Characterizing effects of landscape and morphometric factors on water quality of reservoirs using a self-organizing map

Understanding the pattern of reservoir water quality in relation to morphometry and other landscape characteristics can provide insight into water quality management. We investigated the water quality of 302 reservoirs distributed nationwide in Korea by classifying them using a self-organizing map (SOM), examining how hydrogeomorphometry variables are related to reservoir water quality, and evaluating the effects of variables at different categories including geology, land cover, hydromorphology, and physicochemistry on reservoir water quality through a theoretical path model. The SOM classified the reservoirs into six clusters, from least to most polluted, with differences in physicochemical and hydrogeomorphometry variables between clusters. Water quality exhibits strong relationships with the proportions of urban, agricultural, and forest land cover types in the watersheds. Finally, our results revealed that hydrogeomorphometry of reservoirs and percentages of land cover types within watersheds have a considerable impact on the water quality of adjacent aquatic ecosystems.