پديد آورندگان :
يوسفي زاده، رحيم دانشگاه تبريز، تبريز، ايران , صحت، ساويز دانشگاه زنجان، زنجان، ايران , غلام نيا، خليل پژوهشكده هواشناسي، تهران، ايران , ملكي، علي اداره كل هواشناسي مازندران، ساري، ايران , عينالي، گلزار دانشگاه تبريز، تبريز، ايران
كليدواژه :
سنجش از دور , پردازش تصاوير ماهواره اي , برف مرز , شبكه عصبي , استان مازندران
چكيده فارسي :
در سالهاي اخير تغييرات زيادي در سطوح برفي به خاطر تغيير اقليم در مناطق مختلف ايران اتفاق افتادهو مازندران از اين قاعده مستثني نبوده است.تخمين صحيح توزيع فضايي برف، براي برآورد تابآوري و آسيبپذيري منطقه، برنامهريزيهاي تأمين آب، مديريت ريسك و بحران سيل، بسيار كاربردي و ضروري مي باشد. فنآوري سنجشازدور فرصت جديدي را فراهم آورده تا بتوان محاسباتي گسترده تر، دقيقتر و آسان تر را نسبت به مدلهاي زمينآماري،جهت برآوردتغييرات برف انجام داد. در اين پژوهش به بررسي تغييرات برف مرز استان مازندران در يك دوره 18 ساله از سال 1380 تا پايان 1397 پرداخته شد و تغييرات برف مرز استان در فصل زمستان شناسايي گرديد. سپس با دادههاي اقليمي شبيه سازي شده استاندارد سازمان زمين شناسي آمريكا كه براي تغيير اقليم 1472 تهيه گرديد به پيش نگري روند تغييرات برف مرز استان در سال 1429براي فصل زمستان با استفاده از مدل شبكه عصبيMLP پرداخته شد و ميزان تغييرات آن نسبت به زمان حال محاسبه گرديد. سپس با استفاده روش منحنيROC دقت مدل براياين فصل زمستان 50/98درصد ارزيابي گرديد كه مبين دقت بالاي مدل شبكه عصبي براي شبيه سازي برف مرز استان ميباشد.
نتايج مبين آن است كه در سال 1429 ارتفاع برف مرز استان در فصل زمستان حدود 800 متر نسبت به شرايط حاضر به سمت ارتفاعات بالاتر جابجا خواهد شد و از ارتفاع حدود 2750 متر فعلي به 3560 متر خواهد رسيد و اين شرايط مي تواند چالش هاي عديده اي در منابع آبي استان بوجود آورد.
چكيده لاتين :
According to meteorologists studying climate and atmospheric change , snow monitoring is essential; Because the surface expansion and physical properties of snow are affected by daily changes and even long-term climatic changes and sometimes affect.Snow storage in mountainous basins is the main source of surface water currents in spring. Accumulation of snow and gradual melting of snow masses, provides favorable conditions for the infiltration and feeding of groundwater and the creation of permanent and seasonal rivers in catchments. Iran is a mountainous country and is also located in arid and semi-arid territory and most of its rainfall falls in the cold season, which is snow in the mountains. Mountains hold water reserves in the form of snow for other times of the year. The Alborz mountain range, as a water dividing line on its northern and southern slopes, manages water resources. Important rivers that flow in the southern slopes of Alborz make life possible in the interior of Alborz. As the temperature decreases, this mountain range changes the type of precipitation to snow on its slopes and maintains the snow reserves as a safe bed during the dry days of the year. Climate change and global warming are causing changes in the snow border area in the mountains, resulting in drought. Border snow fluctuations are more affected by temperature changes than annual rainfall, because if there is no decrease in rainfall, increasing the temperature will increase the height of the border snow.According to meteorologists studying climate and atmospheric change, snow monitoring is essential; Because the surface expansion and physical properties of snow are affected by daily changes and even long-term climatic changes and sometimes affect. In recent years, climate change has caused temporal and spatial changes in the amount and type of precipitation in Mazandaran province, which in turn adds to the importance of this issue. Accurate estimation of cover level is considered as one of the central and basic operations in the field of water resources management, especially in areas where snowfall has a large share in precipitation. Snow storage in mountainous basins is the main source of surface water currents in spring. Accumulation of snow and gradual melting of snow masses provide favorable conditions for the infiltration and feeding of groundwater and the creation of permanent and seasonal rivers in catchments. According to studies, about 60% of the country's surface water and 57% of groundwater is fed by melting snow.
The deep correlation between the height of the border snow at the end of the cold season predicts the occurrence or non-occurrence of drought for the following year In recent years , many changes in snow levels have occurred due to climate change in different parts of Iran and Mazandaran is no exception to this rule. Accurate estimation of snow spatial distribution is very useful and necessary for estimating the resilience and vulnerability of the area , water supply planning, risk management and flood crisis. Remote sensing technology provides a new opportunity to perform broader , more accurate and easier calculations than geostatistical models to estimate snow changes. In this study, the snow changes in the border of Mazandaran province in an 18-year period from 2001 to the end of 2018 were studied and the snow changes in the border of the province in winter were identified. Then , with the climatic data of the standard of the American Geological Survey, which was prepared for climate change in 2093, the trend of snow changes in the province border in 2050 for the winter was predicted using the MLP neural network model and the amount of changes compared to the present time was calculated. Took. Then, using the ROC curve method , the accuracy of the model for this chapter was evaluated 98.50%, which indicates the high accuracy of the neural network model to simulate the snow of the province border.
The results show that in 2050, the height of snow in the border of the province in winter will be about 800 meters compared to the current conditions will move to higher altitudes and from the current height of about 2750 meters will reach 3560 meters and these conditions can be many challenges. Created in the province's water resources.