典型沙洲形态与河道的关系

沙洲是冲积河道泥沙长期淤积的产物,河道既为沙洲提供发育空间又约束沙洲自由发展.以沙洲的卫星图片为依据,选取长江、汉江、西江、湘江、黑龙江、密西西比河及额尔齐斯河的653个单个沙洲及所在河道作为统计对象,初步划分了3种典型沙洲形态:椭圆形、竹叶形和镰刀形,并统计分析了3种沙洲自身形态及其与河道的关系.研究表明,椭圆形沙洲分布最为广泛数量最多,其次是竹叶形和镰刀形沙洲.竹叶形沙洲的周长和面积一般较大,镰刀形居中,椭圆形较小.沙洲面积与周长,沙洲面积与河宽都呈幂函数关系.沙洲洲面中点的宽度与河宽相关性好,相关系数依次是,镰刀形＞竹叶形＞椭圆形;沙洲周长与河宽相关性较好,相关系数依次是镰刀形＞竹叶形＞椭圆形.沙洲将河道分成主汊和支汊,3种典型沙洲的河道分汊比均保持在0.09至0.97之间.     

Reconstruction of the characteristics of a natural alluvial river–floodplain system and hydromorphological changes following human modifications: the Danube River (1812–1991)

Based on detailed historical surveys from 1812, the natural riverine landscape of a 10.25‐km‐long reach of the Danube River in the Austrian Machland region prior to channelization is analysed. Anthropogenically induced changes of fluvial dynamics, hydrological connectivity and aquatic habitat composition are discussed, comparing the situations following channelization (1925) and flow regulation (1991). In 1812 the alluvial river–floodplain system of the Danube River comprised a highly complex channel network, numerous gravel bars and extensive islands, with the main channel and side arms (eupotamon) representing about 97% of the entire water surface at low flow. The floodplain was characterized by relatively flat terrain and numerous natural trenches (former active channels) connected to the main channel. These hydromorphological conditions led to marked expansion/contraction of the water surface area at water level fluctuations below bankfull (‘flow pulse’). The high degree of hydrological connectivity enabled intensive exchange processes and favoured migrations of aquatic organisms between the river and floodplain habitats over a period of approximately 90 days per year. Overall in 1812, 57% of the active zone (active channels and floodplain) was inundated at bankfull water level. Channelization and construction of hydropower plants resulted in a truncated fluvial system. Consequently, eupotamal water bodies decreased by 65%, and gravel/sand bars and vegetated islands decreased by 94% and 97%, respectively, whereas the area of the various backwaters doubled. In 1991 the former ‘flow pulse’ was halved due to artificial levees and embankments, greatly diminishing hydrological connectivity and decoupling large areas of the floodplain from the main channel. Active overflow, formerly playing an important role, is now replaced by backwater flooding and seepage inflow in isolated water bodies. Copyright © 2003 John Wiley & Sons, Ltd.     

黑河流域水循环系统的分布式模拟(Ⅰ)——模型开发与验证

从水循环的物理机制着手，在考虑人工侧支循环的基础上，以现代地理信息技术为数据处理平台，开发了黑河流域水循环系统的分布式模拟模型。文中系统描述了模型结构，从水循环过程和能量循环过程2个方面对模型各要素的过程模拟进行了阐述，其中水循环过程包括蒸发蒸腾、入渗与径流、地下水运动、地下水流出和地下水溢出、坡面汇流与河道汇流、人工侧支循环等要素过程。在获取各类输入参数后，采用1km网格、以日为时间步长对黑河流域上、中游地区(36 728个网格单元)进行了1981～2002年的逐日模拟。结果表明，所建立的分布式模型对月径流过程和日平均流量过程具有较高模拟精度。校正期内前后两个验证期均得到良好验证。该模型可用于预测未来环境变化条件下流域水资源演变。     

分布式水文模型EasyDHM在玛纳斯河流域径流模拟中的应用

玛纳斯河流域作为新疆干旱区典型的内陆河流域,其年径流量主要来源于高山区融雪径流。掌握该流域的径流变化规律,对探讨该地区气候、水文及水资源、生态环境之间的联系以及预测未来山区径流的变化规律具有重要意义。以玛纳斯河流域作为研究对象,基于分布式水文模型EasyDHM(Easy Distributed Hydrological Model),利用DEM、实测河网、土壤、土地利用及水文气象数据构建玛纳斯河流域分布式水文模型研究该流域径流过程。通过模型参数率定及验证发现,该模型精度较高,验证期内各站点纳什效率系数均在0.75以上,说明EasyDHM分布式水文模型的泛化能力较好,可应用于该流域的水雨情势分析,为预防和减轻春季融雪型洪水灾害提供了理论依据。     

