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Eder, Markus, Francesca Perosa, Severin Hohensinner, Michael Tritthart, Sabrina Scheuer, Marion Gelhaus, Bernd Cyffka i in. "How Can We Identify Active, Former, and Potential Floodplains? Methods and Lessons Learned from the Danube River". Water 14, nr 15 (24.07.2022): 2295. http://dx.doi.org/10.3390/w14152295.
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Floodplains are a fundamental source of multiple functions and services. Despite their various benefits, a dramatic reduction in floodplain areas has occurred in most large river systems over the last few centuries, and is still ongoing. Human modifications (such as river regulation, dam construction, and land use changes) due to economic growth, increasing population size, etc., were and still are drivers of major floodplain losses. Therefore, studies offering solutions for floodplain preservation and restoration are of great importance for sustainable floodplain management. This paper presents methods to identify active, former, and potential floodplains, and their application to the Danube River. We used hydraulic data, historical sources, and recent geospatial data to delineate the three floodplain types. Fifty hydraulically active floodplains larger than 500 ha were identified. According to our results, the extent of Danube floodplains has been reduced by around 79%. With the support of different representatives from the Danube countries, we identified 24 potential floodplains. However, the share of active and potential floodplains in relation to former floodplains ranges between 5% and 49%, demonstrating the huge potential for additional restoration sites. This analysis contributes to an understanding of the current and the past floodplain situation, increases awareness of the dramatic floodplain loss along the Danube, and serves as a basis for future floodplain management.
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Natho, Stephanie. "How Flood Hazard Maps Improve the Understanding of Ecologically Active Floodplains". Water 13, nr 7 (30.03.2021): 937. http://dx.doi.org/10.3390/w13070937.
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Floodplains are threatened ecosystems and are not only ecologically meaningful but also important for humans by creating multiple benefits. Many underlying functions, like nutrient retention, carbon sequestration or water regulation, strongly depend on regular inundation. So far, these are approached on the basis of what are called ‘active floodplains’. Active floodplains, defined as statistically inundated once every 100 years, represent less than 10% of a floodplain’s original size. Still, should this remaining area be considered as one homogenous surface in terms of floodplain function, or are there any alternative approaches to quantify ecologically active floodplains? With the European Flood Hazard Maps, the extent of not only medium floods (T-medium) but also frequent floods (T-frequent) needs to be modelled by all member states of the European Union. For large German rivers, both scenarios were compared to quantify the extent, as well as selected indicators for naturalness derived from inundation. It is assumed that the more naturalness there is, the more inundation and the better the functioning. Real inundation was quantified using measured discharges from relevant gauges over the past 20 years. As a result, land uses indicating strong human impacts changed significantly from T-frequent to T-medium floodplains. Furthermore, the extent, water depth and water volume stored in the T-frequent and T-medium floodplains is significantly different. Even T-frequent floodplains experienced inundation for only half of the considered gauges during the past 20 years. This study gives evidence for considering regulation functions on the basis of ecologically active floodplains, meaning in floodplains with more frequent inundation that T-medium floodplains delineate.
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Grenfell, S., i M. Grenfell. "Characterising the late Quaternary facies stratigraphy of floodplains in South Africa". South African Journal of Geology 124, nr 4 (1.12.2021): 963–76. http://dx.doi.org/10.25131/sajg.124.0056.
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Abstract South African river floodplains and their alluvial deposits reflect a diversity of geological and geographical drivers. We use a genetic geomorphic classification system originally developed for dryland wetlands to characterise geomorphic processes and potential successions of sedimentary fill for South African floodplains. Using case studies from the literature, we consider differences between alluvial rivers and mixed bedrock-alluvial rivers in the context of macro-scale geomorphic setting, and evaluate the impact of the setting on floodplain persistence and potential as a palaeo-environmental archive. Sedimentary facies associations represented in South African floodplains, including lateral and oblique accretion, channel, channel infill, levee vertical accretion, floodplain vertical accretion and debris flow deposits, are also evaluated. Floodplains of South Africa’s interior are typically mixed bedrock-alluvial as channel beds are set upon or close to bedrock and sediment thickness is limited. By contrast some floodplains in tectonic basin settings have sediment deposits exceeding 30 m in thickness. The resulting rivers are alluvial, and thus able to adjust their width, depth and slope to accommodate changes in discharge and sediment supply. Similarly, coastal floodplain rivers are alluvial due to downcutting during the last glacial maximum and subsequent sedimentary infilling as sea levels rose. When considering the potential of floodplains as palaeoarchives of environmental change, two considerations emerge. First, floodplain stratigraphy is not a response to a single variable due to complex process-form feedbacks. Rather, floodplain stratigraphy is an outcome of both autogenic and allogenic processes. Second, most South African floodplains are zones of sediment recycling, and as such, preservation potential is typically low. Thus, although floodplain settings of the interior may be a few million years old, the sediment within them may be only thousands to tens of thousands of years old. Our review indicates that research has historically focused on meandering river and mixed bedrock-alluvial anabranching river floodplains, while understanding of other floodplain sub-types remains limited.
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Gordon, Brad A., Olivia Dorothy i Christian F. Lenhart. "Nutrient Retention in Ecologically Functional Floodplains: A Review". Water 12, nr 10 (4.10.2020): 2762. http://dx.doi.org/10.3390/w12102762.
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Nutrient loads in fresh and coastal waters continue to lead to harmful algal blooms across the globe. Historically, floodplains—low-lying areas adjacent to streams and rivers that become inundated during high-flow events—would have been nutrient deposition and/or removal sites within riparian corridors, but many floodplains have been developed and/or disconnected. This review synthesizes literature and data available from field studies quantifying nitrogen (N) and phosphorus (P) removal within floodplains across North America and Europe to determine how effective floodplain restoration is at removing nutrients. The mean removal of nitrate-N (NO3−-N), the primary form of N in floodplain studies, was 200 (SD = 198) kg-N ha−1 year−1, and of total or particulate P was 21.0 (SD = 31.4) kg-P ha−1 year−1. Based on the literature, more effective designs of restored floodplains should include optimal hydraulic load, permanent wetlands, geomorphic diversity, and dense vegetation. Floodplain restorations along waterways with higher nutrient concentrations could lead to a more effective investment for nutrient removal. Overall, restoring and reconnecting floodplains throughout watersheds is a viable and effective means of removing nutrients while also restoring the many other benefits that floodplains provide.
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Fernandes, João N., João B. Leal i António H. Cardoso. "Influence of floodplain and riparian vegetation in the conveyance and structure of turbulent flow in compound channels". E3S Web of Conferences 40 (2018): 06035. http://dx.doi.org/10.1051/e3sconf/20184006035.
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The present study aims at understanding the changes in the channel conveyance and in the turbulent flow structure due to the presence of both submerged vegetation in the floodplains and riparian vegetation. An experimental campaign was carried out comprising uniform compound channels flows (i) without any kind of vegetation, (ii) with synthetic grass in the floodplains, (iii) with synthetic grass in the floodplains and rods in the interface between main channel and the floodplain and (iv) with synthetic grass in the floodplains and artificial shrubs in the interface between main channel and the floodplain. For comparison, the water depth in all flow cases was kept constant. Accurate acoustic Doppler velocimetry was used to evaluate the 3d velocity field and the turbulence structures characteristics.
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Scown, M. W., M. C. Thoms i N. R. De Jager. "An index of floodplain surface complexity". Hydrology and Earth System Sciences 20, nr 1 (26.01.2016): 431–41. http://dx.doi.org/10.5194/hess-20-431-2016.
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Abstract. Floodplain surface topography is an important component of floodplain ecosystems. It is the primary physical template upon which ecosystem processes are acted out, and complexity in this template can contribute to the high biodiversity and productivity of floodplain ecosystems. There has been a limited appreciation of floodplain surface complexity because of the traditional focus on temporal variability in floodplains as well as limitations to quantifying spatial complexity. An index of floodplain surface complexity (FSC) is developed in this paper and applied to eight floodplains from different geographic settings. The index is based on two key indicators of complexity, variability in surface geometry (VSG) and the spatial organisation of surface conditions (SPO), and was determined at three sampling scales. FSC, VSG, and SPO varied between the eight floodplains and these differences depended upon sampling scale. Relationships between these measures of spatial complexity and seven geomorphological and hydrological drivers were investigated. There was a significant decline in all complexity measures with increasing floodplain width, which was explained by either a power, logarithmic, or exponential function. There was an initial rapid decline in surface complexity as floodplain width increased from 1.5 to 5 km, followed by little change in floodplains wider than 10 km. VSG also increased significantly with increasing sediment yield. No significant relationships were determined between any of the four hydrological variables and floodplain surface complexity.
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Hughes, Francine M. R. "Floodplain biogeomorphology". Progress in Physical Geography: Earth and Environment 21, nr 4 (grudzień 1997): 501–29. http://dx.doi.org/10.1177/030913339702100402.
