State Key Laboratory of Hydroscience and Engineering, Tsinghua University, Beijing 100084, China.
State Key Laboratory of Plateau Ecology and Agriculture, Qinghai University, Xining, Qinghai 810016, China; State Key Laboratory of Hydroscience and Engineering, Tsinghua University, Beijing 100084, China.
Sci Total Environ. 2018 Dec 1;643:1166-1177. doi: 10.1016/j.scitotenv.2018.06.195. Epub 2018 Jul 4.
The headwater region of the Yellow River (HRYR) is one of the most important water supply areas of the whole river basin, which has suffered a serious water shortage problem for recent years. A better understanding of impacts of climate and catchment changes on runoff variation will help to determine efficient measures to deal with the runoff reduction in the Yellow River. The Budyko complementary relationship between the partial elasticity of runoff (R) with respect to precipitation (P) and that with potential evapotranspiration (E) was used in this study to partition the effects of climate and catchment changes on runoff variation at the HRYR. The upper and lower bounds of the contributions of climate and catchment changes to runoff variation were determined for every five years during 1961-2010. Results show that the complementary relation method based on the Budyko hypothesis can partition the contributions of climate and catchment changes to runoff variation effectively. And the climate changes are the main reasons (account for 60%-70% of the runoff variation) for runoff reduction at the HRYR. The sensitivity coefficient of R with respect to P has a significant decreasing trend at the 0.05 level with arid ratio (E/P) and that with respect to E has a significant increasing trend at the 0.05 level with E/P, indicating that with drying climate, R becomes more insensitive to climate changes. More precipitation is consumed by evapotranspiration returning to the atmosphere, leading to the runoff reduction at the HRYR.
黄河河源区（HRYR）是整个流域最重要的供水区之一，近年来一直面临严重的水资源短缺问题。更好地了解气候和流域变化对径流量变化的影响，将有助于确定应对黄河径流量减少的有效措施。本研究采用径流对降水（P）和潜在蒸散（E）的偏弹性（R）与 Budyko 互补关系，将气候和流域变化对 HRYR 径流量变化的影响进行划分。确定了 1961 年至 2010 年间每五年气候变化和流域变化对径流量变化的贡献的上下限。结果表明，基于 Budyko 假设的互补关系方法可以有效地划分气候和流域变化对径流量变化的贡献。气候变化是 HRYR 径流量减少的主要原因（占径流量变化的 60%-70%）。R 对 P 的敏感性系数与干旱比（E/P）呈显著下降趋势，而 R 对 E 的敏感性系数与 E/P 呈显著上升趋势，表明随着气候的干燥，R 对气候变化的敏感性降低。更多的降水被返回大气的蒸散发消耗，导致 HRYR 径流量减少。
