School of Ecological and Environmental Sciences, East China Normal University, Shanghai, 200241, China; Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, East China Normal University, Shanghai 200241, China; Institute of Eco-Chongming (IEC), Shanghai 200062, China.
School of Ecological and Environmental Sciences, East China Normal University, Shanghai, 200241, China; Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, East China Normal University, Shanghai 200241, China; Institute of Eco-Chongming (IEC), Shanghai 200062, China.
Sci Total Environ. 2020 Nov 1;741:140395. doi: 10.1016/j.scitotenv.2020.140395. Epub 2020 Jun 20.
Increasing dryness conditions under global warming are posing severe threats to water resources management in China. Projecting river basin responses to dryness conditions is beneficial to effectively managing water resources. However, existing studies have seldom considered the impact of multiple dryness conditions on future river basin health under global warming. Therefore, we combine the 3- and 12-month standard precipitation evapotranspiration index (SPEI) and reliability-resilience-vulnerability framework (RRV) to map future river basin health based on the responses of basins across China to different dryness conditions from 2021 to 2050. The calculation is based on downscaled outputs of 10 models from the Coupled Model Intercomparison Project Phase 5 (CMIP5) for three future emission scenarios (i.e., RCP2.6, RCP4.5 and RCP8.5). The results show that water deficits are projected to occur in most areas of China and significantly increase in the basins located in the northern part of China in the next 30 years due to global warming effects. The conditions in parts of the basins located in the northern part of China (especially in the Northwest River basins and Yellow River basin) are projected to be unhealthy and deteriorate significantly in the future, while the basins located in the southern part of China are projected to be moderate. The health status is anticipated to be worse under the RCP8.5 scenario than the RCP2.6 and RCP4.5 scenarios. Integrated results from the three thresholds indicated that normal dryness is applicable to most areas of northeastern, northern and southern China, while abnormal dryness is applicable to the remaining areas. Our findings could help reduce the impact of future dryness conditions on water resources and provide insights into risk planning and management for river basins in China under global warming.
在全球变暖的背景下，干燥天气的出现频率不断增加，这对中国的水资源管理造成了严重威胁。预测流域对干旱条件的响应，有利于有效管理水资源。然而，现有研究很少考虑在全球变暖背景下，多种干旱条件对未来流域健康的影响。因此，我们结合 3 个月和 12 个月标准降水蒸散指数（SPEI）和可靠性-弹性-脆弱性框架（RRV），根据中国各流域对不同干旱条件的响应，来绘制未来流域健康状况。该计算基于 10 个耦合模式比较计划阶段 5（CMIP5）模型的降尺度输出，用于三个未来排放情景（即 RCP2.6、RCP4.5 和 RCP8.5）。结果表明，由于全球变暖的影响，未来 30 年内，中国大部分地区预计将出现水资源短缺，并在中国北方流域显著增加。预计中国北方部分流域（特别是西北流域和黄河流域）的情况将不健康，并在未来显著恶化，而中国南方流域则预计将处于中等水平。与 RCP2.6 和 RCP4.5 情景相比，RCP8.5 情景下的健康状况预计会更差。三个阈值的综合结果表明，正常干旱适用于中国东北、北部和南部的大部分地区，而异常干旱适用于其余地区。我们的研究结果有助于减轻未来干旱条件对水资源的影响，并为中国流域在全球变暖背景下的风险规划和管理提供参考。
