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1.
Although in-channel and floodplain large wood (LW) has been recognized as an important component of lotic ecosystems, there is still limited knowledge on the recruitment, mobility and retention of LW in rivers with an intermittent hydrological regime. In this study, we analysed the LW characteristics and related reach-scale variables of 22 reaches in a Mediterranean intermittent river (Evrotas, Greece) in order to identify predictors of in-channel and floodplain LW distribution. Our results indicated high downstream variation in LW volumes in the fluvial corridor (0.05–25.51 m3/ha for in-channel LW and 0–30.88 m3/ha for floodplain LW). In-channel and floodplain LW retention was primarily driven by the hydrological regime of the studied reaches (i.e. perennial or non-perennial) with higher volumes of LW observed in perennial sections. The width of the riparian corridor was an important predictor of LW storage at the reach scale. Non-perennial reaches had a disproportionally larger number of relatively small-diameter living trees at the expense of mature trees with larger diameters typical for riparian stands functioning as LW recruitment areas in perennial reaches. The smaller dimensions of in-channel LW in non-perennial reaches, coupled with the dominance of loose LW pieces, implies frequent LW transport during ordinary flood events. Nevertheless, overall low LW retention in the fluvial corridor under non-perennial flow regime predicts low volumes of mobilized LW. In contrast, the recruitment of relatively long and large-diameter LW from mature riparian stands in perennial reaches, together with additional LW stabilization by banks, bed sediments, living trees or other LW pieces decreases the potential for further LW transport. © 2020 John Wiley & Sons, Ltd.  相似文献   

2.
After more than 300 years of river management, scientific knowledge of European river systems has evolved with limited empirical knowledge of truly natural systems. In particular, little is known of the mechanisms supporting the evolution and maintenance of islands and secondary channels. The dynamic, gravel‐bed Fiume Tagliamento, Italy, provides an opportunity to acquire baseline data from a river where the level of direct engineering intervention along the main stem is remarkably small. Against a background of a strong alpine to mediterranean climatic and hydrological gradient, this paper explores relationships between topography, sediment and vegetation at eight sites along the active zone of the Tagliamento. A conceptual model of island development is proposed which integrates the interactions between large woody debris and vegetation, geomorphic features, sediment calibre and hydrological regime. Islands may develop on bare gravel sites or be dissected from the floodplain by channel avulsion. Depositional and erosional processes result in different island types and developmental stages. Differences in the apparent trajectories of island development are identified for each of the eight study sites along the river. The management implications of the model and associated observations of the role of riparian vegetation in island development are considered. In particular, the potential impacts of woody debris removal, riparian tree management, regulation of river flow and sediment regimes, and changes in riparian tree species' distribution are discussed. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   

3.
Field, laboratory, and numerical modelling research are increasingly demonstrating the potential of riparian tree colonization and growth to influence fluvial dynamics and the evolution of fluvial landforms. This paper jointly analyses multi‐temporal, multispectral ASTER data, continuous river stage and discharge data, and field observations of the growth rates of the dominant riparian tree species (Populus nigra) along a 21 km reach of the Tagliamento River, Italy. Research focuses on the period 2004–2009, during which there was a bankfull flood on 24 October 2004, followed by 2 years with low water levels, nearly 2 years with only modest flow pulses, and then a final period from 15 August 2008 that included several intermediate to bankfull flow events. This study period of increasing flow disturbance allows the exploration of vegetation dynamics within the river's active corridor under changing flow conditions. The analysis demonstrates the utility of ASTER data for investigating vegetation dynamics along large fluvial corridors and reveals both spatial and temporal variations in the expansion, coalescence, and erosion of vegetated patches within the study reach. Changes in the extent of the vegetated area and its dynamics vary along the study reach. In sub‐reaches where riparian tree growth is vigorous, the vegetated area expands rapidly during time periods without channel‐shaping flows, and is subsequently able to resist erosion by bankfull floods. In contrast, in sub‐reaches where tree growth is less vigorous, the vegetated area expands at a slower rate and is more readily re‐set by bankfull flood events. This illustrates that the rate of growth of riparian trees is crucial to their ability to contribute actively to river corridor dynamics. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

