Material and Methods
Study area
Jiuyuangou watershed (37°33′ to 37°38′ N, 110°16′ to 110°26′ E) is in
the hilly and gully region of the Loess Plateau and a first-class
tributary on the left bank of Wuding River in Yulin City, Shaanxi
Province, China(Figure 1). The basin has a gully density of 5.34 km
km–2, area of 70.7 km2, and
altitude of 820 to 1180 m. The main soil type is Malan loess, which is
loose, porous, and prone to erosion. The basin topography is
representative of the hilly and gully region of the Loess Plateau. In
1953, the Yellow River Water Conservancy Commission established the
Suide Test Station in Suide, and determined Jiuyuangou—the
representative area of the first sub-area of the Loess Hills and Gully
region—as the Yellow River soil and water conservation ecological
construction demonstration area.