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1.
东洞庭湖是全球易危(VU)物种小白额雁(Anser erythropus)最关键的越冬地之一。三峡大坝的运行,对东洞庭湖的秋季水文情势产生了较大影响,并直接影响洲滩植被的生长。这种影响如何进一步影响小白额雁越冬,是小白额雁越冬栖息地保护迫切需要认识的关键科学问题。选择水文特征差异较大的2011年和2012年秋、冬季,分别在自然洲滩和水位管理区洲滩开展野外监测和调查,研究越冬稳定期小白额雁种群的空间分布及洲滩植被特征。研究结果表明,2011年东洞庭湖枯水期比常年水文情势提前约45 d,自然洲滩植被盖度、生物量显著高于水位管理区洲滩(p0.05),小白额雁迁徙到达时,种群中67.6%的个体分布于水位管理区的洲滩;而2012年东洞庭湖枯水期比较接近常年的水文情势,自然洲滩植物物种丰富度显著低于水位管理区洲滩(p0.05),73.2%的小白额雁种群个体分布于自然洲滩。两年不同的水位情势直接影响东洞庭湖洲滩植物特征(p0.05),但小白额雁在两年都选择栖息在植被盖度低且生物量低的洲滩取食(p0.05)。由于2011年枯水期提前,导致自然洲滩不适宜小白额雁取食,水位管理区洲滩成为越冬小白额雁的主要栖息地;而2012年湖泊退水节律较正常,东洞庭湖内适宜越冬小白额雁栖息的范围较大,栖息在水位管理区洲滩内的越冬小白额雁数量显著减少。  相似文献   

2.
水分梯度下洞庭湖洲滩植物群落多样性特征   总被引:1,自引:0,他引:1  
靳朝  雷霆 《湿地科学》2015,(2):177-183
为了揭示因水文条件改变而发生变化的洲滩植物分布规律,以洞庭湖洲滩植物为研究对象,沿泥沙洲滩、泥沙-湖草洲滩过渡带、湖草洲滩、湖草-芦苇(Phragmites australis)洲滩过渡带、芦苇洲滩的带状顺序,分析植物群落α多样性和β多样性特征,研究群落多样性与土壤水分之间的关系。结果显示,从泥沙洲滩到芦苇洲滩,土壤含水量呈递减趋势;随着土壤含水量递减,群落物种丰富度不断增加,但群落Shannon-Wiener指数并没有显著改变(p0.05);从泥沙洲滩到湖草-芦苇洲滩过渡带,群落间相似性显著增强(p0.05),物种替换率变化幅度不明显(p0.05),而从湖草-芦苇洲滩过渡带到芦苇洲滩,群落间相似性显著降低(p0.05),物种替换率明显变大(p0.05),β多样性增大。一旦湿地水文条件改变,洞庭湖洲滩植被分布也将发生变化,并促使原有植被发生逆向演替。  相似文献   

3.
鄱阳湖湿地水位与洲滩淹露模型构建   总被引:5,自引:1,他引:4  
周霞  赵英时  梁文广 《地理研究》2009,28(6):1722-1730
水是控制湿地生态过程的一个重要因子,为了研究洲滩变化和湿地草洲生长发育规律,以便更好地监测和保护湿地生态系统,有必要研究鄱阳湖水体变化特征,分析湿地洲滩水位的时空动态变化和洲滩淹露规律。本文以鄱阳湖国家级自然保护区为例,在对鄱阳湖多年水位进行分析的基础上,利用多时相遥感影像和DEM提取湿地洲滩特征;并在GIS支持下综合考虑地形、鄱阳湖水位、湖泊缓冲区等因素,建立了湿地水位及洲滩淹露模型。时空验证结果表明,该模型具有较好的模拟效果,精度在85%以上。同时,本文根据研究区特点及水体在TM2、7波段的特征差异,构建了一个新的水体指数FDWI,提取水体精度达到98%,特别是对潮湿的沙地、植被和云有很好的区分能力。  相似文献   