4.
Storage of large woody debris in the wide, mountain, Czarny Dunajec River, southern Poland, was investigated following two floods of June and July 2001 with a seven‐year frequency. Within a reach, to which wood was delivered only by bank erosion and transport from upstream, wood quantities were estimated for eighty‐nine, 100 m long, channel segments grouped into nine sections of similar morphology. Results from regression analysis indicated the quantity of stored wood to be directly related to the length of eroded, wooded banks and river width, and inversely related to unit stream power at the flood peak. The largest quantities of wood (up to 33 t ha?1) were stored in wide, multi‐thread river sections. Here, the relatively low transporting ability of the river facilitated deposition of transported wood while a considerable length of eroded channel and island banks resulted in a large number of trees delivered from the local riparian forest. In these sections, a few morphological and ecological situations led to the accumulation of especially large quantities of wood within a small river area. Very low amounts of wood were stored in narrow, single‐thread sections of regulated or bedrock channel. High stream power facilitated transport of wood through these sections while the high strength of the banks and low channel sinuosity prevented bank retreat and delivery of trees to the channel. Considerable differences in the character of deposited wood existed between wide, multi‐thread channel sections located at different distances below a narrow, 7 km long, channellized reach of the river. Wood deposited close to the downstream end of the channellized reach was highly disintegrated and structured into jams, whereas further downstream well preserved shrubs and trees prevailed. This apparently reflects differences in the distance of wood transport and shows that in a mountain river wider than the height of trees growing on its banks, wood can be transported long distances along relatively narrow, single‐thread reaches but is preferentially deposited in wide, multi‐thread reaches. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

5.
In parallel with research on surface sediment characteristics of evolving island features (patches) along an island‐braided reach of the Tagliamento River, Italy, the present research reconstructed the development of the sampled sites using historical information coupled with field measurements. Since any field sediment sampling programme inevitably focuses on small areas (of the order of a few metres), the historical sources were assessed bearing in mind their spatial resolution and geographical accuracy in relation to the size of the sampled sites, and the information they could provide regarding the historical evolution of those sites. The analysis combined four sources of information: (i) river stage records revealed flood events that had the potential to reset bar surfaces and float in wood and seeds to initiate vegetation colonization; (ii) oblique ground photographs identified areas of the river's active corridor where riparian vegetation colonization appeared to have been initiated by specific flood events; (iii) dendrochronology was used to estimate the age of sampled sites; (iv) field‐measured geographical locations of the sampled sites were combined with historical vertical areal imagery to further establish sampling site age and changes in vegetation cover from 1944 to 2012. A chronosequence of sampled sites (0, 2, 8, 12, 40 years) was established. Vegetation colonization and island development showed a statistically significant development trajectory among sites of each age across the 40 year period following formative floods in 1965–1966, 2000, 2004 and a flow pulse in 2010. The trajectory progressed through pioneer and building island stages until vegetated areas became part of established islands. Evidence from the younger sites indicates that the pioneer island phase lasts up to eight years. Evidence from the oldest site indicates a building island phase lasting a maximum of 30 years, but probably a lot less. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

6.
Tree roots contribute to the resistance of riparian sediments to physical deformation and disintegration. Understanding reinforcement by roots requires information on root distributions within riparian soils and sediments. Continuous‐depth models or curves have been proposed to describe vertical root density variations, providing useful indicators of the types of function that may be appropriate to riparian trees, but have generally been estimated for terrestrial species or broad vegetation types rather than riparian species or environments. We investigated vertical distributions of roots >0.1 mm diameter of a single riparian tree species (Populus nigra L.) along the middle reaches of a single river (Tagliamento River, Italy), where Populus nigra dominates the riparian woodland. Root density (hundreds m?2) and root area ratio (RAR in cm2 m?2) were measured within 10 cm depth increments of 24 excavated bank profiles across nine sites. Sediment samples, extracted from distinct strata within the profiles, were analysed for moisture content, organic matter content and particle size. Statistical analyses identified two groups of wetter and drier profiles and five sediment types. Following loge‐transformation of root density and RAR, linear regression analysis explored their variation with depth and, using dummy variables, any additional influence of moisture and sediment type. Significant linear regression relationships were estimated between both root density and RAR and depth which explained only 15% and 8% of the variance in the data. Incorporating moisture and then sediment characteristics into the analysis increased the variance explained in root density to 29% and 36% and in RAR to 14% and 26%. We conclude that riparian tree root density and RAR are highly spatially variable and are poorly explained by depth alone. Complex riparian sedimentary structures and moisture conditions are important influences on root distributions and so need to be incorporated into assessments of the contribution of roots to river bank reinforcement. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