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Floodplains are unique ecosystems because of their linear form, the sometimes extreme dynamism of their geomorphology and because they process large fluxes of energy and materials from upstream areas. This article focuses on the importance of hydrological inputs to floodplains through 1) their influence on the arrangement of landforms and vegetation communities and 2) the connections between flooding regimes and the regeneration and turnover time of floodplain vegetation. Many researchers have demonstrated close links between the arrangement of vegeta tion communities and sedimentary landform types, elevation, soil characteristics, tolerance to flooding and availability of soil moisture. It is suggested that plants on floodplains are found along a combined gradient of available moisture and oxygen which can be viewed simultaneously as a flooding frequency gradient and a complex soil moisture gradient. Discussion of experi mental work on floodplains demonstrates the importance of these gradients to a range of flood plain species in different environments. The relationships between these environmental gradients and the apparent high level of overlap between planform patterns of landforms and vegetation communities on floodplains are related to lag times in different parts of vegetation communities. Flood regimes greatly influence the availability of areas suitable for vegetation regeneration from year to year and the age structure of floodplain communities over decadal time frames. Biotic factors also influence biogeomorphological relationships on floodplains and range from sediment- trapping by vegetation to the impacts of beaver and grazing animals on floodplain hydrology and vegetation. Restoration of floodplains is high on the agenda in many countries and it is argued that, for sustainable results, restoration of hydrological pathways is essential. Planned flood releases below dams in several African countries have had varied success rates but the develop ment of models for managing flows to achieve different restoration targets is the start of an integrated approach to restoring complex floodplain ecosystems.
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Werther, Lukas, Natascha Mehler, Gerrit Jasper Schenk i Christoph Zielhofer. "On the Way to the Fluvial Anthroposphere—Current Limitations and Perspectives of Multidisciplinary Research". Water 13, nr 16 (11.08.2021): 2188. http://dx.doi.org/10.3390/w13162188.
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Floodplains represent a global hotspot of sensitive socioenvironmental changes and early human forcing mechanisms. In this review, we focus on the environmental conditions of preindustrial floodplains in Central Europe and the fluvial societies that operated there. Due to their high land-use capacity and the simultaneous necessity of land reclamation and risk minimisation, societies have radically restructured the Central European floodplains. According to the current scientific consensus, up to 95% of Central European floodplains have been extensively restructured or destroyed. Therefore, question arises as to whether or when it is justified to understand Central European floodplains as a ‘Fluvial Anthroposphere’. The case studies available to date show that human-induced impacts on floodplain morphologies and environments and the formation of specific fluvial societies reveal fundamental changes in the medieval and preindustrial modern periods. We aim to contribute to disentangling the questions of when and why humans became a significant controlling factor in Central European floodplain formation, and how humans in interaction with natural processes and other chains of effects have modified floodplains. As a conclusion, we superimpose emerging fields of research concerning the onset of the Fluvial Anthroposphere and provide 10 specific thematic objectives for future multidisciplinary work.
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Schoor, Margriet M. "The Relation between Vegetation and Hydrology/Geomorphology in the Gemenc Floodplain Forest, Hungary". Water Science and Technology 29, nr 3 (1.02.1994): 289–91. http://dx.doi.org/10.2166/wst.1994.0122.
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In the Gemenc floodplain along the river Danube in Southern Hungary, six vegetation zones have been identified. Together with soil and geomorphological data, these vegetation zones are interpreted to form a hypothesis of succession for the Gemenc floodplain. As the Gemenc floodplain is comparable with the Dutch floodplains, from a hydrological, geomorphological and floristic point of view, the results can be used in plans for the rehabilitation of the floodplains of the river Rhine in the Netherlands.
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Brown, T. T., i C. A. Fuller. "Stress and parasitism of white-footed mice (Peromyscus leucopus) in dry and floodplain environments". Canadian Journal of Zoology 84, nr 12 (grudzień 2006): 1833–39. http://dx.doi.org/10.1139/z06-183.
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We hypothesized that flooding represents an environmental stressor that might affect the corticosterone levels, parasite prevalence, and life history of small mammals living in floodplain environments. We compared populations of white-footed mice ( Peromyscus leucopus (Rafinesque, 1818)) on floodplains and dry areas. We found more males on floodplains (p = 0.008) and more females on dry areas (p = 0.005). There were no differences in mass (p > 0.05) or intestinal parasite prevalence (p = 0.665) between dry and floodplain habitats, but bot fly larvae were significantly more prevalent in males living on floodplains (p = 0.043). Floodplain animals had significantly higher levels of corticosterone than dry-area animals in fall, and lower levels in summer (F[1,20] = 4.483, p = 0.047). In addition, we found that animals with intestinal parasites had higher levels of corticosterone than those that were without parasites (p = 0.014) or that harbored bot fly larvae (p = 0.001). Floodplains seem to be harsher environments than dry areas, but this may be a result of differences in habitat rather than a direct result of flooding.
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Thonon, I., H. Middelkoop i M. van der Perk. "The influence of floodplain morphology and river works on spatial patterns of overbank deposition". Netherlands Journal of Geosciences - Geologie en Mijnbouw 86, nr 1 (kwiecień 2007): 63–75. http://dx.doi.org/10.1017/s0016774600021326.
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AbstractFloodplain topography and related hydraulic patterns of overbank flow constitute a major control on the amounts and patterns of sediment deposition on floodplains. We studied the differences in sediment deposition at two scales along two river branches of the lower River Rhine in the Netherlands: the Waal and IJssel River. Human alterations like levelling and embankment construction have severely impacted the floodplains along the Waal River branch (average discharge: 1500 m3·s‒1), whereas the relatively wide floodplains along the IJssel River (average discharge: 250 m3·s‒1) still exhibit their characteristic ridge-and-swale topography and natural levees. We found that, in general, the amounts of sediment deposited sediment decreases with increasing distance to the sediment source. Clay and organic matter content generally increase with decreasing floodplain elevation. These trends are, however, far less pronounced in the Waal River floodplains than in the IJssel River floodplains. Sediment deposited on the IJssel River floodplains also contains significantly more sand than the sediment deposited on the Waal River floodplains, probably because of the absence of minor embankments along the IJssel River and its higher sinuosity. Furthermore, during inundation the individual Waal River floodplains receive more sediment per unit area than the IJssel River floodplains. At the scale of the river branch, however, the conveyance losses in the Waal River are less than in the IJssel River, because of the larger surface area of the floodplains along the IJssel River relative to its water and sediment discharge during flood events. This discrepancy stresses that both the individual floodplain sections and the total river branch should be taken into account when studying the role of overbank deposition as part of a river’s sediment budget.
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Nafikova, Elvira, Dmitry Alexandrov, Anastasia Platonova, Kamila Gayanova i Kamilla Chuvashaeva. "Depletion of the floodplain-channel complex of the river (Belaya river, Republic of Bashkortostan)". E3S Web of Conferences 244 (2021): 01012. http://dx.doi.org/10.1051/e3sconf/202124401012.
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The article presents a comprehensive assessment of the geoecological risk of the Belaya River floodplain (Republic of Bashkortostan, Russia). The risk assessment of the floodplain-channel complex includes the risk of depletion by the plant species composition and the risk of depletion of the ecological and hydrological states. Geographic information maps of the floodplain were compiled for vegetation and floodplain forests and wetlands. The extent of forest cover was chosen as an indicator of the floodplain’s resilience to the risk of depletion and decline. The calculation of the risk of depletion of floodplains based on the ecological and hydrological state was carried out taking into account the changes in floodplain areas over the past 10 years, data on the catchment of ground and surface waters, “sealed” areas and the annual average discharge. The assessment and zoning of the river floodplain territory was carried out according to the proposed method.
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Garnett, Jeffrey A., i Darold P. Batzer. "Longitudinal variation in community structure of floodplain fishes along two rivers of the southeastern USA". Canadian Journal of Fisheries and Aquatic Sciences 71, nr 9 (wrzesień 2014): 1291–302. http://dx.doi.org/10.1139/cjfas-2013-0422.
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Many studies have examined whether longitudinal variation exists in fish communities within stream channels. Yet despite the acknowledged importance of adjacent floodplain ecosystems, no study has investigated longitudinal variation in fish communities in floodplain wetlands. We conducted a study to determine if distinct fish communities exist between upper and lower river floodplains. We predicted that floodplains in the upper portions of a watershed will be dominated by opportunistic riverine fish. In contrast, floodplains farther downstream in the watershed will primarily consist of obligate floodplain fishes. We sampled fishes at 21 floodplain sites along the lengths of the Oconee–Altamaha and Broad–Savannah river systems of Georgia, USA, during the 2008 and 2009 flood seasons. A modified mark–recapture method was utilized to estimate probabilities of species detection and occupancy. Ordination and analysis of similarity using species site occupancy estimates identified two unique communities related to floodplain position, and indicator species analysis supported our hypothesis of community distinction based on life history traits. Water resource managers should consider how flood pulse character influences fish communities when regulating flow regimes.
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Hauer, F. Richard, Harvey Locke, Victoria J. Dreitz, Mark Hebblewhite, Winsor H. Lowe, Clint C. Muhlfeld, Cara R. Nelson, Michael F. Proctor i Stewart B. Rood. "Gravel-bed river floodplains are the ecological nexus of glaciated mountain landscapes". Science Advances 2, nr 6 (czerwiec 2016): e1600026. http://dx.doi.org/10.1126/sciadv.1600026.
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Gravel-bed river floodplains in mountain landscapes disproportionately concentrate diverse habitats, nutrient cycling, productivity of biota, and species interactions. Although stream ecologists know that river channel and floodplain habitats used by aquatic organisms are maintained by hydrologic regimes that mobilize gravel-bed sediments, terrestrial ecologists have largely been unaware of the importance of floodplain structures and processes to the life requirements of a wide variety of species. We provide insight into gravel-bed rivers as the ecological nexus of glaciated mountain landscapes. We show why gravel-bed river floodplains are the primary arena where interactions take place among aquatic, avian, and terrestrial species from microbes to grizzly bears and provide essential connectivity as corridors for movement for both aquatic and terrestrial species. Paradoxically, gravel-bed river floodplains are also disproportionately unprotected where human developments are concentrated. Structural modifications to floodplains such as roads, railways, and housing and hydrologic-altering hydroelectric or water storage dams have severe impacts to floodplain habitat diversity and productivity, restrict local and regional connectivity, and reduce the resilience of both aquatic and terrestrial species, including adaptation to climate change. To be effective, conservation efforts in glaciated mountain landscapes intended to benefit the widest variety of organisms need a paradigm shift that has gravel-bed rivers and their floodplains as the central focus and that prioritizes the maintenance or restoration of the intact structure and processes of these critically important systems throughout their length and breadth.
