Showing papers in "International Journal of River Basin Management in 2018"

A Brief review of flood forecasting techniques and their applications

Abstract: Flood forecasting (FF) is one the most challenging and difficult problems in hydrology. However, it is also one of the most important problems in hydrology due to its critical contribution in reduc...

Prediction of riprap stone size under overtopping flow using data-driven models

Abstract: Rock riprap is commonly used to protect levees, embankment dam, steep channels, and other structures being vulnerable to deteriorative erosion caused by overtopping flow. A review of the literature...

FLOODSS: Iowa flood information system as a generalized flood cyberinfrastructure

Abstract: This article presents the vision, implementation, and case studies of the Iowa Flood Information System (IFIS) towards the vision for next-generation decision support systems for flooding. The IFIS...

Serious gaming for participatory planning of multi-hazard mitigation

Abstract: Collaborative, holistic, and proactive planning for basin-wide water management solutions addressing multiple water-related hazards is challenging. Shared vision planning (SVP) and decision support...

The Iowa Watersheds Project: Iowa's prototype for engaging communities and professionals in watershed hazard mitigation

Abstract: After more than a century of intensive changes in the state's agricultural watersheds, repeated record floods motivated Iowa to innovate in its flood recovery and disaster mitigation efforts following the 2008 floods. The state created the Iowa Flood Center (IFC) and authorized the creation of Watershed Management Authorities. With enhanced funding from the federal government for disaster recovery, the groups collaborated in four watersheds as part of the Iowa Watersheds Project. The Watershed Management Authorities brought together governmental organizations and local stakeholders, developed watershed plans, defined potential flood and nutrient reduction projects, identified willing landowners for project locations in one subwatershed, and hired consultants to design and build the projects. The IFC coordinated efforts across the four watershed areas, provided hydrologic assessments for each, carried out monitoring and modelling to evaluate the performance of all the constructed projects, and deve...

Analysis of land use change impacts on flash flood occurrences in the Sosiani River basin Kenya

Abstract: This paper investigates the impacts of land use changes on river peak discharges during floods and its contribution to flood occurrence in the Sosiani River basin in the Rift Valley province of Kenya. The land use maps used in the study were derived from the Landsat imagery employing remote sensing and GIS techniques. Two-dimensional Rainfall–Runoff–Inundation (RRI) model was utilized in simulating the flash flood events. The results indicated an increase in river peak discharge due to extensive deforestation in the past decades and increase in farmlands which covers up to 75% of the total watershed area. According to the observed discharge data and generated land use maps, expansion of farmlands from 15.3% (in the early 1970s) to 75.2% (2013) and urban areas from 0.4% (in the early 1970s) to 10% (2013) have triggered the observed river peak discharge to increase from 167 m3/s (1970) to 233 m3/s (2013). Two land use change scenarios were tested for urbanization and reforestation using the calibrat...

Adaptive delta management: a comparison between the Netherlands and Bangladesh Delta Program

Abstract: In the Netherlands, the central government, water authorities, provinces and municipalities are working together on a new Delta Program on Flood Risk Management and Fresh Water Supply (DP). Its pri...

Water institutions in the Awash basin of Ethiopia: the discrepancies between rhetoric and realities

Abstract: This paper strived to describe the features of water institutions in the Awash basin from a historical perspective based on reviews of water laws, policies, and administrative documents, as well as interviews with water actors using snowball techniques. The result revealed that institutions had rapidly been changing but not coherently built. The most centralized duties and powers of institutions, coupled with financial and technical limitations created difficulty in enforcing the laws. The policy was comprehensive and inculcated the principles of Integrated Water Resource Management. Yet, it did not properly cascade down to the lower level as it was fundamentally top-down. Several stakeholders were not involved in the policy-making process. Water institutions were overwhelmingly more rhetoric than action oriented. Customary water institutions were undermined. Therefore, critical steps need to be taken towards enforcing formal water institution, recognizing the role of customary practices, and invo...

