This picture illustrates a typical core project site, where a series of sediment plots are being protected by a key dam constructed upstream. The earth barriers serving as sediment traps are shown as horizontal lines across the width of the gully. Young poplars line the top of the dam, and from their heights one can detect the age of these dams. Water stored in the reservoir provide irrigation to these plots and other low-level plots. This site is at Shaanxi's Hengshan County (ºáɽÏØ).