعت باد می باشد.
نتیجه گیری: در بازه زمانی 27 ساله مورد بررسی شرایط غبارناکی بر منطقه سیستان حاکم بوده و در مقایسه با سایر مناطق ایران از وضعیت بحرانی تری از غبارناکی برخوردار می باشد بطوریکه فراوانی و شدت طوفان های گردوغبار در این منطقه نسبت به سایر مناطق بیشتر می باشد. از آنجاییکه غبارناکی منطقه سیستان به وضعیت دریاچه هامون مرتبط است بنظر می رسد بهترین راه جهت کاهش طوفان های گردوغبار احیای این دریاچه بوده تا بتوان شرایط تشکیل این پدیده را به حداقل رساند.

کلیدواژه‌ها


عنوان مقاله [English]

Dust storms analysis in the Sistan region using DDI and DSI indices and wind speed, visibility and PM10 parameters

نویسنده [English]

  • Abbas Miri
Department o f Range and Watershed Management, Faculty of Soil and Water, University of Zabol, Zabol, Iran
چکیده [English]

Background and objectives: In the recent decades dust storms have become serious natural hazards in the world. Although dust storms have been investigated in various aspects variation in wind speed and visibility and the frequency of dust storms requires more investigation. In this study, diurnal, monthly and yearly variation of parameters including wind speed, visibility and PM10 (particulate matter 10 micrometers or less in diameter) and frequency of dust storms is studied in the Sistan region for the twenty seven-year period.
Materials and methods: The Sistan in the southeast part of Iran is considered as the study area. Sistan has an arid and semi-arid climate with very low precipitation (59 mm) and air humidity and high evaporation (nearly 4820 mm) and annual temperature (22°C). To analysis the diurnal, monthly and yearly variation of wind speed and visibility, the collected data at the Zabol meteorological station were obtained from the Iran Meteorological Organization for study period. DDI (Dusty Days Index; the days with wind speed more than 15 m/s and visibility less than 1000 m) and DSI (Dusty Index) were applied in this study to analysis the monthly and yearly frequency of dust storms during 1991-2018. Furthermore, the hourly concentration of PM10 was received from the meteorological and environmental stations of the respective centers during 2013-2018.
Results: The results show similar diurnal, monthly and yearly patterns of wind speed, visibility and PM10 variation in all months during study period. The highest PM10 concentration and lowest visibility were observed at 10:30 am in accords with highest wind speed. The lowest PM10 and highest visibility occurred at 7:30 pm in accord with lowest wind speed. The greatest values of DDI, DSI and PM10 were observed in June. Furthermore, the greatest values of DDI, DSI and PM10 were observed in 2001 during study period. The period of 1999-2004 is dusty than the periods of 1990-1999 and 2005-2018 as DSI is 14, 174 and 66 days respectively. A strong correlation was observed between wind speed and visibility, wind speed and PM10 concentration and, visibility and PM10. These result show that either PM10 concentration or visibility depend on wind speed. Furthermore, a positive relationship was observed between PM10 and DSI and DDI.
Conclusion: In stud period, the Sistan region is dusty than other regions of Iran due to having greater frequency and intensity of dust storm. As the dustiness of Sistan is highly dependent on the situation of Hamoun lake, lake recovery is critical to reduce the intensity and frequency of dust storms.

کلیدواژه‌ها [English]