4.
鄱阳湖典型洲滩植物群落结构变化及其与土壤养分的关系   总被引:4,自引:0,他引:4  
由于鄱阳湖独特的水文特征与潜育化的土壤环境,湿地植物根系生长过程及其对环境的适应机制近年来受到国内外研究人员的高度关注.2011年,以鄱阳湖典型洲滩3种植物群落为研究对象,采用野外调查和统计分析相结合的方法,研究了鄱阳湖典型洲滩植物群落结构变化和群落分布与土壤养分之间的关系.研究结果表明,从水体到泥滩至阶地,鄱阳湖典型洲滩植物呈现带状演替,沿泥滩到阶地的方向,植物群落分别为虉草(Phalaris arundinacea)群落带、灰化薹草(Carex cinerascens)群落带和篱蒿(Artemisia selengensis)群落带;3种植物群落的优势种高度与地表生物量有相同的变化趋势;月降水量越大,则篱蒿群落的Shannon-Wiener生物多样性指数越高;土壤有机碳、全氮和全磷含量能影响植物群落优势种的高度.加强鄱阳湖典型洲滩植物群落结构变化对湿地土壤环境的适应性过程与机制的研究,对于了解鄱阳湖洲滩湿地植物群落的生态演替及演化机制具有重要科学意义.  相似文献   

5.
互花米草引种对苏北潮滩湿地TOC、TN和TP分布的影响   总被引:5,自引:0,他引:5  
分析了TOC、TN和TP在苏北潮滩湿地不同生态带沉积物和植被中的分布状况,结果表明:TOC和TN的水平和垂向平均含量以互花米草滩为最高,其次分别为盐蒿滩、芦苇滩和光滩。TP的平均含量以光滩为最高,依次由海向陆逐渐减小。在生物量最大期间(秋季),单位面积上互花米草体内TOC、TN和TP的累积量远大于盐蒿和芦苇。互花米草主要通过以下4个方面对研究区潮滩湿地TOC、TN和TP的分布产生影响:(1)互花米草滩面较高的沉积速率;(2)互花米草对整个潮滩湿地不同植被分布格局的改变;(3)互花米草有着高生产力以及巨大的地下生物量;(4)互花米草的生长特性使其在生长过程中对磷的需求量很大。  相似文献   

6.
《地理学报》2006,61(12):1332-1344
第1期黄河源地区草地退化空间特征!!!!!!!!!!!张镱锂刘林山摆万奇等(3)干旱生态系统净初级生产力估算及变化探测!!!!!张杰潘晓玲高志强等(15)珠江口红树林湿地演变的遥感分析!!!!!!!!!!黎夏刘凯王树功(26)水沙研究长江口水沙入海通量的观测与分析!!!!!!!汪亚平潘少明H.V.Wang等(35)长江干流径流的时序结构与长期记忆!!!!!!!!!王国杰姜彤陈桂亚(47)降水—植被耦合关系及其对黄土高原侵蚀的影响!!!!!!!!!!!许炯心(57)不同水沙条件下黄河下游二级悬河的发展过程!!!!!杨吉山许炯心廖建华(66)风水复合侵蚀研究述评!!!!!!!!!!!!!!!宋阳刘连友严…  相似文献   

7.
李梦凡  张奇  李云良  姚静 《热带地理》2016,36(4):700-709
采用具有物理机制的二维水动力模型MIKE 21,基于2006 年长江枯水与1953―2000 年长江平均来水条件(平均条件)2 种情景,模拟比较2 种情景下鄱阳湖退水期(7―12 月)洲滩出露过程,阐释长江来水变化对鄱阳湖洲滩出露特征的影响。结果表明:2006 年长江来水减少导致鄱阳湖洲滩出露开始时间提前,与平均条件相比提前1 个月;洲滩出露50%面积仅历时约0.5 个月,比平均条件缩短约1.5 个月;长江枯水对鄱阳湖洲滩出露分布影响最显著的时段为8―11 月,8 月上旬洲滩增加的出露面积主要分布在赣江入湖三角洲和东部湖湾,而8月中旬―11 月末增加的出露面积主要分布在中部开敞湖区和北部入江通道洲滩;长江枯水对鄱阳湖中北部洲滩出露天数的影响大于南部湖区,对修水和赣江北支入湖三角洲的影响大于赣江中支和南支入湖三角洲,对鄱阳湖国家级自然保护区的影响明显大于南矶山自然保护区;长江来水变化还显著影响洲滩出露速率,2006 年长江水情下洲滩自开始出露至到达最大出露面积(8 月初―10 月中旬)期间的平均出露速率(25 km2/d),与平均条件下洲滩自开始出露至到达最大出露面积(9 月初―12 月末)期间的平均出露速率(14.5 km2/d)相比增大了72%。  相似文献   