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Hallberg, Lukas, Faruk Djodjic i Magdalena Bieroza. "Phosphorus supply and floodplain design govern phosphorus reduction capacity in remediated agricultural streams". Hydrology and Earth System Sciences 28, nr 2 (26.01.2024): 341–55. http://dx.doi.org/10.5194/hess-28-341-2024.
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Abstract. Agricultural headwater streams are important pathways for diffuse sediment and nutrient losses, requiring mitigation strategies beyond in-field measures to intercept the transport of pollutants to downstream freshwater resources. As such, floodplains can be constructed along existing agricultural streams and ditches to improve fluvial stability and promote deposition of sediments and particulate phosphorus. In this study, we evaluated 10 remediated agricultural streams in Sweden for their capacity to reduce sediment and particulate phosphorus export and investigated the interplay between fluvial processes and phosphorus dynamics. Remediated streams with different floodplain designs (either on one side or both sides of the channel, with different width and elevation) were paired with upstream trapezoidal channels as controls. We used sedimentation plates to determine seasonal patterns in sediment deposition on channel beds and floodplains and monthly water quality monitoring. This was combined with continuous flow discharge measurements to examine suspended sediment and particulate phosphorus dynamics and reduction along reaches. Remediated streams with floodplains on both sides of the channel reduced particulate phosphorus concentrations and loads (−54 µg L−1, −0.21 kg ha−1 yr−1) along reaches, whereas increases occurred along streams with one-sided floodplains (27 µg L−1, 0.09 kg ha−1 yr−1) and control streams (46.6 µg L−1). Sediment deposition in remediated streams was five times higher on channel beds than on floodplains and there was no evident lateral distribution of sediments from channel to floodplains. There was no effect from sediment deposition on particulate phosphorus reduction, suggesting that bank stabilization was the key determinant for phosphorus mitigation in remediated streams, which can be realized with two-sided but not one-sided floodplains. Further, the overall narrow floodplain widths likely restricted reach-scale sediment deposition and its impact on P reductions. To fully understand remediated streams' potential for reductions in both nitrogen and different phosphorus species and to avoid pollution swapping effects, there is a need to further investigate how floodplain design can be optimized to achieve a holistic solution towards improved stream water quality.
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Poi, Alicia S. G., Juan J. Neiff, Sylvina L. Casco i Luciana I. Gallardo. "Macroinvertebrates of Eichhornia crassipes (Pontederiaceae) roots in the alluvial floodplain of large tropical rivers (Argentina)". Revista de Biología Tropical 68, S2 (22.10.2020): S104—S115. http://dx.doi.org/10.15517/rbt.v68is2.44342.
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Introduction: Eichhornia crassipes is a dominant aquatic plant of neotropical-river floodplains and is invasive in warm waters of different continents. Plants provide food and habitat for fish, especially Prochilodus lineatus and Gymnotus omarorum, which are relevant to subsistence fishing by local indigenous communities. Objective: In this study we describe the main traits of E. crassipes floating meadows, and analyze the abundance and composition of macroinvertebrate assemblages associated with their roots in two floodplain wetlands of the Paraná River (within the Ramsar site Wetlands Chaco) and of the Pilcomayo River (within the Pilcomayo River National Park). Methods: During spring and summer, the macroinvertebrates were collected in monospecific stands of E. crassipes with a net of 962 cm2 area and 500 µm mesh size. Leaf density, the biomass of leaves and roots, the length of leaves and roots, and the water quality were measured simultaneously. Results: Temperature, oxygen concentration, and nutrient content were significantly higher and electrical conductivity was lower in the Pilcomayo than in the Paraná floodplain. E. crassipes growing in the Pilcomayo floodplain had longer leaves and less root biomass than those found in the Paraná floodplain. The number of macroinvertebrates per 1 000 g root dry weight and per m2 was significantly different between both floodplains, but the taxon richness was similar. Non Metric Multidimensional Scaling analysis differentiated the abundance of 14 selected taxa between both floodplains, and showed a high correlation between the environmental variables and macroinvertebrate abundance. The most abundant taxonomic groups in the Paraná River floodplain were oligochaetes (Naididae), ostracods mainly Cytheridella ilosvayi and larvae of non-biting midges (Chironomidae). Two families, Hydrobiidae (Heleobia parchappii) and Chironomidae accounted for 49.3 % of the total abundance in the Pilcomayo floodplain. The prawns Macrobrachium jelskii and M. amazonicum, frequent in the Pilcomayo floodplain, were not found in the Paraná floodplain. Conclusions: The different environmental conditions in both floodplains affect the abundance, composition, and the dominance of macroinvertebrate assemblages; however, the total taxa richness was similar. The area occupied by E. crassipes in the floodplains of these rivers provides the habitat that contributes most to overall biotic diversity, which must be considered in management strategies.
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Morton, SR, KG Brennan i MD Armstrong. "Distribution and Abundance of Ducks in the Alligator Rivers Region, Northern Territory". Wildlife Research 17, nr 6 (1990): 573. http://dx.doi.org/10.1071/wr9900573.
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Aerial surveys between 1981 and 1984 were used to identify monthly trends in the abundance of wandering whistling-duck Dendrocygna arcuata, plumed whistling-duck D. eytoni, radjah shelduck Tadorna radjah, Pacific black duck Anas superciliosa, and grey teal A. gibberifrons on five floodplains of the Alligator Rivers region, 250 km east of Darwin in the monsoonal north of the Northern Territory. Ground surveys were conducted during the same period on one of the floodplains, the Magela plain, to provide more detailed information. The Magela floodplain was inhabited by few ducks during the wet season (November to March), but numbers then increased to dramatic peaks in the late dry season. The Nourlangie floodplain and Boggy Plain (a large backswamp of the South Alligator floodplain) showed similar patterns, but the numbers of ducks were usually fewer. Ducks were uncommon on the shallower East Alligator and Cooper floodplains except for relatively brief periods in the wet season. The ground surveys suggested that ducks sought out the persistent swamps that characterise the Magela floodplain in the dry season. Ground surveys also indicated that aerial surveys underestimated densities; on the basis of correction factors calculated from the ground surveys, peak numbers on the five floodplains were roughly estimated to be 400 000 wandering whistling-ducks, 70 000 plumed whistling-ducks, 20 000 radjah shelducks, 50 000 Pacific black ducks, and 50 000 grey teal. Pink-eared ducks Malacorhynchus membranaceus and hardhead Aythya australis were recorded sporadically in low numbers. The Alligator Rivers region acted as a dry season refuge for large concentrations of ducks because of the atypical persistence of freshwaters on the Magela and Nourlangie floodplains and some of the backswamps of the South Alligator, such as Boggy Plain. The large aggregations appear to be unique in Australia.
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Okoth, Joseph Micheal, Daniel Otim i Edwin Kamalha. "Characterizing River Manafwa Floodplain and Adjacent Soils". East African Journal of Engineering 7, nr 1 (23.04.2024): 60–73. http://dx.doi.org/10.37284/eaje.7.1.1884.
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The objective of this study was to characterise Manafwa River floodplain and adjacent soils. Soil samples were collected from 0 - 20 cm depth in fallowed and cultivated Manafwa floodplain soils for laboratory analysis. Treatments included upland (control), floodplains fallowed for a year, floodplains fallowed for over a year, cultivated floodplains within 5 m and 50 m away from the river banks. Each treatment was replicated three times (3 blocks), and samples collected were analysed for K, Na, available P, total N, exchangeable acidity, pH, organic matter, moisture content, sand, silt, and clay. The soil sampling results were subjected to statistical Analysis of Variance (ANOVA) using Randomised Complete Block Design (RCBD), and the difference between treatment means were dictated using F-, student’s t and F-LSD/pairwise comparison tests. There was statistically no significant (p > 0.05) difference among different floodplains and uplands studied. Upland soils posted 71.67% for the highest pH and 0.09%, 0.87%, 9.74 ppm, 2.23 ppm and 7.264% for the lowest available N, organic matter, Phosphorous, Sodium and Moisture Content, respectively. Cultivated floodplain soil posted highest total P at 29.16 ppm and pH at 6.39% while fallowed floodplains lowest pH at 5.34%, highest available N at 0.32%, highest organic matter at 4.02%, highest K at 21.33%, highest Na at 13.93%, highest exchangeable acidity at 2.32 Cmol/Kg, highest clay content at 14.33%, lowest sand composition at 38.00%, highest silt composition at 54.8% and highest Moisture Content of 32.472%. As depicted by soil fertility analysis results, Manafwa River floodplain and adjacent soils have the capacity to accommodate and boost crop production and productivity. Any nutrients lost to leaching could be gained from subsequent fallowing and sustainable soil fertility management, proper drainage, crop rotation, adding organic manure, and cover cropping, among others
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Manh, N. V., B. Merz i H. Apel. "Sedimentation monitoring including uncertainty analysis in complex floodplains: a case study in the Mekong Delta". Hydrology and Earth System Sciences Discussions 10, nr 1 (11.01.2013): 325–73. http://dx.doi.org/10.5194/hessd-10-325-2013.