  • Dust Storms
  • Wind speed
  • Visibility
  • Sistan
1.Ackerman, S.A., and Cox, S.K. 1989. Surface weather observations of atmospheric dust over the southwest summer monsoon region. Meteorol. Atoms. Phys. 41: 9-34.
2.Ahmadi, H., Dadashi Roudbari, A.A., and Jafari, M. 2016. The effect of boundary layer height on dust storm in southwest of Iran (Case study: February 21-24, 2016). J. Natural Environ. Hazard. 8: 9. 151-74. (In Persian)
3.Alipour, G. 2001. Suitable plants and tropical desert reclamation. Almighty. 106p. (In Persian)
4.Amarloei, A., Jonidi Jafari, A., Asilian Mahabadi, H., and Asadollahi, K. 2011. The evaluation of Pm10, Pm2.5 and Pm1 concentration during dust storm events in Ilam city, from Mar 2013 through
Feb 2014. Sci. J. Ilam Uni. Med. Sci.22: 240-59. (In Persian)
5.Arami, S.A., Ownegh, M., Mohammadian Behbahani, M., Akbari, M., and Zarasvandi, A.R. 2018. Statistical analysis of spatio-temporal pattern of dust storms in the west and southwest of Iran. J. Water Soil Cons. 25: 61-83.
6.Bagnold, R.A. 1935. The movement of desert sand. Geogr. J. 342-65.
7.Birkett, C.M. 2000. Synergistic remote sensing of lake Chad: variability ofbasin inundation. Remote Sens. Environ. 72: 218-36.
8.Chepil, W.S., and Woodruff, N.P. 1957. Sedimentary characteristics of dust storms; part II, visibility and dust concentration. Am. J. Sci. 255: 104-14.
9.Coe., M.T., and Foley, J.A. 2001. Human and natural impacts on the water resources of the lake Chad Basin. J. Geophys. Res. 106: 3349-56.
10.Deng, X., Tie, X., Wu, D., Zhou, X., Bi, X., Tan, H., Li, F., and Jiang, C. 2008. Long-term trend of visibility and its characterizations in the Pearl River Delta (PRD) region, China. Atmos. Environ. 42: 1424-35.
11.Ekhtesasi, M.R., Moradi, N., and Rostami, F. 2002. Investigate the change pattern of dust storms using horizontal visibility Index (Hv) and the standard precipitation index (SPI) (a case study of Esfahan city). The fifth conference of  The fifth conference of science and watershed engineering, Esfahan, Iran (2002).
12.Ette, A.I.I., and Olorode, D.O. 1988. The effects of the Harmattan dust on air conductivity and visibility at Ibadan, Nigeria. Atmos. Environ. 22: 2625-27.
13.Farajzadeh Asl, M., and Alizadeh,K. 2010. Spatio temporal analysis of dust storms in Iran. Plan. Space Plan. 15: 65-86. (In Persian)
14.Fiedler, S., Schepanski, K., Knippertz, P., Heinold, B., and Tegen, I. 2014. How important are atmospheric depressions and mobile cyclones for emitting mineral dust aerosol in north Africa? Atmos. Chem. Phys. 14: 8983-9000.
15.Ghaderi, F., Karami, M., Shekaari, P., and Jafari, J. 2018. Atmospheric dust deposition trend and its relation with selected climatic and spatial factors in Javanrood township. J. Water Soil Cons. 24: 123-140.
16.Gherboudj, I., Beegum, S.N., and Ghedira, H. 2017. Identifying natural dust source regions over the middle-east and north-Africa: estimation ofdust emission potential. Earth-Sci. Rev.165: 342-55.
17.Ginoux, P.J.M., Prospero, T.E., Hsu Gill, N.C., and Zhao, M. 2012. Global-scale attribution of anthropogenic and natural dust sources and their emission rates based on modis deep blue aerosol products. Rev. Geophys. 50: 3.
18.Gong, S.L., Zhang, X.Y., and Zhao, T.L. 2004. Sensitivity of asian dust storm tonatural and anthropogenic factors. Geophys. Res. Lett. 31: 7.
19.Goudie, A.S. 2018. Dust storms and ephemeral lakes. Desert. 23: 153-64.
20.Goudie, A.S., and Middleton, N.J.1992. The changing frequency of dust storms through time. Clim. Change.20: 197-225.
21.Goudie, A.S, and Middleton, N.J. 2006. Desert dust in the global system. Springer.
22.Goudie, A.S., and Middleton, N.J. 2001. Saharan dust storms: nature and consequences. Earth-Sci. Rev. 56: 179-204.
23.Hagen, L.J. 1976. A wind erosion predication system to meet user needs. J Soil Water Conserves. 46: 106-11.
24.Hamidianpour, M., Mofidi, A., and Saligheh, M. 2016. Analysis ofthe nature and structure of the windof Sistan. Iran. J. Geogra. 10: 83-109. (In Persian)
25.Kharazmi, R., Tavili, A., Rahdari,M.R., Chaban, L., Panidi, E., and Rodrigo-Comino, J. 2018. Monitoring and assessment of seasonal land cover changes using remote sensing. J. Environ. Monit. Asses. 190: 356. (In Persian)
26.Mallone, S., Stafoggia, M., Faustini, A., Paolo Gobbi, G., Marconi, A., and Forastiere, F. 2011. Saharan dust and associations between particulate matter and daily mortality in Rome, Italy.
119: 1409-14.
27.McTainsh, G.H., Chan, Y.C., and McGowan, H. 2005. The 23rd October 2002 dust storm in eastern Australia: characteristics and meteorological conditions. Atmos. Environ. 39: 1227-36.
28.Mctainsh, G., and Tews, E. 2007. Soil Erosion by wind: Dust Storm Index (DSI). National monitoring and evaluation framework, prepared for the National Land and Water Resources Audit (NLWRA), Canberra. 27p.
29.McTainsh, G.H., and Pitblado, J.R. 1987. Dust storms and related phenomena measured from meteorological records in Australia. Earth Surf. Proc. Land. 12: 415-24.
