Abstract: Based on the land use change data and by using 137Cs tracer technique, this paper studied the change process of soil erosion intensity in Yangjuangou watershed in Loess Hilly Region. Since the 1980’s, the land use intensity in the watershed decreased gradually. In 1980〖KG-*2〗-〖KG-*7〗2006, the slope arable land decreased from 949 hm2 to 02 hm2, while the forest land, shrub land, orchard land, and grassland increased from 0 to 511 hm2, from 0 to 192 hm2, from 0 to 180 hm2, and from 769 hm2 to 801 hm2, respectively. The soil erosion intensity was in the order of slope arable land > shrub land > orchard land > grass land > forest land. In 1980, 1984, 1996, and 2006, the soil erosion intensity was 64089, 53624, 49039, and 36414 t·km-2·a-1, respectively, being changed from intense to moderate. Soil and water conservation and vegetation restoration were the main causes of the decrease of soil erosion intensity in the study area.

Key words: filamentous macroalgae, river ecosystem, urbanization, methane (CH₄) emission.