Mitigation and Management of Agricultural Drought Assessment in Arjunanadhi and Kousiganadhi Sub-Basins in Tamil Nadu, India

Abstract

Agricultural drought refers to circumstances when rainfall and soil moisture are insufficient and results in unhealthy crop growth and reduction in crop yield. In the year 2009, the overall rainfall deficiency for the country was 22% and resulted in a decrease in food grain production by 16 million tonnes. During the years 2014, 2015 and 2016, large parts of the country were affected by drought causing widespread hardships to the affected population since the calamity encompassed major agricultural States in the country. It has been mentioned in the detailed project report of the Irrigated Agriculture Modernization and Water-Bodies Restoration and Management (IAMWARM) that the Arjunanadhi sub-basin generally has temperature and drought occurs once in five years. Agricultural droughts affect whole societies, leading to higher food costs, threatened economies, and even famine. To mitigate such effects, scientific research is needed to monitor and then predict them. So an attempt has been made to analyse the drought in the Arjunanadhi and Kousiganadhi sub-basins in Tamil Nadu on a scientific approach in all the aspects of drought in the agricultural context. Moreover, a justification of drought-prone areas for inclusion and exclusion and modification is needed according to Drought Prone Area Programme ( DPAP AND DDP (1994) criteria norms based on Drought severity Assessment by Moisture Index (MI) method. Also, the agricultural drought assessment was carried out by the Standardized Precipitation Evapotranspiration Index (SPEI) method and compared the severity maps in summer and Kharif seasons for the years 2003 and 2014. The Agricultural Drought Severity Index (ADSI) method has been applied for drought characterization and using remote sensing dataset for February in the year 2015 and prepared a map using ArcGIS. The results showed that Viruthunagar, Kariyapatti, and Aruppukottai experienced severe drought conditions. Hence, the Arjunanadhi and Kousiganadhi sub-basins are experienced severe drought conditions except for the stations Kavalur and Gudalore. Hence, 75 percent of the sub-basins experienced severe drought conditions. So, the drought management method as rainwater harvesting (RWH) is proposed as an independent water supply during a drought and can help mitigate flooding of low-lying areas and reduces demand on wells and may enable groundwater levels to be maintained. Also it delineated rainwater harvesting locations in the region using an Arc GIS. The results showed that a few drought-proof measures are recommended in these basins and help the Government towards effective utilization of its water resources and allocation of funds in drought.