| The rapid urbanization and industrialization process,while promoting rapid socio-economic development and improvement of people’s living standard,indirectly brings a series of ecological problems such as unreasonable land use,sharp reduction of ecological resources and degradation of ecosystem functions,etc.The aggravation of ecological problems will eventually evolve into geological hazards,making the contradiction between regional environmental resources and human intensify.In order to study the impact of ecological environment changes on geological hazards in the process of urbanization and to explore the suitable model of coordinated human-land development,this paper takes Guangdong-Hong Kong-Macao Greater Bay Area as the research object,uses the MaxEnt model in machine learning algorithm to carry out geological hazard sensitivity evaluation and analyzes the spatial autocorrelation and spatial clustering characteristics of geological hazard sensitivity by Moran index;adopts the spatial analysis method and the principle of landscape ecology to The spatial analysis method and the principle of landscape ecology were used to reveal the landscape background pattern of Guangdong-Hong Kong-Macao Bay Area,and to quantitatively evaluate the spatial and temporal heterogeneity and evolutionary characteristics of regional ecological environment quality and landscape fragmentation;Based on the In VEST model,we analyze the spatial and temporal variation patterns and evolutionary characteristics of ecosystem service functions in the Guangdong-Hong Kong-Macao Greater Bay Area;we analyze the relationship between ecological changes and geological hazard sensitivity in the Guangdong-Hong Kong-Macao Greater Bay Area through Pearson correlation and bivariate local spatial autocorrelation.The main conclusions are as follows:(1)The results of the MaxEnt model showed that the AUC value reached 0.822 and the model was highly accurate;the results of the contribution analysis of the evaluation factors showed that the normalized vegetation index(NDVI)and annual rainfall were the most contributing factors.The global Moran’s I index of geological hazard sensitivity indicates that there is a significant positive spatial correlation in the study area,and the local Moran’s I index indicates that the study area is dominated by two types of agglomerations:high-high(H-H)and low-low(L-L),among which the high-high agglomerations are mainly distributed in areas with intensive human activities and high intensity of infrastructure construction.The high agglomeration areas are mainly located in areas with intensive human activities and high infrastructure construction,while the low agglomeration areas are located in areas with low human disturbance and favorable ecological conditions.(2)In the Guangdong-Hong Kong-Macao Bay Area,forest land and arable land are the main landscape types;from 1980 to 2017,the dominance of construction land has increased year by year,the dominance of arable land has decreased,the overall landscape fragmentation in the region has intensified,the shape of landscape types tends to be irregular and the overall landscape type diversification has increased;the overall ecological environment quality in the region is at a medium quality level,and the overall trend is a continuous decline,and its spatial differentiation shows an overall The distribution pattern of "low in the center and high in the surroundings";the deterioration of Eco-environmental quality from 1980 to 2017 is significant,forming an Eco-environmental quality deterioration area centered on Guangzhou,Foshan,Dongguan and Shenzhen,and an Eco-environmental quality improvement area centered on Zhuhai and southeastern Jiangmen;the integrated index of landscape fragmentation in 1980,2000 and The average values of landscape fragmentation index in 1980,2000 and 2017 were 0.206,0.216 and 0.210,respectively,with an overall trend of increasing first and then decreasing,and the spatial evolution of landscape fragmentation index from 1980 to 2017 showed a distribution pattern of "deterioration in the middle and improvement around".(3)The overall comprehensive function of ecosystem services in the Guangdong-Hong Kong-Macao Greater Bay Area is at an intermediate level,but the overall trend is declining,The spatial distribution is highly heterogeneous,with an overall distribution pattern of "low in the center and high in the surroundings",and the spatial degradation of the integrated ecosystem service function from 1980 to 2017 is significant and widely distributed in each of the study area.The spatial degradation of the integrated ecosystem service function from 1980 to 2017 was significant and widely distributed in the study area.Among them,habitat quality service function and ecosystem carbon sequestration function continue to degrade,and their spatial distribution shows an overall pattern of "low at the center and high around";soil conservation function as a whole is at a lower level and shows a trend of enhancement followed by degradation,and the overall spatial differentiation shows a pattern of clustering in the low value area at the center and alternating high and low distribution around.The spatial enhancement of soil conservation function from 1980 to 2017 is significant,and the enhanced areas are mainly concentrated in Zhaoqing City,Jiangmen City,Huizhou City and the eastern part of Guangzhou City;the overall water conservation function is at a higher level and shows a continuous enhancement trend,and the spatial differentiation characteristics show a "low in the northwest and high in the northeast" in 1980.The spatial pattern of "low in the middle and high around" in 2000 and 2017,and the spatial enhancement of water content function from 1980 to 2017 is significant,and the enhanced areas are mainly concentrated in Zhaoqing City and Jiangmen City.(4)There are significant negative correlations between changes in ecological environment quality,changes in landscape fragmentation,changes in integrated functions of ecosystem services and geological hazard sensitivity in different time periods from 1980 to 2017;it is found that changes in ecological environment quality,changes in landscape fragmentation and changes in integrated functions of ecosystem services have stronger effects on geological hazards from 2000 to 2017;1980 to 2017 The spatial mismatch between changes in ecological environment quality,landscape fragmentation,integrated ecosystem service function and geological hazard sensitivity is significant;the spatial trade-off relationship between changes in ecological environment quality and geological hazard sensitivity increases significantly with time,while the coordination relationship strengthens slightly,and the spatial trade-off relationship between changes in landscape fragmentation,integrated ecosystem service function and geological hazard sensitivity increases significantly.The spatial trade-offs between changes in landscape fragmentation,changes in integrated ecosystem service functions and geological hazard sensitivity will be significantly enhanced,while the coordination relationship will be weakened. |
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