Accelerated soil erosion due to deforestation and agriculture is an important resource concern in China (Wang et al. 2005), resulting in the largest reforestation program in the world. The Northeastern Forestry University in Harbin investigated whether new geospatial technologies can improve watershed restoration strategies, including reforestation (Ji 2012). To implement new geospatial technologies, an advanced digital landscapes with synthetic river networks are required, and the Yongcui catchment (50 km2) in Heilongjiang Province was selected as a demonstration site.
The Northeastern Forestry University in Harbin conducted a demonstration analysis in the Yongcui catchment to address the hypothetical impacts of deforestation on soil erosion and its potential impacts on streams and rivers (Ji 2012). First, NetMap was used to build a digital landscape and synthetic river using a 2m DEM (a higher resolution DEM was available for the research watershed, although 12m DEMs exist for a majority of the country). Next, a surface erosion model in NetMap (WEPP, Flanigan and Livingston 1995, Elliot et al. 2001) was applied using a climate simulation; other parameters including vegetation (forest, unforested), soils, and distance of hillslopes to streams. The WEPP model incorporates relationships between slope steepness and erosion, the slope profile and sediment delivery to streams, influence of soil type, and the frequency and magnitude of rain storms.