中国冲积大河的河型分布与成因

结合遥感影像、野外调查和水沙数据,以冲积大河为研究对象,分析中国大河的河型分布及成因。中国大河的冲积河段以弯曲与辫状河型为主,局部河段为分汊与网状河型。综合考虑河型分布的一般性和特殊性,认为相对输沙率(来沙量与输沙能力之比)、相对河岸侵蚀切应力(近岸水流切应力与河岸临界抗冲切应力之比)和河谷地形控制(如节点和宽度)是决定河型成因的3个最主要的因素。     

塔里木河下游生态输水量转化分析

塔里木河下游大西海子水库以下河段自1972年至2000年发生的持续断流是绿色走廊生态劣变的主要原因。从2000年5月至2011年11月,塔里木河下游共进行了10次生态输水。本文利用输水期间的地下水监测资料,运用水均衡法对大西海子以下河段历次输水过程中的水量转化进行了计算,量化了河道水量的转化项与塔里木河下游地下水的恢复程度,揭示了塔里木河下游河道径流一补给转化一蒸腾耗散的水文过程,文中结论可为今后进一步优化输水方案、合理配置区域水资源以及植被的有序恢复提供科学依据。     

Fish assemblage patterns across a gradient of flow regulation in an Australian dryland river system

Hydrological regime, physical habitat structure and water chemistry are interacting drivers of fish assemblage structure in floodplain rivers throughout the world. In rivers with altered flow regimes, understanding fish assemblage responses to flow and physico‐chemical conditions is important in setting priorities for environmental flow allocations and other river management strategies. To this end we examined fish assemblage patterns across a simple gradient of flow regulation in the upper Murray–Darling Basin, Australia. We found clear separation of three fish assemblage groups that were spatially differentiated in November 2002, at the end of the winter dry season. Fish assemblage patterns were concordant with differences in water chemistry, but not with the geomorphological attributes of channel and floodplain waterholes. After the summer‐flow period, when all in‐channel river sites received flow, some floodplain sites were lost to drying and one increased in volume, fish assemblages were less clearly differentiated. The fish assemblages of river sites did not increase in richness or abundance in response to channel flow and the associated potential for increased fish recruitment and movement associated with flow connectivity. Instead, the more regulated river's fish assemblages appeared to be under stress, most likely from historical flow regulation. These findings have clear implications for the management of hydrological regimes and the provision of environmental flows in regulated rivers of the upper Murray–Darling Basin. Copyright © 2010 John Wiley & Sons, Ltd.     

Stream temperature dynamics within a New Zealand glacierized river basin

Knowledge of river thermal dynamics for glacierized basins is limited, despite the high sensitivity of these systems to climatic change/variability. This study examined spatio‐temporal water column and streambed temperature dynamics within a New Zealand glacierized river basin over two melt seasons. Water column temperature was recorded at three sites along the mainstem channel and four hillslope/groundwater‐fed tributaries. Air temperature, precipitation and stream discharge were monitored to characterize hydroclimatological conditions. Streambed temperature was monitored at the upper and lower main river sites at 0.05, 0.2 and 0.4 m depth. Water column temperature rose on average 0.6°C km^?1 along the glacier‐fed mainstem. Temperature was elevated during warmer periods but the downstream increase was reduced due to greater meltwater production (consequently a larger total stream flow volume for atmospheric heating) plus a proportional reduction in warmer groundwater contributions. Hillslope/groundwater‐fed tributaries yielded a range of temperature patterns, indicating variable sourcing (meltwater or rainfall) and residence times. In the upper basin, streambed temperature was warmer than the water column, suggesting groundwater upwelling; however, during high runoff events, water column and streambed temperature converged, indicating downwelling/heat advection by channel water. At the lower site, streambed temperature mirrored the water column, suggesting greater surface water/atmospheric influences. Key drivers of stream thermal regime were: (1) relative water source contributions, (2) prevailing hydroclimatological conditions, (3) distance from source, (4) total stream flow volume and (5) basin factors (specifically, valley/channel geomorphology and riparian forest). High magnitude precipitation events produced a contrasting stream thermal response to that reported elsewhere. In contrast to European alpine research, streams showed a reduced thermal range owing to the relatively mild, wet melt season climate. This New Zealand case study highlights the importance of understanding basin‐specific modification of energy and hydrological fluxes for accurate prediction of stream thermal dynamics/habitat and ecological response to climatic variability and change. Copyright © 2007 John Wiley & Sons, Ltd.     

