River Channel Changes Research Articles

Hydromorphological conditions of the lower Vistula in the development of navigation and hydropower

The article presents general principles of development of the lower Vistula channel in the Holocene period, with a particular emphasis on the unintentional human interference in the fluvial processes associated with deforestation and cultivation of cereals and root crops. It also characterises the basic hydraulic engineering works in the form of construction of embankments, adjustment of the bed and construction of the Wloclawek barrage as factors of deliberate human interference and their impact on channel changes. The article characterises morphological and morphodynamic conditions of the basic bed forms, i.e. sandy and gravel bars and pools determining the possibility of river transport, and its development in time and space (depth of navigable route). Perspectives of multi-directional hydraulic development are presented, including the main cascade developments of the lower Vistula. The article presents the opportunities for a comprehensive use of the waterway, which forms route E40 in the section of the lower Vistula, taking into account sustainable development and compensation in the form of restoration of the valley bottom. DOI: 10.12736/issn.2300-3022.2013206 Introduction The use of river waters for economic purposes is dependent on the hydromorphological features of their channels, shaped by the climate and human activity. The climate affects the fluvial processes by precipitation (water regime) and air temperature (growth of vegetation in the basin and ice phenomena), phenomena independent of humans. Human activity can have a direct and indirect impact on changes in river channels. The first case concerns a change in the structure of forests for agricultural fields; such works accelerate the natural water flow (runoff) and increase the supply of load to channels. In the second case we are dealing with deliberate water management, aimed at control of the water regime by all kinds of hydraulic structures, including embankments, adjustment of channels or dams. An additional factor affecting the development of inland navigation is the change in technical conditions of vessels, e.g. an increase in draft of river boats associated with the transition to motor power. However, the river water regime and the transport volume of bed load have a leading role in the conditions of development of water transport and hydropower; those phenomena shape the channel patterns with the system of bed mesoforms of positive sandbars and the opposing negative forms, pools. They determine the parameters of waterways (width and depth of water routes), durability and functionality of hydraulic structures, including hydropower (reservoir filling time). The purpose of this article is to present the main stages and general trends in the development of the bottom of the lower Vistula (dolna Wisla) valley on the section from the mouth of the Narew to the mouth of the Vistula (dolna Wisla) to the Baltic Sea (Fig. 1), with particular emphasis on the influence of human economic activity. This applies mainly to changes in the spatial arrangement of the river channel, as well as to vertical movements of the bottom associated with the process of erosion and deposition of clastic load, mainly bed load. The main purpose is to define the dynamics of bed mesoforms like sandbars and pools, with an indication of possible directions of adaptation in terms of development of international waterway E40, improvement for ferry and road passages, construction of dams, improvement (elimination) of flood conditions while maintaining sustainable development (environmental protection). Furthermore, the article is to present the possible full utilisation of water in the lower Vistula (dolna Wisla) for economic purposes, including revitalization of the valley floor. The study has been prepared on the basis of the literature and own research in the field of hydromorphological changes occurring in the lower Vistula (dolna Wisla) channel. The analysis Z. Babinski, M. Habel | Acta Energetica 2/15 (2013) | 83–90

Transformation of a lowland river from a meandering and multi-channel pattern into an artificial canal: retracing a path of river channel changes (the Middle Obra River, W Poland)

At the beginning of the nineteenth century, a significant change in sedimentation took place along the middle course of the Obra River (W Poland): a “natural” channel bed was replaced by three artificial canals. Before that time the Obra River bed had been characterized by various river patterns (braided, meandering and disappearing in wetlands). GPR (ground-penetrating radar) surveys and the analysis of satellite and aerial images were carried out to retrace the natural river course near the village of Kopanica. The GPR, ground-truthed with core data, revealed that at least two types of the river pattern had been functioning here before the period of the hydrotechnical works: a large-scale meandering pattern (width-to-depth (w/d) ratio ranging from 15 to 40) and a relatively smaller-scale multi-channel pattern (w/d = 11–22). Possibly, the transformation was caused by forming a series of large floods followed by in-channel aggradation and avulsions. Next, the multi-channel pattern was artificially transformed into the North Obra Canal. This paper discusses possibilities of a creation of network of channels that were active after the construction of the North Obra Canal in the beginning of the nineteenth century. Such intervention would increase natural values of the presented section of the Obra valley. The presented study also shows that a detailed analysis of history and evolution of a given river course is needed before undertaking any restoration works.

