【作者】 尹小玲；

【导师】 张红武；

【作者基本信息】 清华大学 ， 水利工程， 2009， 博士

【摘要】 咸潮灾害是珠江河口近年来影响地区枯季供水的主要原因之一,保障枯季供水安全已经成为关系到地区经济和人民生活的重大社会问题。科学、合理地调度珠江上游水库,增加河口枯季径流作用,是解决珠江三角洲枯季供水危机的重要手段和途径。然而,珠江河口水动力过程和上游流域的水资源系统都十分复杂,上游水库调水压咸具有线路长、范围广、持续时间久、影响因素多、精度要求高的特点。因此,将珠江河口和上游流域作为一个整体系统,寻求科学、合理的枯季补淡压咸水库调度方法是当前迫在眉睫、急需深入研究的一个重要课题。基于此,论文进一步研究和认识珠江河口咸潮的发展规律和特点,建立和应用珠江数字流域模型分析和预测流域枯季水文过程,进而研究补淡压咸水库调度的科学方法。论文主要研究工作和创新成果有:1.分析研究磨刀门河口径流对咸潮的作用特点,明确提出将上游来流划分为3个不同范围考虑梧州补淡压咸控制流量;分析研究了盐度对潮汐变化的响应关系,提出以三灶站日加权潮位曲线谷值对应时间为参考起点的最佳集中补水时机选取方法。2.通过对数字流域模型原理和区间流域地质地貌水文特点的具体分析,阐明了模型在区间流域应用的适用性;首次建立起适用于龙滩-梧州区间的数字流域模型,作为区间流域径流分析的专业技术手段。3.分析梧州枯季径流变化规律和特点,运用模型数值试验,揭示了枯季梧州流量对龙滩泄流的响应规律。4.建立了基于数字流域模型进行区间径流预报的调度方案综合预测模式:即分水平年调度预案、月旬中长期调度预测和实时降雨修正短期调度预测3个层次,由粗到精、由远到近、相互结合、逐层修正。5.模拟分析研究了不同水平年枯季调度预案和调度水量,提出月、旬调度预测方法,并给出相关具体方案和控制要点;进一步通过模型实现了根据实时降雨资料对调度方案的短期滚动修正;初步建立起一套适用于珠江口补淡压咸水库合理调度的科学方法和分析工具。更多还原

【Abstract】 Saline water intrusion is one of main factors impacting water supply in dry season at the Pearl River estuary. Safeguarding water supply has become a significant social problem concerning economy development and people’s living standards in this region. Rational reservoir operation, which is designed to increase runoff at estuary in dry season, is a key approach to solve water shortage problem in dry season at the Pearl River delta. However, both the dynamic processes at the Pearl River estuary and water resource system of its upstream basin are very complex. Dispatching water from upstream reservoirs to suppress saline water faces many complex problems such as long route, large span, wide range, long duration, numerous influence factors and high precision requirement. Therefore, searching rational reservoir operation method in dry season for supplementing freshwater to repulse saline water by considering the Pearl River estuary and its upstream basin as a whole, is an extremely urgent problem. Based on this, further summarizing of rules and characteristics of slat tide at the Pearl River estuary is present in this paper. A digital watershed model of the Pearl River basin is proposed and applied on discussing its hydrological characteristics in dry season. Rational reservoir operation method is studied for optimized the result of supplementing freshwater to suppress saline water. The main conclusion and innovative achievement of this paper are listed as follows:1. The characteristics of runoff effecting on saline water intrusion at Modaomen estuary were analyzed firstly. And then, we clearly propound that the upstream runoff should be divided into three regions to investigate the dominant discharge of freshwater supplement. The response relationship of salinity to tide variation is also analyzed, a selection method searching for the best opportunity to begin water supplement is proposed. A methodology of science was suggested that the best time to begin water supplement is the time corresponding with weighted daily lowest tidal level at Sanzao hydrological station.2. The applicability of the model at sectional watershed was illustrated and demonstrated basing on the integrated analysis of digital watershed model principle and particular geological, geomorphologic and hydrological conditions of the sectional watershed. A digital watershed model, which is suitable for Longtan-Wuzhou section, is built up for the first time, and can be applied on runoff analysis in these areas.3. The rules and characteristics of runoff variation at Wuzhou in dry season are studied. The response pattern of the runoff discharge at Wuzhou to Longtan discharge at dry season is obtained by using numerical experiment.4. A comprehensive prediction model of dispatching scheme is established basing on regional runoff forecast by using the digital watershed model. The prediction model is composed of three levels; those are dispatching preparedness for different level years, long-period prediction for month or ten-days and short-period modification for real-time rainfalls. These three different scale models are mutual combined with each other and cascade modified layer-by-layer.5. Dispatching preparedness and dispatching water amount for different level years in dry season are simulated and discussed. A prediction method of water dispatching for month or ten-days is proposed, detailed scheme and key factors are also provided. Short-period rotational correction on dispatching scheme according to real-time rainfall data is achieved by using our model. Furthermore, a set of scientific methods and analysis tools, which are suitable for rational reservoir operation for supplementing freshwater to suppress saline water at the Pearl River estuary, have been preliminarily established.更多还原