基于土地利用变化的景观生态风险评价——以广东省海岸带为例

Landscape ecological risk assessment based on land use change——A case study of coastal zone of Guangdong Province.

以广东省海岸带为研究区,基于2005、2010、2015和2020年4期土地利用数据,采用土地利用转移矩阵、景观生态风险指数模型和空间自相关分析等方法,对近15年广东省海岸带土地利用动态特征和景观生态风险进行定量评价,并进一步揭示其时空演变特征。结果表明:(1)2005—2020年,广东省海岸带土地利用类型以林地、耕地和建设用地为主,林地和耕地分别占研究区总面积的59%和23%以上;土地利用主要转移特征为建设用地增加了2560.70 km ^(2),其中80.10%由耕地和林地转移而来;(2)近15年来,研究区生态状况以低风险、较低风险和中风险区为主,共占研究区总面积的76%以上,低风险区与较低风险区面积占比由48.79%减少到38.33%,中风险区面积占比由24.16%增加到38.27%;(3)2005—2020年广东省海岸带景观生态风险呈现正相关关系,在空间上呈集聚效应,“高—高”风险区主要分布沿海城市附近,“低—低”风险区主要分布在珠三角城市。研究结果揭示了广东省海岸带土地利用转移特征和景观生态风险时空演变特征,为海岸带土地资源的合理开发、景观格局的优化以及政策制定提供理论依据。

Landscape ecological risk is an important factor affecting national security and restricting the sustainable development of the economy and healthy society.The landscape ecological risk evaluation method based on land use change could reflect the spatial pattern of impact of human activities on ecological processes.Although the coastal zone of Guangdong province has experienced drastic land use changes affected by human activities,the spatiotemporal heterogeneity of ecological risk in this region has not been thoroughly investigated.In this study,we used land-use transfer matrix,landscape ecological risk and spatial autocorrelation model,to explore the spatiotemporal variations in land use change and landscape ecological risk in coastal zone of Guangdong province from 2005—2020.The results showed that:(1)The land use type was dominated by forestland,cropland and built-up land in coastal zone of Guangdong province.Forestland and cropland account for more than 59%and 23%of the study area.The main characteristics of land use changes was:The built-up land increased by 2560.70 km 2,of which 80.10%was converted from forestland and cropland.(2)During the past 15 years,the landscape ecological risk status in coastal zone of Guangdong province was mainly low ecological risk and medium ecological risk,which accounts for more than 76%of the total landscape area.The area of low ecological risk areas decreased from 48.79%to 38.33%,and the area of medium risk areas increased from 24.16%to 38.27%.(3)The landscape ecological risk in coastal zone of Guangdong province showed positive correlation from 2005 to 2020,and tended to aggregate in space.The high-high value(H—H)risk concentration areas were mainly distributed around the seaside cities,and the low-low value(L—L)risk concentration areas were mainly distributed in the cities of Zhujiang Delta.This study reveals the spatiotemporal variations in landscape ecological risk in coastal area of Guangdong province during the past 15 years.The results could provide a theoretical basis for the sustainable development of land resources,optimization of landscape patterns and policy formulation in coastal area.