تحليل زماني و مكاني خشك‌سالي با استفاده از شاخص‌هاي خشك‌سالي و گشتاورهاي خطي در حوضه بويين اصفهان

Temporal and spatial analysis of drought in Boein Aquifer using drought indices and linear moment technique

ﺑﻬﺮهﺑﺮداري ﻓﺰاﯾﻨﺪه از ذﺧﺎﯾﺮ آب زﯾﺮزﻣﯿﻨﯽ و در ﻧﺘﯿﺠﻪ اﻓﺖ ﺳﻄﺢ اﯾﺴﺘﺎﺑﯽ و ﮐﺎﻫﺶ اﯾﻦ ذﺧﺎﯾﺮ، ﻣﺪﯾﺮﯾﺖ ﺟﺎﻣﻊ ﻣﻨﺎﺑﻊ آب زﯾﺮزﻣﯿﻨﯽ و ﺳﻄﺤﯽ را ﺑﻪﻃﻮر ﺟﺪي ﻣﻮرد ﺗﻮﺟﻪ ﻣﺴﺌﻮﻻن و ﺑﺮﻧﺎﻣﻪرﯾﺰان ﻗﺮار داده اﺳﺖ. ﺑﻪ ﻧﺤﻮي ﮐﻪ ارزﯾﺎﺑﯽ و ﻣﺪﯾﺮﯾﺖ ﻣﻨﺎﺑﻊ آب ﺑﻪﻋﻨﻮان ﯾﮑﯽ از ﻋﻮاﻣﻞ ﮐﻠﯿﺪي ﺗﻮﺳﻌﻪ ﺟﺎﻣﻊ ﻣﺤﺴﻮب ﻣﯽﺷﻮد. در اﯾﻦ ﭘﮋوﻫﺶ، آﺑﺨﻮان ﺑﻮﯾﯿﻦ اﺳﺘﺎن اﺻﻔﻬﺎن در ﺣﻮزه آﺑﺨﯿﺰ ﺑﺎﺗﻼق ﮔﺎوﺧﻮﻧﯽ ﻣﻮرد ﺑﺮرﺳﯽ ﻗﺮار ﻣﯽﮔﯿﺮد. ﺷﺎﺧﺺ اﺳﺘﺎﻧﺪارد ﺑﺎرش )SPI(، ﺷﺎﺧﺺ ﺧﺸﮑﺴﺎﻟﯽ ﻫﻮاﺷﻨﺎﺳﯽ )RDI( و ﺷﺎﺧﺺ اﺳﺘﺎﻧﺪارد آب زﯾﺮزﻣﯿﻨﯽ )GRI( در ﭘﺎﯾﻪ ﻫﺎي زﻣﺎﻧﯽ ﺳﻪ، ﺷﺶ، 24 ،12 و 48 ﻣﺎﻫﻪ و ﺷﺎﺧﺺ ﺳﻄﺢ زﯾﺮﮐﺸﺖ )CLI( در ﻣﻘﯿﺎس ﺳﺎﻻﻧﻪ ﻣﺤﺎﺳﺒﻪ ﺷﺪﻧﺪ. ﻧﺘﺎﯾﺞ ﻧﺸﺎن داد، ﺑﯿﺸﺘﺮﯾﻦ ﻫﻤﺒﺴﺘﮕﯽ ﺷﺎﺧﺺ ﺑﺎرش اﺳﺘﺎﻧﺪارد ﺑﺎ ﺷﺎﺧﺺ آب زﯾﺮزﻣﯿﻨﯽ اﺳﺘﺎﻧﺪارد در ﭘﺎﯾﻪ ﻫﺎي زﻣﺎﻧﯽ 18 و 24 ﻣﺎﻫﻪ واﻗﻊ ﺷﺪه، ﺑﯿﻦ اﯾﻦ دو ﺧﺸﮑﺴﺎﻟﯽ ﺗﺎﺧﯿﺮ ﻓﺎز زﻣﺎﻧﯽ 1/5 ﺗﺎ دو ﺳﺎﻟﻪ وﺟﻮد دارد. ﺑﺮﺧﻼف ﻧﺘﺎﯾﺞ ﺑﺮﺧﯽ ﻣﻨﺎﺑﻊ، ﻫﻤﯿﺸﻪ ﺑﺎ اﻓﺰاﯾﺶ ﭘﺎﯾﻪ زﻣﺎﻧﯽ، ﻫﻤﺒﺴﺘﮕﯽ ﺑﯿﻦ ﺷﺎﺧﺺ ﺧﺸﮑﺴﺎﻟﯽ ﻫﻮاﺷﻨﺎﺳﯽ و ﺧﺸﮑﺴﺎﻟﯽ آب زﯾﺮزﻣﯿﻨﯽ اﻓﺰاﯾﺶ ﭘﯿﺪا ﻧﻤﯽﮐﻨﺪ. ﺑﺮرﺳﯽ ﻫﻢزﻣﺎن ﺷﺎﺧﺺﻫﺎي ﺧﺸﮑﺴﺎﻟﯽ ﻫﻮاﺷﻨﺎﺳﯽ و آب زﯾﺮزﻣﯿﻨﯽ و ﺷﺎﺧﺺ ﺳﻄﺢ زﯾﺮﮐﺸﺖ ﺑﯿﺎﻧﮕﺮ ﻓﺎﺻﻠﻪ زﯾﺎد ﺷﺎﺧﺺ آب زﯾﺮزﻣﯿﻨﯽ اﺳﺘﺎﻧﺪارد ﺑﺎ دو ﺷﺎﺧﺺ دﯾﮕﺮ در ﺳﺎلﻫﺎي 1383 ﺗﺎ 1387 اﺳﺖ ﮐﻪ ﻣﯽﺗﻮاﻧﺪ ﺑﻪ دﻟﯿﻞ ﻣﺪﯾﺮﯾﺖ ﻧﺎﻣﻨﺎﺳﺐ ﺣﺎﮐﻢ ﺑﺮ ﻣﻨﻄﻘﻪ ﺑﺎﺷﺪ. در ﺳﺎلﻫﺎي اﺧﯿﺮ اﯾﻦ ﺳﻪ ﺷﺎﺧﺺ ﺑﻪ ﻫﻢ ﻧﺰدﯾﮏ ﺷﺪهاﻧﺪ ﮐﻪ دﻟﯿﻞ اﺻﻠﯽ آن اﻋﻤﺎل ﻣﺪﯾﺮﯾﺖ ﺑﯿﺸﺘﺮ ﺑﺮ ﻣﺼﺮف آب ﺑﻪوﺳﯿﻠﻪ ﺳﺎزﻣﺎنﻫﺎي ذيرﺑﻂ ﺑﻮده اﺳﺖ. ﺑﺮاي ﺗﻌﯿﯿﻦ ﻣﻨﺎﻃﻖ ﻫﻤﮕﻦ ﺧﺸﮑﺴﺎﻟﯽ، ﺣﺎﻟﺖﻫﺎي ﻣﺨﺘﻠﻒ ﺗﺮﮐﯿﺐ ﻣﻘﯿﺎسﻫﺎي زﻣﺎﻧﯽ و ﻣﮑﺎﻧﯽ ﺑﺎ اﯾﺠﺎد 39 ﺳﻨﺎرﯾﻮ ﻣﺨﺘﻠﻒ و اﻧﺠﺎم 390 ﻫﺰار ﺑﺎر ﺷﺒﯿﻪﺳﺎزي ﺑﺮرﺳﯽ ﺷﺪ. در 90 درﺻﺪ ﻣﻮارد ﻫﯿﭽﯿﮏ از ﻣﻌﯿﺎرﻫﺎي ﻫﻤﮕﻨﯽ اﻗﻨﺎع ﻧﺸﺪﻧﺪ ﮐﻪ ﻧﺸﺎن ﻣﯽدﻫﺪ، ﺗﮑﻨﯿﮏ ﮔﺸﺘﺎورﻫﺎي ﺧﻄﯽ روش ﻣﻨﺎﺳﺒﯽ ﺑﺮاي ﺗﻌﯿﯿﻦ ﻣﻨﺎﻃﻖ ﻫﻤﮕﻦ ﺧﺸﮑﺴﺎﻟﯽ آب زﯾﺮزﻣﯿﻨﯽ ﻧﯿﺴﺖ ﮐﻪ دﻟﯿﻞ آن ﻣﯽﺗﻮاﻧﺪ ﻏﯿﺮﺗﺼﺎدﻓﯽ ﺑﻮدن داده ﻫﺎ ﺑﺎﺷﺪ. در ﻧﺘﯿﺠﻪ، زﻣﺎﻧﯽ ﻣﯽﺗﻮان از ﻧﺘﺎﯾﺞ ﺗﮑﻨﯿﮏ ﮔﺸﺘﺎور ﺧﻄﯽ ﺑﻪ ﺧﻮﺑﯽ ﺑﻬﺮه ﺑﺮد ﮐﻪ ﻣﺎﻫﯿﺖ داده ﻫﺎ ﺗﺼﺎدﻓﯽ ﺑﺎﺷﻨﺪ.

