道路网络对景观生态风险的影响——以云南省红河流域为例

Effects of road network on landscape ecological risk:A case study of Red River watershed

道路网络扩展既影响周围的景观格局,也对生态过程造成直接或间接的影响。以云南省红河流域为研究区域,利用GIS和RS技术,进行格网划分,从空间上分析道路对景观格局和土壤侵蚀的影响,并通过基于景观格局和过程的景观生态风险指数计算,分析道路网络扩展影响下的景观生态风险规律。结果表明:红河流域道路周围景观类型以耕地、林地和草地为主,其中林地和草地的格局风险指数随着距离道路的增加而减少,受道路影响显著;一级路、三级路和四级路缓冲区内土壤侵蚀量随着距离道路的增加而减少,三四级路分布广泛,更容易发生土壤侵蚀;道路密度和基于景观格局和过程的景观生态风险指数在空间分布上具有一定的相关性。

Large-scale construction of road affects landscape pattern around,and also,ecological process directly or indirectly.Taking the Red River watershed in Yunnan Province as a case,and by using GIS and RS technology,this paper analyzed the effects of road on landscape pattern and soil erosion,and,through the calculation of landscape ecological risk indices based on landscape pattern and process,approached the landscape ecological risk pattern under road network expansion.In the Red River watershed,the landscape types near roads were mainly arable land,woodland,and meadow,and the landscape ecological risk indices based on the landscape pattern of woodland and meadow generally decreased with increasing distance to roads,suggesting that the landscape patterns of woodland and meadow were influenced obviously by roads.The soil erosion modulus in the buffer zones of the first-class roads,third-class roads,and fourth-class roads decreased with increasing distance to roads,and the third-and fourth-class roads were widely distributed,more easily to be eroded.The landscape ecological risk index based on the landscape pattern and process had a certain positive correlation with road density in spatial distribution.