【作者】 符传君；

【导师】 练继建；

【作者基本信息】 天津大学 ， 水利水电工程， 2008， 博士

【摘要】 南渡江是海南岛的第一大河流,近年来,南渡江干流各种蓄水、引水、提水工程的兴建,人为地改变了天然径流情况,在一定程度上影响(甚至破坏)了河流生态系统的健康。同时,近年来由于泥沙开采过度,造成河床过低,使海水倒灌现象日益严重,目前南渡江河口地区面临严重的生态环境问题。本文针对南渡江河口水资源的生态效应及高效利用展开了系统的研究,主要内容和创新之处包括:运用小波方法对天然年径流进行了多时间尺度分析,并利用不同尺度下的低频成分预测水文序列的变化趋势;将模糊数学理论中的层次分析法引入到水资源分析中,并对海口市的水资源利用程度进行了模糊评价。研究表明,南渡江下游河口地区水资源开发利用程度并不高,具有很大的开发利用潜力。在分析生态需水概念的基础上,以最小生态基流为思路,利用多种方法计算了南渡江河口的河道内生态需水量和河道外生态需水量。结果表明,南渡江下游天然来流量基本上可以满足生态基流的要求,河流生态系统生物繁衍条件基本完好,生态系统处于较健康状态。基于盐水入侵水动力学方法,对入侵距离和流量之间的关系进行研究。建立河道的平面二维数学模型,模拟了小流量下河口盐水入侵状况,分析了盐水入侵距离随时间的变化趋势以及流量变化对盐水入侵的影响。从河流功能出发,建立了以河流的服务功能、环境功能、利用功能及生态功能为要素的评价指标体系;运用层次分析法进行综合评价,得出各指标对河流生态健康的影响指数;并分析了橡胶坝工程对河流生态健康的影响,分析表明,工程对龙塘坝下游生态环境影响较小,生态取水方案可行。在总结南渡江河流水生态系统服务功能的基础上,建立了河流生态系统服务经济价值评价指标体系,并对南渡江河口段增蓄水资源的价值量进行了研究。基于灰色预测模型和改进BP神经网络进行水资源需求预测,预测结果很好地反映了影响因子与水资源需求增长之间的非线性关系。另外,本文从工程措施、用水分配管理等方面对南渡江河口水资源的高效利用进行了研究。更多还原

【Abstract】 Nandujiang River is the greatest river in Hainan Province. In recent years, with the construction of different kinds of water diversion, storage and lifting works, the natural flow conditions were artificially changed, which affect (or even destroy) the health of river ecosystem.Meanwhile, excessive sand exploration in recent years leds to lowering of riverbed, and sea water intrusion is becoming more and more serious. Nandujiang River Estuary is confronted with serious ecological and environmental problem now.Systematical research was carried out in this thesis on the ecological effect and high efficiency utilization of water resources of Nandujiang River Estuary. Main contents and innovation points are:Multiple time scale analysis and variation trend analysis are carried out for natural annual runoff with wavelet method. The low frequency component was adopted in forecasting of hydrosequence tendency. The analytical hierarchy process in theory of fuzzy mathematies was introduced into water resources analysis, herein, the utilization degree of water resources of Haikou City is evaluated. Analytical hierarchy process was adopted for evaluation of utilization degree of water resources in Haikou City.Research indicates that the water resource development and utilization degree of Nandu River Estuary is not high, and there is still a large potentiality.Based on the concept of ecology water need and minimal ecology base runoff, the ecology water requirement in and outside of river channel of Nandujiang River was computed with multiple methods.The natural flow rate of downstream of Nandu River basically meets the requirement of suitable ecology base runoff. The biologic reproduction condition and the river ecosystem is basically in good condition.As for salt water intrusion, hydrodynamic method was adopted to study the relationship between intrusion distance and flow rate of river.The salt water encroachment status of estuary under low discharge was simulated and the relationship of salt water encroachment distance vs. time was analyzed, as well as the influence of discharge variation on salt water encroachment.An evaluating indicator system was established for functions of river, including the service function, environment function, utilization function and ecology function of river. Comprehensive evaluation was carried out with analytical hierarchy process to obtain the influence of each index on river ecology health. The influence of rubber dam works on river ecology was also analyzed. Analysis shows that the project has little impact on ecological environment downstream of Longtang Dam and the water intaking scenario is feasible.The service functions of water ecosystem of Nandujiang River were summed up, based on which, an economic value evaluating indicator system was established for service of ecosystem of river. The value of increased water impoundment of Nandu River estuary was studied.Water demand forecast was carried out based on gray predictive model and modified BP neural network and the results reflect the nonlinear relationship between water demand growth and impact factors well.In addition, high efficiency utilization of water resources of Nandujiang River Estuary was studied from the aspect of engineering measures and water distribution and management.更多还原