Temporal river channel changes in the Gila Box Riparian National Conservation Area, Arizona, USA

Human activities have led to the serious decline and degradation of riparian areas in the Southwestern United States. Areas in Arizona, such as the Gila Box Riparian National Conservation Area, are protected to conserve and restore these unique ecosystems. This study investigated temporal change in the channel form and sinuosity of the Gila River in the Gila Box Riparian National Conservation Area. Specifically, cross sections were measured in 1994, 2001, and 2008 to evaluate changes in channel form. Aerial photographs between 1935 and 2007 were also compared to assess changes in channel sinuosity. Based on cross-sectional measurements, the thalweg was significantly deeper in 1994 than in 2001 and 2008, while width-depth ratios were significantly lower in 2008 than in 1994 and 2001. These measurements indicate that the channel is stabilizing. Sinuosity changed only slightly. Overall, climate patterns that cause large flood events appear to have been the major influence on the channel form. Still, exclusion of livestock and all-terrain vehicles, which increased vegetation in the riparian areas, also appeared to mitigate flood impacts. The stream channel appears to have been more resilient to the impacts of the flood in 2005, when vegetation was better established, than to the flood of 1993, when past management influences were still lingering.

SURFACE SEDIMENTS,SEDIMENTARY SUBENVIRONMENTS AND SHORELINE EVOLUTION OF MODERN YELLOW RIVER DELTA

Based on the data from field samples and remote sensing survey,combined with historical information,we summarized the types of surface sediments and sedimentary subenvironments of the modern Yellow River Delta in this paper.According to the history of the Yellow River channel changes and dam building,the delta was subdivided into seven subenvironments.The surface deposits were dated and the shoreline changes from 1976—2009 reestablished with the seven times of Landsat remote sensing data of the delta.Since the Yellow River channel shifted to the current Qingshuigou course in 1976,the coastal area above the low tidal level has decreased by 318.78km2.

DRIVERS OF RIPARIAN TREE INVASION ON A DESERT STREAM

ABSTRACTUnderstanding mechanisms of exotic species' invasions is essential to managing riparian landscapes throughout the world. In the southwestern USA, the two most dominant invaders of riparian habitats are the exotic tree species tamarisk (Tamarix ramosissima, Tamarix chinensis, and their hybrids) and Russian olive (Elaeagnus angustifolia). These plants were introduced around 1900, and their success may be facilitated by river regulation, river channel changes, and precipitation patterns. We hypothesized that riparian invasion in Canyon de Chelly, Arizona, was initiated by a change point event such as plantings, dam construction, or channel incision and that establishment near a change point was tied to flood events. We aged tamarisk, Russian olive, and native cottonwood trees from study sites in Canyon de Chelly and used tree ring analysis to determine the year of establishment and the elevation of the germination point relative to the channel. We used Bayesian Poisson regression and information theoretics to identify change points and precipitation variables driving annual tree establishment. We found that most tamarisk and Russian olive trees established in the late 1980s, and most cottonwoods established in 1930‐1950 and 1980‐2000. Regression models indicated that change points occurred in 1983 for Russian olive and 1988 for tamarisk, and precipitation was important for establishment. Although plantings and river regulation probably played a role in tree invasion, our results suggest that these species required precipitation and stream channel change for widespread establishment in Canyon de Chelly. The factors driving riparian invasions may not be those often associated with degraded rivers, such as altered hydrographs and land management changes, thus requiring analyses of the full range of ecological and physical processes. Copyright © 2012 John Wiley & Sons, Ltd.

