基于地球系统数据产品降尺度模拟缺资料的天山南坡山区流域气候-径流过程

Quantitative forecast and analysis of streamflow are the basis of rational utilization and management of surface water resources. However, the scarce climatic and hydrological observation data and the complicated climate-hydrological processes in the Tianshan Mountains limit the application of traditional methods of streamflow forecast. Selecting the Kaidu River and the Aksu River basin on south slope of the Tianshan mountains as the typical mountainous watershed, and regarding the climate-runoff processes and the responses of streamflow to climate change as the key issues, this project will study the dynamic processes of the climate driven streamflow. Combining the regional climate models (RegCM) and statistics, we will develop a data downscaling method for the mountainous watersheds in the Tianshan mountains based the earth system data product (ESDP). We will improve the traditional distributed hydrological models, and study the production and converge mechanism of streamflow by using the integrated modelling methods consist of the wavelet analysis, ensemble empirical mode decomposition (EEMD), artificial neutral network (ANN), etc. Using the integrated modelling method, we will also simulate the runoff process that is driven by climate change, and quantitatively analyze the constituents of streamflow as well as contribution rate of precipitation and temperature to runoff, and forecast the variations in streamflow for future climate change scenarios. We believe that research results of the project will provide some scientific evidences for use and management of water resource in south slope of the Tianshan Mountains.

科学的径流预报和径流成分解析，是对地表水资源管理和利用的基础。然而，位于我国新疆的天山地区，气候-径流过程复杂，气候与水文观测站点稀少、资料缺乏，这种情况限制了传统的径流预报与径流成分解析方法的应用。本项目，拟选择发源于天山南坡、径流量较大的典型山区流域——开都河与阿克苏河流域作为研究靶区，以气候-径流过程为主线 ，以径流对气候变化的响应为核心，研究气候要素驱动径流变化的动态过程；在充分利用气候水文观测站点数据的基础上，基于地球系统数据产品，结合动力降尺度和统计降尺度方法，综合运用小波分析、集合经验模式分解、人工神经网络等多方法集成的综合建模技术，改进传统的分布式水文模型，研究天山南坡山区流域降水与冰雪消融过程的产/汇流机制，模拟气候变化驱动径流变化的气候-径流过程，定量化解析降水和气温对径流来源构成的贡献，预测未来气候情景下的径流变化，从而为天山南坡水资源管理和利用提供科学依据。

本世纪以来，由于受全球气候变化的影响，许多国家与地区都面临着水资源安全问题。天山被誉为“中亚水塔”，发源于山区的径流是我国新疆及周边其他国家发展所依赖的主要水资源。然而，由于天山地区气候与水文观测站点稀少、数据缺乏，气候-径流过程复杂，使其水资源定量估算与科学评价成为一个难题。本项目基地球系统数据产品，并结合有限的实际观测资料，通过多方法集成建模，高分辨率地重建了天山地区近40年来气温与降水数据；以气候-径流过程为主线，以径流对气候变化的响应为核心，从流域尺度上定量化地认识了天山南坡典型山区流域的气候-水文关系，揭示了气候变化驱动径流变化的机理，定量地分析气候变化对径流变化的贡献；并基于RCP4.5和SSP245情景，模拟了未来30年典型山区流域出山口径流的变化。本项目研究已经发表16篇学术论文，获得了5个关键数据集，培养了5名博士。本项目所形成的研究方法与技术，以及取得的关键数据，为进一步科学地认识气候变化背景下我国西北干旱地区山区气候-径流过程机理，定量估算流域水资源丰枯变化奠定了基础。