7.
Large wood tends to be deposited in specific geomorphic units within rivers. Nevertheless, predicting the spatial distribution of wood deposits once wood enters a river is still difficult because of the inherent complexity of its dynamics. In addition, the lack of long‐term observations or monitored sites has usually resulted in a rather incomplete understanding of the main factors controlling wood deposition under natural conditions. In this study, the deposition of large wood was investigated in the Czarny Dunajec River, Polish Carpathians, by linking numerical modelling and field observations so as to identify the main factors influencing wood retention in rivers. Results show that wood retention capacity is higher in unmanaged multi‐thread channels than in channelized, single‐thread reaches. We also identify preferential sites for wood deposition based on the probability of deposition under different flood scenarios, and observe different deposition patterns depending on the geomorphic configuration of the study reach. In addition, results indicate that wood is not always deposited in the geomorphic units with the highest roughness, except for low‐magnitude floods. We conclude that wood deposition is controlled by flood magnitude and the elevation of flooded surfaces in relation to the low‐flow water surface. In that sense, the elevation at which wood is deposited in rivers will differ between floods of different magnitude. Therefore, together with the morphology, flood magnitude represents the most significant control on wood deposition in mountain rivers wider than the height of riparian trees. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

8.
Using the River Tagliamento, Italy, as an example, we examine the role of self-organisation in the formation and dynamics of vegetated islands in fluvial ecosystems. We consider how various biogeomorphic processes, such as feedbacks between tree growth and sedimentation, influence island self-assembly, as well as the potential influences of island landforms on resource distribution and shifts in ecosystem state. Despite the abundance of island landforms of different sizes and ages in island-braided reaches along the River Tagliamento, island formation is only found within a specific hydrological and sedimentary envelope, and depends upon a delicate balance of biotic-abiotic feedbacks. As a result, island landforms tend to be lost when river functioning is altered by human interventions. We argue that the specific biogeomorphic processes and self-organisation associated with river island dynamics offer an example of biogeomorphic inheritance, in which reciprocal feedbacks between species and geomorphic processes favour engineer species and promote the future development of the landforms. Thus, islands represent extended phenotypes – or external expressions of genetic traits – of key riparian ecosystem engineers. This capacity to modify the physical environment has important implications for landform evolution and riparian biodiversity. In conclusion, we propose several topics that merit investigation to improve our understanding of the biogeomorphology and self-organisation of river island systems.  相似文献   

9.
We use field measurements and airborne LiDAR data to quantify the potential effects of valley geometry and large wood on channel erosional and depositional response to a large flood (estimated 150-year recurrence interval) in 2011 along a mountain stream. Topographic data along 3 km of Biscuit Brook in the Catskill Mountains, New York, USA reveal repeated downstream alternations between steep, narrow bedrock reaches and alluvial reaches that retain large wood, with wood loads as high as 1261 m3 ha−1. We hypothesized that, within alluvial reaches, geomorphic response to the flood, in the form of changes in bed elevation, net volume of sediment eroded or aggraded, and grain size, correlates with wood load. We hypothesized that greater wood load corresponds to lower modelled average velocity and less channel-bed erosion during the flood, and finer median bed grain size and a lower gradation coefficient of bed sediment. The results partly support this hypothesis. Wood results in lower reach-average modelled velocity for the 2011 flood, but the magnitude of change in channel-bed elevation after the 2011 flood among alluvial and bedrock reaches does not correlate with wood load. Wood load does correlate with changes in sediment volume and bed substrate, with finer grain size and smaller sediment gradation in reaches with more wood. The proportion of wood in jams is a stronger predictor of bed grain-size characteristics than is total wood load. We also see evidence of a threshold: greater wood load correlates with channel aggradation at wood loads exceeding approximately 200 m3 ha−1. In this mountain stream, abundant large wood in channel reaches with alluvial substrate creates lower velocity that results in finer bed material and, when wood load exceeds a threshold, reach scale increases in aggradation. This suggests that reintroducing small amounts of wood or one logjam for river restoration will have limited geomorphic effects. © 2020 John Wiley & Sons, Ltd.  相似文献   

