Abstract:
Landscape ecological risk can be attributed to the cumulative effect of long-term disturbance in the regional landscapes by various risk sources. Fortunately, zoning control strategy can be expected to optimize the regional ecological risk using the dynamic perspective of the "history-present-tuture" of risk occurrence. This study aims to scientifically understand the spatial differentiation pattern of landscape ecological risks, and then formulate spatial zoning management and control strategies. A systematic investigation was also made on the dynamic risk management and control needs of rapidly urbanized areas. The new framework was established for the landscape ecological risk assessment and management zoning from the spatiotemporal dynamic perspective of "history-present-tuture". Taking the Jiangyin City of Jiangsu Province as the research area, the differentiated management and control strategy of risks was proposed to explore the spatiotemporal process, evolution characteristics, and future trends of landscape ecological risk. The combination characteristics of landscape risk levels were obtained from the coupling perspective of "history-present-tuture". The results showed that: 1) The cultivated land decreased by 12.76% from 2005 to 2020, whereas the construction land increased by 13.53% with the evolution of urbanization. There was a drastic transformation of landscape types, where the landscape fragmentation continued to increase. Among them, there was the more serious conversion of cultivated and ecological land into construction land. The fragmentation and uneven distribution were found in the landscape of cultivated and ecological land, with a significant trend in the agglomeration distribution of construction land. 2) The ecological risk presented a spatial distribution pattern of "low in the north and high in the south". The low-risk areas were distributed in the northern waters and the core area of township construction land, whereas, the high-risk areas were distributed in the southern waters, along the river, and the marginal area of township construction land expansion. Therefore, Jiangyin City was focused mainly on the expansion of construction land in the process of rapid urbanization. The high intensity and scattered construction caused the fragmentation landscape of cultivated and forest land, indicating the high risk. 3) The landscape ecological risks were categorized as the maintenance, upgrading, mitigation, and fluctuation types, according to the dynamic process of risks. The proportion of risk maintenance type was the highest, followed by upgrading and easing types, while the fluctuation type shared the lowest proportion. Furthermore, the control needs and trends of risks were further analyzed in the different regions to determine the specific prevention areas, according to the current situation and future trends of risks. There were also significant variations in the urgency of risk prevention for the management and control in different regions. Among them, much attention should be paid to the high-risk areas with serious out-of-control or a basic level of control. In summary, the risk assessment and management framework with the perspective of a "history-present-tuture" landscape is beneficial to understanding the complex interaction between landscape and external disturbances in the urbanized areas from the dynamic process of time and space. The findings can also provide the decision support for the urban ecological risk management for the optimization of regional territorial spatial layout.