8.
鄱阳湖流域水沙时空演变特征及其机理   总被引:12,自引:1,他引:11  
运用改进的Mann-Kendall(M-K)趋势与突变检验以及线性回归分析等方法,系统分析了鄱阳湖流域的赣江、抚河、信江、饶河和修河等五大支流的5个主要水文控制站(外洲、李家渡、梅港、虎山、万家埠)1956-2005年的水沙序列,在系统搜集流域内水库信息的基础上,深入探讨了流域内水沙变化的原因.研究结果表明:(1)鄱阳湖流域各支流的水沙变化特征相异;除李家渡站径流无明显变化外,其余4站都有增加趋势(但未达到95%的置信度水平1.五大支流的输沙量变化比较复杂,外洲站、李家渡、梅港站和虎山站的输沙量在1985年以后减少的趋势显著,而万家埠站的输沙量直到1999年才开始减少;(2)森林覆盖率对输沙量变化的影响远远大于其对径流变化的影响,森林对减少湿季径流量的作用不明显,但对枯季径流量增加的影响显著.(3)水利设施(尤其是水库)对五大支流的水沙变化影响很大,尤其对输沙量的影响最为明显,这也是鄱阳湖流域大部分水文观测站输沙量减少的主要原因.  相似文献   

9.
南京长江新济洲群湿地保护与恢复规划设计   总被引:1,自引:0,他引:1  
以南京长江新济洲群湿地为例,分析了在长江中下游开展洲滩湿地生态恢复的重要意义和必要性,在分析了南京长江新济洲群湿地退化现状及其驱动因素的基础上,对其保护和恢复规划设计进行了探讨,希望为长江中下游洲滩湿地的保护和生态恢复提供思路和借鉴。  相似文献   

10.
多环芳烃(polycyclic aromatic hydrocarbons,PAHs)作为典型的持久性有机污染物,广泛存在于环境中。河口湿地的沉积物能吸收和累积环境中的多环芳烃,研究沉积物中多环芳烃的含量、污染水平和来源,对开展河口海岸区保护、环境管理和污染物控制具有重要意义。在福州市闽江河口的塔礁洲、道庆洲、蝙蝠洲和鳝鱼滩布设了23个采样点,于2020年10月18日至20日,采集了表层(0~5 cm深度)沉积物样品,测定了16种多环芳烃类化合物的含量,分析了表层沉积物中多环芳烃的来源、污染水平和生态风险。研究结果表明,闽江河口塔礁洲、道庆洲、蝙蝠洲和鳝鱼滩表层沉积物中多环芳烃总含量的范围为15.85~381.52 ng/g,塔礁洲和道庆洲表层沉积物中多环芳烃的含量明显大于蝙蝠洲和鳝鱼滩;塔礁洲、道庆洲、蝙蝠洲和鳝鱼滩表层沉积物中的多环芳烃以高环数多环芳烃为主,其主要来源于周围工业废水排放、化石燃料燃烧、交通工具尾气排放、农业生物质燃烧,船舶运输过程中的石油泄漏和燃料不完全燃烧是表层沉积物中少量低环数多环芳烃的主要来源;道庆洲表层沉积物被多环芳烃轻微污染;塔礁洲、道庆洲、蝙蝠洲和鳝鱼滩表层沉积物中5种多环芳烃类化合物的含量对周围环境有中等生态风险。  相似文献   

