黄土高原中部典型流域植被恢复对径流的影响

针对黄土高原植被恢复后水文要素变化和水文要素之间关系不明确的问题，以黄土高原中部半湿润型气候的延河流域为研究对象，利用通用陆面模型CLM5.0，模拟1980—2018年土地覆盖变化对流域关键水文要素和水文要素之间关系的影响。结果表明：延河流域耕地面积从1980年的3277km2减少到2018年的2400km2，减少了26.76%，而林地和草地面积分别增加了244km2和528km2。土地覆盖变化导致延河流域年径流量和年径流系数明显减小，减幅分别为12.34%和11.46%。土地覆盖变化导致延河流域多年平均月径流量和多年平均月径流系数明显减小，其对丰水季径流量影响较小，对枯水季径流量影响较大，并使年内径流分配趋于集中化。本研究可为黄土高原水资源开发利用及科学管理提供参考。

Vegetation Restoration and Its Impact on Runoff in Typical Areas of Middle Loess Plateau

Since the end of the 1990s, large-scale ecological restoration projects have been implemented in the Loess Plateau, which significantly changed land use types and land cover. These projects enhanced ecosystem service functions and improved soil and water loss to a certain extent. More and more attention has been paid to the impact of these projects on the hydrological processes. The Yanhe River Basin, with a semi humid climate in the middle of the Loess Plateau, was taken as an example. The community land model (CLM) version 5.0 was used to simulate the impact of land cover changes on key hydrological elements and their relationships in this basin over 1980 through 2018. The results showed that the cultivated area was decreased from 3277km2 in 1980 to 2400km2 in 2018, a decrease of 26.76%. Woodland and grassland area was increased by 244km2 and 528km2, respectively. The annual runoff and annual runoff coefficient was decreased significantly due to the change of land cover, which were 12.34% and 11.46%, respectively. The change of land cover also led to the decrease of monthly mean runoff and the coefficient, which had a less influence in the wet season and a larger influence in the dry season, making the annual runoff distribution to be centralized. To guide the rational use of the water resource and build a harmonious ecological environment in the Loess Plateau, understanding the hydrological process and its changing had a great theoretical value and practical significance.