Bridging the Data Gap: Validating Satellite-Derived Water Levels in Inland Waters with Varied Morphologies for Improved Water Management

Satellite altimetry has been in use for the past 30 years. During this time, the precision of water level monitoring has significantly improved due to advancements in technology and substantial enhancements in algorithms and modeling approaches. Many validation studies have demonstrated satellite data's high accuracy and applicability in regions with limited data availability. However, comprehensive validation of altimetry satellite data for inland waters across diverse topographies and morphologies is still lacking. This study addresses this gap by assessing multi-satellite data (Jason-3, Sentinel-3, and ICESat-2) to monitor inland water bodies with distinct and varying characteristics. The selected study sites along the Indus River include Tarbela Dam in the mountainous upper Indus Basin, Chashma Barrage in the central basin, and Guddu and Sukkur Barrages in the lower basin. Manchar Lake, one of South Asia’s largest freshwater lakes, was analyzed to explore the potential of satellite data in monitoring natural lakes. Furthermore, three locations along the Mekong River were included to examine the effects of dam operations on water level time series. Altimetry data demonstrated reasonable accuracy in flat regions, but precision declined in mountainous terrains. Additional filtering techniques are necessary to mitigate distorted satellite signals and improve performance in these challenging areas.