Yanfeng Wu

Accurate quantification of wetland depression water storage capacity (WDWSC) is imperative for comprehending the wetland hydrologic regulation functions to support integrated water resources management. Considering the challenges posed by the high acquisition cost of high-resolution lidar DEM or the absence of field measurements for most wetland areas, urgent attention is required to develop an accurate estimation framework for WDWSC using open-source, low-cost, multi-source remote sensing data. In response, we developed a novel framework, WetlandSCB, utilizing coarse-resolution terrain data for accurate estimation of WDWSC. This framework overcame several technical difficulties, including biases in above-water topography, incompleteness and inaccuracy of wetland depression identification, and the absence of bathymetry. Validation and application of the framework were conducted in two national nature reserves of northeast China. The study demonstrated that, by integrating the priority-flood algorithm, morphological operators, and prior information, one can accurately delineate the wetland depression distribution, with overall accuracy and kappa coefficient both exceeding 0.95. The use of a water occurrence map can effectively correct numerical biases in above-water topography, with Pearson coefficient and R² increasing by 0.33 and 0.38, respectively. Coupling spatial prediction and modeling with remote sensing techniques yielded highly accurate bathymetry estimates, with < 3 % relative error compared with field measurements. Overall, the WetlandSCB framework achieved estimation of WDWSC with < 10 % relative error compared with field topographic and bathymetric measurements. The framework and its concept are transferable to other wetland areas globally where field measurements and/or high-resolution terrain data are unavailable, contributing to a major technical advancement in estimating WDWSC in river basins.

Peatlands are globally important carbon sinks, yet these are increasingly threatened by climate change and human disturbances. Among degradation indicators, surface subsidence is gradual and challenging to monitor, particularly in alpine peatlands. This study applied SBAS-InSAR techniques to analyze surface deformation in the Zoige peatland of the eastern Qinghai—Tibet Plateau using Sentinel-1 SAR data from 2017 to 2023. The results showed a maximum interannual subsidence of −167.92 mm and a peak seasonal deformation of −144.11 mm, with a cumulative average of −23.99 mm (−3.43 mm·yr⁻¹). Approximately 80.9% of peatlands within the protected area exhibited subsidence. Drainage ditch construction emerged as the dominant driver, while climatic factors such as precipitation and temperature exhibited seasonal effects. Subsidence was more pronounced in drier years and during winter months. These findings highlight the spatial heterogeneity and seasonal dynamics of peatland subsidence and underscore the urgent need for hydrological restoration and long-term monitoring to mitigate degradation in alpine peatland ecosystems.

As an important ecosystem service, water conservation is influenced by land use related to human activities. In this study, we first evaluated spatial and temporal changes in water conservation in Baicheng City, western Jilin Province, from 2000 to 2020. Then, we identified three different scenarios: the natural development scenario (NDS), cropland protection scenario (CPS), and ecological protection scenario (EPS). We coupled the Patch-generating Land Use Simulation (PLUS) and Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) models to predict the distribution of land use types and water conservation in Baicheng City under these scenarios for 2030. The results showed the following: (1) The average water conservation in Baicheng City from 2000 to 2020 was 7.08 mm. (2) Areas with higher water conservation were distributed in the northwest and northeast, while lower water conservation areas were distributed in the central and southwest of Baicheng City. (3) The simulation results of the future pattern of land use show an increasing water conservation trend in all three scenarios. Compared with the other two scenarios, the ecological protection scenario is the most suitable option for the current development planning of Baicheng City. Under the ecological protection scenario (EPS), ecological land is strictly protected, the area of agricultural land increases to some extent, and the overall structure of changes in land use becomes more rational. This study provides a reference for land resource allocation and ecosystem conservation.