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Abstract. Quantity and quality of sediment deposition in complex floodplains are affected by many uncertain factors, ranging from suspended sediment transport dynamics in rivers and floodplain channel interactions to internal floodplain processes. In consequence, any point measurement of sedimentation in floodplains contains a high degree of uncertainty calling for a careful analysis of the measured data. However, uncertainty analyses are not documented in publications on floodplain sedimentation data. Therefore the presented work illustrates a field sampling strategy aiming at the quantification of uncertainties associated to sediment deposition data, as well as the spatial variability of sediments deposition on floodplains. The study was performed in the Mekong Delta (MD), being an example for a large and complex floodplain with a high degree of anthropogenic disturbances. We present a procedure for the quantification of the uncertainty associated to the data, based on the design of the monitoring campaign and floodplain characteristics. Sediment traps were distributed strategically over the floodplain in clusters of three mat traps representing one monitoring point. The uncertainty originating from collection of the traps in ponding water is quantified by lab experiments. The uncertainty of a single monitoring point is then quantified in a Monte Carlo simulation, propagating the uncertainty from the different uncertainty sources to final uncertainty bounds of the monitored sediment data. For the case study area, it is shown that there are no correlations in the spatial distribution of sedimentation in floodplains. This can be explained by the highly complex channel and dike system and the high number of hydraulic structures. However, it can be shown that within single floodplain compartments the spatial deposition variability depends on the dike levels and operation and location of hydraulic structures.
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Scown, M. W., M. C. Thoms i N. R. De Jager. "An index of floodplain surface complexity". Hydrology and Earth System Sciences Discussions 12, nr 4 (30.04.2015): 4507–40. http://dx.doi.org/10.5194/hessd-12-4507-2015.
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Abstract. Floodplain surface topography is an important component of floodplain ecosystems. It is the primary physical template upon which ecosystem processes are acted out. There has been a limited appreciation of floodplain surface complexity because of the traditional focus on temporal variability in floodplains as well as limitations to quantifying spatial complexity. An index of floodplain surface complexity (FSC) is developed in this paper and applied to eight floodplains from different geographic settings. The index is based on the two key indicators of complexity; variability in surface geometry (VSG) and the spatial organization of surface conditions (SOC) and was determined at three sampling scales. Relationships between these measures of spatial complexity and environmental drivers, namely; flow variability (mean daily discharge [Q], the coefficient of variation of daily discharge [QCV], the coefficient of variation of mean annual discharge [QCVAnn], the coefficient of variation of maximum annual discharge [QCVMax]), sediment yield (SY), valley slope (Vs), and floodplain width (Fpw) were examined. FSC, VSG, and SOC varied between the eight floodplains and this was dependent upon sampling scale. All complexity values declined with increasing Fpw in either a power, logarithmic, or exponential function. There was little change in surface complexity with floodplain widths greater than 10 km. VSG was significantly related to SY and no significant relationships were determined between any of the hydrological variables and floodplain surface complexity.
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Daskin, Joshua H., Filipe Aires i A. Carla Staver. "Determinants of tree cover in tropical floodplains". Proceedings of the Royal Society B: Biological Sciences 286, nr 1914 (30.10.2019): 20191755. http://dx.doi.org/10.1098/rspb.2019.1755.
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Tree cover differentiates forests from savannas and grasslands. In tropical floodplains, factors differentiating these systems are poorly known, even though floodplains cover 10% of the tropical landmass. Seasonal inundation potentially presents trees with both challenges (soil anoxia) and benefits (moisture and nutrient deposition), the relative importance of which may depend on ecological context, e.g. if floods alleviate water stress more in more arid ecosystems. Here, we use remotely sensed data across 13 large tropical and sub-tropical floodplain ecosystems on five continents to show that climatic water balance (i.e. precipitation—potential evapotranspiration) strongly increases floodplain tree cover in interaction with flooding, fire and topography. As predicted, flooding increases tree cover in more arid floodplains, but decreases tree cover in climatically wetter ones. As in uplands, frequent fire reduced tree cover, particularly in wet regions, but—in contrast with uplands—lower elevation and sandier soils decreased tree cover. Our results suggest that predicting the impacts of changing climate, land use and hydrology on floodplain ecosystems depends on considering climate-disturbance interactions. While outright wetland conversion proceeds globally, additional anthropogenic activities, including alteration of fire frequencies and dam construction, will also shift floodplain tree cover, especially in wet climates.
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SAIKIA, ARUPJYOTI. "Jute in the Brahmaputra Valley: The making of flood control in twentieth-century Assam". Modern Asian Studies 49, nr 5 (21.04.2015): 1405–41. http://dx.doi.org/10.1017/s0026749x14000201.
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AbstractFlood protection in the Brahmaputra's floodplains began rather late and was implemented precisely to protect the important commercial crop of jute. To begin with, in the early twentieth century, after a long wait and much speculation, action was finally taken to make the Brahmaputra's floodplains more productive to the British Empire. Soon the commercial production of jute began in the floodplains. This article explains how the Brahmaputra's floodplains were converted into the British empire's eastern-most jute frontier. The article also explains the political economy of flood management in Assam in the second half of the twentieth century. Further, explaining the shifting relations between state, capital, and floodplain, the article shows how these schemes achieved only partial success and at the cost irreversible ecological damage.
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Kirichenko-Babko, Marina, Yaroslav Danko, Małgorzata Franus, Witold Stępniewski i Roman Babko. "Riparian Ground Beetles (Coleoptera) on the Banks of Running and Standing Waters". Water 12, nr 6 (23.06.2020): 1785. http://dx.doi.org/10.3390/w12061785.
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Rivers and their floodplains offer a wide variety of habitats for invertebrates. River ecosystems are subject to high anthropic influence: as a result the channel morphology is changed, swamps are drained, floodplains are built up, and rivers are polluted. All this has radically changed the environment for the inhabitants of the floodplains, including riparian stenotopic species. Although riparian arthropods are oriented primarily to the production of hydro-ecosystems, the type of water body—lentic or lotic—has a determining effect in the structure of communities. Most riparian arthropods have evolutionarily adapted to riverbanks with significant areas of open alluvial banks. This paper considered the structure of assemblages of ground beetles associated with the riverbanks and the shores of floodplain lakes and their differences. The banks of rivers and the shores of floodplain lakes were considered separately due to the differences in the habitats associated with them. Our results showed that riverbanks, which experience significant pollution, were actively colonized by vegetation and were unsuitable for most riparian ground beetles. The shores of floodplain lakes, being an optional habitat for riparian arthropods, cannot serve as refugia. Thus, the transformation of floodplain landscapes and river pollution creates a problem for the biological diversity of floodplain ecosystems, since riparian stenotopic species of the riverbanks become rare and disappear.
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Krásná, Kateřina, Lenka Štěrbová, Marcela Prokopová, Jiří Jakubínský, Pavel Vyvlečka i Vilém Pechanec. "Ecological Status of Floodplains and their Potential to Carbon Storage: Case Study From Three Watersheds in the South Moravian Region, Czech Republic". Journal of Landscape Ecology 16, nr 3 (1.12.2023): 94–131. http://dx.doi.org/10.2478/jlecol-2023-0019.
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Abstract Floodplains are important ecosystems that contribute to the ecological stability of the landscape. A number of ecosystem functions and services are significantly influenced by ecological aspects of floodplain habitats. This article focuses on the ecological quality and estimated amount of carbon stored in the biomass of habitats located in the studied watersheds, with an emphasis on floodplains. The habitats and their ecological quality were determined and assessed using the Biotope Valuation Method (BVM), an expert method for evaluating habitat (biotope) types based on eight ecological characteristics, mainly concerning various aspects of their biodiversity and vulnerability. The objective of this study is to compare the resulting assessments of habitats located in floodplains with assessments of habitats situated in the surrounding landscape. The study was carried out on three selected small stream watersheds in the South Moravian Region of the Czech Republic, which differ from each other in terms of the predominant land use and the overall level of anthropogenic pressure on the landscape. The results indicate that floodplains have a higher ecological value compared to the surrounding landscape, except for floodplains in areas with intensive agriculture. The ability of floodplains to store carbon in biomass turned out to be higher in the watershed with a higher percentage of tree stands, where woody plants store significantly more carbon in the biomass compared to other types of vegetation. It has been shown that human pressure on floodplains and land use significantly affects ecosystem functions and services. In addition to the intensity of agriculture, these were, in particular, pressures from an expansion of built-up areas and infrastructure developments, and forest management. In this study, forest stands in floodplain were more stable and had a more beneficial species composition than forests in the surrounding landscape.
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Waldner, PhD, Leora S. "Floodplain creep and beyond: An assessment of next-generation floodplain problems". Journal of Emergency Management 5, nr 4 (1.07.2007): 39. http://dx.doi.org/10.5055/jem.2007.0013.
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Since the 1970s, local jurisdictions have made great strides in protecting their floodplains through land use ordinances. Jurisdictions that joined the National Flood Insurance Program have prohibited structures in the regulatory floodway, and several jurisdictions have gone a step further, prohibiting structures in the 100-year floodplain. What next? If local governments are successfully keeping structures away from floodplains, have they adequately addressed floodplain issues—or do other problems remain unaddressed? This research examines Atlanta-region counties, and uncovers four potential next-generation problems, including the following: (1) floodplain creep (expansion of the floodplain) resulting from increased impervious surfaces and development; (2) the unrestricted development of homes in the 100-year floodplain of small dams; (3) cumulative riparian effects of cut and fill practices; and (4) lack of information for prospective homeowners of floodplain-burdened property.
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Heyden, Janika, i Stephanie Natho. "Assessing Floodplain Management in Germany—A Case Study on Nationwide Research and Actions". Sustainability 14, nr 17 (25.08.2022): 10610. http://dx.doi.org/10.3390/su141710610.