11.
洞庭湖区的泥沙淤积效应   总被引:7,自引:0,他引:7  
以1951-2005 年长系列实测泥沙等资料为依据, 从泥沙淤积特性与资源环境之间的关系上, 探讨了洞庭湖区的泥沙淤积效应。研究表明: 由于洞庭湖区始终处于淤积状态, 加之人类活动影响, 导致了泥沙淤积循环演进的格局, 以至于使泥沙的灾害性效应与资源性效应 均在湖区得到充分的显示。主要表现在: ① 塑造了水体滩地、泥沙滩地、湖草滩地、芦苇滩地等类型滩地, 构成了湖泊巨系统的主体; ② 孕育或诱发了泥沙淤积→洲滩扩展、围垦→调洪功能下降、鱼类资源枯竭、生物多样性减少灾害链: 泥沙淤积→洲滩扩展→洪涝、水质污染; 泥沙淤积→植被洲滩浮涨→血吸虫病、害鼠致害灾害链; 泥沙淤积→洪溃决堤→土地沙 化灾害链。这些淤积型泥沙灾害链给湖区直接或间接地造成巨大的经济损失。③ 近55 年间, 泥沙塑造土地约98.13×108hm2, 人类合理开发利用洲滩资源获得了巨大的经济效益, 就地挖沙加高防洪大堤2~3 m, 累积土石方约55×108 m3, 节省了购买大量原材料的开支。  相似文献   

12.
According to a long series of measured sediment data, the sedimentation effects of the Dongting Lake Area (DLA) were studied in light of the relationship between sedimentation characteristics and resources and environment. The result shows that the long-term deposition and the impact of human activities have led to a cycle of the evolution of sedimentation pattern, resulting in sediment disaster effects and resources effects in the DLA. The main features are as follows: 1) The water beach, silt beach, lake marsh beach, reed beach and other types of beach shaped by sedimentation effects constitute the main body of the giant lake system. 2) The disaster chains are induced, i.e., sedimentation → marshland expansion and reclamation → flood function decline, fish resource depletion, biodiversity reduction disaster chain, sedimentation → marshland expansion → floods, water pollution disaster chain, sedimentation → marshland floating vegetation rising → schistosomiasis, rodents virulence disaster chain, sedimentation → flood embankment bursting → land desertification disaster chain. 3) Sedimentation has created about 98.13×104 hm2 of land in the past 55 years. Rational development and utilization of marshland resources have produced tremendous economic benefits.  相似文献   

13.
洞庭湖区的泥沙淤积效应   总被引:4,自引:1,他引:3  
According to a long series of measured sediment data, the sedimentation effects of the Dongting Lake Area (DLA) were studied in light of the relationship between sedimentation characteristics and resources and environment. The result shows that the long-term deposi- tion and the impact of human activities have led to a cycle of the evolution of sedimentation pattern, resulting in sediment disaster effects and resources effects in the DLA. The main features are as follows: 1) The water beach, silt beach, lake marsh beach, reed beach and other types of beach shaped by sedimentation effects constitute the main body of the giant lake system. 2) The disaster chains are induced, i.e., sedimentation → marshland expansion and reclamation → flood function decline, fish resource depletion, biodiversity reduction dis- aster chain, sedimentation → marshland expansion → floods, water pollution disaster chain, sedimentation → marshland floating vegetation rising → schistosomiasis, rodents virulence disaster chain, sedimentation → flood embankment bursting → land desertification disaster chain. 3) Sedimentation has created about 98.13×104hm2 of land in the past 55 years. Ra-tional development and utilization of marshland resources have produced tremendous eco- nomic benefits.  相似文献   

