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1.
By using field-survey hydrological data of the related control stations in Dongting Lake and the Yangtze River mainstream in 1951–2010, the evolution characters of water exchange abilities between the two water bodies and their response to the operation of the Three Gorges Reservoir(TGR) from different time scales are analyzed based on their hydraulic relations. The results are shown as follows. Firstly, during July-September, the replenishment ability of Three Outlets to Dongting Lake is stronger, and in January-March, the replenishment ability of Dongting Lake to Yangtze River is stronger. Secondly, there has been an obvious inter-decadal wave on the water exchange coefficient between Dongting Lake and Yangtze River. In 1951–1958 and 1959–1968, the replenishment ability of Three Outlets to Dongting Lake was stronger, but in 2003–2010, the replenishment ability of Dongting Lake to Yangtze River has been strengthened. Thirdly, the spill-division ability of Three Outlets weakens, and the water of Dongting Lake coming from Three Outlets decreases either in typical years or under different dispatching modes of the TGR after the operation of the Three Gorges Reservoir. Furthermore, the water of Dongting Lake coming from Four Rivers takes the dominant position, which obviously enhances the replenishment ability of Dongting Lake to Yangtze River. Fourthly, if the effect of the runoff fluctuation in the basin is not considered, the evolution characters of the exchange capacities and the exchange process between Dongting Lake and Yangtze River in different time scales are generally changed with the variation of the water exchange amount between them, although the factors influencing the water exchange capacities between them is very complex. These show that there is an in-line growth or decline relation between the river-lake water exchange ability and the river-lake water exchange amount.  相似文献   

2.
The lower Yellow River still faces the threat of flood due to the unusual precipitation caused by global environmental change, river channel sedimentation, hidden danger in the dike and unfavorable river regime of "hanging river". According to the characteristics of the dike-break flood of the Yellow River, this paper has simulated, in six different scenarios, the dike-break flood routing by inputting the terrain data, typical historical flood data and land use data of study area to two-dimensional unsteady flow model. The results show that: firstly, the routing process of flood will occupy other rivers on the way and return to the rivers after reaching the lower reaches; secondly, in the same river reach, flood inundating area of north band is bigger than that at corresponding location of south bank under the same historical flood; thirdly, it is different in the degree of flood inundation in different regions due to different geographical locations in flood plain; fourthly, the area of mainstream where flood is deep and flow velocity is quick is relatively smaller, but the area of non-mainstream, where flood is shallow and flow velocity is slow, is relatively big; and finally, the possible influenced area of the dike-break flood is 141,948 km^2.  相似文献   

3.
Data of flood, drought, hailstorms, and low temperature events in Xinjiang from 1949 to 2012 were analyzed with the diffusion method to assess the risk of the most common types of disasters in Xinjiang. It was proved that the frequency and intensity of meteorological disasters of the study area showed an increasing trend associated with global warming. Among the four types of disasters, surpass probability of drought was the largest, followed by hailstorm, low temperature and flood in turn. Moreover, the wavelet method analysis revealed that greater oscillations had occurred since 2000, which may be associated with the occurrence of extreme climatic changes. The spatial distribution of frequencies reveals that the northern slope of Tianshan Mountains is a multiple disaster area, the southern slope of Tianshan is the area where more floods and hailstorms occur, and the west of Turpan-Hami Basin is the area wind is prevalent. The relationships between disaster-affected areas and corresponding meteorological and socio-economic indexes were also analyzed. It indicated that there were significant positive correlations between the areas affected and the most meteorological and socio-economic indicators except the grain acreage.  相似文献   

4.
近10年洞庭湖区土地利用变化时空特征   总被引:4,自引:0,他引:4  
The research on the land use/cover change is one of the frontiers and the hot spots in the global change research. Based on the Chinese resource and environment spatial-temporal database,and using the Landsat TM and ETM data of 1990 and 2000 respectively, we analyzed the spatial-temporal characteristics of land use/cover changes in the Dongting Lake area during the last decade. The result shows that during the last ten years there were three land-use types that had changed remarkably. The cultivated land decreased by 0.57% of the total cultivated land. The built-up land and water area expanded, with an increase of 8.97% and 0.43% respectively. The conversion between land use types mostly happened among these three land-use types, especially frequently between cultivated land and water area. The land-use change speed of land-use type is different. Three cities experienced the greatest degree of land-use change among all the administrative districts, which means that the land use in these cities changed much quickly. The following changed area was the west and south of the Dongting Lake area. The slowest changed area is the north and east area.  相似文献   

