峰丛洼地流域植被覆盖度时空演变及其归因

采用像元二分模型估算2000～2020年桂西南峰丛洼地流域的植被覆盖度,并借助Theil-Sen Median趋势分析、Mann-Kendall检验方法以及Hurst指数等分析方法对研究区域内植被覆盖度的空间分布、未来趋势和可持续性进行深入解析,最后引入地理探测器对其驱动力因素进行定量化分析.结果表明:(1)年际变化上,流域21a间植被覆盖度呈递增趋势,增速为0.6754a-1.喀斯特区域增长速率(0.774a-1)>非喀斯特区域增长速率(0.5751a-1);(2)空间尺度上,研究区域植被覆盖度整体上呈现出“北高东低”的格局,其中82.68%的区域植被覆盖度显著增加,仅有0.61%区域表现为显著减少;(3)未来变化趋势上,区域植被覆盖度的Hurst指数介于0～1之间,平均值为0.8207,呈现出向右单峰偏斜,即研究区未来植被覆盖度呈现出持续改善的趋势;(4)驱动力机制上,土地利用/覆被(LULC)是整个研究区域植被覆盖度的主导因素;各驱动因子对植被覆盖度空间分布均表现出明显的交互作用,其中土地利用/覆被(LULC)与人口密度(pop)的交互作用最强.

Spatiotemporal evolution and attribution of vegetation coverage in the peak - cluster depression basins

In this paper, the pixel dichotomy model, coupled with the Theil-Sen Median trend, Mann-Kendall test and Hurst index, is used to characterize the vegetation coverage in the peak-cluster depression basins in Southwest Guangxi from 2000 to 2020, and finally the Geodetector is applied to quantify the driving factors. The results show that: (1) Interannual variations in vegetation cover in the basin demonstrate an increasing trend over the 21-year period, with an overall growth rate of 0.6754a^-1(0.774a^-1 in karst areas and 0.5751a^-1 in non-karst areas); (2) There is a pattern of "high in the north and low in the east", in which 82.68% of the study area have a significant increase and only 0.61% show a significant decrease; (3) The Hurst index of regional vegetation coverage trends to be between 0~1, with an average value of 0.8207, showing a single peak deviation to the right and a trend of continuous improvement in the future; (4) In terms of driving mechanism, land use/cover (LULC) is the dominant factor of vegetation coverage in the whole study area; all drivers showed significant interactions on the spatial distribution of vegetation coverage, among which the interaction between LULC and population density (pop) was the strongest.