2005-2015年贵阳市生境退化程度对土地利用变化的响应

基于2005和2015年贵阳市土地利用数据，利用InVEST模型，分析了2005-2015年贵阳市生境退化程度对土地利用变化的响应，结果表明:（1）2005-2015年贵阳市城镇建设用地、农村居民点和有林地大幅增加，水田和旱地大幅下降，其他地类变化相对较小；水田和旱地转化为城镇建设用地、农村居民点和有林地最为突出；（2）10年间，贵阳市生境退化程度以下降为主，生境退化程度增加区主要分布在南部，下降区主要分布在北部、东部和西部；（3）生境退化程度热点变化以低值减少和高值减少为主；生境退化程度热点空间变化主要分布于南部。退耕还林政策及快速城镇化引起的水田和旱地转化为有林地、城镇建设用地和农村居民点是导致该区生境退化程度变化的主要因素。 

Habitat degradation degree in response to land use change in Guiyang City from 2005 to 2015

Guiyang City is an important central city in southwest China. It is located in a typical karst ecological vulnerability region. In recent years, the land use of the city has been reshaped by a series of ecological protection planning and rapid economic development, which has heavily influenced on habitat quality. In order to investigate such influence and associated spatial pattern on the urban habitat degradation degree in both karstic and ecologically vulnerable region, this paper attempts to analyze the characteristics of land use change between 2005 and 2015 in the city, based on the land use data, by using Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) model. The results show that, (1) Urban construction land, rural settlement and forestland have a sharp increase trend, while paddy field and dry land have an obvious decrease trend from 2005 to 2015 in Guiyang City. The other land use types have little change in this decade. It is prominent that numerous dry lands have been converted to forestland, land for construction and rural settlement, as well as paddy field converted to forestland. (2) During the past ten years, the habitat degradation degree generally has a decreasing trend over the city, which is dominated by slight decrease. The rise of the degradation degree mainly occurs in the south area, while the decreases of the degree are located in the north, east and west of the city. (3) Decreases of high value and low value are main types in change of habitat degradation degree hot-spots in Guiyang City. Increasing region of high value is mainly situated in south part of Guiyang, while increasing region of low value and decreasing regions of high value and low value are mainly in north, east and west parts of Guiyang City. Area change of threat land use types (e.g. paddy field, dry land, urban construction land, rural settlement, road, industrial and mining land) exerts a positive impact on habitat degradation degree while area change of natural land use types (e.g. forestland, shrub, grassland, water) has a negative impact on habitat degradation degree. The conversions from paddy field and dry land to urban construction land, rural settlement and forestland due to Green for Grain Project and rapid urbanization are main reasons for the change of habitat degradation degree in Guiyang City.