بررسي ارتباط بين روند تغيير شوري خاك، كاربري اراضي و فاكتورهاي اقليمي (مطالعه موردي: شادگان، خوزستان)

Investigation of the Relationship Between Soil Salinity Trend, Land Use and Climatic Factors Change (Case Study: Shadegan, Khuzestan)

زﻣﯿﻨﻪ و ﻫﺪف: ﻫﺪف از اﯾﻦ ﻣﻄﺎﻟﻌﻪ ﺑﺮرﺳﯽ ارﺗﺒﺎط ﺑﯿﻦ روﻧﺪ ﺗﻐﯿﯿﺮ ﺷﻮري ﺧﺎك، ﮐﺎرﺑﺮي اراﺿﯽ و ﻓﺎﮐﺘﻮرﻫﺎي اﻗﻠﯿﻤﯽ در ﻣﻨﻄﻘﻪ ﺷﺎدﮔﺎن ﻣﯽ ﺑﺎﺷﺪ. روش ﺑﺮرﺳﯽ: در اﯾﻦ ﺗﺤﻘﯿﻖ اﺑﺘﺪا ﺑﺎ اﺳﺘﻔﺎده از روش ﺗﺠﺰﯾﻪ و ﺗﺤﻠﯿﻞ ﻣﺆﻟﻔﻪ ﻫﺎي اﺻﻠﯽ و 54 ﻧﻤﻮﻧﻪ ﺧﺎك ﻣﻮﺟﻮد، ﻧﻘﺸﻪ ﺷﻮري ﺧﺎك ﺑﺮاي ﺳﺎل ﻫﺎي 2006 ،1990 و 2015 ﺗﻬﯿﻪ ﺷﺪ. ﺳﭙﺲ ﺑﺎ اﺳﺘﻔﺎده از ﺗﺼﺎوﯾﺮ ﻣﺎﻫﻮاره اي، ﻧﻘﺸﻪ ﻫﺎي ﮐﺎرﺑﺮي اراﺿﯽ ﺑﺮاي ﺳﺎل ﻫﺎي ﻣﺬﮐﻮر ﺗﻬﯿﻪ و روﻧﺪ ﺗﻐﯿﯿﺮات ﻣﺸﺨﺺ ﮔﺮدﯾﺪ. ﻫﻤﭽﻨﯿﻦ ﺗﻐﯿﯿﺮات ﻓﺎﮐﺘﻮرﻫﺎي اﻗﻠﯿﻤﯽ )دﻣﺎ و ﺑﺎرش( ﻃﯽ دوره زﻣﺎﻧﯽ 1990-2015 ﻣﻮرد ﺑﺮرﺳﯽ ﻗﺮار ﮔﺮﻓﺖ. ﯾﺎﻓﺘﻪﻫﺎ: ﻧﺘﺎﯾﺞ ﻧﺸﺎن داد ﮐﻪ ﮐﺎﻫﺶ ﻣﯿﺰان ﺑﺎرﻧﺪﮔﯽ و اﻓﺰاﯾﺶ درﺟﻪ ﺣﺮارت ﻣﻮﺟﺐ اﻓﺰاﯾﺶ ﺷﻮري ﺧﺎك در ﻃﯽ 25 ﺳﺎل ﺷﺪه و از ﻃﺮﻓﯽ آﺑﯿﺎري اراﺿﯽ ﮐﺸﺎورزي ﺑﺎ آب ﺷﻮر ﺑﺎﻋﺚ اﻓﺰاﯾﺶ ﺷﻮر ﺷﺪن ﺧﺎك ﺷﺪه اﺳﺖ. ﺑﺤﺚ و ﻧﺘﯿﺠﻪﮔﯿﺮي: ﺑﺎ ﺗﻮﺟﻪ ﺑﻪ اﯾﻦ ﮐﻪ ﻗﺴﻤﺖ ﻫﺎي ﻏﺮﺑﯽ ﻣﻨﻄﻘﻪ در ﻣﺠﺎورت ﺗﺎﻻب ﻫﻮراﻟﻌﻈﯿﻢ ﻣﯽ ﺑﺎﺷﻨﺪ و اﯾﻦ ﺗﺎﻻب داراي آب ﺷﯿﺮﯾﻦ، ﺷﻮر و ﻟﺐ ﺷﻮر اﺳﺖ ﻣﯽ ﺗﻮان ﮔﻔﺖ ﮐﻪ آﺑﯿﺎري اراﺿﯽ ﮐﺸﺎورزي ﺑﺎ اﯾﻦ آب ﻣﻮﺟﺐ ﮔﺮدﯾﺪه ﮐﻪ اراﺿﯽ در اﯾﻦ ﻣﻨﻄﻘﻪ ﺑﯿﺶ ﺗﺮ ﺷﻮر ﺷﻮﻧﺪ. ﻫﻤﭽﻨﯿﻦ ﺷﻮر ﺷﺪن ﺧﺎك ﻣﻨﺠﺮ ﺑﻪ ﺗﻐﯿﯿﺮ ﮐﺎرﺑﺮي، از اراﺿﯽ ﮐﺸﺎورزي ﺑﻪ اراﺿﯽ ﻏﯿﺮﮐﺸﺎورزي و در ﻧﻬﺎﯾﺖ ﺑﺎﻋﺚ ﺑﯿﺎﺑﺎن زاﯾﯽ در ﻣﻨﻄﻘﻪ ﺷﺪه اﺳﺖ.

Background and Objective: The purpose of this study is to investigate the relationship between trend of soil salinity, land use and climatic factors in the region of Shadegan, Khuzestan. Method: In this study, using principal component analysis and 54 samples of soil, soil salinity maps were prepared for the years 1990, 2006 and 2015. In the next step, land use maps of the region for the mentioned years have been prepared using satellite images and trend changes are determined. On the other hand, changes in climatic factors (temperature and precipitation) for the period of 1990-2015 were evaluated. Findings: Results showed that, reducing precipitation and increasing temperature caused increasing soil salinity during 25 years and also agricultural land and irrigation by saline water increases the salinity of the soil. Discussion and conclusion: Locating Hoor al-Azim wetland in the western part of the region, although it has fresh, brackish and saline water, it may have negative effects on soil salinity of the area because of using in agriculture irrigation. Finally, it can be concluded that soil salinity of the land might change land use and it can cause desertification in the region.