Fluvial adjustments in response to glacier retreat: Skaftafellsjökull, Iceland

This study describes changes to the proglacial drainage network of Skaftafellsjökull, Iceland from 1998 to 2011. Proglacial landscapes are highly sensitive to glacier retreat, and the retreat of glaciers around the world has accelerated since the mid‐1990s. Skaftafellsjökull has retreated at an average rate of 53 m per year since 1999. From 1999 to 2003, the river incised and formed a sequence of now abandoned channels and fluvial terraces extending ∼1 km downstream from the glacier. Retreat of the glacier from an over‐deepened ice‐contact slope meant that there was a positive correlation between the distance of glacier retreat and the amount of fluvial incision. Incision was episodic, occurring annually in response to drainage reactivation and reorganization. On an annual basis, the rate of retreat is moderately negatively correlated with the rate of incision. This is partly because the ice‐contact slope decreases away from the position of maximum glacier extent, and also because more sediment is released with faster retreat, counteracting the effect of retreat down an ice‐contact slope. From 2003 onwards, proximal terrace formation ceased, as a proglacial lake became established. Downstream of the lake outlet further incision deepened the channel, with most change occurring during a flood in 2006, where incision in the upstream confined reach was accompanied by downstream aggradation and terrace formation. These observations indicate that proglacial changes in response to glacier retreat are a result of the interactions of river channel incision and terrace formation, aggradation, lake development, and flooding, which together control river channel changes, sediment redistribution and sandur stratigraphy.

Frequency pattern of turbulent flow and sediment entrainment over ripples using image processing

Abstract. River channel change and bed scourings are source of major environmental problem for fish and aquatic habitat. The bed form such as ripples and dunes is the result of an interaction between turbulent flow structure and sediment particles at the bed. The structure of turbulent flow over ripples is important to understand initiation of sediment entrainment and its transport. The focus of this study is the measurement and analysis of the dominant bursting events and the flow structure over ripples in the bed of a channel. Two types of ripples with sinusoidal and triangular forms were tested in this study. The velocities of flow over the ripples were measured in three dimensions using an Acoustic Doppler Velocimeter with a sampling rate of 50 Hz. These velocities were measured at different points within the flow depth from the bed and at different longitudinal positions along the flume. A CCD camera was used to capture 1500 sequential images from the bed and to monitor sediment movement at different positions along the bed. Application of image processing technique enabled us to compute the number of entrained and deposited particles over the ripples. From a quadrant decomposition of instantaneous velocity fluctuations close to the bed, it was found that bursting events downstream of the second ripple, in Quadrants 1 and 3, were dominant whereas upstream of the ripple, Quadrants 2 and 4 were dominant. More importantly consideration of these results indicates that the normalized occurrence probabilities of sweep events along the channel are in phase with the bed forms whereas those of ejection events are out of phase with the bed form. Therefore entrainment would be expected to occur upstream and deposition occurs downstream of the ripple. These expectations were confirmed by measurement of entrained and deposited sediment particles from the bed. These above information can be used in practical application for rivers where restoration is required.

River Channel Change Simulation of Khoshke Rud Farsan River and Bank Erosion Process Using a Numerical Depth Averaged Model, CCHE2D

Bank erosion in populated areas could cause fatalities and property damage if banks collapse abruptly, compromising the integrity of residential buildings and civil facilities. Bank erosion study is in general a very complex problem because of it involves multi-processes such as bank surface erosion, bank toe erosion and bank material mechanic failure, etc. Each of these processes is related to several parameters: sediment size distribution, bank material cohesion, slope, homogeneity, consolidation, soil moisture and ground water level, as well as bank height. The bank erosion rate is also related to the strength of the flow in the river indicated by the flow shear stress, water depth and channel curvature, etc. In this study, the numerical model CCHE2D has been applied to study real-world bank erosion cases in a mountain river, Khoske Rud Farsan River, Iran, which is a braided river with high sediment loads and channel mobility; the bank erosion of this river is dominated by floods during rainy seasons.

黒部川における河床変動,河床材料分布,植生の変化に関する研究

The Kurobe river which is very steep river on alluvial fan yields a mass of sediments from drainage basin. Depositing sediments in dam reservoirs deteriorate a function of water storage. Therefore, the cooperating sediment flushing of Unazuki dam and Dashidaira dam is made in the latter period of floods to maintain the capacity of dam reservior water storage from 2001. After stopping gravel dredging in the downstream of Kurobe river, vegetation growth on sand bank has gradually begun. And then dense vegetation growth cause bed scouring of channel thalweg in downstream reach. The purpose of this study is to deepen the understanding of river channel change by investigating relationship between flood flows, gravel dredging, bed variations and vegetation growth over time in the Kurobe river and to conducts a proper river management.