10.
The Tagliamento River: A model ecosystem of European importance   总被引：5，自引：0，他引：5  
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11.
Rivers are dynamic components of the terrestrial carbon cycle and provide important functions in ecosystem processes. Although rivers act as conveyers of carbon to the oceans, rivers also retain carbon within riparian ecosystems along floodplains, with potential for long‐term (> 102 years) storage. Research in ecosystem processing emphasizes the importance of organic carbon (OC) in river systems, and estimates of OC fluxes in terrestrial freshwater systems indicate that a significant portion of terrestrial carbon is stored within river networks. Studies have examined soil OC on floodplains, but research that examines the potential mechanistic controls on OC storage in riparian ecosystems and floodplains is more limited. We emphasize three primary OC reservoirs within fluvial systems: (1) standing riparian biomass; (2) dead biomass as large wood (LW) in the stream and on the floodplain; (3) OC on and beneath the floodplain surface, including litter, humus, and soil organic carbon (SOC). This review focuses on studies that have framed research questions and results in the context of OC retention, accumulation and storage within the three primary pools along riparian ecosystems. In this paper, we (i) discuss the various reservoirs for OC storage in riparian ecosystems, (ii) discuss physical conditions that facilitate carbon retention and storage in riparian ecosystems, (iii) provide a synthesis of published OC storage in riparian ecosystems, (iv) present a conceptual model of the conditions that favor OC storage in riparian ecosystems, (v) briefly discuss human impacts on OC storage in riparian ecosystems, and (vi) highlight current knowledge gaps. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

12.
Habitat degradation in river ecosystems has considerably increased over the past decades, resulting in detrimental effects on aquatic and riparian communities. During the last two decades, the value of large wood as a resource for river restoration and recovery has been increasingly documented. However, post-project appraisal of the associations between restored large wood, morphological complexity and river ecology as a result of river restoration is extremely rare and thus scientific knowledge is essential. To investigate restored wood-induced morphological response and sediment complexity in an overwidened reach along a low gradient lowland river (River Bure, UK), two sub-reaches containing 12 jams initiated by wood emplacement in 2008 and 2010 and a sub-reach free of wood were studied. Wood surveys recording the dimensions and number of wood pieces in jams, geomorphological mapping of the reach illustrating the spatial distribution of features in and around the jams and in a section free of wood, and sediment sampling (analysed for particle size, organic content and plant propagule abundance) of five recurring patch types surrounding each jam (two wood-related patches and three representing the broader river environment) were performed. Wood jams partially spanned the river channel and contained large pieces of wood that created more open structures than naturally-formed wood jams. Where no wood was introduced, the channel remains wide and the gravel bed is buried by sand and finer sediment. In the restored reaches, fine sediment has accumulated in and around the wood jams and has been stabilised by vegetation colonisation, enhancing flow velocities in the narrowed channel sufficiently to mobilise fine sediment and expose the gravel bed. Sediment analysis reveals sediment fining with time since wood emplacement, largely achieved within the two wood-related patch types. Fine sediment retained around the wood shows a relatively higher plant propagule content than other patch types, suitable for sustaining plant succession as the vegetated side bars aggrade. Although channel narrowing and morphological adjustment has occurred surprisingly rapidly in this low energy, over-widened reach following wood introduction (2–4 years), sustaining the recovery in the longer term to suitably support flora and fauna communities depends on the continued delivery of wood by ensuring a natural supply of sufficiently large wood pieces from riparian trees both upstream and within the reach.  相似文献   

