چکیده انگلیسی مقاله |
Drought is one of the environmental disasters which is very frequent in arid and semi-arid regions of the country. Rainfall defects have different effects on groundwater, soil moisture, and river flow. The purpose of this study was to evaluate vegetation and land surface temperature for drought and wet season analysis in Qom, Chaharmahal Bakhtiari, Isfahan and Markazi provinces using Terrasse Madis satellite images, precipitation data of synoptic stations located in the region, indices Remote sensing such as TCI, VCI, VHI is used to detect changes occurring in the 17 year (MADIS) and 20 years (precipitation, for verification) intervals. For this purpose, firstly, April, May and June were selected as samples by examining the rain gauge and synoptic data of existing stations and by using standardized precipitation index (SPI) model of April, May and June. In this study, satellite images (MOD11A2, MOD13A3) were acquired from 2000 to 2017 and pre-processed and processed such as geometric and radiometric correction, then standardized precipitation index with temperature conditions, vegetation status index and health index. Vegetation was compared in combination with Moda Tera satellite imagery. The results showed that among the surveyed fishes, the highest drought trend was observed in the eastern part of these provinces and covered more than 50% of the area. The trend of changes in this slope was statistically significant. According to the results of correlations, the TCI index with the SPI index had a strong correlation with other indices. It can also be concluded that the Modis images and the processed indices along with the climate indices have the potential for drought monitoring. Using maps derived from drought indices can help improve drought management programs and play a significant role in mitigating drought effects. |