14.
利用增强型植被指数(enhanced vegetation index,EVI),采用Mann-Kendall方法和Sen’s斜率估计方法,研究2000~2014年洞庭湖区的植物面积及其变化趋势,以及其与水位之间的关系。研究结果表明,枯水年洞庭湖区的植物面积最大,平水年的次之,丰水年的最小;2000~2014年期间,洞庭湖区增强型植被指数的变化存在空间异质性,东洞庭湖区的大部分区域的增强型植被指数无显著变化,南洞庭湖区的大部分区域的增强型植被指数显著增大;洞庭湖区18.08%的区域的增强型植被指数显著增大,这些区域主要集中在高滩地(平均海拔为26.61 m);7.51%的区域的增强型植被指数显著减小,这些区域主要集中在低滩地(平均海拔为25.79 m);随着湖泊水位的上升,洞庭湖区植物面积在减少,当洞庭湖水位为24 m时,最适合植物生长,当洞庭湖水位低于24 m时,洞庭湖区的植物面积受水位变化的影响较小。  相似文献   

15.
The Dongting Lake is located in the south beach of the middle reaches of the Yangtze River. Its catchment, with an area of 262,823 km2 or about 12% of the total Yangtze River catchment, is situated between 28o43?29o32扤 and 112o54?113o8扙, and crosses Hubei and Hunan provinces in administrative division. The main tributaries include Xiangjiang, Zishui, Yuanjiang, Lishui rivers (4 Tributaries) and some local rivers, such as Miluo River, Xinqiang River and other little streams. In the nor…  相似文献   

16.
The sediments of the Dongting Lake come from four channels (one of them was closed in 1959), connected with the Yangtze River, four tributaries (Lishui, Yuanjiang, Zishui and Xiangjiang) and local area, and some of them are transported into the Yangtze River in Chenglingji, which is located at the exit of the Dongting Lake, some of them deposit into drainage system in the lake region and the rest deposit into the lake. The annual mean sediment is 166,555x104 t, of which 80% come from the four channels, 18% from the four tributaries and 2% from local area, whereas 26% of the total sediments are transported into the Yangtze River and 74% deposited into the lake and the lake drainage system. Based on topographic maps of 1974, 1988 and 1998, and the spatial analysis method with geographic information system (GIS), changes in sediment deposition and erosion are studied in this paper. By overlay analysis of 1974 and 1988, 1988 and 1998, erosion and sediments deposition areas are defined. The main conclusions are: (1) sediment rate in the lake is larger than erosion rate from 1974 to 1998. The mean deposition in the lake is 0.43 m; (2) annual sediment deposition is the same between 1974-1988 and 1988-1998, but the annual volume of deposition and erosion of 1988-1998 is bigger than that in 1974-1988; (3) before the completion of the Three Gorges Reservoir, there will be 7.82x108 m3 of sediments deposited in the lake, which would make the lake silted up by 0.33 m; (4) in the lake, the deposition area is found in the north of the east Dongting Lake, the south-west of the south Dongting Lake, and the east of the west Dongting Lake; while the eroded area is in the south of the east Dongting Lake, the middle of the south Dongting Lake, the west of the west Dongting Lake, as well as Xiangjiang and Lishui river flood channels.  相似文献   

17.
Based on the measured hydrological data from 1951 to 2008, the chain hydrological effect between Jingjiang River and Dongting Lake is analyzed by comparative method after the Three Gorges Project operation. The result indicates that 1) the scouring amount in Jingjiang River made up 78.9% of the total from Yichang to Chenglingji, and its average scouring intensity was higher than the latter; 2) the water and sand diversion rates at the three outlets of the Jingjiang River were reduced by 2.33% and 2.78% separately; 3) the proportion of multi-year average runoff and sediment through the three outlets in the total into the Dongting Lake decreased by 7.7% and 24.4% respectively; 4) in Dongting Lake, the speed of sediment accumulation was lowered by 26.7%, in flood season, the runoff amount was 20.2% less than the multi-year average value, leading to seasonal scarcity of water year by year. The former prolonged the lake life, while the latter induced droughts in summer and fall in successive years, shortage of drinking and industrial water, shipping insecurity, as well as ecological problems such as decrease of birds and quick increase of Microtus fortis; 5) The multi-year average values of sediment and flood transporting capacity at the lake outlet were respectively increased by 26.6% and 3.7%, the embankments were protected effectively. Then, to adapt to the new change of the river-lake relation, some suggestions were put forward, such as optimizing further operation program of the Three Gorges Reservoir, reexamining the idea of river and lake regulation, and maintaining connection of the river and the lake.  相似文献   