5.
IntroductionFlood disasters have been serious since the ancient bines. AJthough we have Strengthened the harnessingofbig rivers since the founding of new Chin4 the threat still edeStS (see FigUre l). The Yellow myer hasbeen well known for its flood disasters since long time %o in China. There more than 1500 river burstShappened to the Yellow hiver in the paSt 2000 or 3000 years. Whereas floods of the Changjiang caverwere comparatively not serious in history, but its flood disasters have …  相似文献   

6.
Land subsidence is a geohazard phenomenon caused by the lowering of land elevation due to the compression of the sinking land soil body, thus creating an excessive constraint on the safe construction and sustainable development of cities. The use of accurate and efficient means for land subsidence prediction is of remarkable importance for preventing land subsidence and ensuring urban safety. Although the current time-series prediction method can accomplish relatively high accuracy, the predicte...  相似文献   

7.
The East Dongting Lake National Nature Reserve in China is listed as a Ramsar Wetlands due to its global significance for migratory waterbird conservation, especially for the geese. For example, more than 90% of East Asian population of the vulnerable Lesser White-fronted Goose(Anser erythropus), and large numbers of Bean Goose(Anser fabilis) and Greater White-fronted Goose(Anser albifrons) over winter here every year from October to the next March. However, the habitats and food quality of the wintering geese have been threatened by hydrological alternation due to the operation of the Three Gorges Dam. Understanding the diets of these geese is fundamental for their conservation. We used the stable isotopic ratios of the body tissues of three predominant goose species(i.e. Ans?er erythropus, Anser fabilis and Anser albifrons) and their potential diet items(6 grass species), and applied smooth transition autoregressive(SIAR) mixing models to quantify the contribution of different food items to their diets. The results showed that the δ13C values of the blood samples were significantly different from those of feather, and the difference was consistent for the three kinds of geese. These results indicated that clear dietary shifts from their breeding place at the Arctic to the wintering place at Dongting Lake. The δ13C values of the blood samples of the geese showed there were no significant difference(ANOVA, p=0.265) suggesting that they share the same food sources at Dongting Lake. Moreover, the multiple-source mixing models(i.e. SIAR model) indicated that no single plant had a contribution greater than 35% to the diet of geese at 0.95 confident levels(0.50 and 0.95 credibility intervals of the posterior distributions range from 0.24-0.25 and 0.32-0.34, respectively). The results indicated that the geese had no preference for a particular plant. The findings suggested that the features at patch level(e.g. vegetation greenness and development stage) but not plant species might be the decisive factor in the habitat selection of the geese. Therefore,the management actions aiming to maintain habitat quality were critical for the waterbird conservation in Dongting Lake.  相似文献   

8.
Based on the drought/flood grades of 90 meterological stations over eastern China and summer average sea-level pressure (SLP) during 1850–2008 and BPCCA statistical methods, the coupling relationship between the drought/flood grades and the East Asian summer SLP is analyzed. The East Asian summer monsoon index which is closely related with interdecadal variation of drought/flood distribution over eastern China is defined by using the key areas of SLP. The impact of the interdecadal variation of the East Asian summer monsoon on the distribution of drought/flood over eastern China in the last 159 years is researched. The results show that there are four typical drought and flood spatial distribution patterns in eastern China, i.e. the distribution of drought/flood in southern China is contrary to the other regions, the distribution of drought/flood along the Huanghe River–Huaihe River Valley is contrary to the Yangtze River Valley and regions south of it, the distribution of drought/flood along the Yangtze River Valley and Huaihe River Valley is contrary to the other regions, the distribution of drought/flood in eastern China is contrary to the western. The main distribution pattern of SLP in summer is that the strength of SLP is opposite in Asian continent and West Pacific. It has close relationship between the interdecadal variation of drought/flood distribution patterns over eastern China and the interdecadal variation of the East Asian summer monsoon which was defined in this paper, but the correlation is not stable and it has a significant difference in changes of interdecadal phase. When the East Asian summer monsoon was stronger (weaker), regions north of the Yangtze River Valley was more susceptible to drought (flood), the Yangtze River Valley and regions south of it were more susceptible to flood (drought) before the 1920s; when the East Asian summer monsoon was stronger (weaker), the regions north of the Yangtze River Valley was prone to flood (drought), the Yangtze River Valley and regions south of it were prone to drought (flood) after the 1920s. It is indicated that by using the data of the longer period could get much richer results than by using the data of the last 50–60 years. The differences in the interdecadal phase between the East Asian summer monsoon and the drought/flood distributions in eastern China may be associated with the nonlinear feedback, which is the East Asian summer monsoon for the extrinsic forcing of solar activity.  相似文献   