Historical water level change of Lake Weishan in East China from 1758–1902 AD: relationship with the flooding of the Yellow River

In order to understand high-resolution environmental changes, historical water level changes on decadal and centennial scales have been conventionally analyzed employing documentary records and lake sediments. However, annual records are still limited. Here we report the discovery of water level observations (up to monthly) in the historical literature of the Qing Dynasty (1644–1912 AD). We reconstruct the chronologies of annual mean, maximum and minimum water level changes of Lake Weishan from 1758–1902 AD. The chronologies are compared with the precipitation data (dryness/wetness index data) of four stations in the vicinity of Lake Weishan (i.e., Heze, Jinan, Linyi and Xuzhou). We suggest that the annual water level changes are related to the amount of precipitation at the four stations. In addition, the flooding of the Yellow River significantly affects Lake Weishan, always resulting in extremely high annual mean, maximum and minimum water levels in the lake. The flooding in 1871 and 1873 AD even destroyed the banks between Lake Weishan-Zhaoyang-Nanyang and Lake Dushan, thus forming a united lake. In particular, we identify a high water level interval from 1851–1855 AD, just prior to the Yellow River channel change event in 1855 AD.

Oxbow Lakes as Indicators of River Channel Change: Leaf River, Mississippi, USA

This study uses oxbow lakes to ascertain the extent and nature of change in a river's form, focusing on the effects of post-1950s floodplain gravel extraction on the geomorphology of the Leaf River in southeastern Mississippi, USA. The river and oxbow lakes of a 5 km reach were examined for the effects of local and upstream floodplain and in-channel gravel mining. Data from 12 cross-sections suggests that the present-day river is 35% wider and 12% shallower than the cross-sectional geometry in cutoffs that pre-date 1955. Field measurements reveal that the Leaf River was relatively stable from at least 1911 to the early 1940s, but has since undergone an average of 2.65 m of degradation in the study reach. Survey data from a nearby USGS stream gage show that degradation began abruptly in the mid 1970s, most likely as a result of in-stream mining and pit avulsions on a major tributary that deprived downstream areas of bed load and created profile adjustments.

Fluvial geomorphology 2008–2009

This progress report on the discipline of fluvial geomorphology reviews 134 papers, 112 of which were published in Earth Surface Processes and Landforms ( ESPL) during the calendar years of 2008 and 2009. It continues where the last report for 2006 and 2007 ( Stott, 2010 ) ended. Papers are again grouped by themes to cover 10 subdisciplines within the subject area. The themes were chosen by classifying all geomorphological articles published in ESPL for the same period, of which 38% were within the subject area of fluvial geomorphology. Themes (in order of number contributing to the total) were: fluvial sediment transport; soil erosion and control; modelling the fluvial environment; river management, restoration and effects of vegetation on fluvial systems; gully and hillslope sediment transfer; river regulation, channel change and human influences; advances in methodology in fluvial geomorphology; fluvial hydraulics; fluvial chronology; and bank erosion in fluvial systems. The 2006–2007 and 2008–2009 periods are compared and it was found that broadly the same themes retained their popularity (in terms of numbers of papers published) as in the previous report for 2006–2007.

Comparing historical-hydrogeomorphological reconstitution and hydrological-hydraulic modelling in the estimation of flood-prone areas – a case study in Central Portugal

Abstract. The Arunca River basin in Central Portugal has a historical record of hazardous events related to floods, causing widespread disturbance. This article describes the application of two approaches based on well-known methods for the estimation of flood-prone areas: (i) historical-hydrogeomorphological reconstitution, applied to the entire Arunca River basin, and (ii) hydrological-hydraulic modelling, applied to four sections selected from different (upper, middle and lower) sectors of the basin and including urban and rural areas along the Arunca River. The mapping of the flood-prone areas obtained by these two methods was compared in order to identify the main differences and similarities. Human interventions (river channel and floodplain morphological changes) were found to be the main factor explaining the differences and similarities between the results obtained by both methods. The application of hydrological-hydraulic modelling proved important in reinforcing the results of the historical-hydrogeomorphological method; it also helped in complementing the results produced by the latter method in urban areas and in areas with insufficient historical records. The application of the historical-hydrogeomorphological method, in turn, allowed for the size of the flood-prone areas to be determined where the primary data (e.g. geometry, roughness and flow) was not accurate enough for hydrological-hydraulic modelling. The methodological approach adopted demonstrates the strong complementary relationship between the different existing methods for estimating flood-prone areas, and may be reproduced for other drainage basins.

