بررسی اثرات سدسازی و تغییر رژیم هیدرولوژی رودخانه کارون بر شوری اراضی و رخداد پدیده گرد و غبار در دشت خوزستان

نوع مقاله: مقاله پژوهشی

نویسنده

دانشیار علوم و مهندسی خاک، دانشگاه علوم کشاورزی و منابع طبیعی خوزستان

چکیده

این مطالعه برای بررسی اثر سدسازی و تغییر رژیم هیدرولوژی رودخانه کارون بر زیست بوم منطقه انجام شد.برای بررسی تغییرات دبی و شوری رودخانه کارون، از آمارهای یک دوره چهل ساله (95-1355) رودخانه کارون در ایستگاه ملاثانی استفاده شد. هم­چنین تغییرات شوری و سدیمی خاک، در محدوده معینی از دشت خوزستان، به وسعت حدود 6800 هکتار در پایین دست شهر اهواز و در شمال تالاب شادگان، در طی سال­های 1369، 1389 و 1395 مقایسه شد. نتایج نشان داد میزان شوری از سال 1369 تا 1395 رو به افزایش است. با تغییر رژیم هیدرولوژی رودخانه کارون و کاهش دبی آن، از یک سو کیفیت آب ­­­به شدت کاهش یافته و میزان املاح نیز به بیش از دو برابر افزایش یافته است. از سوی دیگر ممانعت از جریان سیلابی دشت، سبب شوری شدید خاک­ها شده است. به طوری­که مساحت اراضی با شوری بیش از 30 دسی زیمنس بر متر برای وسعت 6800 هکتاری مورد مطالعه، از 5248 هکتار (2/77%) در سال 1369 به 6754 هکتار (3/99%)  در سال 1395 افزایش یافته است. به دلیل ایجاد این میزان از شوری که فراتر از حد تحمل گیاهان شور دوست بومی است، پوشش گیاهی منطقه از بین رفته و خاک لخت شده است. در این مناطق عاری از پوشش گیاهی در مواجه با بادهای دائمی منطقه، طوفان­هایی از گرد و غبار ایجاد شده است. بنابراین تغییر رژیم هیدرولوژی رودخانه، عامل بخشی از مشکلات فعلی کیفیت هوا به­شمار می­آید. از این­رو بازنگری و تجدید نظر در عوامل موثر در تغییر رژیم هیدرولوژی از جمله اقدامات سد سازی و انتقال از سرشاخه­ها ضرورت دارد.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Effects of Dam Construction and the Karoon River’s Change of Hydrology Regime on Soil Salinity and Dust Storms of Khuzestan Plain

نویسنده [English]

  • Siroos Jafari
Effects of Dam Construction and the Karoon River’s Change of Hydrology Regime on Soil Salinity and Dust Storms of Khuzestan Plain
چکیده [English]

Introduction
     Khuzestan plain is part of Mesopotamia. This plain was long ago irrigated and drained due to floods (Rangzan and Jafari, 2017). Then, plants started to grow everywhere in this area. With the construction of dams in the past decades, the flooding was hindered; however, since soils were saline, civil plant could not grow anymore (Anonymous, 2011). Therefore, these lands became bare and dust storms started to happen in the plain. In this research, we studied soil salinity and its sources or agents in these area (Ayers and Westcot, 1976). We specially focused on evaluation of dam contractions and effects of the Karoon Rivers’ hydrology regime change on the ecology of certain areas of Khuzestan plain.
 
Methodology
We focused on studies done by Rangzan and Jafari on the Karoon River (at Mollasani station) over a forty-year period in order to investigate its discharge and salinity changes (Anonymous, 2011). Dam construction data in the same period were collected. Also, soil salinity and alkalinity were recorded during summer for 6800 hectares in the south of Ahvaz and north of Shadegan Wetland, over a period of 25 years, in 1991 and 2011. Soil EC was also determined in extracted paste in 2017. Sodium absorption ratio (SAR) was calculated from Na, Ca, and Mg concentrations determined in these extracted pastes. Soil salinity and alkalinity (SAR) maps were drawn by Arc GIS Ver. 10.3. For this manure, ECe and SAR were partitioned in 10 levels from 0-90 and polygons were shown in these ranges for all provided maps.

کلیدواژه‌ها [English]

  • Flood
  • Salt Accumulation
  • SAR
  • Gotvand Dam
1-    Anonymous, 2011. Semi-detailed soil survey of East Karoon River bank. KhuzestanWater and Power Authority – Sazab-Pardazan Consulting Company. (In Persian).

