黄河玛曲砾质网状河段河间湿地形态特征及发育程度（英文）

Both interchannel wetlands and multi-channels are crucial geomorphologic units in an anastomosing river system. Planform characteristics and development of interchannel wetlands and multi-channels control the characteristics of anastomosing rivers. To understand the role that interchannel wetlands play in the development of anastomosing rivers, a study was conducted on the Maqu Reach of the Upper Yellow River(MRUYR), a gravel-bed anastomosing river characterized by highly developed interchannel wetlands and anabranches. Geomorphologic units in the studied reach were extracted from high resolution satellite imagery in Google Earth. The size distributions of interchannel wetlands and interchannel wetland clusters(IWCs), a special combination of interchannel wetlands and anabranches, were investigated. Geomorphologic parameters, including the ratio of interchannel wetland area to IWC area(P), shoreline density(D_l), and node density(D_n) were used to analyze planform characteristics of IWCs and the development of multi-channels in the studied reach. The results suggest that small or middle sized interchannel wetlands and large or mega sized IWCs are more common at the study site. The area of IWC(S_u) is highly correlated with other geomorphologic parameters. P increases with increasing S_u, and the upper limit is about 80%, which indicates that the development of interchannel wetlands and anabranches in the IWC is in the equilibrium stage. In contrast, D_l and D_n show a tendency to decrease with increasing S u due to diverse evolution processes in IWCs with different sizes. There are three main reasons leading to the formation of IWCs: varying stream power due to the meandering principal channel; development of the river corridor due to the weakening of geologic structure control; and high stability of interchannel wetlands due to conservation by shoreline vegetation.     

黄河玛曲砾质网状河段河间湿地形态特征及发育程度

河间湿地是网状河流体系中与多河道系统同等重要的地貌单元,其特征和发育程度与河道系统共同决定着网状河流的特性。本文以黄河玛曲网状河段作为研究对象,利用高分辨率Google Earth影像对研究河段河道与河间湿地等微地貌单元进行提取,利用湿地面积与湿地数对河间湿地的组成进行了分析,利用河间湿地面积占比、岸线密度、分汊点密度3个地貌参数,对河间湿地群体（河间湿地与分支河道特定组合体）的平面形态及多河道发育程度进行了研究。结果表明,河间湿地个体以中小型的为主,河间湿地群体则以大型和巨型的为主。河间湿地群体的发育程度与河间湿地群体面积（S_u）明显相关,河间湿地面积占比（P）随S_u的增大而增大,P值70%是河间湿地发育成熟的指标,而P值80%基本是河间湿地发育的上限值,此时河间湿地与分支河道基本达到动态平衡态。岸线密度、分汊点密度随S_u的增加呈减小趋势,这种变化主要是由于不同大小河间湿地群体中河道发育过程差异导致。黄河玛曲段河间湿地群体的形成在于弯曲主河道的主导作用、地形限制因素削弱导致的河道带的发育,以及植被维护的河岸使得河间湿地群体得以较长时间保存。     

1990年以来黄河第一湾齐哈玛河段砾质网状河的演变特征

黄河第一湾的网状河型因其砾石质的河床质而与砂床质网状河明显不同,但是其具体的冲淤特性、河道与河间地的稳定性等是否与砂质网状河具有相似之处,尚待揭示。以齐哈玛乡主河道长约为12 km的砾石质网状河段为研究对象,利用1990年、2001年、2013年和2016年共4期Landsat遥感影像数据和2011年与2013年两期Google Earth高分辨率图像数据,结合野外采样观测分析其1990-2016年间的平面形态变化与沉积特征。结果表明：砾石质网状河整体具有很高的稳定性,众多分支河道与河间地无明显冲淤现象。网状带面积仅增加2.43%,陆地与水体面积比例接近1∶1;网状带部分小型河间湿地及河间岛屿呈现碎片化现象,导致河间湿地个数逐渐增加,最大增加率为62.16%。河道主流线长期左右迁移交替变化,且变化率相对稳定,受主流线迁移的影响,主河道内部河间岛屿形态变化较大,其河岸变化率为5 m/a。网状河众多支河道非常稳定,平均河宽变化率仅为1 m/a左右。河岸沉积物以细砂或粉砂为主,黏土含量较高,粒度分布曲线呈现多峰,这与砂质网状河流河岸以泥质沉积物为主略有不同,但河岸及河间湿地茂密的植被保护了众多分支河道免受侵蚀、维持了河道的稳定性,这也是砾石质网状河流体系具有高稳定性的重要原因。     

