Assessment of impact of climate change on the streamflow of Idamalayar River Basin, Kerala

Autor: C. Reshma, R. Arunkumar
Jazyk: angličtina
Rok vydání: 2023
Předmět:
Zdroj: Journal of Water and Climate Change, Vol 14, Iss 7, Pp 2133-2149 (2023)
Druh dokumentu: article
ISSN: 2040-2244
2408-9354
DOI: 10.2166/wcc.2023.456
Popis: This study investigates the impacts of climate change on water availability in the Idamalayar basin, Kerala. Soil and Water Assessment Tool (SWAT), Hydrologic Engineering Centre – Hydrologic Modelling System (HEC-HMS), and bias-corrected climate change data were used to simulate future streamflows. The performances of SWAT and HEC-HMS were assessed using four statistical indices (R2, Nash–Sutcliffe efficiency, percentage bias, and RSR). SWAT slightly outperformed HEC-HMS. The CMIP6 general circulation models (GCMs) were selected using PROMETHEE-2. The variations in climate variables and streamflows were studied for three future periods, i.e., near-future (2031–2040), mid-future (2051–2060), and far-future (2071–2080) under three shared socio-economic pathway (SSP) scenarios (SSP126, SSP245, and SSP585). The projections of GCMs show different patterns in variation of precipitation. Generally, there is a slight increase in annual precipitation. However, there was a notable decline in peak in July. An additional peak was often seen in October. The maximum and minimum temperatures showed a decreasing trend. The average annual streamflow reduction under SSP126 was approximately 25.63, 27.92, and 26.24% in the near, mid, and far future, respectively. Under SSP245, the average decrease was 30.71, 16.06, and 19.06% for the near, mid and far future, respectively. For SSP585, there was 12.73% increase in the far-future period. HIGHLIGHTS Water availability in the Idamalayar catchment is studied using five CMIP6 GCMs under three SSP scenarios, for three future periods.; Different GCMs project the variation in water availability differently.; Generally, there is a decrease in the streamflow except in the far-future period under SSP585.; The variation in streamflow calls for better management practices.;
Databáze: Directory of Open Access Journals
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