Assessment of Annual Water-Balance Models for Diverse Indian Watersheds

Hydrological responses of a watershed are often cumbersome to identify because they exhibit spatiotemporal variation. Rather, it is interesting to observe the hydrologic responses of a basin at a microlevel scale. Thus, a study to incorporate spatial variability through the use of remote sensing techniques in water resources management would be interesting. This study used various watersheds in the state of Uttarakhand, India to compute water yield using simplified models, such as the lumped Zhang model, the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model, and the more comprehensive and parameter-intensive Soil and Water Assessment Tool (SWAT) model. The focus of the study was to gain knowledge about the methodology to adopt for computing water yield if it has to be implemented on diverse watersheds. Nine diverse watersheds were considered, varying in precipitation pattern, temperature, area, topography, discharge, and climatic conditions. The study clearly indicates whether to choose the lumped Zhang model, which provides the average values for the entire basin, a pixel-level assessment model, or a more comprehensive SWAT model. The methods were assessed for their applicability in pre- and post-climate change scenarios.