Evolution of Landscape Ecological Risk at the Optimal Scale: A Case Study of the Open Coastal Wetlands in Jiangsu, China

Abstract

Detailed analysis of the evolution characteristics of landscape ecological risk is crucial for coastal sustainable management and for understanding the potential environmental impacts of a man-made landform landscapes (MMLL). As a typical open coastal wetland, large-scale human activities (e.g., tidal reclamation, fishery activities, wind farm construction, and port construction) have substantially affected the evolution of the coastal ecological environment. Previous landscape ecological risk assessment studies have documented the effectiveness of assessing the quality of ecological environment processes. However, these studies have either focused on the noncoastal zone, or they have not considered the evolution of the spatial characteristics and ecological risk evolution of the landscape at an optimal scale. Here, we present a landscape ecological risk pattern (LERP) evolution model, based on two successive steps: first, we constructed an optimal scale method with an appropriate extent and grain using multi–temporal Landsat TM/OLI images acquired in the years 2000, 2004, 2008, 2013 and 2017, and then we calculated landscape ecological risk indices. Based on this model, the entire process of the spatiotemporal evolution of ecological risk patterns of the open coastal wetlands in Jiangsu, China, was determined. The principal findings are as follows: (1) The main landscape types in the study area are tidal flats and farmland, and the main features of the landscape evolution are a significant increase in aquafarming and a substantial decrease in the tidal flat area, while the landscape heterogeneity increased; (2) In the past 20 years, the areas of low and relatively low ecological risk in the study region were greatly reduced, while the areas of medium, relatively high, and high ecological risk greatly increased; the areas of high-grade ecological risk areas are mainly around Dongtai and Dafeng; (3) The area of ecological risk from low-grade to high-grade occupied 71.75% of the study area during 2000–2017. During the previous periods (2000–2004 and 2004–2008), the areas of low-grade ecological risk were transformed to areas of middle-grade ecological risk area, while during the later periods (2008–2013 and 2013–2017) there was a substantial increase in the proportion of areas of high-grade ecological risk. Our results complement the official database of coastal landscape planning, and provide important information for assessing the potential effects of MMLL processes on coastal environments.

Spatial–Temporal Evolution and Correlation Analysis of Ecosystem Service Value and Landscape Ecological Risk in Wuhu City

“…The magnitude of landscape ecological risk depends on the intensity of the external disturbance and internal resistance of the landscape ecosystem in the study area [29]. Based on the relationship between the landscape pattern of ecosystems and ecological risk and referring to the existing research results, the landscape fragmentation index, landscape isolation index, landscape dominance index, landscape disturbance index, landscape vulnerability index and landscape loss index were used to construct the landscape ecological risk index model [30,31]. The formulas are as follows:…”

Research on Land Use Changes and Ecological Risk Assessment in Yongjiang River Basin in Zhejiang Province, China

“…Changes of landscape structures and functions in the Yongjiang River Basin caused by land use transfer were used to reflect responses of risk receptors to human development activities [57,58]. Dynamic changes in a landscape pattern in the study area were reflected clearly through quantification of landscape indexes corresponding to the landscape index method.…”

“…D i is the landscape advantage which shows advantages of a plaque in one landscape type and proves its importance in the landscape. a, b, c are the weights of C i , N i , and D i , which value 0.5, 0.3, and 0.2 with references to existing research results [57,58]. F i denotes the structural vulnerability of the landscape ecosystem.…”

“…According to the study area and previous studies [57][58][59], the fish net should be 2-5 times the average plaque area in the study area [59]. A 2 km × 2 km grid was created by using ARCGIS10.3 fish net tool, and the study area was divided into 1058 risk regions.…”

Coastal Landscape Vulnerability Analysis in Eastern China—Based on Land-Use Change in Jiangsu Province

“…Few people assessed rapidly urbanizing areas, which are mainly affected by human activities. In addition, from the perspective of the classification of natural areas, related research always ignored administrative boundaries and used a grid scale to reveal ecological vulnerability [13]. Considering that the different changes in land use in the process of urbanization always depend on the development planning of different regions, it is necessary to study the temporal and spatial changes of ecological vulnerability at the county scale.…”