Spatial and temporal distribution of rainfall trends in Bist-Doab region of Punjab (1901–2010)

Abstract

It has been established that the global climate changes are real and these could have imperative effects on various environmental variables including rainfall in many countries around the world. Changes in precipitation regime directly affect water resources management, agriculture, hydrology and ecosystems of a region. For this reason it is important to investigate the changes in the spatial and temporal rainfall pattern in order to improve water management strategies and improve the exiting approaches. In this study, an analysis has been made to study the spatial and temporal variability of rainfall over the period of 110 years (1901-2010) on annual, seasonal and monthly basis in order to understand the regional pattern of rainfall in Bist-doab region of Punjab. Nonparametric statistical method (Mann–Kendall rank correlation method) is employed in order to verify the existence of trend in annual, seasonal and monthly rainfall and the distribution of the rainfall during the year. The magnitude of the trends have also been analyzed using the Sen’s slope estimator. To explore the spatial distribution of trends of rainfall the detected trends were spatially interpolated using spatial analysis techniques in a GIS environment. The results show the existence of a generalized negative trend for the entire region.