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After a long history of floodplain degradation and substantial losses of inundation areas over the last decades, a rethinking of floodplain management has taken place in Germany. Floodplains are now acknowledged as important areas for both biodiversity and society. This transformation has been significantly supported by nationwide research activities. A systematic assessment of the current floodplain management is still lacking. We therefore developed a scheme to assess floodplain management through the steps of identification, analysis, implementation, and evaluation. Reviewing the data and literature on nationwide floodplain-related research and activities, we defined key elements of floodplain management for Germany. We concluded that research activities already follow a strategic nationwide approach of identifying and analyzing floodplains. Progress in implementation is slow, however, and potentials are far from being reached. Nevertheless, new and unique initiatives enable Germany to stay on the long-term path of giving rivers more space and improving floodplain conditions.
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Haque, A. B. M. Mahfuzul, Leontine Visser i Madan Dey. "Institutional Arrangements in Seasonal Floodplain Management under Community-based Aquaculture in Bangladesh". Asian Journal of Agriculture and Development 8, nr 1 (15.06.2011): 1–18. http://dx.doi.org/10.37801/ajad2011.8.1.1.
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Seasonal floodplains under private and public ownership in the Indo-Ganges river basin provide food and income for millions of people in Bangladesh. Floodplain ownership regimes are diverse, covering the whole spectrum from public to private ownership. The paper compares community-based fish culture projects in these floodplains and analyzes the institutional arrangements of three different Floodplain Management Committees (FMC). The paper aimed to understand the complex institutional relations that govern ownership, access, and control of the floodplains under community-based fish culture (CBFC) to increase fish production and the livelihoods of the poor. We followed the stakeholders representing the various institutions and organizations such as the Department of Fisheries (DoF), Department of Land (DoL), and FMC. Other important stakeholders were the lease-holders of public water bodies in the floodplains, private landowners, seasonal, and professional fishers. The analysis demonstrates a significant increase of benefits to all stakeholders, including the poor, through the sharing of benefits derived from their involvement in the project. The willingness of different social classes to work together, the adoption of new technologies, and the societal embeddedness of local government institutions appear to be important inputs for policy making.
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Tóth, Péter. "Investigation of the Spatial Changes in Overbank Floodplains and Sedimentations on the Study Site of the Middle Tisza". Műszaki Katonai Közlöny 33, nr 3 (30.11.2023): 77–90. http://dx.doi.org/10.32562/mkk.2023.3.7.
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River systems and their floodplains can be studied and evaluated according to different aspects. The natural processes of the Tisza were mostly influenced by the river training and levee construction works named after Vásárhelyi, as well as the main channel regulation works. After the construction of the embankments, the fluvial formation of the natural floodplains ceased, as these processes limited it to areas of the floodplain along the main channel. Another consequence of the river regulations is that the river is forced to deposit the sediment transported during the floods in this narrow floodplain causing increased filling up, so the role of floodplains in flood conveyance has increasingly been reduced. In this study, the author aimed to investigate the bed changes that occurred as a result of the river regulation works, as well as the sediment accumulation in the flood plain, focusing on a typical section of the Middle Tisza.
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Martin, Simon, Stefan Klingler, Peter Dietrich, Carsten Leven i Olaf A. Cirpka. "Structural controls on the hydrogeological functioning of a floodplain". Hydrogeology Journal 28, nr 8 (22.08.2020): 2675–96. http://dx.doi.org/10.1007/s10040-020-02225-8.
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AbstractFloodplains are often conceptualized as homogeneous sediment bodies which connect streams with their respective catchment and buffer agricultural inputs. This has led to a general bias within the hydrological community towards research on sites where the floodplain is a clear conduit for groundwater flow. In humid temperate regions of central Europe, floodplains have experienced rapid environmental changes since the last glaciation, yielding significant bedrock weathering and predominantly fine-grained, highly stratified hillslope and floodplain sediments. Such heterogeneous sedimentary architecture leads to conceptual ambiguities in the interpretation of the hydrogeological functioning of floodplains, thus raising the question: Do floodplains act as barriers or conduits to groundwater flow? This study analyzes the Ammer floodplain close to Tübingen in south-western Germany as a representative mid-section floodplain in a temperate climate where the regional bedrock-geology is dominated by mudstones. Geological, geophysical, and geochemical characterization and monitoring techniques were combined to shed light on the internal geological structure as a key control modulating the floodplain hydrology. Two partially separate groundwater systems were identified: a gravel body at the bottom of the Quaternary sediments and a Holocene confined tufaceous aquifer, separated by low-permeability clays. Despite flow being predominantly along-valley, sulfate concentrations in the floodplain aquifers showed evidence of a strong connection to the gypsum-bearing hillslope, particularly where tributary valley sediments are present (e.g., alluvial fans). Results from a floodplain water balance suggest the hillslope- and floodplain-aquifer material act as a barrier to hillslope groundwater recharge, where a large fraction may be bypassing the local floodplain groundwater system.
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Morton, SR, KG Brennan i MD Armstrong. "Distribution and abundance of grebes, pelicans, darters, cormorants, rails and terns in the Alligator Rivers Region, Northern Territory". Wildlife Research 20, nr 2 (1993): 203. http://dx.doi.org/10.1071/wr9930203.
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Aerial surveys between 1981 and 1984 were used to identify monthly trends in the abundance of Australian pelicans (Pelecanus conspicillatus), darters (Anhinga melanogaster), little pied cormorants (Phalacrocorax melanoleucos), and whiskered terns (Chlidonias hybrida) on five floodplains of the Alligator Rivers region, 250 km east of Darwin in the monsoonal Northern Territory. Ground surveys were conducted during the same period on one of the floodplains, the Magela plain. The aerial surveys indicated that the Magela floodplain was inhabited by few of these birds during the wet season (November-March), but that numbers then increased substantially in the dry season. The Nourlangie floodplain showed similar patterns, but the numbers of birds tended to be lower. Birds were generally uncommon on the shallower East Alligator and Cooper floodplains. Ground surveys suggested that the birds sought out the persistent swamps that characterise the Magela floodplain in the dry season. Ground surveys also indicated that aerial surveys underestimated densities; on the basis of correction factors calculated from ground surveys, peak numbers on the five floodplains were roughly estimated to be about 2000 darters, 9000 little pied cormorants, 55 000 Australian pelicans and 50 000 whiskered terns. Little black cormorants (Phalacrocorax sulcirostrus) were sometimes abundant, but their sporadic occurrence prevented analysis of seasonal trends. Australasian grebes (Tachybaptus novaehollandiae), great cormorants (Phalacrocorax carbo), pied cormorants (Phalacrocorax varius), buff-banded rails (Rallus philippensis), Baillon's crakes (Porzana pusilla), white-browed crakes (Poliolimnas cinereus), purple swamphens (Porphyrio porphyrio), Eurasian coots (Fulica atra), silver gulls (Larus novaehollandiae), white-winged terns (Chlidonias leucoptera), gull-billed terns (Gelochelidon nilotica) and Caspian terns (Hydroprogne caspia) were recorded in low numbers. The Alligator Rivers region acted as an important dry season refuge because of the unusually persistent fresh waters of the Magela and Nourlangie floodplains and some of the backswamps of the South Alligator, such as Boggy Plain.
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Horáčková, Jitka, Štěpánka Podroužková i Lucie Juřičková. "River Floodplains as Habitat and Bio-Corridors for Distribution of Land Snails: Their Past and Present". Journal of Landscape Ecology 8, nr 3 (1.12.2015): 23–39. http://dx.doi.org/10.1515/jlecol-2015-0012.
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Abstract River floodplains of Czech rivers serve as refugia to woodland or hydrophilous gastropods, in current intensively agriculturally utilised, urbanised and largely fragmented landscape. This habitat often form one of the last refuge and replace the natural habitat of these species. River floodplains also represent linear bio-corridors in landscape and allow gastropods to spread through the landscape in both directions, up and down the stream. We showed based on available fossil mollusc successions that development of the floodplain mollusc fauna took place quite different way in various river floodplains, depending on their specifics and geographical location, because especially the ones situated in the chernozem area of the Czech Republic had very different history in comparison with those in higher altitudes. The species richness and composition of recent floodplain malacofauna arises from historical development of particular area/site and depends also on environmental factors such as an elevation, humidity gradient, vegetation type and its biomass, light conditions of the site and soil reaction. Recently, the invasive plants represent a serious problem for current floodplain ecosystems; species richness and abundances of terrestrial mollusc floodplain assemblages are changing due to their effect. The impact on gastropods is species-specific and was described for the following species: Impatiens glandulifera, Fallopia japonica subsp. japonica, F. sachalinensis, F. ×bohemica.
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Hill, Nicholas M., i David J. Garbary. "Habitat may limit herb migration at the northern edge of the Appalachian deciduous forest *This paper is dedicated to our botanical mentor, the late Dr. Sam P. Vander Kloet." Botany 89, nr 9 (wrzesień 2011): 635–45. http://dx.doi.org/10.1139/b11-055.
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Forest herbs account for greater species richness than any other plant type in deciduous forests and are the most vulnerable to anthropogenic disturbances. We examined whether the limited distribution of rare Appalachian forest herbs in Nova Scotia is related to edaphic specialization or a history of anthropogenic disturbance. Remnant populations are restricted to floodplain forest, where both habitat factors and disturbance history differ significantly from those of adjacent upland sugar maple forest. Contrasting soil and litter layers between floodplain stands and adjacent upland sites revealed the latter to be deficient in key cations (calcium, magnesium, boron); however, regression models for uplands and for floodplains showed that native herb richness was related to soil fertility in each case. Soil calcium accounted for most of the species richness variation among floodplains for native herbs and for a large seeded guild that contains most of the rare species on floodplains. Given the widespread anthropogenic decalcification of forest soils throughout eastern North America, conservation efforts must (i) increase and connect deciduous forest floodplain ecosystems and (ii) understand how to manage and create suitable cation-rich migration corridors in the forest landscape.