Optimized expressions to evaluate the flow discharge in main channels and floodplains using evolutionary computing and model classification

Abstract: Due to momentum exchange between main channel and floodplains, the flow hydraulics in compound channels is taken into account as a comparatively complicated system. Most studies in this research fields are focused on prediction of the cross-sectional average velocity and total flow discharge. In quite a few situations, however, the sub-section or individual flow discharges are imperative rather than the total discharge. For instance, in flood conditions and in the case of spill of water on the floodplains, the bed and suspended sediment loads are inevitably transported by the main channel flow discharge. In current investigation, using laboratory stage-discharge datasets from canals with compound channel sections, the individual flow discharges in the main channel and over floodplains are predicted applying gene-expression programming (GEP), model tree (MT), and evolutionary polynomial regression (EPR) and then compared with traditional divided channel methods. Results showed that the proposed sof...

The impact of urbanization on the streamflows and the 100-year floodplain extent of the Sims Bayou in Houston, Texas

Abstract: The Houston Metropolitan Statistical Area has experienced rapid population growth in the past decades. The impact of this growth on the streamflows and 100-year floodplain extent in the Sims Bayou over the 1980–2000 period has been studied and is reported. Development and imperviousness over time was determined using parcel data provided by the Harris County Appraisal District and Fort Bend Central Appraisal District, and aerial photographs. The change in the annual streamflow volume over time was studied, and found to have a statistically significant increasing trend. A similar analysis of the annual instantaneous peak flows showed that, although an increasing trend in their values is not apparent, there is a statistically discernible increase in their variability. Strong relationships between the annual streamflow volume and annual instantaneous peak flow, and the imperviousness were found. The imperviousness increased from 15% in 1980 to 18% in 2000. For the 100-year 24-h storm event, hydrologi...

Expanding the horizons of integrated flood risk management: a critical analysis from an Irish perspective

Abstract: Millions of people around the world are exposed to some degree of flood hazard, with the level of exposure increasing with climate change. Arising from the scale of recent flood experiences across Europe, the European Union adopted the Floods Directive in 2007 to bring about greater assessment and management of flood risk across the EU and encapsulating the paradigm shift that involves a more holistic approach to flood management by requiring consideration of both structural and non-structural measures. This paper explores the evolution of flood management in Ireland, and highlights gaps concerning understanding of human–environment behavioural interactions. The paper promotes the importance of exploring how people’s perception of the environment and the design of urban landscapes may influence behaviour; important considerations in the advancement of a more integrated flood risk management system.

Land use as possible strategy for managing water table depth in flat basins with shallow groundwater

Abstract: In flat plains groundwater affects agricultural production outcomes and risks. Agricultural land use decisions, however, may strongly impact groundwater levels available for production. This paper explores the scope for managing groundwater levels through land use decisions in a sub-basin of the Salado River in the Argentine Pampas, a very flat area that plays a key role in world agricultural production. A spatially distributed hydrological model implemented with MIKE SHE software was used to establish the impacts of different land uses on groundwater dynamics, and to assess the interdependencies among spatially close decision-makers sharing a water table (WT). Additionally, groundwater level changes in response to climate variability were quantified. We found land use has strong effects on WT levels both for oneself (e.g. pastures can lead to significant decreases (up to 4.5 m) in WT levels) and others, in the form of strong interdependencies that exist between farmers sharing a WT where land use...

Ten reasons to set up sediment budgets for river management

Abstract: Rivers are dynamical systems with alternating patterns of sedimentation and erosion. Both sedimentation and erosion may have negative consequences from a perspective of river management. A sediment budget is a most valuable tool for taking measures in river management that deal with sediment dynamics effectively. Drawing-up a sediment budget is time consuming and complicated, but very rewarding in that it strongly increases our understanding of the functional behaviour of a river system and the human impact thereon. The main goal of this article is to provide river managers with arguments in favour of sediment budget studies. This is done by illustrating the benefits of channel sediment budgets for river management using examples from the rivers Scheldt and Rhine. We present 10 reasons for drawing-up sediment budgets for river management: sediment budgets help to: (1) create order in the apparent chaos of data, (2) identify morphological problems, (3) find smart solutions to problems, (4) set rese...

