School of Water Resources and Environment, China University of Geosciences, Beijing 100083, PR China; MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing 100083, PR China.
School of Water Resources and Environment, China University of Geosciences, Beijing 100083, PR China; MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing 100083, PR China.
Sci Total Environ. 2020 May 10;716:137072. doi: 10.1016/j.scitotenv.2020.137072. Epub 2020 Feb 1.
Understanding the impacts of climate change on runoff is of great importance for water resource assessments and adaptation strategy developments especially for the areas where scare and unevenly distributed water are available. Compared to the hydrological modelling method, the climate elasticity method is more flexible with the advantage of using few data in addressing the issue of investigating the effects of climate change on runoff. This study employed Budyko-based climate elasticity method, combined with temperature-based Blaney-Criddle equation, to obtain the elasticities of runoff to two major climate variables, and then applied this methodology to the upper reach of Heihe River basin, China. The runoff elasticity to precipitation in the study area was estimated to be 0.56-0.57, and the elasticity to temperature was -0.017 to -0.018. Precipitation increases showed a positive effect to runoff increases, and temperature increases showed a negative effect. Performances of 18 General Circulation Models (GCMs) of the Coupled Model Intercomparison Project Phase 5 (CMIP5) were assessed and the best GCMs were selected based on the entropy weighted TOPSIS approach. CSIRO-Mk3.6.0, CCSM4, and CanESM2 were ranked the first three with the best performances in simulating the observed precipitation and temperature over the study area. Climate projections from the above three GCMs showed that precipitation increased by 10% and 12% on average during the two periods of 2021-2050 and 2051-2080, producing 5.6% and 6.7% decreases in the projected long-term runoff compared to those in baseline period (1961-1990). Temperatures were projected to be increased by 2.0 °C and 2.9 °C for the two periods, resulting in the future long-term runoff decreased by nearly 2.0% and 2.9%, respectively.
理解气候变化对径流量的影响对于水资源评估和适应战略的制定非常重要，特别是对于那些水资源稀缺且分布不均的地区。与水文模型方法相比，气候弹性方法更加灵活，具有使用少量数据解决气候变化对径流量影响问题的优势。本研究采用基于 Budyko 的气候弹性方法，结合基于温度的 Blaney-Criddle 方程，获得了径流量对两个主要气候变量的弹性，然后将该方法应用于中国黑河流域上游。研究区的降水弹性估计为 0.56-0.57，温度弹性为-0.017 至-0.018。降水增加对径流量增加有积极影响，温度升高对径流量减少有负面影响。评估了耦合模式比较计划第 5 阶段（CMIP5）的 18 个通用环流模型（GCM）的性能，并根据基于熵的 TOPSIS 方法选择了性能最佳的 GCM。CSIRO-Mk3.6.0、CCSM4 和 CanESM2 在模拟研究区观测到的降水和温度方面表现最佳，排名前三。这三个 GCM 的气候预测显示，在 2021-2050 年和 2051-2080 年两个时期，降水分别增加 10%和 12%，与基准期（1961-1990 年）相比，预测的长期径流量减少 5.6%和 6.7%。预计两个时期的气温将分别升高 2.0°C 和 2.9°C，导致未来长期径流量分别减少近 2.0%和 2.9%。