Sediment load and storage in the lower yellow river during the late holocene

.The Yellow River is one of the largest riverine sediment routing system in the world. Like many other rivers, the sediment load of the Yellow River can not be regarded as constant in its long history due to changes in climate and human activities. This study determined sediment storage on the floodplains of the lower Yellow River in five historical periods after the year 602 bc mainly based on data of 93 boreholes, 182 radiocarbon dates in the Huang‐Huai‐Hai Plain and maps of historical changes of the lower Yellow River channel. Furthermore, the mean annual sediment outputs from the upper and middle reaches of the Yellow River were calculated in the five periods through investigating the sediment delivery ratio of the lower Yellow River under different conditions of artificial levees. Our findings suggest that the sediment output from the upper and middle Yellow River increased slowly before the year around 1128, but was lower than half of the current value on average. It has been in the past about 1000 years that the sediment output from the upper and middle Yellow River escalated. The Loess Plateau is the principal sediment source of the Yellow River. The comparison of historical changes in sediment load of the lower Yellow River with those in the natural conditions and in human activities on the plateau reveals that the changes in sediment yield from the plateau could be attributed mainly to the variations of population, cultivating area, and climate changes on the plateau.

Application of remote sensing and geographic information system in change detection of the Netravati and Gurpur river channels, Karnataka, India

The Netravati and Gurpur (N–G) river basins are tectonically active due to a number of seismically active faults/lineaments and their proximity to Mulki–Pulicat Lake axis. The gradient of the river channels has gradually reduced (after ∼10 km from their origin) and has forced the rivers to flow slowly in meandering and zigzag paths. The nature and intensity of meanders are governed by geological and tectonic conditions of the river basins. Significant changes in river channels, between the years 1910 and 2005, have been detected in three blocks – Block-I (Netravati) and Blocks-II and III (Gurpur) – and studied in detail by comparing topographic maps with Indian Remote Sensing Satellite, LISS-III images through GIS techniques. The block-wise qualitative and quantitative changes of these channels indicate that they are narrowed and migrate towards south due to neotectonic activities, formation of braided islands, variation in flow intensity and anthropogenic interventions like construction of vented dams and sand mining.

Quantification of braided river channel change using archival digital image analysis

AbstractHistorical archives of grey‐scale river channel imagery are extensive. Here, we present and test a methodology to extract detailed quantitative topographic data from such imagery of sand‐bed rivers. Extracting elevation information from rivers is difficult as they are characterized by a low relative relief (<4 m); the area of interest may be spatially extensive (e.g. active channel widths >500 m in large braided rivers); the rate of change of surface elevation is generally low except in the vicinity of individual channel banks where the rate of change is very high; there is the complication that comes from inundation; and there may be an added complication caused by blockage of the field of view by vegetation. Here, we couple archival photogrammetric techniques with image processing methods and test these for quantification of sand‐bed braided river dynamics, illustrated for a 500 m wide, 3 km long reach of the South Saskatchewan River, Canada. Digital photogrammetry was used to quantify dry areas and water edge elevations. A methodology was then used to calibrate the spectral signature of inundated areas by combining established two media digital photogrammetric methods and image matching. This allowed determination of detailed depth maps for inundated areas and, when combined with dry area data, creation of complete digital elevation models. Error propagation methods were used to determine the erosion and deposition depths detectable from sequential digital elevation models. The result was a series of elevation models that demonstrate the potential for acquiring detailed and precise elevation data from any historical aerial imagery of rivers without needing associated calibration data, provided that imagery is of the necessary scale to capture the features of interest. We use these data to highlight several aspects of channel change on the South Saskatchewan River, including bar movement, bank erosion and channel infilling. Copyright © 2010 John Wiley & Sons, Ltd.

Fluvial geomorphology

This progress report on the discipline of fluvial geomorphology reviews 147 papers published in 21 key journals during the calendar years of 2006 and 2007. Papers are grouped by themes to cover 10 subject areas. The themes were chosen by classifying all geomorphological articles published in a single leading journal for the same period, of which (44%) were within the subject area of fluvial geomorphology. Themes (in order of number contributing to the total) were: ‘River management, restoration and effects of vegetation on fluvial systems’; ‘Soil erosion and control’; ‘Fluvial hydraulics’; ‘Fluvial sediment transport’; ‘Gully and hillslope sediment transfer’; ‘Modelling the fluvial environment’; ‘River regulation, channel change and human influences’; ‘Advances in methodology in fluvial geomorphology’; ‘Bank erosion in fluvial systems’; and ‘Holocene fluvial chronology’.