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Pusey, Bradley J., Timothy D. Jardine, Stuart E. Bunn i Michael M. Douglas. "Sea catfishes (Ariidae) feeding on freshwater floodplains of northern Australia". Marine and Freshwater Research 71, nr 12 (2020): 1628. http://dx.doi.org/10.1071/mf20012.
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Flooding of the terminal floodplains of northern Australian rivers provides a greatly expanded, productive habitat accessed by both freshwater and estuarine fishes. This study aimed to determine the extent to which sea catfishes (Ariidae) make use of floodplains and the reasons for doing so (i.e. spawning, feeding). Nine species were collected from floodplains and adjacent distributaries of the Mitchell and Flinders rivers; floodplain use was largely restricted to freshwater species. Evidence of prior wet season spawning was recorded for some species, and mesenteric lipid deposits indicated that fish were in good condition. However, little evidence of spawning on floodplains was found. Stomach content analysis and stable isotope analysis indicated dietary partitioning, particularly between freshwater and estuarine species, but also within freshwater species, and indicated that some species were responsive to variations in food availability. Isotope analyses suggest extensive movement between freshwater, estuarine and marine habitats at different life history stages for the catfish assemblage studied. Terminal floodplains of northern Australian rivers provide important temporary habitat for adult sea catfishes to feed upon, but do not appear to be used as spawning grounds.
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Higgisson, William, Dianne Gleeson, Linda Broadhurst i Fiona Dyer. "Genetic diversity and gene flow patterns in two riverine plant species with contrasting life-history traits and distributions across a large inland floodplain". Australian Journal of Botany 68, nr 5 (2020): 384. http://dx.doi.org/10.1071/bt20074.
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Gene flow is a key evolutionary driver of spatial genetic structure, reflecting demographic processes and dispersal mechanisms. Understanding how genetic structure is maintained across a landscape can assist in setting conservation objectives. In Australia, floodplains naturally experience highly variable flooding regimes that structure the vegetation communities. Flooding plays an important role, connecting communities on floodplains and enabling dispersal via hydrochory. Water resource development has changed the lateral-connectivity of floodplain-river systems. One possible consequence of these changes is reduced physical and subsequent genetic connections. This study aimed to identify and compare the population structure and dispersal patterns of tangled lignum (Duma florulenta) and river cooba (Acacia stenophylla) across a large inland floodplain using a landscape genetics approach. Both species are widespread throughout flood prone areas of arid and semiarid Australia. Tangled lignum occurs on floodplains while river cooba occurs along rivers. Leaves were collected from 144 tangled lignum plants across 10 sites and 84 river cooba plants across 6 sites, on the floodplain of the lower and mid Lachlan River, and the Murrumbidgee River, NSW. DNA was extracted and genotyped using DArTseq platforms (double digest RADseq). Genetic diversity was compared with floodplain-river connection frequency, and genetic distance (FST) was compared with river distance, geographic distance and floodplain-river connection frequency between sites. Genetic similarity increased with increasing floodplain-river connection frequency in tangled lignum but not in river cooba. In tangled lignum, sites that experience more frequent flooding had greater genetic diversity and were more genetically homogenous. There was also an isolation by distance effect where increasing geographic distance correlated with increasing genetic differentiation in tangled lignum, but not in river cooba. The distribution of river cooba along rivers facilitates regular dispersal of seeds via hydrochory regardless of river level, while the dispersal of seeds of tangled lignum between patches is dependent on flooding events. The genetic impact of water resource development may be greater for species which occur on floodplains compared with species along river channels.
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Akodu, D. O., A. F. Aiyesanmi i W. B. Tomori. "Contamination and Possible Health Risks of Polycyclic Aromatic Hydrocarbons in Soil and Crops from Cultivated Floodplains of Some Rivers in Ekiti State, Southwest Nigeria". Journal of Applied Sciences and Environmental Management 27, nr 8 (3.09.2023): 1865–73. http://dx.doi.org/10.4314/jasem.v27i8.33.
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The demand for food in Nigeria has increased pressure on land use including floodplains despite possible contamination from the river catchments. The objective of this paper is to evaluate the contaminations and possible health risk of polycyclic aromatic hydrocarbons (PAHs) in soil from Irintan (Ogbese), Omi-Eye (Erio) and Egbigbu (Ayetoro) cultivated floodplains in Ekiti State, Nigeria using standard techniques. The soil samples were collected from 0-30cm depth at 5m, 25m and 45m perpendicular distances to the river course at lower, middle and upstream. The crop samples randomly collected on the floodplains were Talinum triangulare, Caspicum annum and Zea mays from each farm. Samples were appropriately treated and analyzed for polycyclic aromatic hydrocarbons and results used to estimate the possible health risk. PAHs concentration at each of the farm sites was found to be more than their corresponding controls.The ∑PAHs (µg/kg) in soil ranged 0.62-3.20, 0.38-2.33 and 0.09-1.75 at Irintan (Ogbese), Omi-Eye(Erio) and Egbigbu (Ayetoro) floodplains respectively and these values were categorized unpolluted. The ∑PAHs (µg/kg) was 1.24, 0.64 and 21.15 for T. triangulare, 2.62, 2.76 and 18.43 for C. annum and 0.70, 1.78 and 1.31 for Z. mays at Irintan, Omi-Eye and Egbigbu floodplain respectively. All the Benzo (a) pyrene equivalent concentration were less than the cancer screening value except in T. triangulare and C. annum at Egbigbu floodplain suggesting possible carcinogenic health concern in T. triangulare and C. annum at the floodplain. There could be a cause for concern for the consumption of these food crops by the exposed population.
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Ahmed, Hassan, Norio Tanaka i Nobuyuki Tamai. "Flow modeling and analysis of compound channel in river network with complex floodplains and groynes". Journal of Hydroinformatics 13, nr 3 (26.10.2010): 474–88. http://dx.doi.org/10.2166/hydro.2010.020.
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Presented here are flow simulations of a network of natural rivers flanked by one or two large and complex floodplains with impermeable groynes and bridge embankments using one- and quasi-two-dimensional dynamic flow models. The effects of the large floodplain storage capacity, momentum transfer interaction and apparent shear stress at the vertical interface between the main channel and floodplain on the flow-simulated discharge and water depth values could be well explained. The two models were tested and validated in the Arakawa River basin, Kanto Region, Japan. The simulated results show that the large floodplain storage capacity greatly affected the flow discharge and water depth results and cannot be neglected. The quasi-two-dimensional river flow model was used in a flow simulation of a compound channel with complex floodplains with groynes and gave more acceptable results. In the simulated case, the average reduction in flood discharge using floodplain groynes was about 7–15%. Thus, floodplain groynes can be effective for flood protection and attenuation.
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Molinari, Bianca, Ben Stewart-Koster, Tim J. Malthus i Stuart E. Bunn. "Assessing Spatial Variation in Algal Productivity in a Tropical River Floodplain Using Satellite Remote Sensing". Remote Sensing 13, nr 9 (28.04.2021): 1710. http://dx.doi.org/10.3390/rs13091710.
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Studies of tropical floodplains have shown that algae are the primary source material for higher consumers in freshwater aquatic habitats. Thus, methods that can predict the spatial variation of algal productivity provide an important input to better inform management and conservation of floodplains. In this study, a prediction of the spatial variability in algal productivity was made for the Mitchell River floodplain in northern Australia. The spatial variation of aquatic habitat types and turbidity were estimated using satellite remote sensing and then combined with statistical modelling to map the spatial variation in algal primary productivity. Open water and submerged plants habitats, covering 79% of the freshwater flooded floodplain extent, had higher rates of algal production compared to the 21% cover of emergent and floating aquatic plant habitats. Across the floodplain, the predicted average algal productivity was 150.9 ± 95.47 SD mg C m−2 d−1 and the total daily algal production was estimated to be 85.02 ± 0.07 SD ton C. This study provides a spatially explicit representation of habitat types, turbidity, and algal productivity on a tropical floodplain and presents an approach to map ‘hotspots’ of algal production and provide key insights into the functioning of complex floodplain–river ecosystems. As this approach uses satellite remotely sensed data, it can be applied in different floodplains worldwide to identify areas of high ecological value that may be sensitive to development and be used by decision makers and river managers to protect these important ecological assets.
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Nagayama, Shigeya, Munehiro Oota, Tomohiko Fujita, Jyun-ichi Kitamura, Toshifumi Minamoto, Seiichi Mori, Masayuki Kato i in. "Autumn dispersal and limited success of reproduction of the deepbody bitterling (Acheilognathus longipinnis) in terrestrialized floodplain". Knowledge & Management of Aquatic Ecosystems, nr 423 (2022): 4. http://dx.doi.org/10.1051/kmae/2022004.
