变化环境下基于双层包气带水分运移机制的流域植被-水文双向耦合模型研究

mportant developments of Youth Science Foundation : establishment of a water transport mechanism based on double aerated with surface water - groundwater coupling model IHM. Proposed a novel theory-Two Layer Vadose Zone, which can much improve the physical mechanism of soil moisture movement, and better quality and quantity describe the surface water and groundwater interaction..Academic achievement: 1) published 16 high level of academic papers ( 7 articles with SCI index, 9 articles for EI index; 2) 1 monograph: surface water and groundwater in the integrated model of unsaturated zone moisture dynamics; 3) CIWEM "Highly Commended the Paper Award for 2010, the applicant ranked first..Research: In this research, the rural plain area in the Capital City of China, Beijing with water eco-system protection function has been selected as the study location which experiences period of drought and wetness annually. Based on the eco-hydrology methodology and support of the ecological field surveys and continuous observation means for eco-hydrology environmental elements, combined with experiments of vegetation water stress mechanism in wetland, integrated multiple geo-information technology and methods, the research would obtain valuable long-term multiple spatial and temporal scale quantity data on water and environmental concerns. The data would then be used to develop a regionally spatial and temporal distributed eco-hydrology model integrated water cycle process model and vegetation response model under various impact of climate, agricultural, and environmental changes. The objective of the research is to reveal the process and mechanism of regional hydrological changes in the suburbs of metropolitan, and determine the functionality and correlation between the process of water circle under controlled environment and the response of vegetation growth. The topic is an interdisciplinary research for hydrology and ecology, as well as integration with modern information technology. It will enrich and perfect the eco-hydrology theory study, and will offer the valuable theory data for the future environmental and hydrologic research. It is of great significance to establish a regional sustainable development pattern for balance of regional development and protection of aquatic natural resources.

青年基金重要进展：建立了基于双层包气带水分运移机制的地表水-地下水耦合模型IHM。提出双层包气带创新理论，使集成模型考虑包气带土壤水分运移规律时，物理机制更趋完善，更好地描述地表水-地下水相互作用过程。学术成绩：1）发表学术论文16篇，SCI 7篇，EI 9篇;2）出版学术专著1部;3）获2010年度CIWEM国际水与环境管理特许协会最佳论文奖，申请人排名第一。研究内容：应用遥感技术与野外监测方法结合获取多元环境变量，建立长时间尺度流域水文集成模型。通过人工控制实验方法与野外生态监测研究结合，在多要素环境参量获取基础上，建立植被生长模型。以动态土壤水分联接水文模型与植被模型，分析流域水循环过程和植被系统的时空变化规律，环境变化对其影响与作用机制，以及水文过程和植被间的交互作用机制。通过数值模拟与数理统计分析，揭示流域水生态交互机制和特征，及特定情景和生态目标的区域水生态功能识别与管理研究

本项目是在前一个青年基金研究基础上进一步深化和拓展，研究对象从单一的水文过程扩展到流域植被与水文过程相互作用机制的描述。应用遥感技术与野外监测方法结合获取多元环境变量，建立长时间尺度流域水文集成模型。通过人工控制实验方法与野外生态监测研究结合，在多要素环境参量获取基础上，以HYDRUS3D动态土壤水分联接水文模型与植被模型，基于GLUE不确定性方法，分析流域水循环过程和植被系统的时空变化规律，以及水文过程和植被间的交互作用机制。通过 HadCM3 降尺度数据与水文模型耦合，探讨了未来气候变化情景下妫水河流域日最高、最低气温与降水量的变化情况。基于统计降尺度模型 SDSM，生成了两种气候变化情景下的日最高气温、最低气温和降水量数据，模拟了该流域在未来气候变化下的水文生态响应。结果显示：HSPF，SWAT和MIKESHE模型在妫水河流域均具备良好的适用性，从参数敏感度和径流比较得出HSPF模型模拟精度更高。本研究通过GLUE方法分析三种模型参数的敏感性、参数间相关性、“异参同效”现象及模型预报的不确定性范围，为模型在该区水文预测等提供参考和依据。应用HYDRUS-3D 对两种不同植被（湿地森林和百喜草）土壤含水量进行模拟，研究期间内湿地森林 20-50cm 土层土壤含水量随着土壤深度增加呈上升趋势，且变化程度较大；百喜草 10-30cm 土层土壤含水量随着土壤深度增加呈下降趋势，且变化程度小。总的来说，湿地森林 10-30cm 土壤水分变化与降水变化趋势有较好一致性，百喜草仅 10cm 变化与降水较为一致，降水对湿地森林土壤水分的影响比百喜草大。妫水河流域未来 90 a 的 气温总体呈升高趋势，而降水量和地表流量呈减小趋势; 高温室气体排放情景下日最高气温、最低气温、降水量和地表流 量的 10 a 变化率分别为 0.462 ℃、0.453 ℃、－0.010 mm、－0.051 m3 /s，低温室气体排放情境下分别为 0.263 ℃、0.264 ℃、－0.014 mm、－0.044 m3 /s，流域干旱加剧的可能性进一步加大。本研究可为当地的水资源管理部门制定合理的控制措施提供科学依据。