建立在水动力关系基础上桃河阳泉段河道渗漏补给量的计算

阳泉市桃河上游河谷冲洪积层孔隙地下水，以其涌水量大、开采成本低成为当地的重要供水水源。其资源量除受河流径流量的大小影响外，更与河水与地下水的动力关系密切相关，本文根据两者间的水动力关系分为顶托渗漏和自由渗漏两个过程，并根据实测渗漏量计算出含水层参数，进而结合当地的水井工程布置情况，对河流渗漏量进行了计算。     

Urbanisation and Shallow Groundwater: Predicting Changes in Catchment Hydrological Responses

The impact of urbanisation on catchment hydrological response was investigated by using a process-based coupled surface water–groundwater model (MODHMS). The modelling estimated likely changes in river discharge as a result of land-use change in the Southern River catchment in Western Australia, underlined by a highly transmissive aquifer, has permeable soils and a shallow watertable. A significant increase in total annual discharge was predicted as a result of urbanisation area with the runoff coefficient rising from 0.01 to more than 0.40. In contrast with urban areas elsewhere, these changes were mainly due to a shift in the subsurface water balance, leading to significant reduction in evaporative losses from the soil profile and shallow watertable after urbanisation (from nearly 80 % of infiltration to less than 20 %). The infiltration of roof and road runoff and establishment of subsurface drainage adopted in local construction practice leads to higher groundwater recharge rates and subsequently groundwater discharge to the urban drainage network. Urban density and groundwater abstraction for urban irrigation most strongly influence the urbanisation impact on catchment fluxes. The results shows that urban development leads to a production of ‘harvestable’ water; and depending on local needs, this water could be used for public and private water supply or to improve environmental flows.     

我国主要河川径流演变规律与归因及其区域特征

从径流演变规律主要分析方法和主要河川径流演变规律、径流主要归因方法和主要河川径流归因分析、案例分析、我国主要河川径流演变规律与径流归因分析区域分布特征4个方面系统总结和梳理了我国近年来在主要河川径流演变规律与归因及其区域特征研究方面取得的主要研究成果。结果表明: Mann-Kendall非参数趋势检验方法是较为常用的径流演变规律分析方法,水文模型法、统计分析方法和Budyko假设的流域水热耦合平衡方法是进行径流变化归因分析的常用方法,其中Budyko假设的流域水热耦合平衡方法应用较为广泛；我国主要河川径流量除西北诸河和西南河流源区部分河流呈增加趋势外,其他区域河川径流大多呈减少趋势；人类活动是引起我国主要河川径流变化的主要原因。     

Water quality as an indicator of hydrogeological conditions: a case study of the Belgrade Groundwater Source (Sava/Danube confluence area)

The City of Belgrade receives most of its drinking water supply from the alluvial aquifer of the Sava River. The wells are radial, placed in the lower part of the aquifer, so they partly run below the Sava riverbed. However, the groundwater quality of the wells in one part of the source (near the confluence of the Sava and Danube rivers) is found to differ somewhat from the groundwater quality of the other wells. The finding gave rise to additional investigations. The results revealed the existence of a deeper, limestone aquifer which is isolated from upper alluvial sediments by a thick layer of clay in most of the terrain. The naturally potential hydraulic contact of the two aquifers was additionally maintained by well operation in this part of the source. According to multiple analyses of groundwater flow using a hydrodynamic mathematical model, a hydrogeological and hydraulic system of groundwater flow was defined. Although the wells are situated adjacent to the river, and some well laterals are below the riverbed, most of the groundwater that flows to the wells is partly from the wider zone of the alluvial aquifer, and partly from the deeper aquifer. The initial results of hydrochemical investigations also showed an unexpected, inverse oxic character of the groundwater in these two aquifers.     

Management of Alluvial Aquifers in Two Southern African Ephemeral Rivers: Implications for IWRM