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The terrestrialization of floodplains has become a concern to river managers and ecologists because it has degraded habitats for floodplain-dependent organisms. We examined the temporal distributions of the endangered deepbody bitterling (Acheilognathus longipinnis) throughout its life history, which is an autumn-spawning annual fish spending its egg and larval stages in unionid mussels and emerging in spring, to understand its population decline in the terrestrialized floodplains of the Kiso River, central Japan. We first validated our A. longipinnis environmental DNA (eDNA) sampling method and observed an 89.3% probability of consistency between the eDNA and the direct capture surveys of 56 floodplain waterbodies (FWBs). Subsequently, the temporal distributions with autumn dispersal (9 of 14 FWBs) were found using time-series eDNA samples collected from 14 FWBs on a floodplain with a length and width of 1.4 and 0.2 km, respectively. In the following spring, juveniles were only detected in the two FWBs connected to the river channel. Moreover, the direct capture data revealed that juveniles occurred in 52.9% (9/17) of the connected FWBs, but only in 5.1% (2/39) of the FWBs isolated from the river channel. Autumn dispersal of A. longipinnis would be disadvantageous for reproduction in terrestrialized floodplains with numerous isolated FWBs.
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Pettit, N. E., P. Bayliss i R. Bartolo. "Dynamics of plant communities and the impact of saltwater intrusion on the floodplains of Kakadu National Park". Marine and Freshwater Research 69, nr 7 (2018): 1124. http://dx.doi.org/10.1071/mf16148.
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The distribution of vegetation communities on floodplains within Kakadu National Park, in tropical northern Australia, is related to micro-topography and, therefore, water depth and duration of flooding. Floodplains of the Kakadu Region, because of their proximity to the coast, are most vulnerable to the impacts of climate change, with saltwater intrusion, as a result of sea-level rise, being a serious risk. Our main objectives were to determine the variability of the distribution of plant communities on the floodplains and understand the potential risk of increased saltwater intrusion to these communities. We present data on the natural salinity-tolerance range of selected floodplain plants and discuss the likely effects of saltwater intrusion on floodplain plant distributions and productivity. The results of change analysis using high spatial-resolution satellite data showed the importance of the variation of water availability in determining patterns of plant communities. Hydrodynamic modelling suggests that sea level rises will result in 40% of the floodplain transformed into saline habitats by 2070. The most obvious effect of this would be the conversion of the freshwater vegetation to salt-tolerant mangroves and other salt-marsh plants, with a concomitant change in animals and their use of these areas.
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Li, Mengfan, i Yunliang Li. "On the Hydrodynamic Behavior of the Changed River–Lake Relationship in a Large Floodplain System, Poyang Lake (China)". Water 12, nr 3 (26.02.2020): 626. http://dx.doi.org/10.3390/w12030626.
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Poyang lake floodplains are hydrologically complex and dynamic systems which exhibit dramatic intra-annual wetting and drying. The flow regime of the Yangtze River was previously known to play an important role in affecting Poyang Lake and its extremely productive floodplains (river–lake relationship). The recent severe declines and recessions in the lake are closely linked to the changed river–lake relationship, resulting in significant hydrological, ecological, and economic problems. This study aims to examine the spatiotemporal heterogeneity of the floodplain hydrodynamic behaviors with respect to impacts of the changed river–lake relationship, characterized by the lake water level, inundation area, and inundation duration based on a floodplain hydrodynamic model of Poyang Lake, and to further quantify the severity of dryness recently endured since 2000. Simulation results show that, in general, the current modified river–lake relationship is more likely to affect the hydrological seasonality of the floodplain system since 2000, relative to the flooding and drying cycles during past decades (1953–2000). The present hydrodynamic behaviors suffered significant change due to the greatest interference from the altered river–lake relationship, particularly for the falling period in October. On average, the floodplain water level and inundation duration decreased by 6 m and 12 days during October, respectively. Additionally, the highest monthly shrinkage rate in floodplain inundation shifted from the period of October–November to September–October, with the mean inundation area decreasing by around 50%, demonstrating an advanced and prolonged dry condition. The spatial responses of the hydrodynamics in the low-slope floodplains are most likely to be affected by the dynamic river–lake relationship, as expected. This study assessed the effects of the altered river–lake relationship on the hydrological regime of the Poyang Lake floodplains in terms of spatiotemporal distributions and changing processes for the periodic inundated behavior, which can support the relevant study of the subsequent ecological effects on the wetlands.
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Morton, SR, KG Brennan i MD Armstrong. "Distribution and abundance of herons, egrets, ibises and spoonbills in the Alligator Rivers Region, Northern Territory". Wildlife Research 20, nr 1 (1993): 23. http://dx.doi.org/10.1071/wr9930023.
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Aerial surveys between 1981 and 1984 were used to identify monthly trends in the abundance of Pacific herons (Ardea pacifica), pied herons (Ardea picata), cattle egrets (Ardeola ibis), great egrets (Egretta alba), little egrets (Egretta garzetta), intermediate egrets (Egretta intermedia), glossy ibis (Plegadis falcinellus), sacred ibis (Threskiornis aethiopica), straw-necked ibis (Threskiornis spinicollis) and royal spoonbills (Platalea regia) on five floodplains of the Alligator Rivers region, 250 km east of Darwin in the monsoonal Northern Territory. Ground surveys were conducted during the same period on one of the floodplains, the Magela. The aerial surveys indicated that the Magela floodplain was inhabited by few of these birds during the wet season (November-March), but that numbers then increased substantially in the dry season. The Nourlangie floodplain and Boggy Plain (a large backswamp of the South Alligator floodplain) showed similar patterns, but the numbers of birds tended to be lower. Birds were generally uncommon on the shallower East Alligator and Cooper floodplains, except for egrets in the wet season. Ground surveys suggested that the birds sought out the persistent swamps that characterise the Magela foodplain in the dry season. Ground surveys also indicated that aerial surveys underestimated densities. On the basis of correction factors calculated from ground surveys, peak numbers on the five floodplains were roughly estimated to be about 4000 pacific herons, 50 000 pied herons, 300 000 egrets (primarily intermediate egrets), 60 000 glossy ibis, 16 000 sacred ibis, 80 000 straw-necked ibis and 35 000 royal spoonbills. Great-billed herons (Ardea sumatrana), white-faced herons (Ardea novaehollandiae), striated herons (Butorides striata), rufous night herons (Nycticorax caledonicus), black bitterns (Dupetor flavicollis) and yellow-billed spoonbills (Platalea flavipes) were recorded sporadically in low numbers. The Alligator Rivers region acted as a dry-season refuge for herons, egrets, ibises and spoonbills because of the unusually persistent fresh waters of the Magela and Nourlangie floodplains and some of the backswamps of the South Alligator, such as Boggy Plain.
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Cao, Yang, i Yosihiro Natuhara. "Effect of Anthropogenic Disturbance on Floristic Homogenization in the Floodplain Landscape: Insights from the Taxonomic and Functional Perspectives". Forests 11, nr 10 (25.09.2020): 1036. http://dx.doi.org/10.3390/f11101036.
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Anthropogenic disturbances pose significant threats to biodiversity. However, limited information has been acquired regarding the degree of impact human disturbance has on the β-diversity of plant assemblages, especially in threatened ecosystems (e.g., floodplains). In the present study, the effects of anthropogenic disturbance on plant communities of floodplain areas (the Miya River, Mie Prefecture, Japan) were analyzed. The taxonomic and functional β-diversity among different degradation levels were compared, and the differences were assessed by tests for homogeneity in multivariate dispersions. In addition, the effects of non-native species and environmental factors on β-diversity were analyzed. As revealed from the results, anthropogenic disturbance led to taxonomic homogenization at a regional scale. The increase in non-native invasions tended to improve homogenization, whereas at a low degradation level, the occurrence of non-natives species was usually related to taxonomic differentiation. Furthermore, though the increase in non-natives and environmental parameters significantly affected the β-diversity of the floodplain area, environmental factors may be of more crucial importance than biotic interactions in shaping species assemblages in this study. The previously mentioned result is likely to be dependent on the research scale and the extent to which floodplains are disturbed. Given the significant importance of floodplains, the significance of looking at floodplains in the different levels of degradation was highlighted, and both invasion of non-native species and environmental factors should be considered to gain insights into the response of ecosystems to anthropogenic disturbance. The findings of this study suggested that conservation programs in floodplain areas should place more emphasis on the preservation of natural processes and forest resources.
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Chen, X., L. Chen, J. Zhao i Z. Yu. "Modeling the hydrodynamic interactions between the main channel and the floodplain at McCarran Ranch in the lower Truckee River, Nevada". Natural Hazards and Earth System Sciences 15, nr 9 (30.09.2015): 2161–72. http://dx.doi.org/10.5194/nhess-15-2161-2015.
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Abstract. This study applied the two-dimensional AdH (adaptive hydraulics) hydrodynamic model to a river reach to analyze flood hydraulics on complex floodplains. Using the AdH model combined with bathymetry and topographic data from the United States Geological Survey (USGS) seamless server and the United States Army Corps of Engineers (USACE), we intended to examine the interactions between the channel and floodplain of a 10 km stretch at McCarran Ranch, which is located at the lower Truckee River in Nevada. After calibrating the model, we tested the dependence of the modeling results on mesh density, input parameters, and time steps and compared the modeling results to the existing gauged data (both the discharge and water stage heights). Results show that the accuracy of prediction from the AdH model may decline slightly at higher discharges and water levels. The modeling results are more sensitive to the roughness coefficient of the main channel, which suggests that the model calibration should give priority to the main channel roughness. A detailed analysis of the floodwater dynamics was then conducted using the modeling approach to examine the hydraulic linkage between the main channel and floodplains. We found that large flood events could lead to a significantly higher proportion of total flow being routed through the floodplains. During peak discharges, a river channel diverted as much as 65 % of the total discharge into the floodplain. During the periods of overbank flow, the transboundary flux ratio was approximately 5 to 45 % of the total river discharge, which indicates substantial exchange between the main channel and floodplains. The results also showed that both the relations of the inundation area and volume versus the discharge exhibit an apparent looped curve form, which suggests that flood routing has an areal hysteresis effect on floodplains.
