Behnaz Asefjah; Yahya Esmaeilpour; Ommolbanin bazrafshan; Hossein Zamani
Abstract
The past decade has seen a major revolution in vegetation monitoring using satellite imagery, resulting in quantitative indicators of vegetation with a professional processor in a web-based interactive development environment. In this study, using MOD13A1 and MOD13Q1 products of Modis sensor, the trend ...
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The past decade has seen a major revolution in vegetation monitoring using satellite imagery, resulting in quantitative indicators of vegetation with a professional processor in a web-based interactive development environment. In this study, using MOD13A1 and MOD13Q1 products of Modis sensor, the trend of temporal and spatial changes of NDVI and EVI indices in Fars province in a period of 16 days from 2000 to 2020 was coded and processed monthly in Google Earth engine system. The results of this study showed that the average index of NDVI index is from minimum 0.11 to maximum 0.495 and the average index of EVI index is 0.1. According to the results obtained in this survey, in all the years from 2000 to 2020 in January, NDVI and EVI values had the highest values compared to other months, so that in January 2019 and January 2020, the highest EVI values averaged 0.22 and the NDVI values Was estimated to be 0.18. The lowest monthly average values of both indices occurred between 2000 and 2005, which indicates that the vegetation has been severely degraded during these years. The results of spatial changes using EVI index showed that the level of vegetation in Fars province in different months varied from 10,000 square kilometers to 22,000 square kilometers and from the perspective of NDVI index from 15,000 square kilometers to 30,000 square kilometers.
Amir Reza Keshtkar; Behnaz Asefjah; Yusef Erfanifard; Ali Afzali
Abstract
The development and implementation of practical natural resources and catchment managementpolicies require a comprehensive knowledge of the system processes (biological, physical, andsocio-economic), their complicated interactions, and how they react to different changes. Thecurrent research assessed ...
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The development and implementation of practical natural resources and catchment managementpolicies require a comprehensive knowledge of the system processes (biological, physical, andsocio-economic), their complicated interactions, and how they react to different changes. Thecurrent research assessed the ecological, physical, and socio-economic consequences ofbiologically-based management scenarios targeting runoff and soil erosion problems in theDarenari catchment. The Darenari catchment with an approximate area of 554 ha is located in Farsprovince, Iran. Three biological activities and 8 management scenarios were considered. Ecologicalconsequences were studied using the weighted land cover area index (WLCAI). Physical effectswere investigated applying the runoff curve number (SCS-CN) hydrologic model. Economic andsocial effects were assessed applying the cost/benefit analysis as well as examining the outcomes ofa social survey. Then, a fuzzy AHP approach was applied to weigh the criteria and ultimately, thebest management option was chosen using FTOPSIS model. The results showed that social criteriawith the highest weight and scenario No 8 was the best scenario and had first priority. The resultsidicated that the multi-criteria decision making techniques included capability of expressingdifferent aspects of the problem and are the perfect tool for watershed resources management.