赣江入湖三角洲上的网状河流体系研究

中国南方的冲积河流有许多属于分汊河流，这已被许多研究者进行过比较深入的分析研究，但赣江在其入湖三角洲上的多河道体系与分汊河道有着明显的不同，它的形成是河流自发调整的结果，而不象分汊河流那样由节点控制。它具有网状河流所具有的地貌和沉积物特征，属于典型的网状河流体系。虽然是低含沙河流，但由于其水动力较弱及汛期基准面的上升，洪泛频繁，可输入河间地以大量的泥沙并在低能环境中发生沉积，使河道及河间地能够协调加积升高，并维持多河道体系的稳定性。     

网状河流体系的基本特征及其影响因素

网状河流近年来受到较多关注,无论从沉积特征还是从地貌及水力学特征看,网状河流都是一种典型的河型,但目前对网状河流的认识还存在一定的局限性,从沉积特征,地貌及沉积微环境特征及形成条件等方面的对网状河流进行了系统的论述和总结。     

Influences of channelization on discharge of suspended sediment and wetland vegetation in Kushiro Marsh, northern Japan

The effects of wetlands on hydrology, water quality, and wildlife habitat are internationally recognized. Protecting the remaining wetlands is one of the most important environmental issues in many countries. However wetlands in Japan have been gradually shrinking due to agricultural development and urbanization, which generally lowers the groundwater level and introduces suspended sediment and sediment-associated nutrients into wetlands. We examined the influences of channelization on discharge of suspended sediment and wetland vegetation in Hokkaido, northern Japan. The impact of river channelization was confirmed not only by the sediment budgets but also by river aggradation or degradation after the channelization and by the resultant vegetational changes. The budgets of suspended sediment demonstrated that wash load was the predominant component accounting for 95% of the total suspended load delivered into the wetland. This suspended sediment was primarily transported into the wetland by flooding associated with heavy rainfall. Twenty-three percent of the wash load and 63% of the suspended bed material load were deposited in the channelized reach, which produced aggradation of about 2 m at the end of the reach. A shorting of the length of the channel, due to channelization of a meandering river, steepened the slope and enhanced the stream power to transport sediment. This steepening shifted the depositional zones of fine sediment 5 km downstream and aggraded the riverbed. Development of the watershed may increase not only the water discharge but also the amount of suspended sediments. The aggradation reduced the carrying capacity of the channel and caused sediment ladened water to flood over the wetlands. The fine sediment accumulated on the wetlands gradually altered the edaphic conditions and wetland vegetation. A low percentage (10 to 15%) of organic contents of wetlands' soil is more evidence indicating that the present condition is far different from normal. Original vegetation such as sedges and Alnus japonica were disappearing from the adjacent areas of the river channel and were being replaced by willow trees (Salix spp.).     

