... pollutant loads from a watershed with delayed thinning and a reference watershed (Takeda and Kageyama, 2001; Takeda, 2002). Specifically, runoff loads of T–N, T–P, COD, and SS in the watershed with ... 1 - Changes in several point sources and domestic wastewater treatments in watersheds. Fig. 1 - Location of Hii River watershed and sampling points. Watershed Item 1990 1995 2000 2005 H1 ... precipitation, under-populated watershed, water quality. INTRODUCTION In recent years, the deterioration of water quality in closed water areas such as lakes, reservoirs, and ponds has been regarded...