Trends Analysis of Rainfall and Temperature over Nagwan Watershed, Hazaribagh District, Jharkhand

Abstract

Trend analysis is performed to find the pattern that prevails in Nagwan watershed area located in Hazaribagh district of Jharkhand (India) having very high average annual rainfall in the range of 1146 mm. The study aims to investigated the impacts of global warming by examine precipitation and temperature change over a period. Non-parametric MK test and Sen’s Slope estimator were used to assess the trend in long-term rainfall and temperature time series (1981-2019). The analysis has been carried out on monthly, seasonal and annual scale to identify meso-scale climate change effect on hydrological regime. The precipitation in the summer showed an increasing trend (Z value +1.67) and there was increasing trend in the seasonal rainfall which influences the total water availability in the watershed. There was increase in minimum temperature during summer season which shows the impact of global warming and may results in increasing the duration of the summer season. The annual average minimum temperature in the watershed showed an increasing trend (Z value +2.08) at 0.05 level of significance indicated hot nights in the summer. The annual average maximum temperature in the watershed showed a decreasing trend (Z value -1.26). Fluctuation and change in trend of rainfall and temperature possess potential risk hence it is important to understand and identify the pattern of rainfall and temperature for assessing impact of climate change and it is necessary to adopt appropriate steps for agriculture crop planning and improving farmer’s capability to cope with challenging situations due to environmental and climate changes.