 

2-    Anonymous., 1991. Semi-detailed soil survey of Farabi sugarcane project. Sugarcane Development Company & By Products – Abso Consulting Company. (In Persian).

 

3-    Ayers, R.S. and Westcot, D.W., 1976. Water quality for agriculture. FAO. No. 29.

 

4-    Bordbar, E., 2016. Correlation between different soil characteristics and land use with water-dispersible clay content in some Khuzestan’s soils. M. Sc. Thesis. Agricultural Sciences and Natural Resources University of Khuzestan. (In Persian).

 

5-    Chappell, M., Middleton, M.  And Price, C., 2013. Chemical and physical changes in tropical soils from seawater exposure and subsequent rainwater washes. Procedia Earth and Planetary Science, 7, pp. 131-134.

 

6-    Estaki, A.A., 2004. Effect of dam construction (Hana, Semirum) on the temperature, pH, salinity, alkalinity, and hardness of Hana water River. Iranian Scientific Fisheries Journal, 1, pp. 1-20. (In Persian).

 

7-    Jafari, S. and Nadian, H., 2014. The study of a toposequence soil series and clay mineral assemblage in some soils of Khuzestan province. Journal of Water and Soil Science, Isfahan University of Technology, No. 69, Fall, pp. 151-163. (In Persian).

 

8-    Jafari, S., 2014. Identify and classification of soils diversity in Khuzestan province. Agricultural Sciences and Natural Resources University of Khuzestan. Research project No. 911-81. (In Persian).

 

9-    Kamrakji, S. Mohamed Amer, A.W., El-Didy, Sh. M.A, and Tawfik, A.M., 2016. Salt accumulation in irrigated loamy soil; Lower Euphrates Valley, Syria. Water Science, 30, pp. 1-9.

 

10- Khuzestan Water and Power Authority. 2016. Upper Godvand dam. Website: www.kwpa.com.

 

11- Kim, K.H., Choi, G.H., Kang, C.H., Lee, J.H., Kim, J.Y. and Youn, Y. H. 2003. The chemical composition of fine and coarse particles in relation with the Asian Dust events. Atmospheric Environment, 37, pp. 753-65.

 

12-  Page, A.L. Miller, R.H.  and Keeney, D.R., 1996. Method of Soil Analysis. Part II: Chemical and Mineralogical Properties (Second Ed.). Madison, Wisconsin: SSSA.

 

13- Rahmatizadeh, A., and Jafari, M., 2014. Construction of 15- Khordad and Ghadir dams and its effect on desertification trend of Masileh plain at Qom province. Iranian Journal of Range and Desert Research, 21(3), pp. 494-506. (In Persian).

 

14- Rangzan, N. and Jafari, S., 2017. The effect of soil forming factors on the amount and diversity of clay minerals in the soils and deposits originated from Karoon River in Khuzestan province. Ramin Agriculture & Natural Resources University of Khuzestan. Research project No. 33/95/106. (In Persian)

 

15- Rhoades, J.D., 1996. Salinity: Electrical Conductivity and Total Dissolved Solids. In. Methods of Soil Analysis. Chemical Methods. SSSA and ASA, Madison, WI.

 

16- State Meteorological Organization., 2017. Meteorological office of Chahar-Mahal and Bakhtiari province. Website: www.chbmet.ir (In Persian).

 

17- Sys, C., 1985. Land Evaluation. State University of Ghent, Ghent, Belgium.

 

18- Thomas, G.W., 1996. Soil pH and soil acidity. In Methods of soil analysis: Chemical methods. SSSA and ASA, Madison, WI.

 

19- UNEP/UN., 2001. The Mesopotamian Marshlands: Demise of an Ecosystem. Division of Early Warning and Assessment. United Nations Environment Program. Nairobi, Kenya. TR01-3.

 

20- Wang, H., Jia, X., Li, K. and Li, Y., 2015. Horizontal wind erosion flux and potential dust emission in arid and semiarid regions of China: A major source area for East Asia dust storms. Catena, 133, pp.  373–384.

 

21- Zareiie, H. and Akhondali, A.M., 2007. Evaluation of the place and time of the Karoon River’s water quality changes in Godvand – Shushtar section, and the effect of saline River on its quality. In First zonal symposium on the water use of Karoon and Zayandeh Rood basin, Shahrekord University, Shahrekord. (In Persian).