Temporal variation of Hydro-meteorological variables in a small river basin: A case study of the Savitri River basin, India

Abstract

Abstract This study examines the temporal characteristics of hydro-meteorological variables in the Savitri River basin in India. Eight hydro-meteorological variables observed during the monsoon season (July–September) over a period of 11 years (2000–2010) from two stations (Kangule and Birwadi) are analysed. The variables include daily rainfall, runoff, maximum temperature, minimum temperature, pan evaporation, relative humidity, sunshine duration, and wind speed. Two trend detection methods, namely the Mann-Kendall test and Sen’s slope test, are employed to identify the trend characteristics in these variables. The trend analysis is performed for the indices developed from these variables, which are based on events, such as the number of days of occurrence, annual total, 1-day maximum, yearly average, days of occurrence of events more than the yearly average, 95th percentile, and days of occurrence of events more than 95th percentile. The trend analysis of rainfall shows an increasing trend for all rainfall indices studied. The runoff indices revealed that there is an increase in magnitude and days of occurrence of high flows which may result in flood flow. The indices on maximum temperature, sunshine duration, and relative humidity show a decreasing trend. However, the minimum temperature, pan evaporation, and wind speed show mixed responses. The results indicate that although the two stations are geographically closer to each other, the hydro-meteorological variables show mixed variations due to their difference in elevation and closeness to the peaked region. The present results serve as an important basis for a detailed hydrological analysis of the Savitri River basin.