Drought vulnerability assessment and mapping using Multi-Criteria decision making (MCDM) and application of Analytic Hierarchy process (AHP) for Namakkal District, Tamilnadu, India

Abstract

Abstract Droughts are increasingly impacting our societies due to its slow and steady development over a period of several years. Droughts affect agriculture and lead to devastating results. Droughts are highly dependent on a wide variety of parameters ranging from climatic conditions such as rainfall, temperature, to economic conditions such as population density, irrigated land condition per person, etc. Hence, remote sensing-based studies have the fullest potential to monitor and map drought in comparison to conventional methods. Namakkal district in Tamilnadu, primarily an agrarian region, is one of the several drought-prone regions due to scarcity in rainfall and high temperatures. This study presents the importance of Geographical Information System (GIS) in assessing drought vulnerability in combination with the Analytic Hierarchy Process (AHP). In this study, GIS is used for the spatial analysis of drought for Namakkal district, Tamilnadu, India. Eight parameters such as annual rainfall, monthly rainfall, Landuse/Landcover (LULC), slope, soil type, Normalized Difference Vegetation Index (NDVI), Normalized Difference Water Index (NDWI) and population were chosen and considered for the study. AHP is used to calculate weightage factors of each criterion based on the pairwise comparison matrices. The thematic maps of all the parameters were analyzed and Drought Vulnerability Assessment (DVA) map was generated using GIS. The results of the combined multi-criteria decision making and GIS revealed that 62% of the total area of Namakkal district came under mild drought conditions. The output DVA map will provide ample information on drought severity in the region and vulnerability related to agricultural importance. This study therefore, proposes to map the drought regions using a combination of AHP and GIS. The use of nanotechnology to crop helps in the alleviation of drought-related stress and enhances the growth pattern and therefore, increases crop production and yield.