ﭘﺎﯾﺶ ﺗﻐﯿﯿﺮات ﺳﻄﺢ آب درﯾﺎﭼﻪ اروﻣﯿﻪ ﺑﺎ اﺳﺘﻔﺎده از ﺗﺼﺎوﯾﺮ ﻣﺎﻫﻮارهاي

Monitoring Urmia Lake Water Level Changes Using Satellite Images

بررسي تغييرات سطح آب درياچه ها به منظور حفاظت آنها به لحاظ اهميت، ماهيت و موقعيت اين مجموعه هاي آبي و بهعنوان يك ميراث طبيعي در سال هاي اخيردر بين كشورها در سطح ملي و منطقهاي جايگاه ويژه اي پيدا كرده ا ست . بحران خشك شدن درياچه اروميه با وسعتي حدود نيم ميليون هكتار به عنوان بزرگترين درياچه داخلي ايران، با توجه به تبعات آن، تبديل به يك م سيله ملي شده ا ست . با توجه به تغييرات بارش و دما و رخداد خشك سالي ها و تر سالي هاي شديد در اين حوضه و ويژگيهاي مرفولوژيك آن (شيب كم سواحل) سطح تراز آن دچار نوسانات و تغييرات زيادي ميشود . بطوريكه در سال هاي اخير تو سعه طرحهاي منابع آبي و به ويژه احداث سدهاي مخزني بر روي رودخانه هاي ﻣﻨﺘﻬﯽ ﺑﻪ درﯾﺎﭼﻪ، ﺗﺄﺛﯿﺮ زﯾﺎدي ﺑﺮ ورودي آب و درﻧﻬﺎﯾﺖ ﺗﺮاز آب آن داﺷــﺘﻪ اﺳــﺖ. در اﯾﻦ ﺗﺤﻘﯿﻖ ﺑﻪ ﻣﻨﻈﻮر ارزﯾﺎﺑﯽ ﺗﻐﯿﯿﺮات ﻣ ﺴﺎﺣﺖ درﯾﺎﭼﻪ اروﻣﯿﻪ از داده ﻫﺎي ﭼﻨﺪ زﻣﺎﻧﻪ ﻣﺎﻫﻮارهاي ﻟﻨﺪ ﺳﺖ 7 و 8 ) ﺷﺎﻣﻞ ﺳﻨﺠﻨﺪه ﻫﺎي ETM+ و OLI( در ﺑﺎزه زﻣﺎﻧﯽ ﺳﺎل ﻫﺎي 2001 ﺗﺎ 2019 ﻣﻮرد اﺳﺘﻔﺎده و ﭘﺮدازش ﻗﺮار ﮔﺮﻓﺖ و ﻧﻮﺳﺎن ﻫﺎي ﺳﻄﺢ آب درﯾﺎﭼﻪ در دورهﻫﺎي زﻣﺎﻧﯽ ﻣﺨﺘﻠﻒ اﺳﺘﺨﺮاج ﺷﺪ ﻧﺘﺎﯾﺞ ﺣﺎﮐﯽ از آن اﺳﺖ ﮐﻪ ﻣﺴﺎﺣﺖ درﯾﺎﭼﻪ اروﻣﯿﻪ از 4346.71 ﮐﯿﻠﻮﻣﺘﺮ ﻣﺮﺑﻊ در ﺳﺎل 2001 ﺑﻪ 2285.76 ﮐﯿﻠﻮﻣﺘﺮ ﻣﺮﺑﻊ در ﺳﺎل 2015 ﺳﯿﺮ ﻧﺰوﻟﯽ داﺷﺘﻪ و ﺑﺎ اﻓﺰاﯾﺶ در ﺳﺎل 2019 ﺑﻪ 3705.88 ﮐﯿﻠﻮﻣﺘﺮ ﻣﺮﺑﻊ رﺳﯿﺪه اﺳﺖ. ﻧﻮﺳﺎﻧﺎت آب درﯾﺎﭼﻪ ﻧﯿﺰ از ﺳﺎل 2001 ﺗﺎ 2015 ﺣﺪود 47.39 درﺻﺪ ﮐﺎﻫﺶ و ﺗﺎ ﺳﺎل 2019 ﺑﻪ ﻣﯿﺰان 38.32 درﺻﺪ ﻧﺴﺒﺖ ﺑﻪ ﺳﺎل 2015 اﻓﺰاﯾﺶ ﯾﺎﻓﺘﻪ اﺳﺖ.

Investigating the changes in the water level of the lakes in order to protect them in terms of the importance, nature and position of these water bodies and as a natural heritage in recent years between countries at national and regional level has gained special importance .The drying crisis of Lake Urmia with an area of about half a million hectares as Iran's largest inland lake has become a national issue due to its consequences. Due to the changes in precipitation and temperature and the occurrence of severe droughts and wetlands in this basin and its morphological features (low coastal slope) its elevation level is subject to many fluctuations and changes .In recent years, the development of water resources projects, and in particular the construction of reservoir dams on the rivers leading to the lake, has had a major impact on the water inlet and ultimately its water level.In this study, we used and processed Landsat 7 and 8 satellite weather data (including ETM + and OLI sensors) from 2001 to 2019 to evaluate the changes in the Urmia Lake area. Different time periods were extracted. The results show that the area of Lake Urmia declined from 4346.71 sq km in 2001 to 2285.76 sq km in 2015 and increased to 3705.88 sq km in 2019. Lake water volatility also declined by 47.39 percent from 2001 to 2015 and by 38.32 percent by 2019, according to the report.