گسترش بي‌‌رويۀ باغداري و چالش مديريت منابع آبي در حوضه‌‌هاي بالادستي سدها مطالعۀ موردي: حوضۀ آبريز سد ‌‌علويان

The overexploitation of gardening and the challenge of managing water resources in the upstream dams (Case Study: Alavian Dam Basin

اﻃﻼﻋﺎت ﭘﻮﺷﺶ اراﺿﯽ، ﺑﺮاي ﺑﺴﯿﺎري از ﻓﻌﺎﻟﯿﺖ ﻫﺎي ﺑﺮﻧﺎﻣﻪ رﯾﺰي و ﻣﺪﯾﺮﯾﺖ ﺳﺮزﻣﯿﻦ داراي اﻫﻤﯿﺖ اﺳﺖ. اﻣﺮوزه ﺗﻐﯿﯿﺮات ﮐﺎرﺑﺮي اراﺿﯽ، ﯾﮑﯽ از ﻋﻮاﻣﻞ ﻣﻬﻢ در ﺗﻐﯿﯿﺮ ﺗ ﻨ ﻮ ع ِ ز ﯾ ﺴ ﺘ ﯽ و ﺧﺪﻣﺎت اﮐﻮﺳﯿﺴﺘﻤﯽ در ﯾﮏ ﻣﻨﻄﻘﻪ اﺳﺖ. ﺳﺪﻫﺎ ﺑﻪ ﻋﻨﻮان ﯾﮑﯽ از ﺳﺎزه ﻫﺎي ذﺧﯿﺮة آب، ﻧﻘﺶ ﺑﺴﺰاﯾﯽ در اﯾﻦ ﺗﻐﯿﯿﺮات دارﻧﺪ. ﺣﻮﺿﮥ ﺑﺎﻻدﺳﺖ ﺳﺪﻫﺎ در ﻃﯽ ﺳﺎل ﻫﺎ ﺑﺎ ﮔﺴﺘﺮش ﺑﺎﻏﺪاري و وﯾﻼﺳﺎزي ﺑﯽ روﯾﻪ، ﺗﺪاوم ﺣﯿﺎت و ﭘﺎﯾﺪاري ﮐﺸﻮر را ﺗﻬﺪﯾﺪ ﻣﯽ ﮐﻨﺪ. اﯾﻦ ﻣﻄﺎﻟﻌﻪ ﺑﺎ ﻫﺪف ﺑﺮرﺳﯽ ﺗﺄﺛﯿﺮ اﺣﺪاث ﺳﺪ ﻋﻠﻮﯾﺎن ﺑﺮ ﺗﻐﯿﯿﺮات ﮐﺎرﺑﺮي و ﭘﻮﺷﺶ اراﺿﯽ در ﺣﻮﺿﮥ ﺑﺎﻻدﺳﺖ ﺳﺪ و ﮔﺴﺘﺮش ﺑﯽ روﯾﮥ ﺑﺎﻏﺪاري در ﻓﺎﺻﻠﮥ زﻣﺎﻧﯽ 1990 ﺗﺎ 2016 اﻧﺠﺎم ﺷﺪ. ﺑﺮاي اﯾﻦ ﻣﻨﻈﻮر، اﺑﺘﺪا از ﺗﺼﺎوﯾﺮ ﻣﺎﻫﻮاره اي Landsat، ﺑﻬﺘﺮﯾﻦ ﺗﺮﮐﯿﺐ ﺑﺎﻧﺪي اﻧﺘﺨﺎب و ﻧﻘﺸﮥ ﮐﺎرﺑﺮي اراﺿﯽ ﺑﺎ اﺳﺘﻔﺎده از اﻟﮕﻮرﯾﺘﻢ »ﻣ ﺎﺷ ﯿ ﻦِ ﺑﺮ د ار ِ ﭘ ﺸﺘ ﯿﺒ ﺎ ن « ﻃﺒﻘﻪ ﺑﻨﺪي ﻧﻈﺎرت ﺷﺪه ﺗﻬﯿﻪ ﺷﺪ. ﺻﺤﺖ ﮐﺎرﺑﺮي و ﺿﺮﯾﺐ ﮐﺎﭘﺎ ﺑﺮاي ﺗﻤﺎﻣﯽ ﻧﻘﺸﻪ ﻫﺎ ﺑﻪ ﺗﺮﺗﯿﺐ ﺑﺎﻻﺗﺮ از 94% و 93% ﺑﻪ دﺳﺖ آﻣﺪ. ﻧﺘﺎﯾﺞ ﻧﺸﺎن ﻣﯽ دﻫﺪ ﮐﻪ در ﻃﯽ دورة 26ﺳﺎﻟﻪ، ﻣﺴﺎﺣﺖ ﺑﺎﻏﺎت از 1375/20 ﻫﮑﺘﺎر در ﺳﺎل 1990 ﺑﻪ 2670/06 ﻫﮑﺘﺎر در ﺳﺎل 2016 اﻓﺰاﯾﺶ ﯾﺎﻓﺘﻪ اﺳﺖ و ﻣﯿﺰان ﻣﺼﺮف آب ﺑﺮاي اﯾﻦ ﺑﺎﻏﺎت ﺑﺮاﺳﺎس ﻧﺮم اﻓﺰار NETWAT ﻧﺸﺎﻧﮕﺮ آن اﺳﺖ ﮐﻪ در ﺣﺪود 11836174/2 ﻣﺘﺮﻣﮑﻌﺐ در ﻫﮑﺘﺎر، ﻫﺮﺳﺎﻟﻪ ﻣﺼﺮف آب در ﻗﺴﻤﺖ ﺣﻮﺿﮥ ﺑﺎﻻدﺳﺖ ﻋﻠﻮﯾﺎن اﻓﺰاﯾﺶ ﻣﯽ ﯾﺎﺑﺪ. ﻫﻤﭽﻨﯿﻦ ﺷﺒﯿﻪ ﺳﺎزي ﺗﻐﯿﯿﺮات ﮐﺎرﺑﺮي اراﺿﯽ ﺑﺎ اﺳﺘﻔﺎده از ﻣﺪل زﻧﺠﯿﺮة ﻣﺎرﮐﻮف و ﺳﻠﻮل ﻫﺎي ﺧﻮدﮐﺎر ﻧﺸﺎن دﻫﻨﺪة اﯾﻦ اﺳﺖ ﮐﻪ درﺻﻮرت ﻧﺒﻮد ﻣﺪﯾﺮﯾﺖ، ﺑﺎﻏﺎت از 2670/06 ﻫﮑﺘﺎر در ﺳﺎل 2016، ﺑﻪ 3041/55 ﻫﮑﺘﺎر در ﺳﺎل 2021 ﺧﻮاﻫﺪ رﺳﯿﺪ ﮐﻪ اﻓﺰاﯾﺸﯽ 371/49 ﻫﮑﺘﺎري ﺧﻮاﻫﺪ داﺷﺖ. درﻧﻬﺎﯾﺖ ﺑﺮآورد اﯾﻦ ﺗﻐﯿﯿﺮات، ﺣﺎﮐﯽ از آن اﺳﺖ ﮐﻪ اﮔﺮﭼﻪ اﺣﺪاث ﺳﺪ و ﺗﻐﯿﯿﺮ ﮐﺎرﺑﺮي ﺑﻪ ﺳﻤﺖ ﮐﺸﺎورزي ﻣﻤﮑﻦ اﺳﺖ ﺑﻪ ﻟﺤﺎظ اﻗﺘﺼﺎدي ﺳﻮدﻣﻨﺪ ﺑﺎﺷﺪ، وﻟﯽ ﺑﻪ دﻟﯿﻞ ﮐﺎﻫﺶ ﻣ ﺴ ﺘ ﻤ ﺮ و ر و د ي آ ب ﺑ ﻪ ﻣ ﺨ ﺰ ن ﺳ ﺪ ، ﺑ ﺎ ﻋ ﺚ ا ﺿ ﻤ ﺤ ﻼ ل ﮐ ﺎر ﮐ ﺮ د آ ن د ر ﺗ ﺄ ﻣ ﯿ ﻦ آ ب ﺷ ُ ﺮ ب ، ﺻ ﻨ ﻌ ﺘ ﯽ و ﮐ ﺸ ﺎ و ر ز ي ﻣ ﻨ ﻄ ﻘ ﻪ ﺧﻮاﻫﺪ ﺷﺪ؛ ازاﯾﻦ رو ﻣﺪﯾﺮان ذي رﺑﻂ ﺑﺎﯾﺪ ﺿﻤﻦ ﺣﻔﻆ ﺗﻌﺎدل ﺑﯿﻦ ﻧﯿﺎزﻫﺎي ﺟﺎﻣﻌﻪ و ارﺟﺤﯿﺖ ﻫﺎ، اﺛﺮات ﻣ ﺨ ﺮّ ب درازﻣﺪت ﺳﺪﻫﺎ در ﺣﻮﺿﮥ ﺑﺎﻻدﺳﺖ ﻫﺎ را ﻧﯿﺰ ﻣﺪﻧﻈﺮ ﻗﺮار دﻫﻨﺪ.

the amount of water in the area and vegetation cover. In the present study, changes in the percentage of land cover and land use during the period from 1990 to 2016 were evaluated in the upper basin of the Alavian dam. For this purpose, at first Landsat satellite images were selected, the best band combination was prepared, and the land use map was mapped using the automated logistic support algorithm of the monitored classification, then the land cover map was classified in five classes. In order to evaluate the accuracy of the classification results, the production map was compared with the ground reality map and kappa coefficient and the general classification accuracy was determined by the automation classification method. Based on the results, roughly 1294.86 hectares of gardens have been grown in the range from 1990 to 2016, where the water consumption for these gardens based on the NETWAT software indicates that about 11836174.2 cubic meters per hectare per year, increased water use in the basin upstream of the Alavian. Also, simulation of land use changes was done using Markov chain model and Markov chain auto-cells. The results of the research indicate that the gardens will reach from 2670.06 hectares in 2016 to 3041.555 hectares in 2021, which will be an increase of 371.49 hectares. Ultimately, estimating these changes will imply a continuous reduction in the input of water into the reservoir and its degradation in the supply of drinking water, industrial and agricultural areas.