Monitoring the Meteorological and Hydrological Droughts in the Largest River Basin (Mahaweli River) in Sri Lanka

This study assessed the meteorological and hydrological droughts their relationship over 30 years from 1985 to 2015 in largest river basin (Mahaweli River Basin (MRB)) Sri Lanka. Data 14 rainfall, 5 temperature, streamflow stations near MRB were used present study. Universal drought indices including Standardized Precipitation Index (SPI) Precipitation–Evapotranspiration (SPEI) assess droughts. The Streamflow (SSI) was investigating Correlations between obtained, annual variations observed (in terms of SPI, SPEI, SSI), spatial distributions selected events analyzed. Our results revealed that highest correlation found long-term dry conditions wet zone. In addition, some negative correlations showed opposite behavior correlations. Furthermore, droughts, extreme recorded zone as maximum values, while more prominent distribution performed using SSI an extremely condition 2004. findings are beneficial for policymaking decision-makers assessing risks future.