基于植被动力学方程的干旱区河岸生态水文演化模型研究

The vegetation in the lower reach of rivers in inland arid regions is highly dependent on the stream, and the ecological process and the hydrological process are closely coupled. The evolution of the ecohydrological system is very fast with the impact of the climate change and human activities. The modeling and the evolution law of ecohydrological systems in arid regions, which are at the unequilibrium state, are important issues faced by the ecohydrology. Aiming at that the critical points of catastrophic decline of ecohydrological systems are indeterminate on the riverside in arid regions and the scales of fundamental equations of ecohydrological processes are inconsistent in ecohydrological models, the study will select the lower reach of Tarim River to be the research object. Combining the quantitative method and qualitative method, the observed data of multiple sources are applied to develop the constitutional equation describing the ecological process, which is concerted with the hydrological process, based on the vegetation dynamic equation. The mathematical quantitative equation of the dependent relationship of the ecological variables to the hydrological variables will be set up and the study will open out the dominant coupling mechanism of the ecohydrological processes on the riverside of arid regions. The simulation module of hydrological process on the riverside of arid regions will be built and coupled to the constitutional equation describing the ecological process in order to develop the ecohydrological evolution model on the riverside in arid regions. The model will be validated and consummated by the data of observation stations and remote sensing. The ecohydrological evolution model will be applied to analyze the dynamic properties of the Tarim River ecohydrological system, and reveal the response pattern of ecohydrological processes to the changing environment. The research outcome will promote the development of the theory of the ecohydrological modeling in arid regions, and provide important theoretical basis to the highly efficient use of the water resources in arid regions.

内陆干旱区河流下游的植被对河流强烈依赖，生态与水文过程密切耦合，在气候变化和人类活动影响下生态水文系统演化迅速。处于非平衡态的干旱区生态水文系统的模拟和演化规律是生态水文学面临的重要问题。针对干旱区河岸生态水文系统发生灾难性衰退的临界点不明确、生态水文模型中生态水文过程基本方程尺度不协调的问题，本研究以塔里木河下游为对象，使用多来源的观测数据采用定性和定量结合的方法，基于植被动力学方程发展与水文过程相协调的生态过程控制性方程，建立生态变量依赖水文变量的数学定量关系，识别干旱区河岸生态水文过程的主导性耦合机制；构建干旱区河岸水文过程模拟模块，耦合生态过程控制性方程构建干旱区河岸生态水文演化模型；使用站点监测数据和遥感数据验证完善模型，分析塔里木河生态水文系统的动力学性质，揭示生态水文过程对对变化环境的响应规律。研究成果将推动干旱区生态水文模拟理论的发展，为干旱区水资源高效利用提供理论依据。

干旱区河岸带的生态过程与水文过程密切耦合，并受到环境变化的显著影响，河岸带对地区生态环境具有重要战略意义。本研究以塔里木河中下游为例针对旱区河岸带生态水文系统开展研究。研究内容包括：干旱区河岸生态水文过程的主导耦合机制研究；干旱区河岸生态水文演化模型的构建；干旱区河岸带对变化环境的响应规律研究。.在荒漠区分析了降水量的趋势、周期、突变等特征。使用具有近百年观测值的年径流资料分析了径流的年际和年内变化及趋势性、持续性、突变点和周期。基流是河道径流的一个重要来源，使用水文模型和基流分割方法研究了年基流指数和月基流指数。引入植被覆盖度演化的动力学方程，把生态过程与水文过程相耦合，建立概念性的流域生态水文模型模拟流域内生态水文过程，分析了流域生态水文系统的动力学特性，而动力学系统性质决定于植被动力学方程。设计了周期和自动两种输水模式，基于塔里木河下游河岸生态水文演化模型分析了人工输水的优化方案。各种方案经过长期实施后地下水和植被都能演化趋于稳定状态，相比2000年都有较大的提高。把周期输水和自动输水结合，根据上游来水和农业需水优化输水时间，可以有效提高水资源配置效益，取得更好的生态效果。旱区生态水文过程的演变已经是强烈人类活动干预下的演化，水资源配置方案对此演化具有重要影响。选择规划水平年推荐的水资源配置方案，在英苏断面共设置了8个情景。使用生态水文演化模型模拟了8个情景下地下水位和植被覆盖度的长系列演化过程，得到了生态水文系统的平衡状态。在塔里木河流域开发了基于逻辑斯蒂增长曲线的概念性社会生态水文模型，识别到4个反馈过程，代表了不同子系统和不同空间单元间复杂的相互作用。分析了塔里木河社会生态水文系统的协同演化，获得了对整个系统的动力学性质的认识。演化过程受到不断演化的群体意识的驱动。.研究成果将推动干旱区社会生态水文耦合模拟理论的发展，为干旱区水资源管理和高效利用提供重要理论依据。.