13.
This work addresses the temporal dynamics of riparian vegetation in large braided rivers, exploring the relationship between vegetation erosion and flood magnitude. In particular, it investigates the existence of a threshold discharge, or a range of discharges, above which erosion of vegetated patches within the channel occurs. The research was conducted on a 14 km long reach of the Tagliamento River, a braided river in north‐eastern Italy. Ten sets of aerial photographs were used to investigate vegetation dynamics in the period 1954–2011. By using different geographic information system (GIS) procedures, three aspects of geomorphic‐vegetation dynamics and interactions were addressed: (i) long‐term (1954–2011) channel evolution and vegetation dynamics; (ii) the relationship between vegetation erosion/establishment and flow regime; (iii) vegetation turnover, in the period 1986–2011. Results show that vegetation turnover is remarkably rapid in the study reach with 50% of in‐channel vegetation persisting for less than 5–6 years and only 10% of vegetation persisting for more than 18–19 years. The analysis shows that significant vegetation erosion is determined by relatively frequent floods, i.e. floods with a recurrence interval of c. 1–2.5 years, although some differences exist between sub‐reaches with different densities of vegetation cover. These findings suggest that the erosion of riparian vegetation in braided rivers may not be controlled solely by very large floods, as is the case for lower energy gravel‐bed rivers. Besides flow regime, other factors seem to play a significant role for in‐channel vegetation cover over long time spans. In particular, erosion of marginal vegetation, which supplies large wood elements to the channel, increased notably over the study period and was an important factor for in‐channel vegetation trends. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

14.
In this paper, we present a methodology to construct a sediment budget for meso‐scale catchments. We combine extensive field surveys and expert knowledge of the catchment with a sediment delivery model. The meso‐scale Mediterranean drainage basin of the Dragonja (91 km2), southwest Slovenia, was chosen as case study area. During the field surveys, sheet wash was observed on sloping agricultural fields during numerous rainfall events, which was found to be the main source of sediment. With the sediment yield model WATEM/SEDEM the estimated net erosion on the hillslopes 4·1 t ha–1 y–1 (91% of inputs). The second source, bank erosion (4·2%; 0·25 t ha–1 y–1) was monitored during several years with erosion pins and photogrammetric techniques. The last source, channel incision, was derived from geomorphological mapping and lichenomery and provided 3·8% (0·17 t ha–1 y–1) of the sediment input. The river transports its suspended sediment mainly during high‐flow events (sampled with automated water samplers). About 27% (1·2 t ha–1 y–1) of the sediment delivered to the channel is deposited on floodplains and low terraces downstream (estimated with geomorphological mapping, coring and cesium‐137 measurements). The sediment transported as bedload disintegrates during transport to the outlet due to the softness of the bedrock material. As a result, the river carries no bedload when it reaches the sea. The results imply a build‐up of sediment in the valleys catchment. However, extreme flood events may flush large amounts of sediment stored in the lower parts of the system. Geomorphological evidence exists in the catchment that such high magnitude, low frequency events have happened in the past. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

15.
Quantifying spatial and temporal dynamics of organic matter (OM) is critical both for understanding ecosystem functioning and for predicting impacts of landscape change. To determine the influence of different habitats and coarse particulate OM (CPOM) types upon floodplain OM dynamics, we quantified aerial input, lateral surface transfer, and surface storage of CPOM over an annual cycle on the near-natural floodplain of the River Tagliamento in NE-Italy. Using these data, we modelled floodplain leaf dynamics, taking account of the spatial distribution and hydrologic connectivity of habitats, and using leaf storage as a response variable. Mean aerial CPOM input to the floodplain was similar from riparian forest and islands, but surface transfer was greater from islands, supporting the suggestion that these habitats act as “islands of fertility” along braided rivers. Leaves were the lateral conveyor of energy to more open parts of the floodplain, whereas CPOM was mainly stored as small wood in vegetated islands and riparian forest. Simulating the loss of habitat diversity (islands, ponds) decreased leaf storage on the whole floodplain, on exposed gravel and in large wood accumulations. In contrast, damming (loss of islands, ponds and floods plus floodplain overgrowth) greatly increased storage on exposed gravel. A random shuffle of habitats led to a storage increase on exposed gravel, while that in large wood accumulations and ponds declined. These results disentangle some of the complexities of CPOM dynamics in floodplain ecosystems, illustrate the value of models in understanding ecosystem functioning at a landscape level, and directly inform river management practice.  相似文献   