Alpine wetlands in the Lhasa River Basin, China

The Lhasa River Basin is one of the typical distribution regions of alpine wetlands on the Tibetan Plateau. It is very important to get a better understanding of the background and characteristics of alpine wetland for monitoring, protection and utilization. Wetland construction and distribution in the basin were analyzed based on multi-source data including field investigation data, CBERS remote sensing data and other thematic data provided by 3S technology. The results are (1) the total area of wetlands is 209,322.26 hm2, accounting for 6.37% of the total land area of the basin. The wetlands are mainly dominated by natural wetland, with artificial wetland occupying only 1.09% of the wetland area; marsh wetland is the principal part of natural wetland, dominated by Kobresia littledalei swampy meadow which is distributed in the river source area and upstream of Chali, Damshung and Medro Gongkar counties. The ratio and type of wetlands in different counties differ significantly, which are widely distributed in Chali and Damshung counties (accounting for 62% of the total wetland area). (2) The concentrated vertical distribution of wetlands is at an elevation of 3600–5100 m. The wetlands are widely distributed throughout the Yarlung Zangbo River Valley from river source to river mouth into the Yarlung Zangbo River. Marsh wetland is dominant in the source area and upstream of the river, with the mosaic distribution of lakes, Kobresia littledalei and Carex moorcroftii swampy meadow, shrubby swamp and river; as for the middle-down streams, the primary types are river wetland and flooded wetland. The distribution is in a mosaic pattern of river, Kobresia humilis and Carex moorcroftii swampy meadow, Phragmites australis and subordinate grass marsh, flooded wetland and artificial wetland.     

吉林省西部湿地形成的地质条件

吉林省西部湿地是松辽盆地内的典型湿地,该湿地的形成受多种要素的综合控制,其中,地质条件起到了决定性的作用.控制吉林省西部湿地形成的地质条件主要包括第四纪地层、沉积物组合和新构造运动.吉林省西部湿地形成的地质时代为晚更新世至早全新世.按吉林省西部湿地形成的地质条件,将其划分为遗留型湿地、河流型湿地和风成型湿地3种地质成因湿地类型.其中,遗留型湿地是原有湖泊逐渐衰退后残留的结果,河流型湿地是在晚更新世构造活动和特殊的沉积物组合以及河流改道综合作用的结果,风成型湿地是风蚀洼地切割潜水面的结果.     

Reconstruction of anastomosing river course by means of geophysical and remote sensing surveys (the Middle Obra Valley,western Poland)

Intensive hydro technical works were conducted in the middle course of the Obra River (Poland) at the beginning of the nineteenth century. The ‘natural’ river course (functioning before the major construction works) was transformed into three artificial canals. Ground‐penetrating radar investigations, ground‐truthed with coring and remote sensing surveys, were conducted to reconstruct the course taken by the river prior to the hydro technical works. This work demonstrated that the Obra formerly had an anastomosing planform. Radiocarbon dating indicated that the earliest of the retraced channels were active before 9000 bp . The retraced river system was formed in a proglacial stream valley perpendicularly cut by remains of subglacial tunnels, now partly filled with lakes. The planform consisted of one or two major channels and a number of secondary channels formed by avulsions. During the last 2000 years, some of the avulsions may have been caused by anthropogenic interventions. The sequences of channel fill deposits indicate that particular channels changed from major to secondary ones. Sand deposits filling the bottom and middle parts of the channels point to an important role of upstream sediment supply causing in‐channel aggradation triggering the avulsions. Moreover, spatial variability in river patterns was found within the anastomosing system. Valley sections with meandering anabranches, anastomosing patterns with traces of a lateral migration and traces of a transition from meandering to anastomosing planform were distinguished.     

云南省宁蒗县湿地资源现状与保护管理对策

利用3S技术与实地调查相结合的方法 ,查清了云南省宁蒗县的湿地资源现状。该县共有河流湿地、湖泊湿地、沼泽湿地、人工湿地4个湿地类,8个湿地型。针对湿地管理中存在的问题,提出完善管理机构、强化执法力度等对策。     

新疆伊犁河流域湿地保护与管理

伊犁河流域是新疆境内独特的湿岛,是我国17个优先保护的生物多样性关键地区之一。由于水土资源的大规模开发、工业化和城镇化进程的加速,伊犁河流域湿地受到了严重破坏。分析了伊犁湿地保护面临的主要问题,提出了伊犁河湿地资源保护、开发和合理利用的可持续发展对策。     

