黄河上游复杂水资源弹性系统多重风险共振评估研究

This proposal takes the upper Yellow River region above the Lanzhou hydrological station as study area based on systematic considerations of relevant research progresses at home and abroad. Methods such as system observability-controllability analysis, multi-objectives optimization operation, risk analysis, and resonance analysis are considered. A complex elasticity system of water resources is built. The noise sequences of the system are identified. The regional hazard factors and vulnerability indices from multi-risk sources are selected to build models of system risk measurements. Set different scenarios of the system inputs combining hydrometeorological elements and noise sequences, and of the risk measurements. Regional vulnerability of water resources is analyzed. Regional water resources utilization potential, hydropower potential, and water resources carrying capacity are evaluated. An optimization operation of multi-objective related to regional water supply, electricity generation, and environment (WSEGE) is carried out. Optimal comprehensive objects of the WSEGE are derived. Thresholds of water security are then determined. Elastic limits of the complex elasticity system of water resources are achieved in terms of types of system elasticity and the thresholds of water security. Resonance analysis among the components of the complex elasticity system is carried out. The project is, therefore, expected to (1) achieve the optimal index values of system resonance, (2) clarify the resonance mechanism among components of complex water resources systems and its influences on system risks, (3) obtain resonance evaluation techniques of multi-risk for the complex elasticity systems of water resources, and (4) present suggestions and countermeasures for adaptable utilization of regional water resources. The results from the project will provide theoretical basis and scientific support for regional water security.

本项目在系统分析国内外已有研究成果的基础上，以黄河上游（兰州以上）为研究区域，基于系统观控分析、多目标优化配置、风险分析与系统共振分析等方法，构建复杂水资源弹性系统，辨识系统输入的噪声序列，选取区域多重风险源的致灾因子和易损性指标，建立系统风险度模型，设置不同水文气象要素-噪声序列的混合输入情景和风险度情景，分析区域水资源脆弱性，评价区域水资源利用潜力、水力发电潜力和水资源承载力，开展区域供水-发电-环境多目标优化配置研究，得到区域供水-发电-环境最优综合目标和区域水安全阈值，根据系统弹性类型确定系统的弹性限度，开展复杂水资源弹性系统各要素的共振分析。项目预期将获得最佳的系统共振衡量指标值，阐明复杂水资源弹性系统各要素的共振机理及其对系统风险的影响，获得复杂水资源弹性系统多重风险共振评估技术，提出区域水资源合理利用的建议与对策，为区域水安全保障提供科学支撑。

以复杂水资源系统演变、水安全和共振特征为研究对象，采用综合权重法、相对承载力阈值分析方法、多层次水安全综合评价方法、多目标水库优化调度方法、SRI–HHT算法、随机共振分析等方法，研究了黄河上游及周边区域水资源系统脆弱性、承载力、水安全、气候变化/人类活动对径流的影响、河道水温模拟、径流和枯水的多尺度时间特征及其归因、复杂水文系统的随机共振性质等，取得如下研究成果：（1）黄河上游地区夏秋两季易处于连续缺水的高风险期，年径流变化主要受气候变化影响，季节径流变化主要受人类活动影响。干流大型水库运用是影响干流径流变化的主要因素，支流的土地利用变化和小型水库运用是影响支流径流变化的主要因素；（2）黄河上游径流丰枯具有一致的主空间分布模态（气候影响）和东北—西南反位相分布的次要空间分布模态（人类活动影响）。青藏高原降水、气温和积雪是影响黄河上游径流丰枯空间分布的主要气象因子。青藏高原东北部、东部、北部是影响径流丰枯变化的关键区；（3）径流复杂度与流域降水之间存在着显著的负相关关系。近似熵在描述序列的总体趋势方面优于样本熵，而后者在序列峰谷值辨识方面强于前者；（4）前期降水指数（API）可以描述前期降水的累积值，其对当前天枯水存在显著影响。API具有优化性和多值性两个重要性质，这两个重要性质能有效用地模拟枯水；（5）甘肃省的水资源脆弱性、承载力和水安全区域差异明显。高脆弱区集中分布于西北部的干旱半干旱区；承载力呈现东南高、西北低的分布格局；从东南部向西北部逐渐由安全状态变为不安全状态。水安全等级越高的流域水资源承载力越高，水资源脆弱性越低；（6）黄河上游水文系统存在共振现象。兰州站一定强度的噪声能够增强水文信号的震荡幅度，但随机共振方法不能完全提取有用信号且存在一定时域的畸变；本项目对区域环境保护和高质量发展可提供重要的决策依据，对揭示水文系统风险与安全演变机理、提高径流模拟和预报精度等具有重要意义。