Spatial constraints or spatial dynamics? The spatial spillover effect of networks of flood regulation service flows...

In the face of frequent floods under climate and environmental changes, it is particularly important to measure the supply and demand of flood regulation services. Using the Hainan Island as an illustrative case, this study constructs a spatial spillover model to examine the spatial correlation mode and evolution of regional land-use degree through the network of ecosystem service flow. The research results show that forests, grasslands, and reservoirs function as the primary suppliers of flood regulation services, with forests contributing significantly to the regulation of floods. High flood risk was identified in the eastern, northern, and western regions of the Hainan Island, corresponding to increased demand for flood regulation services in croplands, towns, and rural settlements within these areas. The flow of flood regulation services within the Hainan Island was found to be directed from the center to the surrounding areas, with medium and high service flows predominantly concentrated in the northern and surrounding regions. The degree of land use on the Hainan Island demonstrated an influence on socio-economic development. Additionally, the flow network of ecological services was identified as a crucial factor in spatial spillovers, reflecting the level of interaction between county units.