This paper summarises innovative research into the assessment of long-term groundwater recharge from flood events in dryland environments of the Kuiseb (Namibia) and the Buffels (South Africa) rivers. The integrated water resource management (IWRM) policies and institutions affecting the exploitation of groundwater resources in each of these developing countries are compared. The relatively large alluvial aquifer of the Kuiseb River (～240 Mm³) is recharged from irregular floods originating in the upper catchment. Reported abstraction of 4.6 Mm³ per year is primarily consumed in the town of Walvis Bay, although the groundwater decay (pumping and natural losses along the period 1983–2005) was estimated in 14.8 Mm³ per year. Recharge is variable, occurring in 11 out of 13 years in the middle Kuiseb River, but only in 11 out of 28 years in the middle-lower reaches. In contrast, the Buffels River has relatively minor alluvial aquifers (～11 Mm³) and recharge sources derive from both lateral subsurface flow and floodwater infiltration, the latter limited to a recharge maximum of 1.3 Mm³ during floods occurring once every four years. Current abstractions to supply the adjacent rural population and a few small-scale, irrigated commercial farms are 0.15 Mm³ yr^???1, well within the long-term sustainable yield estimated to be 0.7 Mm³ yr^???1. Since independence in 1990, Namibia’s water resource management approach has focussed on ephemeral river basin management of which the Kuiseb Basin Management Committee (KBMC) is a model. Here, some water points are managed independently by rural communities through committees while the national bulk water supplier provides for Walvis Bay Municipality from the lower aquifers. This provides a sense of local ownership through local participation between government, NGOs and CBOs (community-based organisations) in the planning and implementation of IWRM. Despite the potential for water resource development in the lower Buffels River, the scope for implementing IWRM is limited not only by the small aquifer size, but also because basin management in South Africa is considered only in the context of perennial rivers. Since 2001, water service delivery in the Buffels River catchment has become the responsibility of two newly created local municipalities. As municipal government gains experience, skills and capacity, its ability to respond to local needs related to water service delivery will be accomplished through local participation in the design and implementation of annual ‘integrated development plans’. These two case studies demonstrate that a variety of IWRM strategies in the drylands of developing countries are appropriate depending on scales of governance, evolving policy frameworks, scales of need and limitations inherent in the hydrological processes of groundwater resources.     

Proposed fluvial island classification scheme and its use for river restoration

Fluvial islands are present in nearly all natural and regulated rivers. They are important from hydrological, biological, geopolitical and socio‐economic points of view. As ubiquitous as islands are, consideration of islands is relatively absent in most river restoration concepts. The natural river processes that allow for island formation can easily be integrated into typical river classifications. To begin, an island classification scheme is proposed that can become a tool for improved river classifications and restoration projects. In developing an island classification scheme, the objectives are similar to those of previous river classification methods. By observing island characteristics, inductive generalizations may be made about the river's hydrologic and ecologic potential. In river hierarchies, the distinguishing variables used to describe streams were characteristics that could easily be discerned from their appearances, i.e. field‐determinable features. A similar approach is sought for island classification. The distinguishing characteristics of any island may be sorted into three basic categories: those that can be measured from a topographic map or an aerial photograph; those that can be measured in situ at the island and those that can be inferred from either a known history of the island or from the other characteristics of the island. Once all the suitable characteristics were identified, a matrix for island classification was created which can be used to classify island origin and type. The better that the inter‐relationship between island formation, channel processes and watershed processes are understood, the better the natural bio‐physical regime of the river corridor can be identified and incorporated into restoration plans. Copyright © 2010 John Wiley & Sons, Ltd.     

河流管理的生态水文目标及其量化分析——以长江中游为例

河流生态目标决定河流管理与保护水平．但生态系统的复杂性导致生态目标难以确定并量化成可以实际调控的变量。由于水流是河流生态系统的主导变量，通过建立一系列指标或指标体系，对与生态有关的水文特征的变化进行分析。量化河流生态水文目标，可以作为实施河流管理的可调控变量，指导河流的管理与生态修复实践。采用这一思想．对受三峡工程影响的长江中游进行了河流生态水文目标的探索，提出了四大家鱼的生态水文目标．并进行量化分析，为三峡生态调度提供参考依据。     

黑河流域水循环系统的分布式模拟(Ⅱ)——模型应用

应用作者开发的分布式水文模型WEP－HeiHe，对黑河上、中游流域水收支和水循环要素的时空变化进行了系统剖析；同时，还将模型应用于莺落峡径流预报、山前小河流径流和地下水侧渗量的模拟与预报以及未来下垫面变化条件下的流域水收支预测。结果表明，模型能系统表征流域水循环和水收支各要素的时空分异；对于枯水期的径流预报，达到较高的精度。在对下垫面变化条件下流域水收支预测中表明，尽管涵养林建设增加了截留蒸发，但同时也降低了林地的土壤蒸发，因此总蒸发量增加不明显；涵养林建设会使出山径流略有减少，但同时会稍增加土壤和地下水的蓄变量；退耕还牧对减少蒸发、增加正义峡下泄水量以及降低蓄变量赤字均有明显效果。     

