典型黄土丘陵沟壑区生境质量时空变化及驱动力:以祖厉河流域为例

Spatial and Temporal Changes in Habitat Quality and Driving Forces in Typical Loess Hill and Gully Areas:A Case Study of the Zuli River Basin

黄土丘陵沟壑区是我国重要的生态屏障之一,研究其生境质量的时空变化及其驱动力,对保障我国的生态安全,维护国家生态权益具有重要意义.以祖厉河流域为例,采用Google Earth Engine平台和Landsat遥感数据,系统调查了2000~2020年间遥感生态指数RSEI的时空分布情况,结合变异系数CV、Theil-Sen Median斜率估计、Mann-Kendall显著性检验和Hurst指数,分析了研究区生境质量的时空变化格局,并利用地理探测器方法研究了6个主要的驱动因子对RSEI空间分布的影响,结果表明:①2000~2020年,RSEI值呈先下降后上升的趋势,年均增幅为0.0845·(10 a)^(−1).②20 a间,生境质量改善区域占92.06%,其中显著改善区域占28.49%,改善地区以会宁县境内为主,而生境退化区域仅占7.82%.未来生态状况的变化趋势显示,74.98%的区域呈现持续改善或未来改善的趋势,但仍有23.48%的区域未来存在生态退化的潜在风险.③降水等气候因子是影响祖厉河流域生境质量的关键因素;因子之间的交互作用对生境质量的解释力高于单因子,其中降水因子与高程因子的交互解释力最强;梯田因子与环境因子交互作用能显著增加解释力,说明梯田对改善生境质量起到重要作用.研究结果可为黄土丘陵沟壑区生态环境管理和可持续发展提供科学基础.

Loess hills and gully areas are one of the important ecological barriers in China,and the study of the spatial and temporal changes of its habitat quality and its driving force is of great significance to guaranteeing the ecological security of China and safeguarding the national ecological rights and interests.Taking the Zuli River Basin as an example,the spatiotemporal distribution of the remote-sensing ecological index(RSEI)from 2000 to 2020 was systematically investigated using the Google Earth Engine platform and Landsat remote-sensing data.Combined with the coefficient of variation CV,the Theil-Sen Median slope estimation,the Mann-Kendall test of significance,and the Hurst index,the spatial and temporal changes of habitat quality in the study area were analyzed over a period of 20 years,and the effects of six major driving factors on the spatial distribution of RSEI were investigated using the geodetector method.The results of the study showed that:①From 2000 to 2020,the value of the RSEI showed a downward and then upward trend,with an average annual increase of 0.0845·(10 a)^(−1).②During the 20-year period,the habitat quality improvement area accounted for 92.06%,of which the significant improvement area accounted for 28.49%,and the improvement area was mainly in Huining County,whereas the habitat degradation area only accounted for 7.82%.The trend of future ecological conditions showed that 74.98%of the areas would show a trend of continuous improvement or future improvement,but there would still be a potential risk of ecological degradation in 23.48%of the areas in the future.③Climate factors such as precipitation were the key factors affecting the habitat quality in the Zu Li River Basin;the interaction between factors had a higher explanatory power than that of any single factor on the habitat quality,among which the interaction between the precipitation factor and the elevation factor had the strongest explanatory power.The interaction between the terracing factor and the environmental factor significantly increased the explanatory power of the spatial variance,which indicated that terracing played an important role in improving habitat quality.The results of this study can provide a scientific basis for the management and sustainable development of the ecological environment in the loess hills and gullies.