30.Mehrshahi, D., Nekonam, Z. 2009. Dust storm statistics and dust wind blowing patterns analysis in Sabzevar city. Iran. J. Geogra Soc. 7: 83-104. (In Pesian)
31.Middleton, N.J. 2017. Desert dust hazards: a global review. Aeolian Res. 24: 53-63.
32.Middleton, N.J. 1986. Dust storms in the middle east. J. Arid Environ. 10: 83-96.
33.Middleton, N.J. 1985. Effect of drought on dust production in the Sahel. Nature. 6027: 431.
34.Miri, A., Ahmadi, H., Ghanbari, A., and Moghaddamnia, A. 2007. Dust storms impacts on air pollution and public health under hot and dry climate. Int. J. Energy Environ. 2: 101-05.
35.Miri, A., Dragovich, D., and Dong,Z. 2019. Wind-borne sand mass fluxin vegetated surfaces–wind tunnel experiments with live plants. Catena. 172: 421-34.
36.Miri, A., Dragovich, D., and Dong, Z. 2017. Vegetation morphologic and aerodynamic characteristics ‎reduce aeolian erosion. Sci. Rep. 7: 12831-13084-x.
37.Miri, A., Ahmadi, H., Ekhtesasi, M.R., Panjehkeh, N., and Ghanbari, A. 2009. Environmental and socio‐economic impacts of dust storms in Sistan region, iran. Int. J. Environ. Stud. 66: 343-55.
38.Modarres, R. 2008. Regional maximum wind speed frequency analysis for the arid and semi-arid regions of Iran. J. Arid Environ. 72: 1329-42.
39.Naddafi, K., Ahrampush, M.H.,Jafari, V., and Yonesyan, M. 2008. Investigation of total suspended particles and its ingredients in the central area of Yazd. University of medical sciences– Health Services of Sadoughi,s martyr of Yazd. 16: 25-21. (In Persian)
40.O’Loingsigh, T., McTainsh G.H., Tews, E.K., Strong, C.L., Leys, J.F., Shinkfield, P., and Tapper, N.J. 2014. The dust storm index (Dsi): A method for monitoring broadscale wind erosion using meteorological records. Aeolian Res. 12: 29-40.
41.Orgill, M.M., and Sehmel, G.A. 1976. Frequency and diurnal variation of dust storms in the contiguous USA. Atmos. Environ. 10: 813-25.
42.Patterson, E.M., and Gillette, D.A. 1977. Commonalities in measured size distributions for aerosols having a soil‐derived component. J. Geophys. Res. 82: 2074-82.
43.Prospero, J.M., Ginoux, P., Torres, O., Nicholson, S.E., and Gill, T.E. 2002. Environmental characterization of global sources of atmospheric soil dust identified with the nimbus 7 total ozone mapping spectrometer (Toms) absorbing aerosol product. Rev. Geophys. 40: 2-1-2-31.
44.Rashki, A., Kaskaoutis, D.G., Eriksson, P.G., Qiang, M., and Gupta, P. 2012. Dust storms and their horizontal dust loading in the Sistan region, Iran. Aeolian Res. 5: 51-62.
45.Rashki, A., Rautenbach, CJdeW, Eriksson, P.G., Kaskaoutis, D.G., and Gupta, P. 2013. Temporal changes of particulate concentration in the ambient air over the city of Zahedan, Iran. Air Qual. Atmos. Health. 6: 123-35.
46.Rashki, A., Arjmand, M., and Kaskaoutis, D.G. 2017. Assessment of dust activity and dust-plume pathways over Jazmurian basin, southeast Iran. Aeolian Res. 24: 145-60.
47.Rashki, A., Kaskaoutis, D.G., Goudie, A.S., and Kahn, R.A. 2013. Dryness of ephemeral lakes and consequences for dust activity: The case of the Hamoun drainage basin, southeastern Iran. Sci. Total Environ. 463: 552-64.38.
48.Saghafi, M.A., and Aliakbari, B., AA. 2014. Investigate diurnal and seasonal variation of wind, tempreature in the surface atmospheric  layers in Tehran city. J. Spatial Anal. Environ. Hazard.
1: 17-34. (In Persian)
49.Shahsavani, A., Yarahmadi, M., Mesdaghinia, A., Younesian, M., Jaafarzadeh, N., and Naimabadi, M. 2012. Analysis of dust storms entering Iran with emphasis on khuzestan province. Hakim Res. J. 15: 192-202.(In Persian)
50.Shao, Y., and Wang, J. 2003. A climatology of northeast Asian dust events. Meteorologische zeitschrift.12: 187-196.
51.Stewart, D.A., and Essenwanger, O.M. 1978. Frequency distribution of wind speed near the surface. J. Appl. Meteorol. 17: 1633-42.
52.Tan, M. 2016. Exploring the relationship between vegetation and dust-storm intensity (Dsi) in China. J. Geogr. Sci. 26: 387-96.
53.Vali, A., and Roustae, F. 2018. Investigation of the wind erosion trend in central Iran using dust storm index in the last fifty years. J. Water Soil Sci.21: 189-200. (In Persian)
54.Wang, S., Yuan, W., and Shang, K. 2006. The impacts of different kindsof dust events on PM10 pollutionin northern China. Atmos. Environ.40: 7975-82.
55.Williams, G. 1964. Some aspects of the aeolian saltation load. Sedimentology.3: 257-87.
56.Williams, P., and Young, M. 1999. Costing dust: How much does wind erosion cost the people of south Australia. Policy and economic research unit, CSIRO land and water: Canberra.
57.Xiao, F., Zhou, C., and Liao, Y. 2008. Dust storms evolution in Taklimakan desert and its correlation with climatic parameters. J. Geogr. Sci. 18: 415-24.
58.Yang, B., Bräuning, A., and Zhang, Z. 2007. Dust storm frequency and its relation to climate changes in northern china during the past 1000 Years. Atmos. Environ. 41: 9288-99.