Application of auxiliary data in the object-based classification method: a case study on the Miyun Reservoir area Spatial scale effects of runoff on the water resource conservation forest watershed within the Miyun reservoir basin SOIL EROSION AND ORGANIC MATTER LOSS BY USING FALLOUT ~(137)Cs AS TRACER IN MIYUN RESERVOIR VALLEY Study on plankton community in Miyun reservoir The bacterial diversity in different seasons of Miyun Reservoir