Coupling Water-Energy Balances for Remote Sensing Water Resources Assessment

Accurate water resources assessment is the fundament of integrated water resources management. However, conventional assessment methods rely on sparse gauging networks, empirical reduction procedures, and intensive calibration, which can lead to reduction distortion, failure, and large uncertainty in data-limited basins. This study developed a total remote sensing process framework to assessment water resources. It retrieves precipitation, condensate and evapotranspiration by remote sensing data, and constrains the fluxes into a set of dual-closure equations which simultaneously enforces the water-energy balances. Taking Yongding River Basin as the testing region, the results show that runoff, that is the blue water resources,  generated start from elevation of 2400 m, accumulating along downslope, and reaches the maximum with 2.049 billion m³ at elevation of 1050 m. Below the elevation, the water resources presented a dissipation toward outlet. The assessment is not only reduced the dependency of ground observation, but also increased the detailedness, including formation, retention, dissipation across complex terrain and consumption. It provides a water resource accounting solution for where situ observations are incomplete or inaccessible.