Estimation of Water Balance for Anticipated Land Use in the Potohar Plateau of the Indus Basin Using SWAT

Abstract

Land Use/Land Cover (LU/LC) change is among the dominant driving factors that directly influence water balance by transforming hydrological responses. Consequently, a thorough comprehension of its impacts is imperative for sustainable water resource planning and development, notably in developing worlds such as Pakistan, where agriculture is a major livelihood. This research intends to assess the continuing changes in LU/LC and evaluate their probable repercussions on the hydrological regime of the Potohar Plateau. The maximum likelihood classification (MLC) algorithm for land use classification of the high-resolution satellite imageries, the Cellular-Automata Markov Chain Model (CA-MCM) for the projection of LU/LC maps, and the Soil and Water Assessment Tool (SWAT) in tandem with SWAT-CUP for hydrological modeling were employed in this research. The high-resolution climatic dataset (10 × 10 km) was used in SWAT. The LU/LC analysis revealed a continual propagation of agricultural and built-up lands at the detriment of forest and barren land during the last three decades, which is anticipated to continue in the future, too. Hydrological model calibrations and validations were performed on multi-basins, and the performance was evaluated using different statistical coefficients, e.g., the coefficient of determination (R2), Nash–Sutcliffe Efficiency (NSE), Kling–Gupta Efficiency (KGE), and Percent Bias (PBIAS). The results yielded that the model performed very well and demonstrated the model’s robustness in reproducing the flow regime. The water balance study revealed that the anticipated LU/LC changes are projected to decrease the mean annual surface runoff, water yield, and streamflow due to an increase in percolation, lateral flow, sub-surface flow, and evapotranspiration. More significant variations of the water balance components were observed at the sub-basin level, owing to the heterogeneous spatial distribution of LU/LC, than at the basin level. The outcome of this study will provide pragmatic details to legislative bodies to develop land and water management ameliorative strategies to harness hydrological changes sustainably.

How did blue and green water resource evolute spatially and temporally in the Meijiang River Basin, China?

“…The commonly used hydrological models are the Astrophysics and Cosmology Research Unit (ACRU) model (Jewitt and Schulze, 1999) for agricultural catchment study units, the Stream model (Seyam et al, 2000), the Hydrological Simulation Program-Fortran (HSPF) model (Liu et al, 2021), and the Soil and Water Assessment Tool (SWAT) model (Pisinaras et al, 2013). Among them, the SWAT hydrological model is more cost-effective to simulate the amount of blue and green water resources, and the measured data are used to calibrate the results of the model, making it used more widely than some other models (Gassman et al, 2014;Jeyrani et al, 2021;Idrees et al, 2022). Cruise et al (Cruise et al, 1999;Abbaspour et al, 2009) developed a SWAT model of the south eastern United States to analyze water resource conditions under global climate change.…”