Multi-band remote sensing based retrieval model and 3D analysis of water depth in Hulun Lake, China

Hulun Lake, a large lake located on the cold and arid Hulunbeir grassland in the Inner Mongolia Autonomous Region, is the fifth largest in China and the largest in the north of the country. However, the information on the lake’s characteristics (e.g., water depth versus surface area) is scarce in literature. Based on the lake’s physiographic features, this study developed and used a model that merges the sunlight reflection band with the thermal infrared radiation band to simulate the lake’s characteristics. The model verification and error analysis indicated an optimal model structure of logarithm. Thus, this logarithmic model was selected to analyze the spectral data. The results indicated that the model did a good job in reproducing observed water depths and accurately predicted the depths on 24 September 2007. This showed that this model can be reliably applied to the cold and arid region. Subsequently, the results were used to generate a triangular irregular network (TIN) model, which in turn was used to compute the functional relations between water level, surface area, and volume. The correlation between water level and volume is superior to that between water level and area. The regression equation developed in this study can be used to estimate the volume when water elevation is known.