深圳市湿地的保护与修复研究

湿地对维持社会经济的可持续发展起着重要作用.随着深圳经济的快速发展,湿地面积不断减少,功能退化,削弱了湿地的生态效益和社会效益.深圳市湿地类型有3大类(近海及海岸湿地、河流湿地和湖泊湿地)13种类型,占深圳国土总面积的8.12%。深圳湿地目前面临的主要威胁是:滨海滩涂湿地面积不断减小,生境面临退化;红树林和湿地水草的生存受到威胁;河流水质不断恶化,河流底质污染程度持续加剧。针对深圳湿地存在的主要问题,提出了相应的保护与恢复对策:保护好西部滨海滩涂湿地;控制污染,修复河流自然湿地;加强自然保护区的建设和管理;加强湿地公园的建设和管理;加强湿地监测和科学研究,积极开展国际合作与交流。     

气候变化对中国滨海湿地的影响及对策

我国滨海湿地面临着持续退化和损失的风险,其中气候变化通过海平面上升、海水表层温度上升、风暴潮、海水入侵和海岸带侵袭,以及海洋酸碱度变化等一系列影响,导致了沿海湿地的退化与消失,制约了沿海地区的可持续发展。在总结中国湿地退化现状的基础上,分析了气候变化对中国湿地的影响,并从自发性适应和计划性适应两个方面探讨了潜在的滨海湿地气候变化适应性对策。认为将来可进一步加强对滨海湿地气候变化影响与响应机制的监测和研究,为制定相关政策和培养相关管理人员提供依据。     

生命之源 生存之本——北京市海淀区翠湖国家城市湿地公园建设刍议

北京市海淀区广泛分布着各种湿地,湿地具有为城市提供独特的防洪排涝体系、水源涵养和供给等功能,湿地恢复和建设具有重要的价值和意义。翠湖是海淀区较为重要和珍贵的湿地资源。进入21世纪以后,海淀区对翠湖湿地进行了大力建设,并取得了显著成效。翠湖湿地建设和发展应坚持重在保护、最小干预;坚持生态优先,强化生态保护功能;突出水乡特色,挖掘历史文化内涵等原则。     

江苏长江流域湿地现状及保护管理

依据2009年全省湿地资源调查成果,从湿地类型、面积、分布、动植物资源等方面分析了江苏长江流域湿地资源现状与基本特征,探讨了江苏长江流域湿地资源保护与管理工作的成就和存在的问题,并建议通过加快湿地保护法律法规建设、推进江苏长江流域湿地保护与管理规划编制,加强流域湿地保护体系建设等措施,遏制流域内湿地整体生态质量退化、生态功能下降的趋势,实现江苏长江流域湿地的保护与可持续发展。     

生态文明背景下广州市湿地经济发展研究

发展广州市湿地经济对改善当地民生、推进生态文明建设具有重要作用。广州市具有丰富的湿地资源,包括湿地水资源、湿地动植物资源和湿地旅游资源。目前广州市湿地经济发展模式主要为水产养殖模式、农业耕种模式、供水蓄能模式和生态旅游模式,但在发展过程中存在过度围垦、河流破坏、过度捕捞和盲目养殖、生态旅游开发不成熟等问题。针对存在的问题,提出以生态优先为原则、以统一规划为前提、以复合农业为重点、以生态旅游为特色的湿地经济发展建议。     

吴中区湿地资源现状调查和保护对策

调查了吴中区面积在8hm2以上的湖泊湿地、沼泽湿地、人工湿地以及宽度10m以上、长度5km以上的河流湿地,结果表明:吴中区共有湿地113个斑块,面积180459.69hm2,占吴中行政区划面积的82.95%。湿地水生植物95种,隶属37科60属;鱼类100多种,隶属12目23科;留居、旅经或在该地进行繁殖的鸟类至少170种,隶属16目;两栖动物9种,隶属3科7属;爬行动物24种。通过实施湿地保护立法、开展湿地生态补偿、建立湿地保护区、湿地定位站和退垦还湖、退渔还湿工程对吴中区湿地进行全面保护,以期发挥其更大的生态效益和经济效益。     

