Rapid urbanization and drastic land-use change have led to landscape fragmentation and ecological environment deterioration in the regions along the Grand Canal. Building an ecological network is an important means to improve the connectivity of habitat patches and carry out ecological protection and restoration of territorial space, which is of great significance to ensure regional biodiversity and ecological security. In this article, we took the Huaiyang Section of the Grand Canal (Huaiyang Canal) as the study area, used the ecosystem service assessment model, morphological spatial pattern analysis (MSPA), and the landscape connectivity evaluation method to identify ecological sources, then used the minimum cumulative resistance (MCR) model and the gravity model to extract and grade ecological corridors. Based on these, the ecological network was constructed by combining the identification method of ecological nodes and ecological breakpoints. The aim of this was to provide a reference for the ecological space optimization of Huaiyang Canal and even the entire Grand Canal, the formulation of an ecological protection plan, and the implementation of territorial space ecological restoration. The results showed that the spatial distribution of the water conservation service, soil conservation service, carbon sequestration service, and biodiversity conservation service were significantly different, and the level of ecosystem services showed a trend of continuous degradation from 1990 to 2018. There were 12 ecological source patches comprehensively identified by multiple methods, with a total area of 2007.06 km². In terms of spatial distribution, large ecological source patches were mainly distributed in the central and western areas adjacent to the Grand Canal, while small ecological source patches were scattered in the eastern and southern border regions of the study area. The total length of ecological corridors was 373.84 km, of which the number of the primary ecological corridor, secondary ecological corridor, and tertiary ecological corridor were 9, 7, and 7, respectively, and the suitable width of the ecological corridor was 200–400 m. After optimization, the proposed ecological network was composed of 3 key ecological source patches, 9 important ecological source patches, 23 terrestrial corridors, 10 aquatic corridors, and 18 ecological nodes. Twenty-nine ecological breakpoints were key areas requiring ecological restoration. The overlap rate of the integrated ecosystem service change area and land-use change area was 99%, indicating that land-use change has a significant impact on regional ecosystem services. This study is of great significance for carrying out the ecological protection and restoration of the Huaiyang Canal and adjusting local land-use policies. It also provides a typical case demonstration for identifying an ecological network and formulating ecological restoration planning for other sections of the Grand Canal and cities along the canal.

Rapid, accurate, and non-destructive monitoring after land reclamation is the basis of and key to realizing land restoration evaluation, as well as land use direction decision-making and improvement. However, the biggest problem with the filling reclamation method is the poor soil water retention caused by the insufficient thickness of covering soil (TCS), which results in the loss of soil nutrients. In addition, the cost of filling reclamation has also increased due to the excessive TCS. In this study, multi-source remote sensing data acquisition methods were used to assess the impacts of the TCS of the filling reclamation method on soil water retention and crop growth (CG). We found that as the TCS increases, the overall trend of the CG gradually increases, and the overall trend of the soil water content slowly increases. However, considering the huge economic costs and the cost of soil sources, we suggest that the optimal TCS for the filling reclamation method should be controlled within 40-50 cm. The results of this study provide a reference for the use of multi-source remote sensing technology for rapid evaluation of the restoration effects of reclaimed areas and for the rational utilization of coal chemical wastes.

Integrating ecosystem service value (ESV) into land use optimization is crucial for achieving sustainable development goals. Unlike traditional “post-evaluation” approaches that assess ESV after generating land use plans, this study pioneers a “goal-oriented” method by embedding ESV as an objective to guide land use optimization. A multi-objective particle swarm optimization (PSO) framework, which incorporates ESV with land quantity error, spatial aggregation of farmland and construction land, and economic benefits, was constructed for the research study. Applied to Wuhan, China, for the periods of 2005–2015 and 2010–2020, the results demonstrate the feasibility of the proposed framework in: (1) reducing construction land area while increasing farmland and ecological land; (2) spatially aggregating construction land towards urban functional areas while protecting farmland and ecological land in peri-urban and outer suburban areas; (3) improving spatial aggregation of farmland, construction land, and ecological land; and (4) slightly increasing ESV, particularly in peri-urban and outer suburban areas. The proposed PSO framework provides a valuable tool for optimizing land use layout, enhancing ecosystem service provision, and promoting balanced socio-ecological development.