9.
China is a disaster prone country, and a comprehensive understanding of change of disasters is very important for China’s agricultural development. In this study, statistical techniques and geographic information system tools are employed to quantify the main agriculture disasters changes and effects on grain production in China during the period of 1990–2011. The results show that China’s grain production was severely affected by disasters including drought, flood, hail, frost and typhoon. The annual area covered by these disasters reached up to 48.7×106 ha during the study period, which accounted for 44.8% of the total sown area, and about 55.1% of the per unit area grain yield change was caused by disasters. In addition, all of the disasters showed high variability, different changing trends, and spatial distribution. Drought, flood, and hail showed significantly decreasing trends, while frost and typhoon showed increasing trends. Drought and flood showed gradual changes and were distributed across the country, and disasters became more diversified from north to south. Drought was the dominated disaster type in northern China, while flood was the most important disaster type in the southern part. Hail was mainly observed in central and northern China, and frost was mainly distributed in southern China. Typhoon was greatly limited to the southeast coast. Furthermore, the resilience of grain production of each province was quite different, especially in several major grain producing areas, such as Shandong, Liaoning, Jilin and Jiangsu, where grain production was seriously affected by disasters. One reason for the difference of resilience of grain production was that grain production was marginalized in developed provinces when the economy underwent rapid development. For China’s agricultural development and grain security, we suggest that governments should place more emphasis on grain production, and invest more money in disaster prevention and mitigation, especially in the major grain producing provinces.  相似文献   

10.
A total of 1362 archaeological sites from the Paleolithic Age to the Warring States time in Hubei Province increase gradually from west to east and from high land to low land.The number of Paleolithic sites with altitude of 50-500 m account for 78% of the whole,while 71%-95% of sites from the Neolithic Age to the Warring States time mainly distribute at the areas of 0-200 m.The temporal-spatial distribution of archeological sites in this area is affected by two factors.For one thing,the human beings of every period need to choose the first or the second terrace as living sites which are near water source and are easy to withstand flood.Additionally,affecting by the regional tectonic uplift since the Holocene,down cutting of rivers can form new river valley,and lateral erosion and accumulation of river in stable time of tectonic movement can result in increasing of many new terraces.So,the human beings migrated to adapt to the change of terrace location,leading to the sites increase gradually in the lower areas of the central and eastern parts of this province.For other things,the temporal-spatial distribution of archeological sites in this area is affected by the climate condition.The Paleolithic sites mostly distribute in the Hanshui River Valley in northeastern Shiyan,southeast of Jinzhou and east of Jinmen,which is because rivers distributed in higher areas in this period.During the Chengbeixi Culture period,the sites are rare in the quondam Paleolithic sites distribution area,but increase obviously along the Yangtze River near the southwest Yichang.The spore-pollen record of Dajiuhu Basin indicates that only 23 Chengbeixi cultural sites may be related to more precipitation and flood during the Holocene wet and hot period.The Daxi Culture,Qujialing Culture and Shijiahe Culture are corresponding to middle and top of the Dajiuhu spore-pollen Zone Ⅳ,during which the climate is in order as a whole and is propitious to agricultural development.In the Qujialing Culture period,32 of original 34 Daxi cultural sites disappeared,while 90 sites increase abruptly in the higher highlands in the north of Xiangfan-Jinmen-Xiaogan,which may respect with enlarging of water areas.The Chu Culture period is corresponding to Dajiuhu spore-pollen Zone V,which is in warm and dry Holocene phase,but it seems that the climate condition is still propitious to agricultural cultivation and the number of archeological sites increase heavily to 593.In addition,there are the least archaeological sites in the lake areas of southeast Hubei Province because of low-lying topography with altitude of 0-50 m and the severest flood.  相似文献   

