基于土地利用变化的永定河流域生境质量评估

Habitat quality assessment of Yongding River based on land use change

为揭示永定河流域生境质量演变规律,以永定河(官厅至屈家店河段)流域为研究区,运用InVEST模型,探讨区域内1985~2015年土地利用及生境质量时空演变及其影响因素,并分析其景观格局特征。结果表明:研究区内主要土地利用类型为耕地和林地,土地利用类型变化主要表现为城镇用地和农村居民点面积的增加。研究区总体景观趋于破碎化,其中旱地为研究区域的优势景观。研究区总体生境质量指数呈下降趋势,下降率达6.7%,主要原因为城镇用地的扩张,但河流岸线范围内指数呈上升趋势,表明北京市对永定河的治理成效显著。生境质量指数与人口和GDP呈负相关,表明人口和GDP的增加会降低生境质量指数。今后应加强研究区内草地和林地的保护力度,控制城镇用地面积,提高研究区域生态系统服务功能稳定性。

In order to reveal the evolution of habitat quality in the Yongding River basin, the spatial-temporal evolution of land use and habitat quality and its influencing factors during 1985-2015 were investigated by using InVEST model in the Yongding River(Guanting to Qujiadian section in Beijing City) watershed, and the characteristics of landscape pattern were analyzed to provide a scientific basis for land planning.The results showed that the main land use types in the study area were cultivated land and forest land, and the change of land use types was mainly manifested by the increase of urban land and rural residential area.The overall landscape of the study area tended to be fragmented, and dryland was the dominant landscape in the study area.The overall habitat quality index of the study area showed a decreasing trend, with a decreasing rate of 6.7%,mainly due to the expansion of urban land.However, the index within the river coastline showed an increasing trend, indicating that the governance of Yongding River in Beijing City had achieved remarkable results.The habitat quality index was negatively correlated with population and GDP,indicating that the increase of population and GDP would decrease the habitat quality index.In the future, the protection of grassland and forestland in the study area should be strengthened while control the urban land area, so as to effectively improve the stability of ecosystem service function in the study area.