ارزیابی تغییر اقلیم و کاربری زمین و ارائه برنامه پیشنهادی آمایش کم کربن در حوضه آبخیز دشت کاشان

هدف از این مطالعه بررسی پدیده تغییراقلیم در حوضه دشت کاشان و ارزیابی اثرهای این پدیده و کاربری اراضی بر خشک‏سالی است. به‏منظور شناسایی روند تغییرات در سیمای این حوضه از تصاویر ماهواره لندست در یک دوره سی‏ودوساله استفاده شد. در طبقه‏بندی تصاویر از روش نظارت‏شده و الگوریتم حداکثر احتمال استفاده شد. پردازش اطلاعات در این دوره زمانی حاکی از افزایش سطح اراضی کشاورزی، مسکونی، و صنعتی در دوره 1985-2000 به میزان 5.7 و 0.32درصد و کاهش اراضی مرتع و کشاورزی به میزان 5.6 و 4.7درصد و افزایش اراضی شوره‏زار به مقدار 20درصد در دوره 2000-2017 است. با هدف پیش‏بینی آینده، داده‏های بارش با مدل آماری sdsm برای دوره 2050-2011 محاسبه شد. همچنین، با مدل من‏ کندال روند تغییرات بارش در دوره 1966 تا 2017 بررسی شد. خشک‏سالی از طریق شاخص spi به‏دست آمد. مطالعه هم‏زمان تغییر کاربری و اقلیم با توجه به خشک‏سالی طولانی‏مدت، آسیب‏پذیربودن، و خشک‏بودن حاکی از تحمیل فشارهای زیاد بر محیط زیست منطقه است. در صورت ادامه روند فعلی حوضه دشت کاشان با خسارت جبران‏ناپذیری روبه‏رو می‏شود. ازاین‏رو، این تحقیق راهبرد آمایش سبز (کم کربن) را برای کاهش خطرهای محیط زیستی و خسارات خشک‏سالی در منطقه پیشنهاد می‏کند.

Offer a Low Carbon Proposed Plan

Introduction Land use is generally referred to as the use of land in the present state.Land cover and its changes can cause greenhouse gas emissions Which causes climate change.climate change and land use interact with each other.This matter is of great importance in sensitive areas especially in arid and desert areas. These areas are sensitive to climate change and land use. In the case of climate change detection, the drought study has been very much considered in recent years. Iran is one of the countries that has suffered heavy damage from this natural threat because of being in the dry and desert region of the world. Various researchers have pointed to the relationship between land and climate change around the world.The purpose of this study was to investigate the relationship between land use and land use planningin in relation to climate change. This research proposes the new Land Use Planning approach in relation to land use as a management tool for climate change mitigation and carbon footprint reduction. Introduction Land use is generally referred to as the use of land in the present state. Land cover and its changes can cause greenhouse gas emissions Which causes climate change. climate change and land use interact with each other. This matter is of great importance in sensitive areas especially in arid and desert areas. These areas are sensitive to climate change and land use. In the case of climate change detection, the drought study has been very much considered in recent years. Iran is one of the countries that has suffered heavy damage from this natural threat because of being in the dry and desert region of the world. Various researchers have pointed to the relationship between land and climate change around the world( Cuo, Zhang, Gao, Hao, Cairang ,2013; Delgado, Gaspari, Kruse, 2015).The purpose of this study was to investigate the relationship between land use and land use planningin in relation to climate change. This research proposes the new Land Use Planning approach in relation to land use as a management tool for climate change mitigation and carbon footprint reduction. Material and methodes Introducing the study area Kashan watershed covers about 5574 square kilometers and Located in the north of Isfahan province and southwest of Tehran. The climaye of the study area is classified in dry or desert climate In the plain areas and it is classified in the semiarid climate ,in the mountainous regions according to Domartan method The tools and methods in this research include: A.Land use: In order to study land use changes, Landsat5 MSS images,1985; Landsat7 ETM+ images,2000 and Landsat 8 OLI,2017 were used. B.Climate change weather data available over the 30 year period from 1988 until 2017 at 7 meteorological stations: Kashan, Isfahan, Golpaiegan, Natanz, Meime, Ardestan, Najafabad(table1). This historical, data were obtained from the Islamic Republic of Iran Meteorological Organization (IRIMO) The model was validated using three methods:1. Coefficient of Determination(R^2), 2. rootmeansquare error (RMSE), 3. Mean Squared Error )MAE) C. Low Carbon Land Use Planning(Green land use planning) Green land use planning(GLUP) is to determine the suitable use of each region based on its potential ,so that a land use with lower carbon levels be selected in place of more carbon levels. C1. Standardization of constraints and limitations C2. Weighing the constraints and limitations C3. Multicriteria evaluation by weighted linear combination (WLC) Research findings Classification of images The results of the changes shown tha t Agricultural land use area increased by 5.7%, Bare land area by 0.61%, and Residental area by 0.32% of the total study area during the period (19852000). Range land, Sanddune,Salt land, Garden have decreased by 5.05, 0.92, 0.57 and 0.1% respectively. The results of Investigating the changes during the time period (20002017) show that Salt land, Residental and garden area increased by 12.20, 1.07 and 0.28 percent, respectively, and Range land, agriculture, Bare land and Sanddune area were 5.62, 4.69, 2.52 and 0.73 percent, respectively. Validation of downscaling model The results of the indicators indicate that the SDSM model has a more accuracy than the daily scale in the monthly and seasonal and annual scales for the downscaling of the precipitation parameter in the studied watershed. And in general, this model has a good performance in downscaling region precipitation. The results of Validation of downscaling model Based on the results of the SDSM, RCP4.5 predicts the lowest average rainfall of 0.2 in December and the highest average rainfall of .08 in May. Drought assessment The results of 12month spI index for overall study period during 19502050 show that in 1985 there was a drought in the range from 1.5 to 1.99, which indicates the sever drought on the studied area, In 2000 , the drought is located in the 0.9999 range, which represents a nearnormal drought. In 2017, the average 12month SPI is reduced, and drought is in the 1.99to1.5 range, which indicates hard drought. Based on the SPI index for the next years 2030 (20112050), under the 4.5 scenario, the drought is reduced compared to the baseline and is located on the range of 2 and less range, which indicates an sever drought, indicating that the monthly precipitation Will decrease in 2030 during the climate change. Evaluation of ecological land capability Ecological capability was evaluated for 8 land uses( Agriculture, range land , forestry, conservation, Extensive and intensive tourism and urban and rural development. Green Land Use Planning (Low Carbon Land Use Planning) The green land use planning map was created with priority for land uses with less water consumption and less carbon, to reduce the impact on climate change for the Kashan plain watershed. Reasults The trend of change in Kashan plain watershed shows that at the same time as the study began, the trend of climate change (1985) has increased the agricultural and residential and industrial land araes. In general, these applications have the greatest impact on the rate of evapotranspiration and reduction of water resources and increased greenhouse gas emissions. With the continuation of the climate change trend and the negative trend of drought , the agricultural land and Range land areas have decreased and increased against the salt land areas. This situation is due to the reduction of agricultural land efficiency due to soil salinity and drying of irrigation wells and the abandonment of these lands, especially in the salt lake and the northern lands of Aran, Bidgol, Abu Zayedabad and Nasr Abad.