Estimating soil loss for sustainable land management planning at the Gelana sub-watershed, northern highlands of Ethiopia

Abstract: The study was conducted with the objective of estimating the rate of soil loss using the Revised Universal Soil Loss Equation model for sustainable land management planning at the Gelana sub-waters...

Lessons learned from past ice-jam floods concerning the challenges of flood mapping

Abstract: Delineation of flood hazard and risk on maps is useful as a means of public education and as a basis for measures aimed at lessening future flood damages. In many northern countries, rivers...

Appraisal of water quality in the Lakes of Nainital District through numerical indices and multivariate statistics, India

Abstract: Nainital district is naturally gifted with numbers of natural water bodies. Among these water bodies, the four lakes (Nainital, Bhimtal, Naukuchiatal and Sattal) are the major source of freshwater for the local inhabitants and industries situated in surrounding area. However, the lakes receive an enormous amount of untreated wastewater which imbalances the nutrients concentration in lake water. Therefore, the present study is focused to assess the water quality using water quality indices (NSFWQI, CPI and HPI) based on the concentration of parameters (like DO, BOD, heavy metals, etc.) in the lakes. The envirometric applications (HCA and PCA) were also used to identify the similarity in pollution load at sampling locations and the source of factor responsible for pollution in the lakes. The water samples were collected in pre- and post-monsoon months in the year 2014–2015, from 12 sampling locations. The results indicate that the water quality of lakes is unsuitable for drinking, as the average CPI...

Road-stream crossing an in-stream intervention to alter channel morphology of headwater streams: case study

Abstract: Basin-scale hydrological response on the geomorphology of lowland headwater streams is often neglected during the in-stream engineering works in rural India. Standard protocols to construct road-stream crossing (RSC) reveals that crossing structures at headwater streams of the Kunur River Basin in eastern India are inadequate to maintain longitudinal continuity in channel hydraulics as well as morphology. The role of crossing type (pipe, box, and small bridge) and catchment land cover are also considered for site-wise variation in channel deformation. The detailed geomorphic survey with 10 cross-sections (5 in the upstream and 5 in the downstream of crossing structure) and 1 longitudinal profile from each of the 10 sample sites were used to run one-dimensional flow modelling in Hydrologic Engineering Center’s River Analysis System, statistical analysis of channel morphometry, manning and rational methods for discharge estimation, and hydroengineering equations. Result shows that in comparison with...

Bagged neural network for estimating the scour depth around pile groups

Abstract: Contrary to the single pier, due to the complexity of scour mechanism around pile groups, empirical methods do not give a satisfactory prediction for the scour depth around pier with multiple piles. It was shown recently that artificial neural networks have better prediction performance than empirical methods. In order to exploit the full potential of neural network procedure for predicting scour depth around pile groups, “Bagging” technique is adopted in this paper. The comparison between several different approaches for improving the gener-alization performance of neural networks shows that “Bagging” is the most reliable method. Furthermore, the sensitivity analysis is performed on the data to determine the effect of different inputs on the scour depth around pile groups. This analysis shows that pile diameter and pile spacing are dominant contributors.

Vulnerability, impacts and assessment of climate change on Jakarta and Venice

Abstract: In the next future, cities located in coastal areas are likely to suffer for climatic changes more than all other human systems. The demographic growth, combined with sea-level rise and global warming related to natural causes and anthropogenic activities, endanger those systems. Thence, to effectually cope with new climate forcing, coastal cities need improvements to be sustainable, resilient and liveable, applying flexible design approaches rather than a traditional one. The paper highlights such concepts presenting two case studies of important coastal cities: Venice, in Northern Italy, and Jakarta, the capital city of Indonesia. Although characterized by completely different climatic conditions and living habits, these two metropolises are highly impacted by humans and threatened by similar factors like subsidence and sea-level rise, which increase their exposure to future calamities principally driven by climate change but strictly related to anthropic pressures. The present situation shows t...