冲积河道冲刷过程中横向展宽的初步模拟

本文首先描述了冲积河道横向展宽现象，分析了河岸横向冲刷、崩塌的机理及展 宽原因。然后建立细沙河流一维非均匀悬移质泥沙数学模型，同时结合河道横向展宽模式，预测冲积河道冲刷过程中，粘性土组成的河岸的横向展宽过程。此外，还分析了不同来水来沙条件及河岸土体特性对河道横向展宽和河床冲刷的影响，指出了影响冲积河道横向展宽的主要因素。     

VEGETATION–LANDFORM ASSEMBLAGES ALONG SELECTED RIVERS IN THE CZECH REPUBLIC,A DECADE AFTER A 500‐YEAR FLOOD EVENT

Rivers with a natural flow regime strongly influence the dynamics of riparian plant communities through hydrological and geomorphological processes. In this study, associations between fluvial landforms and vegetation are investigated on three near‐natural rivers in the Czech Republic a decade after a 500‐year return period flood in July 1997. This extreme disturbance destroyed the anthropogenically modified river channels and created suitable conditions for a range of ecosystems with high diversity and ecological stability. Field surveys were conducted on fluvial landforms (bars, islands, banks, floodplains and terraces) along three ‘renaturalized’ rivers, where no technical modifications had subsequently been made to their channels outside urban areas and the floodplains had been left in a post‐flood state. Vegetation species abundance and 13 environmental variables (topographical, hydrological and soil) were investigated in summer 2007, 10 years after the extreme flood disturbance. The results suggest that the recently created fluvial geomorphic forms are key environmental determinants of riparian vegetation distribution patterns. A range of statistical analyses illustrate that some plant species show predictable patterns of occurrence that correspond with the fluvial forms, supporting a fourfold grouping of herbaceous and woody species and the identification of typical plant communities associated with gravel bars, islands, banks, floodplains and terraces. An investigation of the species richness found on different fluvial landforms showed that the highest number of species occurred on the floodplain and decreased gradually towards the channel bed and towards terraces. Investigation of existing conditions in reaches of rivers with natural dynamics of fluvial processes provides valuable information that can be used as an effective tool for planning restoration strategies and precise management. However, the most important finding of this study is the remarkable establishment of complex river corridor vegetation–landform associations within 10 years of a 500‐year flood that removed the heavily cultivated landscape that had existed before the event. Copyright © 2011 John Wiley & Sons, Ltd.     

The Rhine rift valley ground water—river interactions: Evolution of their susceptibility to pollution

The exchange processes between the Rhine river and the alluvial aquifer were analysed in the upper part of the rift valley (upstream of Strasbourg). Hydraulic works, and the consequent suppression of flooding, along the Alsace Rhine floodplain greatly modified these processes. The transfer of persistent toxic micropollutants (organochlorine compounds, mercury), and non-persistent pollutants (organophosphorous compounds: Sandoz spill) from the Rhine to the groundwater-fed streams was exhibited by pollutant bioaccumulation in fish (particularly in the eel) and eutrophication of these streams near the canalized river. Comparison of the hydrological functioning of the two main river floodplains (the Rhine and its tributary, the Ill in the Alsace Rhine plain) shows two completely different exchange processes: in the case of the canalized Rhine, the groundwater is affected by direct transfer of pollutants through the channel bed. In the other case, that of the river Ill, where the floodplain is still widely flooded each year, the self-purification of the floodwaters transferred to the groundwater is very effective: the soil-root system of alluvial forest and meadow apparently having a high purification capacity.     

Application of physical habitat simulation (PHABSIM) modelling to modified urban river channels

Prediction of changes to in‐stream ecology are highly desirable if decisions on river management, such as those relating to water abstractions, effluent discharges or modifications to the river channel, are to be justified to stakeholders. The physical habitat simulation (PHABSIM) system is a well‐established hydro‐ecological model that provides a suite of tools for the numerical modelling of hydraulic habitat suitability for fish and invertebrate species. In the UK, the most high‐profile PHABSIM studies have focused on rural, groundwater‐dominated rivers and have related to low flow issues. Conversely, there have been few studies of urban rivers. This paper focuses on the application of PHABSIM to urban rivers and demonstrates how sensitivity analyses can be used to assess uncertainty in PHABSIM applications. Results show that physical habitat predictions are sensitive to changes in habitat suitability indices, hydraulic model calibration and the temporal resolution of flow time‐series. Results show that there is greater suitable physical habitat over a wider range of flows in a less engineered river channel when compared to a more engineered channel. The work emphasizes the need for accurate information relating to the response of fish and other organisms to high velocities. Copyright © 2004 John Wiley & Sons, Ltd.