The 24th IAHR-APD Congress (24th IAHR-APD Congress)

499 / 2024-05-10 21:04:05

Examining Shoreline Characteristics of Hongze Lake via Remote Sensing: An Assessment of the Influence on Nutrient Distribution

Satellite Imagery,aerial photography,large shallow lake,normalized difference water index

Subtheme 6: Smart Water > Topic 1: Remote Sensing and IoT in Water Conservancy

Eutrophication poses significant threats to freshwater ecosystems globally, with lakes particularly vulnerable to nutrient overloading. This study investigates the complex dynamics of nutrient inputs and shoreline structures in Lake Hongze, a large shallow lake within the Huai River valley. Employing a combination of field sampling, remote sensing techniques, and reprocessing normalized difference water index (NDWI) images, our findings reveal the prevalence of polders and embankments as dominant shoreline features by investigating Band 6 short-wave infrared satellite imagery and on-site aerial photography. The differences in shoreline structures were quantified by computing the grayscale values of NDWI images. Ponds and lake water surface were distinguished by reprocessing the NWDI image. Through the combination of reprocessing NDWI and on-site water sampling, it was found that total phosphorus is significantly higher in areas with higher pond density, but total nitrogen exhibits less correlations. Furthermore, we discuss methodological considerations and suggest avenues for future research, emphasizing the need for more generalized parameterization methods for shoreline structures and advanced techniques for spatially resolved nutrient assessment.