11.
构造沉降和泥沙淤积对洞庭湖区防洪的影响   总被引:13,自引:1,他引:12  
来红州  莫多闻 《地理学报》2004,59(4):574-580
作者利用洞庭盆地多年水准测量资料和洞庭湖近年的泥沙资料,对洞庭盆地的构造沉降速率和泥沙淤积速率进行了分析,从地貌学和水利学角度,对“洞庭湖盆”和“洞庭盆地”这两个不同的空间概念进行了区分,在此基础上,探讨了构造沉降和泥沙淤积对洞庭湖蓄洪空间和防洪大堤的影响。在目前洞庭湖盆被大堤围限的情况下,洞庭盆地的构造沉降运动使洞庭湖的蓄洪空间不断减小;洞庭盆地的构造沉降量虽然在一定程度上缓解了洞庭湖不断萎缩的趋势,但构造沉降对洞庭湖区的防洪形势却是不利的。构造沉降和泥沙淤积均对防洪大堤的质量提出了更高的要求,增大了洞庭湖区防洪的难度。  相似文献   

12.
With the long-term data of the geodetic sea level measurements undertaken in the Dongting Basin and the recent sediment data of Dongting Lake, we analyze the tectonic subsidence rate of the Dongting Basin and the sedimentary rate of Dongting Lake. From the point of view of geomorphology and hydrogeology, we distinguish the two different spatial concepts between "the basin of Dongting Lake" and "the Dongting Basin". Then, we discuss the influences of the tectonic subsidence and the siltation on the levees and the space of storing flood. The better quality of levees is required due to the tectonic subsidence and the siltation, and the difficulties of preventing flood disasters are increasing. The space of storing flood is not affected by the tectonic subsidence, but by the siltation. At present, the sedimentary rate of Dongting Lake is higher than the tectonic subsidence rate of the Dongting Basin. The tectonic subsidence capacity of the Dongting Basin counteracts a part of sedimentary capacity, and the shrinking tendency of Dongting Lake is restrained to a certain extent, but the tectonic subsidence is harmful to the situation of preventing flood disasters in the Dongting Lake area.  相似文献   

13.
洞庭湖演变趋势探讨   总被引:31,自引:1,他引:30  
洞庭湖的演变主要受构造沉降、泥沙淤积和人类活动影响三大因素的控制。目前 ,洞庭湖盆的构造沉降速率虽然较低 (3~ 10mm/a) ,但构造沉降量仍抵消了部分泥沙淤积量 ,在一定程度上抑制了洞庭湖日益萎缩的趋势。由于湖盆中泥沙淤积速率大于构造沉降速率 ,洲滩会继续发育和扩展 ,洞庭湖仍保持淤高的趋势。在“4 35 0工程”完成和三峡建坝后 80年内 ,湖盆泥沙淤积速率将降低到 1 79mm/a ,洞庭湖不断淤高的趋势将得到减缓。  相似文献   

14.
The geological and meteorological setting of the Jianghan–Dongting lake area leads to high precipitation and siltation, but poor water discharge, thus the area is frequently flooded. In the past the river–lake relationship of the Middle Yangtze has been variable but has deteriorated recently under increasing human influence. The Jianghan Plain of the Middle Yangtze becomes a waterlogged lowland under the constant threat of flooding from the perched Jingjiang River. Due to siltation and land reclamation the Dongting Lake has lost most of its regulatory function for the river and has become increasingly vulnerable to flood disasters. The Middle Yangtze River has been undergoing siltation, resulting from a downstream decline of sediment transport capacity, resulting in the elevation of the flood level above the lowlands. Heightening of the levees has caused further siltation of the channel.The Three Gorges Reservoir will provide a buffering period of 50–80 years, during which much of the silt will be trapped in the reservoir and scouring downstream may occur. We should utilize this period to work out an overall resolution to the problem. Construction of a water and silt diversion project in the Honghu Lake and surrounding areas may resolve this problem in the dangerous Chenglingji–Wuhan Segment of the Yangtze. Widening the canals connecting the Middle Yangtze and Han Rivers may function as a discharge-dividing channel of the Yangtze, which may prove to be beneficial.  相似文献   

15.
60年来洞庭湖区进出湖径流特征分析   总被引:2,自引:0,他引:2  
采用集中度与集中期、M-K趋势检验法、变差系数法等方法对洞庭湖入湖径流河流(荆江三口、湖南四水)和出湖径流(城陵矶)年径流量序列进行分析。结果显示:① 洞庭湖区径流集中期为每年6~7月份,最大径流出现时间为6月底7月初;径流集中期合成向量方向介于103.2~190.2°之间,均能够反映各河流进出湖径流量最大值出现的月份。② 径流变差系数介于0.194~0.761之间,说明径流年际变率大。各河流径流极值比均在0.6以上,径流量衰减较为明显。③ 从径流的丰枯交替规律来看,湖南四水水量分配相对较为平均。荆江三口以藕池口丰水年和枯水年概率最大,分别占到32.79%和57.38%,径流年际变化较为剧烈,不利于水资源的合理利用。  相似文献   

