【作者】 粟晓玲；

【导师】 康绍忠；

【作者基本信息】 西北农林科技大学 ， 农业水土工程， 2007， 博士

【摘要】 石羊河流域是我国内陆河流域中水资源开发利用程度最高,用水矛盾最突出的地区,由于不合理的水资源配置,社会经济用水严重挤占生态用水,导致下游民勤绿洲严重的生态危机。面向生态的流域水资源合理配置的研究,可为内陆河流域持续利用水资源、改善脆弱生态环境提供决策依据,具有重要的科学意义和应用价值。论文提出了面向生态的水资源合理配置的概念、理论基础及配置目标、原则与机制,在分析了干旱区水资源配置面临的挑战的基础上,建立了干旱区面向生态的水资源合理配置研究框架体系,主要包括干旱区受水控制的生态系统演变、水资源的生态价值估算、干旱区生态环境需水理论,以及面向生态的水资源合理配置模型与应用。在对石羊河流域水资源条件及转化特点分析的基础上,剖析了石羊河流域受水控制的生态系统的演变机制。基于地下水埋深空间插值分布图和植被分布图获得民勤县不同地下水埋深下不同盖度草地出现的概率,据此确定草地的生态地下水埋深。从气候变化和人类水土资源开发利用活动两方面分析生态演变的驱动因素,得出人类活动引起的水资源的演化是流域下游民勤绿洲生态系统恶化的主导因子。建立了基于水热平衡原理的绿洲适宜规模模型,计算石羊河流域适宜的灌溉面积为21.38万hm2～24.03万hm2。在Costanza等人提出的单位面积生态价值的基础上,提出了静态生态价值的修正系数,建立了适宜于内陆河流域的基于发展阶段系数和资源紧缺度的动态生态价值估算模型,结合石羊河流域土地利用数据和GIS技术获得了流域静态生态价值和动态生态价值空间分布图。结果表明,2000年石羊河流域静态生态价值为4.17亿美元,相当于当年GDP的0.3657倍,且在空间上呈现从上游山区向下游荒漠区递减的规律;动态生态价值为2.35亿美元,下游和上游大,中游较小。动态生态价值的研究为生态价值研究成果进一步在资源合理配置中的应用提供了新的途径。论文阐述了生态需水的基本原理,根据干旱内陆区生态系统的结构,划分生态需水的类型,定义最低生态需水是维持生态系统结构完整的最低需水量,最高生态需水是指生态系统结构完整,且处于良好状态的需水量。采用蒸发降水差法、累积积温法、基于GIS的潜水蒸发法和给水度法等分别计算水面蒸发生态需水、人工绿洲防护林生态需水、天然植被生态需水及恢复生态水位的生态需水量。并估算了石羊河流域各项生态需水。计算结果表明,现状生态需水为1.2418～2.6924亿m3;2010年生态保护目标下生态需水为1.267～2.7902亿m3。现状恢复生态地下水位的补水量35亿m3。遵循生态平衡原则、效率原则及公平性原则,以生态需水的满足程度作为目标函数之一,建立了内陆河流域面向生态需水的水资源合理配置模型系统,包括非灌溉需水预测模型,多目标决策模型,水资源转化模拟模型、计算单元种植结构优化模型。将单元种植结构优化模型嵌套在水资源转化模拟模型中,实现模拟模型与优化模型的耦合。针对石羊河流域,从供水、节水、种植结构调整、虚拟水措施等方面假设不同的水资源模拟情景,应用模型获得了流域水资源配置方案,该方案2010年流域天然绿洲生态用水1.0467亿m3,社会经济净用水15.2937亿m3,实现民勤地下水正均衡0.3亿m3(恢复地下水位),下游蔡旗断面来水3.12亿m3,金川峡水库来水1.73亿m3,流域总灌溉面积21.826万hm2,粮经饲比例为54:31:15,可以满足人均420kg的粮食自给。提出了生态效益分摊系数的理论与简化计算公式以及生态效益计算方法,建立了面向生态的水资源合理配置模型,模型将生态效益和经济效益统一度量,以生态与经济综合效益最大为目标函数,该模型应用于石羊河流域的水资源模拟优化,获得了优化的生态用水和经济用水比例。最后对面向生态的水资源合理配置问题在理论、方法与实践方面提出了需要进一步研究的建议。更多还原