人类土地利用干扰对黑河中游湿地时空变化的影响

干旱区湿地是典型的脆弱生态系统,湿地景观格局变化与人类的干扰活动密切相关。在RS和GIS技术支持下,基于1975-2016年长时间序列遥感影像,利用景观开发强度指数（LDI）和土地利用转移矩阵模型等分析方法,定量评估了人类土地利用干扰对黑河中游湿地时空变化的影响。结果表明：研究区湿地面积总体呈现下降趋势,但人工湿地总体呈增加趋势;湿地景观的异质性、破碎化程度增强,湿地斑块之间的聚集度下降;总体上研究区各类湿地的LDI指数呈上升趋势,湿地的人为干扰程度增强,2001年后湖泊湿地的人为干扰程度最强。在人为干扰下湿地多转化为林地、草地、居工矿用地及耕地。人为干扰对湿地的影响因湿地类型而异。因此,科学评价不同类型湿地的人为干扰状况,对不同类型湿地制定相应的保护策略具有重要意义。     

1993～2003年厦门市湿地动态变化及其驱动因素分析

通过对厦门市1993年TM遥感影像和2003年ETM 遥感影像的解译分析和数据统计,从湿地面积动态变化和湿地消长情况等方面,用单一土地利用动态度等指标对1993~2003年期间厦门市的湿地变化进行了研究。结果表明,1993~2003年期间厦门市天然湿地面积减少了2103hm2,其中有954hm2(滩涂864hm2)转变为非湿地,有1149hm2转变为人工湿地;而人工湿地面积增加了2775hm2,其中养殖场面积从1993年的5778hm2迅猛增加到2003年的9768hm2,年均增长率为6.91%,水库与水塘和盐田则分别减少了961hm2和254hm2。有27.74%、11.41%、9.33%和3.63%的养殖场面积分别是由非湿地、滩涂、盐田和水库与水塘转变而来的;有54.37%的盐田转变成了养殖场,有33.24%、30.24%的红树林转变为非湿地、养殖场,有10.35%、8.64%的滩涂转变为养殖场、非湿地。对社会经济驱动因素的分析表明,经济发展、人口增长和农业生产比较利益因素极大影响着厦门市湿地的动态变化。     

渭河下游河流输沙需水量计算

基于对河流输沙运动特性的分析,认为最小河流输沙需水量是当河流输沙基本上处于冲淤平衡状态时输送单位重量的泥沙所需要的水的体积,通过河段进口即上游断面水流挟沙力 (S_u^*) 与含沙量 (S_u) 比较,分S_u ≤ S_u^*和S_u > S_u^*两种情况,分别建立了最小河段输沙需水量的计算方法。并应用该方法对渭河下游输沙需水量做了计算。计算的空间尺度为渭河下游的咸阳、临潼、华县三个断面,时间尺度为四个代表年的年内月均需水量,分p = 25% (1963年)、p = 50% (1990年)、p = 75% (1982年)、p = 90% (1979年)。计算结果分析表明：渭河各断面汛期月均输沙需水量大于非汛期月均输沙需水量。相较而言,在不同代表年的汛期和非汛期,从咸阳断面至华县断面输沙需水量在增加。在丰水年 (p = 25%),渭河下游咸阳、临潼、华县等3个断面年输沙需水量分别为63.67亿m³、97.95亿m³和103.25亿m³;在平水年 (p = 50%),渭河下游咸阳、临潼、华县等3个断面年输沙需水量分别为49.71亿m³、83.27亿m³和85.08亿m³;在枯水年 (p = 75%),渭河下游咸阳、临潼、华县等3个断面年输沙需水量分别为30.17亿m³、55.14亿m³和65.32亿m³;在特枯水年 (p = 90%),渭河下游咸阳、临潼、华县等3个断面年输沙需水量分别为23.96亿m³、37.91亿m³和38.92亿m³。由丰水年到枯水年,渭河下游各断面年输沙需水量变小。