Trend and variability analysis of rainfall at Jaldhaka River Basin in the Himalayan Foreland, India

Abstract

Understanding the mechanics of future climate and land use requires an understanding of hydrological consequences, which include changes in soil usage. The study's analysis of rainfall data from 13 monitoring stations spread over the Jaldhaka River Basin on monthly, seasonal and annual time periods revealed the substantial temporal pattern. Using data from 1901 to 2022 (122 years) from thirteen IMD gridded stations spread over the Jaldhaka River Basin in India, the temporal variation and trends of the annual, seasonal and monthly rainfall distribution at the Himalayan Foreland were investigated. The nonparametric Mann-Kendal (MK) & modified Mann-Kendal (MMK) along with Sen’s non-parametric estimator of slope and Buishand U test were applied to detect trends and step change analysis, respectively. Three distinct time series' autocorrelation coefficients (ACCs) were computed at a one-time lag and assessed at the 95% significance level in order to apply the MMK test. Significant positive and negative trends have been noticed in the monthly, seasonal, and yearly rainfall time series in all 13 IMD gridded stations in and around the Indian Jaldhaka River Basin (JRB), according to the analysis's findings. In the ArcGIS 10.8 environment, the Thiessen polygon (TP) method was used to interpolate the spatial variation of the monthly, seasonal, and yearly rainfall time series data. In the Jaldhaka River Basin, rainfall patterns and variability study, together with accompanying maps, would be helpful to local stakeholders in organising the effective use of water resources.