Water balance estimation and runoff simulation of Chameliya Watershed, Nepal

Jharana Nepal, Ramesh Raj Pant, Suraj Shrestha, Sudip Paudel, Kiran Bishwakarma, Mahesh Prasad Awasthi & Yam Prasad Dhital 

Abstract

Sustainable water resource management has become increasingly challenging due to the limited availability of hydrometeorological data in remote mountainous areas, making it difficult to assess water balance and simulate runoff at various spatiotemporal scales. This study aims to assess the 30-year (1990–2019) water balance of the Chameliya Watershed in the Mahakali River Basin, Nepal, with a focus on glacier dynamics, utilizing the Spatial Process in Hydrology (SPHY) modeling tool. The data analysis disclosed that the watershed experienced positive water balance for 6 months, primarily during the monsoon season, while the remaining months exhibited negative values. Additionally, a comparison between the recent decade (2010–2019) and the late 1990s revealed an increase in hydrological components, such as discharge and precipitation, alongside a decrease in evapotranspiration and glacier melt. The dynamics of discharge disclose fluctuations among multiple contributors, with rainfall taking precedence, followed by baseflow, snowmelt, and glacier melt in descending sequence. Overall, the study offers a profound understanding of water availability in the Chameliya Watershed and highlights its dynamic changes over the study period. This knowledge holds great significance, especially in remote, inaccessible, and high-altitude regions. It also underscores the necessity of understanding Himalayan hydrological dynamics for precise flood prediction, climate risk assessment, and sustainable resource management amid global climate change.

Keywords: Hydrological modeling; Water balance estimation; Runoff simulation; Water resource management; Chameliya watershed; 

Authors and Affiliations
Jharana Nepal & Kiran Bishwakarm: Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100101, China, University of Chinese Academy of Sciences, Beijing, 100049, China

Ramesh Raj Pant, Sudip Paudel & Mahesh Prasad Awasthi: Central Department of Environmental Science, Tribhuvan University, Kathmandu, Nepal

Suraj Shrestha: Central Department of Hydrology and Meteorology, Tribhuvan University, Kathmandu, Nepal; Kathmandu Center for Research and Education (KCRE), Kirtipur, Kathmandu, Nepal; Institute of Fundamental Research and Studies (InFeRS), Kathmandu, Nepal

Yam Prasad Dhital: Institute of Fundamental Research and Studies (InFeRS), Kathmandu, Nepal; College of Water Resources and Architectural Engineering, Shihezi University, Shihezi, 832000, China

DOI: https://doi.org/10.1007/s12665-024-11430-7