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Čerba, Dubravka, Miran Koh, Barbara Vlaičević, Ivana Turković Čakalić, Djuradj Milošević i Milica Stojković Piperac. "Diversity of Periphytic Chironomidae on Different Substrate Types in a Floodplain Aquatic Ecosystem". Diversity 14, nr 4 (31.03.2022): 264. http://dx.doi.org/10.3390/d14040264.
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Different types of water bodies in lowland river floodplains represent vital biodiversity havens and encompass diverse microhabitats, which are essential for structuring different macroinvertebrate communities. Chironomidae larvae (Diptera) are an inseparable part of these communities, with their high richness and abundance. In three water body types within the Danube floodplain Kopački Rit in Croatia, over the course of four sampling campaigns, we recorded 51 chironomid taxa in periphyton on macrophytes, twigs, and glass slides. The most diverse were chironomid communities on macrophytes, whilst month-old periphyton on twigs supported the least taxa. Cricotopus gr. sylvestris, Dicrotendipes lobiger, Dicrotendipes spp., Endochironomus albipennis, Glyptotendipes pallens agg., Polypedilum sordens and Polypedilum spp. were present in all studied microhabitats. The type of substrate is a very important factor influencing Chironomidae diversity and abundance, which was evident in the presence and dominance of Corynoneura gr. scutellata and Monopelopia tenuicalcar in the dense macrophyte canopy epiphyton. Finding pristine floodplains such as Kopački Rit can be very challenging, as such areas are increasingly altered by human activities. Studies of resident species and the extent to which changes in the parent river influence floodplain communities are important for the protection and restoration of the floodplains.
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Akter, Mahbuba, Tahmina Afroz i Md Ghulam Mustafa. "Aquaculture practices in two seasonal floodplains of Bangladesh". Bangladesh Journal of Zoology 41, nr 2 (13.05.2015): 217–28. http://dx.doi.org/10.3329/bjz.v41i2.23324.
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A comparative technical and economic analysis of two communitybased seasonal floodplains (Khirai and Angrail) of Daudkandi Upazila, Comilla during 2008 to 2010, are represented in this paper. The two floodplains differed mainly in management and fish production which were related to capital investment, variable cost, share of profits and proportional reimbursement to the fishers. Local management committees have been developed in each floodplain with significant differences. Average 142 kg/ha of fish fingerlings (carps such as Catla catla, Labeo rohita, Cirrhinus cirrhosus, Labeo calbasu, Labeo bata and exotic species such as Hypopthalmicthys molitrix, Aristichthys nobilis, Cyprinus carpio, Ctenopharyngodon idella, Pungasius hypophthalmus, Barbonymus gonionotus, Oreochromis niloticus) were stocked at the varying proportions. Fish production obtained were 2.8 to 4.4 mt/ha and 1.1 to 1.3 mt/ha in Khirai and Angrail floodplain, respectively. The average cost of fish production, total income and the net income have been estimated as Tk. 209650 ± 54167.12/ha, Tk. 281306 ± 88263.42/ha and Tk. 71656 ± 35152.51/ha in Khirai floodplain and Tk. 62349 ± 5768.90/ha, Tk. 111930 ± 12711.02/ha and Tk. 49580 ± 6948.26/ha in Angrail floodplain, respectively. The benefit cost ratio (BCR) has been recorded as 1.33 and 1.79 in Khirai and Angrail floodplain, respectively. The results reveal that the fish production and economic benefit was higher in Khirai floodplain.Bangladesh J. Zool. 41(2): 217-228, 2013
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Solodovnikov, Denis. "Methodological Foundation of Ground-Water Dynamic Modeling in River Floodplains on the Example of the Volga-Akhtuba Floodplain". Natural Systems and Resources, nr 3 (grudzień 2018): 67–74. http://dx.doi.org/10.15688/nsr.jvolsu.2018.3.8.
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The necessity for an integrated geographical approach to the study and modeling of ground-water dynamics in river floodplains is substantiated in the article. A preliminary and simplified classification of the types of annual ground and surface water level dynamics is proposed, which can serve as a basis for the differentiation of intrazonal floodplain landscapes. Thus differentiation is a scientific problem. In landscapes characterizing of the floodplains a descriptive approach prevails, and there are no quantitative criteria for differentiating such natural complexes. The research aims to study the interaction of the most important components of the landscape of a river floodplain – surface and groundwater, soil and vegetation. The research methodical feature is to obtain the accurate quantitative characteristics that can be formalized, processed by modern computers and comparable with data from other regions. This will be achieved by modern electronic equipment usage (georadar, spectroradiometer) and the development of digital models of the landscape components dynamics. As a result of the research, objective, compara ble with each other and in long-term dynamics, characteristics of floodplain landscapes will be obtained. The scientific significance of the work is to identify the links of surface and groundwater, soil and vegetation in the rivers floodplains of the arid zone, to obtain an objective quantitative basis for assessing changes in floodplain landscapes. Using the results of the research will allow us to subsequently evaluate the long-term changes in the components of the floodplain landscapes. The applied significance of the research is the ability to use the obtained model to predict the groundwater dynamics, and, accordingly, the forestgrowing conditions of the Volga-Akhtuba floodplain, the state of surface watercourse and underground water sources in rural areas.
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Sándor, Andrea, i Tímea Kiss. "Floodplain aggradation caused by the high magnitude flood of 2006 in the lower Tisza region, Hungary". Journal of Environmental Geography 1, nr 1-2 (1.01.2008): 31–39. http://dx.doi.org/10.14232/jengeo-2008-43855.
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The area of floodplains in the Carpathian Basin was dramatically reduced as a result of river regulation works in the 19th century. Therefore, the accumulation processes were limited to the narrower floodplains. The aims of the presented study are to determine the rate of accumulation caused by a single flood event on the active, narrow floodplain of the Lower Tisza and to evaluate the relations between the aggradation, flow velocity during the peak of the flood and the canopy. The uncultivated lands in the study area cause increased roughness which decreased the velocity of the flood, influencing the rate of aggradation. The highest flow velocity was measured on points where the flood entered to the floodplain and at the foot of the levee. These points were characterised by thick (over 50 mm) and coarse sandy sediment. In the inner parts of the floodplain flood conductivity zones were formed, where the vegetational roughness was small. In the inner parts of the floodplain the rate of aggradation was influenced by the geomorphology and the vegetation density of the area.
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Lóczy, Dénes, József Dezső i Levente Ronczyk. "Floodplain rehabilitation projects in Hungary: Case studies from the Danube, Tisza, Körös and Drava rivers". Glasnik Srpskog geografskog drustva 96, nr 1 (2016): 1–10. http://dx.doi.org/10.2298/gsgd1601001l.
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Floodplains along regulated rivers often suffer from serious environmental degradation. River and floodplain rehabilitation measures along the major rivers of Hungary are motivated by two objectives: to inrease the floodwater retention capacity of floodplains (also beyond the dykes) and to improve the ecological conditions of floodplain habitats (with special regard to oxbow lakes). In this paper reports and documents mostly written in Hungarian are presented for the international public on river and floodplain rehabilitation efforts. Examples for the water management objective are cited from the Tisza and K?r?s Rivers, while interventions promoting the second, nature conservation (and also forestry and agriculture), aim are mentioned from the Danube and Drava Rivers. A common characteristic of the case studies is that they apply ?hard engineering? solutions to environmental problems. Although water availability in the Szigetk?z floodplain has substantially improved after the building of the bottom weir, the efficiency of the recently implemented engineering measures (the emergency reservoirs along the Tisza and water replenishment structures along the Drava) is too early to judge.
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Lóczy, Dénes, József Dezső, Szabolcs Czigány i Ervin Pirkhoffer. "Hydromorphological assessment of the lower Hungarian Drava section and its floodplain". Landscape & Environment 10, nr 3-4 (28.08.2016): 109–16. http://dx.doi.org/10.21120/le/10/3-4/2.
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The hydromorphological properties of rivers and their floodplains receive increased attention both in basic research and water management. A comparison of hydromorphological parameters before and after river regulation (involving floodplain drainage) provides important information for river management, particularly floodplain rehabilitation. The paper assesses a selected reach of the Drava River and the corresponding floodplain utilising two international approaches, the REFORM framework and the Italian Morphological Quality Index.
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Marren, Philip M., James R. Grove, J. Angus Webb i Michael J. Stewardson. "The Potential for Dams to Impact Lowland Meandering River Floodplain Geomorphology". Scientific World Journal 2014 (2014): 1–24. http://dx.doi.org/10.1155/2014/309673.
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The majority of the world's floodplains are dammed. Although some implications of dams for riverine ecology and for river channel morphology are well understood, there is less research on the impacts of dams on floodplain geomorphology. We review studies from dammed and undammed rivers and include influences on vertical and lateral accretion, meander migration and cutoff formation, avulsion, and interactions with floodplain vegetation. The results are synthesized into a conceptual model of the effects of dams on the major geomorphic influences on floodplain development. This model is used to assess the likely consequences of eight dam and flow regulation scenarios for floodplain geomorphology. Sediment starvation downstream of dams has perhaps the greatest potential to impact on floodplain development. Such effects will persist further downstream where tributary sediment inputs are relatively low and there is minimal buffering by alluvial sediment stores. We can identify several ways in which floodplains might potentially be affected by dams, with varying degrees of confidence, including a distinction between passive impacts (floodplain disconnection) and active impacts (changes in geomorphological processes and functioning). These active processes are likely to have more serious implications for floodplain function and emphasize both the need for future research and the need for an “environmental sediment regime” to operate alongside environmental flows.