变化环境下鄱阳湖典型湿地生态水文过程及其调控对策研究

发布时间：2018-04-15 11:00

本文选题：鄱阳湖湿地 + 生态水文　；参考：《武汉大学》2014年博士论文

【摘要】：随着气候变化、经济社会的快速发展,鄱阳湖的水文情势和生态环境发生了较大的改变,直接影响到鄱阳湖湿地生态系统和鄱阳湖生态安全。为维护鄱阳湖生态功能及生态安全,进行变化环境下典型湿地生态水文过程与调控对策研究,具有重大的理论与实践意义。论文的主要工作和创新点如下： 1、利用近50年的实测年径流量及年输沙量资料,采用Mann-Kendall等方法,研究了鄱阳湖流域水沙量的时空分布特性；从流域降雨、用水、水库拦沙、三峡蓄水、水土流失及其治理等方面分析引起鄱阳湖流域水沙变化的主要原因,提出了鄱阳湖流域气候变化降雨量减少对近10年鄱阳湖出入湖径流量的减少影响显著；水库滞沙是鄱阳湖入湖沙量减少的主要原因；出湖沙量变化主要受上游水库群的影响,还有近年湖区采砂的影响。 2、基于鄱阳湖入湖总水量的变化分析,应用长周期旱涝急转指数研究旱涝急转规律,结果表明：在4～5月与6～7月之间,鄱阳湖在长时期内存在旱转涝和涝转旱的交替循环过程,且进入21世纪以来旱转涝和涝转旱的间隔年份不断缩短,表明鄱阳湖流域“旱涝”和“涝旱”转换越来越频繁。 3、鄱阳湖的水文过程决定了其生态系统的结构和功能,其中水位变化是影响其生态系统状态变化的最主要因素。采用CoupModel模型模拟1990-2011年的典型湿地植被呼吸量(碳),然后结合相应时段的鄱阳湖星子站日水位,研究了鄱阳湖湿地生物量的变化及其与鄱阳湖水位的关系。发现当水位大于14m时,总呼吸作用明显变小,持续高水位时,总呼吸作用逐渐减弱；在一定范围,鄱阳湖水位较低并且持续时间越长,累计植物呼吸量呈现逐渐增大的趋势：最大年变幅水位越高,年累计植物呼吸量越小,说明一年内水位变化越剧烈,越不利于湿地植被的生长；最高水位与年累计植物呼吸作用的关系研究表明,当最高水位越高时,年累计植物呼吸作用越低。当最高水位越低时,年累计植物呼吸作用越大。年平均水位与年累计植物呼吸量的关系也呈现同样的规律。 4、建立了模拟鄱阳湖星子站水位与典型湿地植被呼吸量(碳)关系的CoupModel-ANN生态水文模型,并应用该模型探讨了鄱阳湖水利枢纽工程不同调度方案对保护湿地的作用。利用CoupModel-ANN模型进行不同水位方案植被呼吸量的预测,与CoupModel模型模拟的1990-2011年正常年份的植被平均呼吸量进行比较,得出鄱阳湖湿地生态系统恢复与保护的适宜水位为10-14.5m。
[Abstract]:With the climate change and the rapid development of economy and society, the hydrological situation and ecological environment of Poyang Lake have changed greatly, which directly affects the wetland ecosystem of Poyang Lake and the ecological security of Poyang Lake.In order to maintain the ecological function and ecological safety of Poyang Lake, it is of great theoretical and practical significance to study the ecological hydrological process and control countermeasures of typical wetland under changing environment.The main work and innovation of the thesis are as follows:1. Based on the measured annual runoff and sediment discharge data of nearly 50 years, the spatial and temporal distribution characteristics of water and sediment volume in Poyang Lake basin are studied by using Mann-Kendall method, including rainfall, water use, sediment retention by reservoir, three Gorges water storage, etc.The main causes of water and sediment change in Poyang Lake basin are analyzed in soil erosion and its management. It is pointed out that the decrease of precipitation in Poyang Lake basin has a significant effect on the runoff of Poyang Lake in recent 10 years.Reservoir sediment retention is the main reason for the decrease of sediment flow into Poyang Lake, and the change of sediment output is mainly affected by the upstream reservoir group and sand mining in the lake area in recent years.2. Based on the analysis of the change of the total water quantity of Poyang Lake into the lake, the long-period drought and flood index is applied to study the regularity of the rapid change of drought and flood. The results show that between April and May and June to July, there is an alternate cycle between drought and waterlogging in Poyang Lake during a long period of time.In the 21st century, the interval between drought and waterlogging has been shortened, indicating that the conversion of "drought, flood" and "waterlogging" in Poyang Lake basin is becoming more and more frequent.3. The hydrological process of Poyang Lake determines the structure and function of its ecosystem, and the change of water level is the most important factor affecting the change of its ecosystem state.The CoupModel model was used to simulate the respiration rate (carbon) of typical wetland vegetation from 1990 to 2011, and then the relationship between the biomass of the wetland and the water level of Poyang Lake was studied by combining with the daily water level of Xingzi Station in Poyang Lake in the corresponding period.It is found that when the water level is more than 14 m, the total respiration becomes smaller obviously, and when the water level is high, the total respiration gradually weakens, and in a certain range, the water level of Poyang Lake is lower and the duration is longer.The cumulative plant respiration showed a trend of increasing gradually: the higher the maximum annual amplitude water level, the smaller the annual cumulative plant respiration, which indicated that the more severe the water level change within one year, the more unfavorable to the growth of wetland vegetation;The relationship between the maximum water level and the annual accumulative plant respiration shows that the higher the maximum water level, the lower the annual cumulative plant respiration.When the highest water level is lower, the cumulative annual plant respiration is greater.The relationship between annual mean water level and annual cumulative plant respiration is similar.4. A CoupModel-ANN eco-hydrological model was established to simulate the relationship between water level and respiration (carbon) of typical wetland vegetation at Xingzi Station in Poyang Lake, and the effects of different dispatching schemes of Poyang Lake Water Conservancy Project on wetland protection were discussed.The CoupModel-ANN model was used to predict the vegetation respiration of different water level schemes, and compared with the average vegetation respiration in the normal years from 1990 to 2011 simulated by the CoupModel model. It was concluded that the suitable water level for restoration and protection of wetland ecosystem in Poyang Lake was 10-14.5 m.
【学位授予单位】：武汉大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：X143;X171;TV12

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