River Channel Change Following Dam Removal in an Ephemeral Stream

Dam removal is becoming increasingly common for both small and large structures and is motivated by both environmental (e.g. re-establishing longitudinal connectivity) and engineering (e.g. safety) issues. Fluvial systems respond to dam removal by adjusting their forms through various processes and at varying rates. While limited research has investigated these adjustment mechanisms in perennial systems, little is understood regarding these mechanisms in ephemeral systems. The aim of this study is to analyse the geomorphic responses of the ephemeral Bushrangers Creek, central western New South Wales, Australia, following the 2002 removal of a 15 m high dam. Comparisons of pre- and post-dam removal survey data indicate that there has been repeated base-level lowering upstream of the former dam site. Longitudinal profiles of the thalweg before and after dam removal show an average bed lowering of 0.5 m and reveal that a 90 m long channel with a slope in excess of two-times greater than the pre-dam removal channel has formed upstream of the former dam wall.

영상분석기법을 이용한 구하도 복원 대상하천의 하도평가

하천은 다양한 환경조건에 따라 변화될 수 있는 공간으로 구하도를 복원 설계하기 위해서는 현재 하도의 안정성 여부를 파악할 수 있는 하도평가가 필요하다. 하도평가는 대상하천의 지형 및 수리 수문 등 다양한 정보가 요구되지만 국내여건상 과거자료 미비로 인해 시 공간적으로 변화된 하천의 지형학적 정보를 파악하기에는 많은 어려움이 있다. 본 연구는 청미천의 과거 지형도 및 항공사진을 이용한 영상분석을 통해 과거와 현재 하천의 하도변화를 분석하고, 하도평가를 위한 영상분석기법에 대한 적용성을 검토하는데 목적이 있다. 영상분석을 통해 얻은 결과는 구하도 형태 규모, 하도 종 횡단 변화, 미지형 변화 등으로 정량적 분석이 가능하였다. 특히 모래사주의 형상변화는 현재하도의 상태를 파악하는 중요자료로 복원하도 설계 시 하도의 규모, 평수유입유량 등을 선정하기 위한 기초자료가 될 것이다. 이와 같은 결과에서 영상분석기법은 평면적인 정보의 한계는 있으나 복원하도 설계 시 국내 여건을 고려할수 있는 기법으로 활용될 수 있을 것이다. River is able to change by various environmental factors. In order to conduct restoration design of abandoned river channels, it is necessary to evaluate the river through the analysis of past and present river channels. River evaluation requires various data, such as geometry, hydraulic and hydrology, but there is a lot of difficulty to understand topographical information of river change on time and space due to a lack of past data by domestic conditions. This study analyzes the changes in past and present river channels and examines the applicability of river channel evaluation through image analysis using aerial photographs and 1918 year's map. Aerial photograph analysis was conducted by applying the image analysis method and GIS analysis method on Cheongmicheon. As a result of this analysis, we have quantitatively identified the form and size of abandoned channels, changes in the vertical-section and cross-section length of rivers, and micro-landform changes. More importantly, we verified that morphological changes in sandbars due to artificial straightening are important data in identifying the state of current river channels. In these results, although image analysis technique has limitations in two-dimensional information from aerial photographs, we were able to evaluate the changes in river channel morphology after artificial maintenance of the river.

From Research to Application: Management Implications from Studies of Urban River Channel Adjustment

AbstractSince the major article by Wolman in 1967, investigations of river channel change have identified implications for future management. Whereas hard engineering methods originally dominated management of urban drainage, they are now complemented by a range of newer methods collectively constituting a more holistic approach. These methods address at least five concerns: location of urban areas with implications for land‐use planning; retention of precipitation; delay of runoff; management of the effects of runoff within urban areas; and planning for downstream consequences. A conceptual model illustrates the ways in which these methods change process dynamics and affect channel morphology. Spatial variations in process dynamics can be visualized in terms of relational, process, connectivity, and extrinsic drivers. Analysis of empirical studies from a range of world areas shows 47 that make explicit management recommendations. These recommendations, together with results of previous research, provide the basis for a checklist protocol to aid decision‐making by river managers.