Regional planning for ecological protection of rivers in highly urbanized areas

[Display omitted] •The minimum cumulative resistance model is used to quantify the trends of river ecological protection and construction expansion.•Spatial principal component analysis is used to determine the weights of the eight impact factors to assess river ecological risk.•The ecological risk assessed based on the 600 m buffer zone is the most sensitive and reflects the most detailed results.•The 765.51 km2 area in the study area has the potential to become a buffer zone for river ecological protection.•Constructing ecological networks is an effective measure to mitigate ecological risks and is more applicable to developing countries. The ecological risks associated with rapid urbanization have seriously undermined the river’s ecological security. Especially for developing countries, the weak ecological foundation and enormous population pressure have increased the difficulty of river ecological protection. It is urgent to propose a bottom-line planning and management approach for river ecological protection in highly urbanized areas of developing countries. We quantified the minimum cumulative resistance of the river protection and construction land expansion processes. Then, based on the difference between these two minimum cumulative resistances, we assessed the river ecological risk in the Beijing plain area and presented a complete method to regional-level planning and management for river ecological protection. The results show that: 1) The spatial distribution of river ecological risks follows a three-tier ring structure, decreasing from the city center to the suburbs and then to the outer suburbs. The number of river segments with ecological risk levels 1, 2, and 3 are 44, 42, and 23, respectively, accounting for 39.2% of the total length of all river sections, which indicates that a larger number of rivers are facing high ecological risk. 2) The study area was divided into three zones according to the suitability of river ecological protection, with 2476.89, 765.51, and 3832.09 km2, respectively. Zone I and Zone II can be developed as protection nodes and riparian protection zones to develop the river ecological network in the central city. 3) We extracted 133 large ecological patches and 219 potential ecological corridors, which should be connected with the river network to enhance the connectivity of the local ecological landscape. The complete method proposed in this study is more focused and implementable to assist administrators in prot