Rainfall, temperature and reference evapotranspiration trend in the context of climate change over undivided Koraput district, Odisha, India

Abstract

In the present study, an attempt has been made to know the long−term changes in rainfall, temperature, and reference evapotranspiration (ET ) over undivided Koraput o district (Koraput, Malkangiri, Nabarangapur and Rayagada). Rainfall (1901−2017), temperature and ET (1901−2002) data were analyzed in this study. Statistical trend o analysis technique such as Mann−Kendall (M−K) test was used to examine and analyze the data trend. The detailed analysis of the data for 117 years indicates that mean annual rainfall of Koraput, Malkangiri, Nabarangapur and Rayagada is 1316.1 mm, 1180.1 mm, 1451.0 mm and 1270.8 mm, respectively. Statistically significant trends were detected for rainfall, and also the result was statistically significant at 95% confidence interval. Annual rainfall showed an increasing trend at the rate of 2.49, 3.86 mm yr−1 at Koraput, and Malkangiri, respectively, however there was no trend for Nabarangapur and Rayagada districts. Similarly, rainfall during monsoon showed an increasing trend for Koraput (2.73 mm yr−1) and Malkangiri (4.05 mm yr−1). With respect to maximum and minimum temperatures, and ET , all the four districts of the study area showed an o increasing trend. The highest ET trend of 0.112 mm season−1 was observed during o pre−monsoon season at Malkangiri, whereas the lowest significant trend of seasonal ET (0.06 mm season−1) was noticed during the monsoon season at Rayagada. The o study area is mostly undulating in nature, thus increase in rainfall and temperature may aggravate the present soil erosion rate. Various soil and water conservation measures are suggested to manage natural resources and to increase crop productivity under climate change condition. This study will be helpful in planning, management and conservation of natural resources for sustainable development of the region.