Spatial characteristics of ecological degradation and restoration in China from 2000 to 2015 using remote sensing

Ecosystem degradation can lead to adverse consequences and disasters and hence a healthy ecosystem is imperative for human well-being. As a country with a large population and area, China's ecological security has global significance. To determine the effect of existing land use and relevant policies on the ecosystem, we need to understand the current situation of China's ecological degradation and restoration. However, relevant research at the national scale is lacking. We used remote sensing and GIS methods to study the extent, type, and composition of ecological degradation and restoration in China, at the national scale, from 2000 to 2015. The results revealed that the fundamental cause of China's ecological degradation was development and construction, and this kind of degradation is difficult to recover from. In the 15 years, the restoration area of this type of ecological degradation accounted for only 11% of the total degraded area. The total area that was newly constructed was 87,961.04 km(2), of which 66,176.04 km(2)was previously cultivated land. For food security, another 75,258.36 km(2)of cultivated land was reclaimed. The two types of ecological degradation accounted for 71.59% of the total degraded area, and the increasing farmland area alone caused 42.14% of wetland degradation. Existing restoration projects are generally effective, but degradation, especially desertification, in the arid and semiarid regions of the northwest still needs special attention. Above all, ecological protection should be the focus, while ecological restoration the remedy.