16.
There is increasing demand for models that can accurately predict river temperature at the large spatial scales appropriate to river management. This paper combined summer water temperature data from a strategically designed, quality controlled network of 25 sites, with recently developed flexible spatial regression models, to understand and predict river temperature across a 3,000 km2 river catchment. Minimum, mean and maximum temperatures were modelled as a function of nine potential landscape covariates that represented proxies for heat and water exchange processes. Generalised additive models were used to allow for flexible responses. Spatial structure in the river network data (local spatial variation) was accounted for by including river network smoothers. Minimum and mean temperatures decreased with increasing elevation, riparian woodland and channel gradient. Maximum temperatures increased with channel width. There was greater between‐river and between‐reach variability in all temperature metrics in lower‐order rivers indicating that increased monitoring effort should be focussed at these smaller scales. The combination of strategic network design and recently developed spatial statistical approaches employed in this study have not been used in previous studies of river temperature. The resulting catchment scale temperature models provide a valuable quantitative tool for understanding and predicting river temperature variability at the catchment scales relevant to land use planning and fisheries management and provide a template for future studies.  相似文献   

17.
In the first decades of the 20th century, the Ebro River was the Iberian channel with the most active fluvial dynamics and the most remarkable spatial‐temporal evolution. Its meandering typology, the dimensions of its floodplain, and the singularities of its flow regime produced an especially interesting set of river functions. The largest dynamics of the Ebro River are concentrated along the meandering profile of the central sector. During the 20th century, this sector experienced a large alteration of its geomorphological structure. We present here an analysis of this evolution through the cartographic study of a long segment of the river (~250 km) in 1927, 1956 and 2003. The results show a large reduction in bank sinuosity, a progressive loss of fluvial territory, and a large decrease in channel width. These changes are especially clear in the areas previously most ecologically connected with the active channel. The fluvial territory of the river in 2003 was approximately half that found during the first decades of the 20th century. Forest plantations, which were non‐existent in 1927, occupied more than 1500 ha of the study area in the last decade. This intense geomorphological transformation becomes ecologically visible in (i) a 35% reduction of the area occupied by riparian vegetation; (ii) a loss of the heterogeneity of riparian forest spots, which were formerly structured in an irregular mosaic far from the river thalweg; and (iii) a modification of the riparian forest structure, which is currently linear, uniform, thin and very close to the river axis. The ecomorphological alteration was intensified by the remarkable reduction in bank length (13%) and the reduced dynamism of the present river system, indicated by an increase in the percentage of fluvial territory occupied by riparian forests and a reduction in the area occupied by the active channel. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   

18.
The role of wood as a driver of landform development appears to have been overlooked in the interpretation of palaeo‐landscape change along river corridors. Deforested river corridors and wood‐free rivers characterize ‘modern’, managed landscapes, but along natural river corridors both driftwood dynamics and tree reproductive strategies can have a dramatic impact on the style and rate of channel and floodplain development. Therefore, we believe that interpretations of the post‐glacial history of river valleys across the northern temperate climatic zone could be usefully reassessed, incorporating the roles of riparian trees. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

19.
Hydro‐geomorphological assessments are an essential component for riverine management plans. They usually require costly and time‐consuming field surveys to characterize the spatial variability of key variables such as flow depth, width, discharge, water surface slope, grain size and unit stream power throughout the river corridor. The objective of this research is to develop automated tools for hydro‐geomorphological assessments using high‐resolution LiDAR digital elevation models (DEMs). More specifically, this paper aims at developing geographic information system (GIS) tools to extract channel slope, width and discharge from 1 m‐resolution LiDAR DEMs to estimate the spatial distribution of unit stream power in two contrasted watersheds in Quebec: a small agricultural stream (Des Fèves River) and a large gravel‐bed river (Matane River). For slope, the centreline extracted from the raw LiDAR DEM was resampled at a coarser resolution using the minimum elevation value. The channel width extraction algorithm progressively increased the centerline from the raw DEM until thresholds of elevation differences and slopes were reached. Based on the comparison with over 4000 differential global positioning system (GPS) measurements of the water surface collected in a 50 km reach of the Matane River, the longitudinal profile and slope estimates extracted from the raw and resampled LiDAR DEMs were in very good agreement with the field measurements (correlation coefficients ranging from 0 · 83 to 0 · 87) and can thus be used to compute stream power. The extracted width also corresponded very well to the channel as seen from ortho‐photos, although the presence of bars in the Matane River increased the level of error in width estimates. The estimated maximum unit stream power spatial patterns corresponded well with field evidence of bank erosion, indicating that LiDAR DEMs can be used with confidence for initial hydro‐geomorphological assessments. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

20.
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