基于InVEST模型和地理探测器评估城市区生境质量时空变化与影响因素-以南宁市为例

Temporal and spatial variations and influencing factors of habitat quality in urban areas based on InVEST model and geodetector —A case study of Nanning City

关键词:  InVEST模型  地理探测器  时空变化  生境质量  南宁市

Key words:  InVEST model  Geographical detector  Space-time change  Habitat quality  Nanning City

摘要:

理清城市区生境质量变化特点与影响因素对维护其生态安全具有重要意义。基于南宁市土地利用数据，采用InVEST模型和地理探测器对南宁市2000年、2010年2020年生境质量和影响因素进行评估。结果表明：（1）耕地、林地为南宁市主要地类，20年间其面积呈减少趋势，建设用地面积呈增加趋势，生态用地被侵占。（2）2000-2020年南宁市生境质量平均值为3.22、3.21、3.17，呈下降趋势，中等级的生境质量始终占据主导地位，高等级的生境质量主要分布在林地等区域，低等级生境质量分布在主要城区，生境质量持续走低与建设用地增加和林地的减少有关。（3）南宁市的生境退化度整体呈现先下降后上升的趋势，其中隆安县和马山县地区退化最为明显。（4）2000-2020年影响南宁市生境质量的关键因素为人口密度、DEM和年平均降水，其中人口密度均为最主要因素。提出加强人口和土地管理、制定地形差异化生态保护策略、优化土地利用结构等优化建议。研究结果可为未来南宁市合理利用土地资源以及维持当地生物多样性提供参考。

Abstract:

It is important to clarify the characteristics and influencial factors of habitat quality changes in urban areas to maintain its ecological security. Based on the land use data of Nanning city, the habitat quality and influencial factors in 2000, 2010 and 2020 were evaluated by the InVEST model and geographical detector. The results showed that: (1) The main land use/cover types in Nanning were cultivated land and forest land; the area of cultivated and forest lands decreased in the past 20 years, the area of construction land increased, and the area of ecological land use declined. (2) From 2000, 2010 to 2020, the average value of habitat quality in Nanning was 3.22, 3.21 and 3.17, respectively, exhibiting a decreasing trend. The habitat quality of most land uses in Nanning City was in the middle grade; forest lands belonged to the high grade of habitat quality; the main urban areas generally belonged to the low grade of habitat quality. The decreasing trend of habitat quality in the past 20 years could be attributed to the increase of construction land and the decrease of forest land. (3) The degree of habitat degradation in Nanning City showed a trend of decreasing first and then increasing, and the degradation was most obvious in Longan County and Mashan County. (4) The key factors affecting the habitat quality of Nanning City from 2000 to 2020 were population density,Digital Elevation Model(DEM) and annual mean precipitation, among which population density was the most important factor. In order to mitigate the declining status of habitat quality in Nanning City, we suggest to strengthen population and land management, formulate differentiated terrain ecological protection strategies, and optimize land use structure. Our research results provide insightful implications for the rational use of land resources and the maintenance of local biodiversity in Nanning City in the future.