A Satellite View of the Wetland Transformation Path and Associated Drivers in the Greater Bay Area of China during the Past Four Decades

Abstract

As a highly productive and biologically diverse ecosystem, wetlands provide unique habitat for a wide array of plant and animal species. Owing to the strong disturbance by human activities and climate change, wetland degradation and fragmentation have become a common phenomenon across the globe. The Guangdong–Hong Kong–Macao Greater Bay Area (GBA) is a typical case. The GBA has experienced explosive growth in the population and economy since the early 1980s, which has resulted in complicated transitions between wetlands and non-wetlands. However, our knowledge about the transformation paths, associated drivers, and ecological influence of the GBA’s wetlands is still very limited. Taking advantage of the land use maps generated from Landsat observations over the period of 1980–2020, here, we quantified the spatiotemporal transformation paths of the GBA’s wetlands and analyzed the associated drivers and ecological influence. We found that the dominant transformation path between wetland and non-wetland was from wetland to built-up land, which accounted for 98.4% of total wetland loss. The primary transformation path among different wetland types was from coastal shallow water and paddy land to reservoir/pond, with the strongest transformation intensity in the 1980s. The driving forces behind the wetland change were found to vary by region. Anthropogenic factors (i.e., population growth and urbanization) dominated in highly developed cities, while climate factors and aquaculture had a greater influence in underdeveloped cities. The findings presented in this study will provide a reference for wetland management and planning in the GBA.

Low Residents’ Satisfaction with Wetland Leisure Demand in Typical Urban Areas of the Semi-Arid Region in Western China: Spatial Variations and Their Causes

“…Compared to the areas with relative-low residents' satisfaction, areas with relative-high residents' satisfaction have a low population density and adequate wetland area. This kind of spatial pattern of wetlands was seen in most cities in the semi-arid region of Western China where urban areas have rapidly expanded over the past few decades [14,26,29]. The results indicated an unbalanced and inadequate supply-demand contradiction between the population capacity of wetlands and the total population of communities locally.…”

“…Spatial variations in residents' satisfaction with wetland leisure demand and their causes in semi-arid regions remain poorly characterized [7,14]. This study evaluated residents' satisfaction in a typical urban area of a semi-arid region in Western China based on the supplydemand relationships between the population capacity of wetlands and the total population of communities under a framework of physical calculation.…”

“…Numerous studies have evaluated residents' satisfaction with wetland leisure demand in semi-arid regions using subjective methods such as questionnaire surveys and interviews [14][15][16][17]. Evaluations of residents' satisfaction with the half-an-hour life circle have emerged in large numbers, especially in the post-COVID-19 era [16,[18][19][20].…”

“…Consequently, the previous evaluations struggled to objectively quantify residents' satisfaction. Furthermore, there remains a limited understanding of spatial variations in residents' satisfaction and their causes [14,21,22]. The supply-demand relationship between the population capacity of wetlands and the total population of communities provides a means to objectively reflect residents' satisfaction with wetland leisure demand [16].…”