Analysis of Temporal Vegetation Changes in Western Rangelands of Kerman Province Using MODIS Level 3 Data and its Relation to Climate Factors

Vegetation is one of the most important physical properties of the earth's surface that plays an important role in reducing the occurrence of wind erosion and reducing dust particulate matter emissions, especially in arid and semiarid regions. The extent of development or destruction of vegetation in an area is usually affected by climate change at different times. This study aimed to investigate the temporal variations in western rangelands of Kerman province and to determine its relashionship with climate factors using the most accurate model derived from ordinary least squares (OLS) method between meteorological and vegetation data. For this purpose, the monthly data of the Modified Vegetation Difference Index (NDVI) and meteorological variables (mean temperature, precipitation, wind speed, maximum air temperature, and minimum temperature) for the months of April to September during 2000 to 2017 were used. Models were compared to each other and evaluated using the coefficient of determination (R2), Root Mean Square Error (RMSE) and Variance Inflation Factor (VIF). The results showed that the relationship between NDVI and average minimum and maximum temperatures, wind speed and rainfall  has higher accuracy than other models due to higher R2 (0.24) and as well as, lower RMSE (0.196) and VIF (3.2) values. Based on this relationship, the most important climatic factors affecting the vegetation status of the study area were identified as mean minimum temperature, precipitation and surface wind speed. Such results could improve our understanding from the impact of climate change on vegetation conditions in arid regions.