Regional assessment of ecological risk caused by human activities on wetlands in the Muleng-Xingkai Plain of China using a pressure–capital–vulnerability–response model

The establishment of the whole framework of regional ecological risk assessment (RERA) and the selection of corresponding indicators in related subaspects are important scientific issues for wetland RERA research. In this study, a pressure–capital–vulnerability–response model was employed to establish a wetland RERA indicator system of the Muleng-Xingkai Plain, a wetland-concentrated basin in the southeastern Sanjiang Plain, Northeast China. Within this model, the multilevel central places (urban/town/farm areas) and roads, soil erosion mainly stemming from dry croplands and forestlands, and nonpoint source pollution from paddy fields were selected as ecological risk source indicators, i.e., pressure indices, while the ecosystem service value of regional ecosystems was selected as an ecological risk receptor indicator, i.e., capital index. Then, a wetland RERA framework was established incorporating regional eco-environmental vulnerability and response indices. The results showed that (1) the Defense Meteorological Program Operational Line-Scan System (DMSP-OLS) nighttime light intensity data matched the distribution of regional urban/town/farm area very well, therefore this type of dataset may be used to represent regional multilevel central places; (2) the wetlands outside the three nature reserves had higher final risk grades than the wetlands within the three nature reserves, Dongfanghong, Zhenbaodao, and Xingkaihu, which were mostly in the scope of the medium-risk grade (grade 2); (3) because of a high level of human disturbance, high-level settlement points (Mishan County seat, Hulin County seat), the administration bureau of farms in Mudanjiang, and the Dongfanghong Forestry Farm, were also distributed in the final high-risk grades; and (4) the low, medium, high, and very high risk grades accounted for 77.10%, 15.69%, 5.91%, and 1.30% of the study area, respectively. The RERA pressure–capital–vulnerability–response model developed in this paper will be helpful for related research in the future and help in planning and establishing sustainable development and conservation models in the Muleng-Xingkai Plain.