The increasing exploitation of groundwater reserves and consequently the drop in the water level and reduction of the reserves have seriously caught the attention of officials and planners to the integrated management of groundwater and surface water resources. The evaluation and management of water resources are considered as one of the key factors in comprehensive development. Boein Aquifer in Isfahan Province located in the Gavkhooni Basin is studied in this study. The Standard Precipitation Index (SPI), Reclamation Drought Index (RDI) and Groundwater Standard Index (GRI) in the time scales of three, six, 12, 24 and 48 months and Cultivated Land Index (CLI) in annual time scale are calculated. Results showed that the highest correlation between the SPI and GRI is in 18 and 24 months' time scale, and there is a delay of 1.5 to 2 years between these two droughts. Contrary to the results of some references, the correlation between meteorological drought index and GRI does not always increase with increasing the time scale. A synchronic study of the SPI, GRI and CLI shows a large difference between the SRI and the other two indicators in 2004-2008 periods that may be related to the poor management of the region. However, more close values obtained for these three indices in the recent years mainly due to the better management of water consumption by relevant organizations. To determine homogeneous drought regions, different combinations of temporal and spatial scales were used by creating 39 different scenarios and running 390,000 simulations. None of the heterogeneity measures were met in 90% of cases. This indicated that the linear moment technique is not a suitable method for determining homogeneous arid regions of groundwater probably due to the non-random data. Therefore, the linear moment technique will be more useful if the data is random.