基于Budyko假说及GRACE重力卫星观测对流域水量平衡变化的多时间尺度研究

Increasing intensity in global warming and anthropogenic activities has triggered significant changes over regional climates and landscapes, which, in turn, drive the basin water cycle and hydrological balance into a complex and unstable state. Budyko hypothesis is a powerful tool to characterize basin water balance in a long-term average scale. However, due to the absence or unavailability of basin water storage change, the application of Budyko theory was limited to the inter-annual and intra-annual time scales. The launch of GRACE gravimetry satellites provides a great opportunity to quantify terrestrial water storage change, which can be further introduced into the Budyko hypothesis to reveal the dynamics in basin water balance at multiple time steps. This research will target Hai River and Yellow River basins to illustrate how precipitation-evapotranspiration-runoff-soil water storage change and balance within a system over different temporal scales. Moreover, the possible main contributors associated with climate variability and landscape changes triggering such patterns will be examined. Our results are expected to provide deep insights and proof data to water cycle and hydrological water balance variations for the Hai River and Yellow River basins.

气候变暖和人类活动的不断增强, 导致区域气候特征和下垫面性质发生了显著改变, 进而驱动了流域内各水循环及水量平衡发生着复杂的变化。Budyko假说是研究流域水量平衡变化的重要工具，但由于缺乏可靠的流域蓄变量(ΔS)观测数据，使得Budyko理论及其模型只能用于多年平均尺度, 而缺乏对流域水量平衡变化年际或季节尺度的探讨。GRACE重力卫星的发射为大尺度流域的ΔS观测提供了可能，将其反演的ΔS信息引入Budyko理论框架，可为多种时态下流域水量平衡的变化特征及规律提供重要参考。本研究以黄河流域和海河流域为研究区，综合下垫面植被特征、土壤信息、水热季节性变化等因素，从极端气候事件尺度、年际尺度以及年内尺度出发，探讨流域降水-蒸发-径流-蓄变量在不同时间尺度下所呈现的动态平衡机制及驱动因素，以期为流域水循环及水量平衡研究提供科学参考。