18.
洞庭湖年径流泥沙的演变特征及其动因   总被引:18,自引:2,他引:16  
通过对洞庭湖1951~1998年径流泥沙演变过程及其驱动力的全面分析表明, 径流泥沙关系密切, 其相关系数r = 0.9013。年径流量、年输沙量总体均呈同步减少趋势, 在演变过程中表现出明显的阶段性。由于湘、资、沅、澧四水流域产水量大, 森林覆盖率达52%以上, 连年兴建的水利工程及工农业、生活用水量的增加, 未能对四水河流水文特征产生根本性的影响, 其入湖径流泥沙基本处于稳定状态, 故没有对湖泊径流泥沙的演变造成深刻影响。而由长江中游河段的调弦口堵口, 下荆江系统裁弯和葛洲坝截流所引起的3次江湖水沙关系调整, 即是导致洞庭湖径流泥沙缓减速减的主动因子。  相似文献   

19.
Based on the measured hydrological data from 1951 to 2008, the chain hydrological effect between Jingjiang River and Dongting Lake is analyzed by comparative method after the Three Gorges Project operation. The result indicates that 1) the scouring amount in Jingjiang River made up 78.9% of the total from Yichang to Chenglingji, and its average scouring intensity was higher than the latter; 2) the water and sand diversion rates at the three outlets of the Jingjiang River were reduced by 2.33% and 2.78% separately; 3) the proportion of multi-year average runoff and sediment through the three outlets in the total into the Dongting Lake decreased by 7.7% and 24.4% respectively; 4) in Dongting Lake, the speed of sediment accumulation was lowered by 26.7%, in flood season, the runoff amount was 20.2% less than the multi-year average value, leading to seasonal scarcity of water year by year. The former prolonged the lake life, while the latter induced droughts in summer and fall in successive years, shortage of drinking and industrial water, shipping insecurity, as well as ecological problems such as decrease of birds and quick increase of Microtus fortis; 5) The multi-year average values of sediment and flood transporting capacity at the lake outlet were respectively increased by 26.6% and 3.7%, the embankments were protected effectively. Then, to adapt to the new change of the river-lake relation, some suggestions were put forward, such as optimizing further operation program of the Three Gorges Reservoir, reexamining the idea of river and lake regulation, and maintaining connection of the river and the lake.  相似文献   

20.
Based on the measured hydrological data from 1951 to 2008,the chain hydrological effect between Jingjiang River and Dongting Lake is analyzed by comparative method after the Three Gorges Project operation.The result indicates that 1) the scouring amount in Jingjiang River made up 78.9% of the total from Yichang to Chenglingji,and its average scouring intensity was higher than the latter;2) the water and sand diversion rates at the three outlets of the Jingjiang River were reduced by 2.33% and 2.78% separately;3) the proportion of multi-year average runoff and sediment through the three outlets in the total into the Dongting Lake decreased by 7.7% and 24.4% respectively;4) in Dongting Lake,the speed of sediment accumulation was lowered by 26.7%,in flood season,the runoff amount was 20.2% less than the multi-year average value,leading to seasonal scarcity of water year by year.The former prolonged the lake life,while the latter induced droughts in summer and fall in successive years,shortage of drinking and industrial water,shipping insecurity,as well as ecological problems such as decrease of birds and quick increase of Microtus fortis;5) The multi-year average values of sediment and flood transporting capacity at the lake outlet were respectively increased by 26.6% and 3.7%,the embankments were protected effectively.Then,to adapt to the new change of the river-lake relation,some suggestions were put forward,such as optimizing further operation program of the Three Gorges Reservoir,reexamining the idea of river and lake regulation,and maintaining connection of the river and the lake.  相似文献   

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