16.
三峡工程建设背景下的洞庭湖区治水方略探讨   总被引:8,自引:1,他引:7  
贺清云  朱翔 《地理研究》2003,22(2):160-168
在长江三峡工程建设的大背景下,本文分析了洞庭湖区的水灾减灾机制,探讨了洞庭湖区的治水方略,提出应充分发挥三峡水库的调蓄功能,协调江湖关系,改善冲淤关系,加强水利工程建设,实现三峡水库与湖南四水水库的优化调度  相似文献   

17.
基于Copula函数的洞庭湖流域水沙丰枯遭遇频率分析   总被引:1,自引:0,他引:1  
周念清  赵露  沈新平 《地理科学》2014,34(2):242-248
受人类活动的影响,水沙灾害事件相继发生,对人们的生产、生活造成了威胁。以洞庭湖流域代表性水文站的年径流量和年输沙量系列数据为基础,应用P-III型曲线分别拟合并求得“松滋口、太平口、藕池口”三口入湖、“湘江、资江、沅水、澧水”四水入湖和城陵矶站出湖年径流量、年输沙量的边缘分布函数,再采用水文事件遭遇分析中广泛应用的Copula函数,建立洞庭湖流域水沙联合分布模型,分析洞庭湖流域水沙丰枯遭遇频率。研究结果表明洞庭湖三口、四水和城陵矶站的水沙丰枯遭遇频率关系与洞庭湖流域的水沙运动有密切联系,运用该水沙耦合模型可以为洞庭湖流域防洪减灾提供重要的理论依据。  相似文献   

18.
本文利用清光绪22年以来17个时段的多种历史地图和航天航空遥感数据,采用遥感解译、数据统计分析与历史对比方法,分析清末以来洞庭湖区通江湖泊面积的时序变化,探究空间演变特征。结合水利部门发布的典型年份监测数据,检验了遥感获取的湖泊面积精度,误差仅为0.62%。结果显示:洞庭湖通江湖泊面积从1896年的5216.37 km2减少到2019年的2702.74 km2,萎缩率为48.19%。1949年前的53年为明显萎缩期,年均萎缩15.66 km2;20世纪50年代为陡崖式萎缩期,年均萎缩139.05 km2;20世纪60—70年代为快速萎缩期,年均萎缩21.66 km2;1980年以来为基本稳定期,年均萎缩0.13 km2,面积仅减少了5.10 km2。就具体湖泊而言,东洞庭湖是各通江湖泊中面积萎缩最大的湖泊,减幅为922.60 km2;其次是目平湖,减幅为588.05 km2;再次是南洞庭湖,减幅为448.37 km2;七里湖的面积变化很小,但经历了先扩张后萎缩的过程。1998—2002年实施“退田还湖”工程,洞庭湖面积增加了10.50 km2。总体而言,清末以来洞庭湖区通江湖泊的演变主要表现为大通湖的封闭析出、整修南洞庭湖的湖垸置换与南迁、围垦西洞庭湖的局部残存、东洞庭湖的三面合围以及1998年特大洪灾后有限的“退田还湖”。本文为长江流域生态修复和环境保护战略提供了客观资料和技术支撑。  相似文献   

19.
天津地区地面沉降及其对地理环境的影响   总被引:10,自引:0,他引:10  
王若柏  孙东平 《地理学报》1994,49(4):317-323
本文应用现代精密水准资料,结合地质、地震资料对天津及邻近地区地面沉降的发展、演化状况进行了深入研究,从动态观点初步探讨了由于地面沉降所造成的地理环境条件恶化和灾害问题。  相似文献   

20.
洞庭湖区1998年与1954年特大洪涝灾害比较研究   总被引:5,自引:0,他引:5  
彭际作  毛德华 《热带地理》2000,20(2):116-120
在对洞庭湖区深入调查研究的基础上,结合历史资料,从雨情、水情和灾情三个方面对比分析了1998年、1954年特大洪涝灾害的共性和个性。在此基础上揭示了1998年洞庭湖区洪涝灾害形成的原因,并提出了防治对策,为洞庭湖社会经济可持续发展和综合治疗洞庭湖提供了科学依据。  相似文献   

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