Regional Ecological Risk Assessment of Wetlands in the Sanjiang Plain with Respect to Human Disturbance

Abstract

Characterization of the intensity of regional human disturbances on wetlands is an important scientific issue. In this study, the pole-axis system (involving multi-level central places and roads) was recognized as a proxy of direct risk to wetlands stemming from human activities at the regional or watershed scale. In this respect, the pole-axis system and central place theory were adopted to analyze the spatial agglomeration characteristics of regional human activities. Soil erosion and non-point source (NPS) pollution, indicating the indirect effect of human activities on wetlands, were also considered. Based on these human disturbance proxies, which are considered regional risk sources to wetlands, incorporated with another two indicators of regional environment, i.e., vulnerability and ecological capital indexes, the regional ecological risk assessment (RERA) framework of wetlands was finally established. Using this wetland RERA framework, the spatial heterogeneity of risk grades within the Naoli River Basin, a typical concentrated wetland region in the Sanjiang Plain, was analyzed. The results showed that (1) high- and very high-risk source intensity areas displayed a ring-shape distribution pattern, which reflected the influence of the regional pole-axis system; (2) owing to their high ecological capital value per unit area and vulnerability level, the wetlands had the highest risk grade, as did central places (i.e., those areas where county seats and administration bureaus of farms were located). In terms of proportion, the low-, medium-, high-, and very high-risk areas accounted for 72.0%, 16.8%, 10.1%, and 1.1% of the study area, respectively. The identification and classification of risk sources to wetlands that are related to human activity at the watershed scale could provide clear perspectives in order to reduce severe risk sources to these areas, especially those Ramsor Convention-appointed sites of international importance. Moreover, the assessment framework used in this paper will provide a helpful reference for related research in the future. Finally, the new management guidelines proposed in this paper will be beneficial for lowering the ecological risk level of wetlands at the watershed or regional scale for the Sanjiang Plain or other wetland-concentrated regions.

Regional assessment of human-caused ecological risk in the Poyang Lake Eco-economic Zone using production–living–ecology analysis

“…Besides climate change and natural hazards, human activity has been identified as one of the main sources of regional ecological risk [ 1 – 4 ]. With the ongoing urbanization and industrialization, several issues such as natural resource over-exploitation, ecosystem damage, and environmental pollution are becoming increasingly serious [ 5 ].…”

“…Therefore, sustainable development that focuses on the coordination and optimization of the relationship between human production-consumption activities and eco-environmental protection is also becoming increasingly popular globally. Consequently, ecological risk management (ERM), which emphasizes on the prevention of ecological destruction and pollution events, and ecological risk assessment (ERA), which provides a scientific decision basis for ERM, have attracted attention from scientists, politicians, and the general public [ 3 , 4 ]. Related research and practices have proved that ERM and ERA play a crucial role in environmental management and biological/ecological protection, and subsequently, in regional sustainable development [ 2 , 6 ].…”

“…From ERA to RERA, the relevant scale has expanded from single points to regional and landscape scales. With an increasing scale, the focus has shifted to the analysis of spatial heterogeneity of risk sources, receptors, and final integrated risk on a regional scale [ 1 – 4 ]. Consequently, regional ecological risk assessment (RERA) and management (RERM) are becoming important topics in regional eco-environmental management and protection research [ 4 ].…”

“…With an increasing scale, the focus has shifted to the analysis of spatial heterogeneity of risk sources, receptors, and final integrated risk on a regional scale [ 1 – 4 ]. Consequently, regional ecological risk assessment (RERA) and management (RERM) are becoming important topics in regional eco-environmental management and protection research [ 4 ]. A series of methodologies have been developed and practiced in RERA research, such as the “Three-Step Framework” proposed by the United States Environmental Protection Agency [ 8 ], Relative Risk Model (RRM) by Landis and Wiegers [ 9 ], and the Procedure for Ecological Tiered Assessment of Risk by Moraes et al [ 10 ].…”

“…A series of methodologies have been developed and practiced in RERA research, such as the “Three-Step Framework” proposed by the United States Environmental Protection Agency [ 8 ], Relative Risk Model (RRM) by Landis and Wiegers [ 9 ], and the Procedure for Ecological Tiered Assessment of Risk by Moraes et al [ 10 ]. All these provide useful references for related research, such as normally including three basic indexes in the RERA process (i.e., risk source intensity index, risk receptor ecological-value index, and regional eco-environmental vulnerability index), and emphasizing on the spatial differentiation analysis finally [ 1 , 3 , 4 ]. Another important issue in the human-caused RERA study is the identification of ecological risk sources and receptors and the selection of corresponding indexes.…”