【Abstract】 The Shiyang River basin is the region where the degree exploitation and utilization is highest and water conflict is sharpest in the inland river basin of China. The ecological water requirement (EWR) was occupied by economical water utilization because of unreasonable water resources allocation, which resulted in the serious ecological crisis in Minqin oasis, downstream of the Shiyang River basin. The research on water resources reasonable allocation oriented ecology could provide decision-making basis for the sustainable water utilization and fragile eco-environment improvement, so it has remarkable scientific significance and application value.The concept,foundational theories and allocation objectives, principle and mechanism of water resources allocation oriented ecology are proposed in the dissertation. According to the analysis on challenges from the allocation, the framework system of water resources allocation oriented ecology is established which include evolution of ecosystem controlled by water, evaluation of ecosystem value, ecological water requirement, allocation model and it’s application.The evolution mechanism of ecosystem controlled by water in Shiyang River Basin is analyzed. The Probability of three types of covered grassland in different groundwater depth in Minqin basin is obtained based on the spatial distribution of groundwater depth and vegetation. Thus, the groundwater depth suited for the ecosystem could be determined. The driving forces of ecosystem evolution were analyzed through climate change and human exploitation and use on land and water resources. The result shows that the intensive human activities induce reallocation of water resources in the basin, which lead to the deterioration of water-dependant oasis ecosystem. Based on the principle of water and energy balance, the model of oasis-sized is built. The area suitable for irrigation in Shiyang River Basin is only 213,800-240,300 hm2. Presently, irrigation area is 310,000 hm2. The man-made oasis is so large that a total of 70,000-96,000 hm2 of irrigated land should be given up.Referring to the methods presented by Costanza at el, a modified coefficient of the unit area values of ecosystem services was presented. The evaluation method for dynamic value is put forward which based on the developmental coefficient and scarcity degree of ecological resources. The spatial distributions of the dynamic value and static value of the ecosystem services in Shiyang River Basin are obtained which combine the land use data with GIS tool. It is estimated that the static value of the ecosystem services in the Shiyang River Basin is $0.417 billion, equal to 0.3657 times of GDP in 2000, and show descending trends from upstream mountain region to downstream desert region. The annual dynamic value is $0.235 billion, and is larger in upstream and downstream region than in middle region. The dynamic value of the ecosystem services is a new approach in optimal allocation of the natural resources by application the research conclusion about value of ecosystem service.The ecosystem need water so that they can carry out their usual function and provide the services human are used to. The methods of Gap between Evaporation and Precipitation, Cumulated Temperature, Phreatic Evaporation based GIS and Storativity are applied to calculate the ecological water requirement (EWR) for water body of river and lake, shelter–forest ecosystem in artificial oasis, natural vegetation ecosystem in natural oasis, and restoration the ecological groundwater depth. The lowest EWR is to sustain the ecosystem structure integration, and the highest EWR is to sustain the ecosystem structure integration and normal vegetation growth. At the present, it is estimated the lowest total EWR and highest EWR in Shiyang River Basin is 0.1242 and 0.2692 billion m3 respectively, in which of 0.066 to 0.2111 billion m3 need to be allocated for ecosystem. Under the protect objective of ecosystem in 2010, the lowest total EWR and Highest EWR in Shiyang River Basin was estimated as 0.1267 and 0.2790 billion m3 respectively, in which of 0.0685 to 0.2208 billion m3 need to allocated for ecosystem under the integrated water allocation. The EWR for restoration the ecological groundwater depth was estimated as 3.5 billion m3. Under the three principles of ecosystem balance, efficiency and equity, model system of reasonable water resources allocation oriented ecological water requirement is established,which include forecast model of non-irrigation water requirement, multi-objectives decision-making model, water resources transformation model, optimal model of crop plant structure in calculated unit. The optimal model is nested in water resources transformation model, which achieves coupling of the simulated model and optimal model. Taking Shiyang River Basin as an example, the input of the model are eight water resources allocation scenarios from different measurements, such as water supply, water saving, crop plantation structure regulation,and virtual water trade. The reasonable water resources allocation scenario is provided by multi-objectives decision-making model in the Shiyang River Basin. The allocation result is that the water allocation for natural ecosystem is 104.67 million m3, and for groundwater equilibrium is 30 million m3, inflow of Caiqi section is 312 million m3, inflow of Jinchuanxia reservoir is 173 million m3, the total irrigation area is 218260 hm2, and ratio of food crop, economic crop and forage crop are 54:31:15. Food demand per person of420kg could be satisfied. The theoretical formula and simple calculation formula is provided in the dissertation. The model of reasonable water resources allocation oriented ecology is established, in which the ecological benefits and economic benefits were valued together. The objective function of the model is to maximize the total benefits. Apply the model to allocate the water resources in Shiyang River Basin. The optimal proportion between ecological water use and economic water use is obtained.Finally, the advices for further study of water resources allocation oriented ecology on theory, method, and practice were provided.更多还原