横断山区产水量时空分布格局及影响因素研究

运用InVEST模型产水模块开展横断山区1990-2015年产水的量化评估,并开展相应的时空特征及影响因素分析。结果表明:(1)空间分布上,横断山区产水量均表现为南高北低的空间格局,垂直方向上,产水能力随着海拔的增加呈减小趋势。(2)1990-2015年产水深度表现为先小幅增大后明显减小再小幅增大的波动变化趋势。(3)不同土地利用类型的平均产水能力差异较大。其中以建设用地产水能力最强,约为550～920 mm;林地、草地居中,分别为438～650 mm和412～580 mm;未利用地和水域产水能力最弱,分别为273～457 mm和56～237 mm。(4)产水量空间分布与海拔及草地比例呈现显著的负相关,与降水量及林地比例呈显著正相关;时间变化上产水量与降水量呈显著正相关关系。该研究有助于推进山区生态系统服务研究的发展,其结果可为横断山区流域水资源管理、维持区域可持续发展提供科学支撑。

Spatiotemporal and influencing factors analysis of water yield in the Hengduan Mountain region

In this study, we evaluated the water yield in the Hengduan Mountain region from 1990 to 2015 using the water yield module in the InVEST model; we further analyzed the corresponding spatial and temporal characteristics and influencing factors. The results show the following. First, water yield decreased with increasing altitude and tended to decrease from the southern to the northern areas. Second, water yield increased slightly from 1990 to 2000, decreased significantly from 2000 to 2010, and then increased slightly again from 2010-2015. Third, the average water yield varied greatly across different land use types: the water yield capacity of construction lands was the strongest, for about 550-920 mm; that of forests and grasslands were moderate, for about 438-650 mm and 412-580 mm, respectively; that of unused land and water areas were the weakest, for about 273-457 mm and 56-237 mm, respectively. Lastly, there exists a significant negative relationship between the water yield spatial pattern with elevation and grasslands proportion, while there is a positive relationship with precipitation and forests proportion. The temporal changes were attributed to the positive relationship with precipitation. Overall, this study promotes the development of mountain ES (ecosystem services) research, and the results provide scientific support for water resource management and sustainable development in the Hengduan Mountain region.