شبيه‬ سازي اثرات تخصيص بهينه آب بر منابع آب زيرزميني در دوره‬ هاي تنش ماهانه (دشت باغملك، استان خوزستان)

Simulating the Effect of Optimal Water Allocation on Groundwater in Monthly Stress Periods (Baghmalek Plain, Khuzestan Province

تخصيص بهينه آب ميتواند يك راهكار مناسب براي افزايش بهرهوري منابع آب در نواحي خشك و نيمه خشك ﻣﺤﺴﻮب ﮔﺮدد. ﺑﺪﯾﻦ ﻣﻨﻈﻮر، ﻣﻨﺎﺑﻊ اﺻﻠﯽ ﻣﺼﺮف آب در دﺷﺖ ﺑﺎﻏﻤﻠﮏ )اﺳﺘﺎن ﺧﻮزﺳﺘﺎن( در ﺣﺪ ﻓﺎﺻﻞ ﻣﻬﺮ ﻣﺎه 1392 ﺗﺎ ﺷﻬﺮﯾﻮر ﻣﺎه 1393 و رﻗﻮم ﺳﻄﺢ اﯾﺴﺘﺎﺑﯽ ﺑﻪ ﻣﺪت9 ﺳﺎل )1381 ﺗﺎ 1390( ﺷﻨﺎﺳﺎﯾﯽ و ﺗﺤﻠﯿﻞ ﺷﺪﻧﺪ. ﻣﺪل ﺗﻮﺳﻌﻪ داده ﺷﺪه در اﯾﻦ ﺗﺤﻘﯿﻖ از ﺗﺮﮐﯿﺐ دو ﻣﺪل ﺑﻬﯿﻨﻪﺳﺎزي ﭼﻨﺪﻫﺪﻓﻪ اﻟﮕﻮي ﮐﺸﺖ و ﺷﺒﯿﻪﺳﺎزي آب زﯾﺮزﻣﯿﻨﯽ ﺑﻪ دﺳﺖ آﻣﺪ. ﻫﻤﭽﻨﯿﻦ رﻓﺘﺎر ﺟﺮﯾﺎن آب زﯾﺮزﻣﯿﻨﯽ ﺑﺮ ﭘﺎﯾﻪ روش ﻋﺪدي ﺗﻔﺎﺿﻞ ﻣﺤﺪود ﺑﺎ اﺳﺘﻔﺎده از ﻧﺮماﻓﺰار Modflow ﺑﺮاي ﺗﺤﻠﯿﻞ ﺳﻨﺎرﯾﻮﻫﺎي ﺑﻬﯿﻨﻪ ﺑﺮداﺷﺖ، ﺷﺒﯿﻪﺳﺎزي ﮔﺮدﯾﺪ. ﺳﺎلﻫﺎي ﻣﻄﺎﻟﻌﻪ ﺑﻪ 36 دوره ﺗﻨﺶ ﻓﺼﻠﯽ ﺗﻘﺴﯿﻢ ﺷﺪه و ﻫﺪاﯾﺖ ﻫﯿﺪروﻟﯿﮑﯽ، آﺑﺪﻫﯽ وﯾﮋه و ﻣﻘﺪار ﺗﻐﺬﯾﻪ در اﯾﻦ دورهﻫﺎ ﻣﻮرد واﺳﻨﺠﯽ ﻗﺮار ﮔﺮﻓﺖ. ﻧﺘﺎﯾﺞ ﻧﺸﺎن داد ﮐﻪ ﻣﺪل ﺟﺮﯾﺎن ﺑﺎ وارﯾﺎﻧﺲ ﺧﻄﺎي 3/05 و 3/92 ﺑﻪﺗﺮﺗﯿﺐ ﺑﺮاي ﻓﺮآﯾﻨﺪﻫﺎي واﺳﻨﺠﯽ و ﺻﺤﺖﺳﻨﺠﯽ دﻗﺖ ﺷﺒﯿﻪﺳﺎزي ﻗﺎﺑﻞ ﻗﺒﻮﻟﯽ دارد. ﻋﻼوه ﺑﺮ اﯾﻦ، ﭘﯿﺶﺑﯿﻨﯽ ﺳﻄﺢ اﯾﺴﺘﺎﺑﯽ ﭘﺲ از ﺳﻨﺎرﯾﻮي ﺑﺮداﺷﺖ ﺑﻬﯿﻨﻪ ﻧﺸﺎن داد ﮐﻪ دورهﻫﺎي اﺻﻠﯽ ﻣﺪﯾﺮﯾﺖ آب زﯾﺮزﻣﯿﻨﯽ در ﻣﺎهﻫﺎي اردﯾﺒﻬﺸﺖ و ﺧﺮداد ﻗﺮار دارﻧﺪ

Optimized water allocation may be considered as a valuable solution to increase the productivity of water resources in arid and semi-arid areas. To achieve this purpose, the main resources of water consumption in Baghmalek plain (Khuzestan province) for duration of October 2013 to September 2014 and also water table heights for nine years (2002 to 2011) were evaluated. In this study, the final model was developed by combining the two cropping pattern multiobjective optimization and groundwater simulation models. Also, groundwater flow was simulated for addressing optimal discharge scenarios based on finite difference numerical approach using Modflow software. Study years were divided into 36 seasonal stress periods and hydraulic conductivity, specific yield and recharge were calibrated in these periods. The results showed that the flow model had an acceptable simulation accuracy by variance error of 3.05 and 3.92 in calibration and verification processes, respectively. Furthermore, the prediction of water table after the optimal discharge scenario indicated that the May and June months were the main periods of groundwater management.