Spring disappearance in the Himalayas: An appraisal on climate change

Código

I-EBHE0072

Autores

Dr. Netrananda Sahu

Tema

WG 1.06: Water for biodiversity in a changing world

Resumo

Springs are the major sources of surface water in the Himalayan region. Spring disappearance is now a common issue in the Himalayan region especially in the upper part of Himachal Pradesh due to both climate change and anthropogenic activities. Recent observation has been reported that the spring-water discharge has been decreased year after year. In this study, we focused on the reduction of spring-water discharge in response to climatic data from 1981 to 2021. The trend of temperature and rainfall have been analyzed using Mann-Kendall and Sen's slope test. The r value was denoted that the rainfall has the strong association (r=0.94) with the spring-water discharge. The rainfall-runoff MIKE 11 NAM hydrological model used to estimate and assess the discharge trends of spring-water in response to daily average rainfall data. After model calibration and simulation, it was found that spring-water runoff, both observed and simulated were decreased tremendously almost 29% within past 40 years. The validation results (NSE=0.79, R-squared=0.944, RMSE=0.23, and PBIAS=32%) showed that the model was well performed. However, reduced spring-water discharge was made sensitive to the hydrological (groundwater stress, base flow, and stream water flow) and environmental entities (drinking water, evaporation, soil moisture, and evapotranspiration). The associated socioeconomic changes are posing new societal issues for the local people. This study will help the researcher, policy maker and water managers to work about spring disappearances and its consequences in the Himalayan region.