Flood risk management in Europe: the EU ‘Floods’ directive and a case study of Ireland

Abstract: The ‘Floods’ Directive sets out a basic framework for good practice in flood risk management comprising a screening exercise, the Preliminary Flood Risk Assessment, to identify the Areas of Potenti...

Real-time consequences of riparian cattle trampling for mobilization of sediment, nutrients and bacteria in a British lowland river

Abstract: Rivers and their catchments support multiple human needs, necessitating integrated management of land and water resources. Agricultural land use, specifically the impacts of riparian cattle trampling, potentially significantly contributes to damage to river systems. This study addresses a knowledge gap stemming from the paucity of prior research correlating generation of pollutants with cattle activity locally and in ‘real time’. Turbidity, soluble reactive phosphorus and faecal coliforms were analysed at upstream control and downstream impact sites correlated with cattle activity over a 65 m river margin throughout a two-month summer period. Riparian cattle trampling impacted water quality, specifically turbidity and faecal coliform levels. Average turbidity increased by more than 90% between upstream and downstream sites during cattle activity, whilst average faecal coliform counts almost doubled. Findings for phosphorus concentrations were less conclusive, perhaps due to filtration of suspended...

Prediction models for flow resistance in flexible vegetated channels

Abstract: The analysis of flow resistance due to vegetation remains an issue in the hydraulic industry, although it has been systematically studied for several decades, accurate prediction of the resistance is still a challenge. This is because most of the previous studies used synthetic vegetation to model flow–vegetation interactions. This paper presents the applications of the artificial neural network (ANN) and gene expression programming (GEP) as advanced tools, to predict the flow resistance (n) of natural vegetation using a grassed swale and laboratory channel, irrespective of the grass height with relative to flow depth. To achieve this, hourly discharges and water depths were measured in the grassed swale for different rainfall events using the electromagnetic current metre. Experiments were performed in the laboratory channel using the same grass, in order to get additional data. From the results obtained regression equation was developed for predicting the flow resistance through the use of dimen...

Hydrometeorological impact of climate change in two Mediterranean basins

Abstract: The impact of climate change in specific hydrological issues is investigated in two Mediterranean watersheds of the island of Crete, Koutsoulidis, and Giofyros, by using the HBV hydrological model....

Modelling water flow in a complex watershed in humid a tropical area using SWAT: a case study of Taabo watershed in Ivory Coast

Abstract: Understanding the water balance of a basin is the most important aspect in water resources development and management programmes. The objective of this study was to implement an agro-hydrological model (SWAT) to model water flow transport within the river network with a perspective to reduce the sedimentation and eutrophication of lakes in Ivory Coast. The daily simulation of SWAT model carried out in the period from 1979 to 1990 has been divided into warm-up (1979–1981), calibration (1982–1986) and validation (1987–1990). For calibrating the model, a preliminary sensitivity and uncertainty analysis in the SUFI-2 algorithm was performed based on 19 hydrologic parameters. The model has given good results of performance and robustness. All statistical parameters (Nash-Sutcliffe coefficient (NS) and the coefficient of determination (R2)) used to achieve the model performance of above 0.7 for the calibration period and around 0.6 for the validation period. As for the uncertainty criteria (P-factor and...

The spatial pattern of large wood in a large low gradient river: the Barwon–Darling River

Abstract: It is hypothesized that the organization of wood within the Barwon–Darling River, Australia; a large low-gradient dryland river, differs to current models of wood in rivers. Current models are dominated by studies in high-energy systems where wood is highly mobile and non-uniform in their distribution. Large wood in this system is not highly mobile because of low-stream powers, high-wood densities and a low ratio of wood size to bankfull widths. This study analyses the organization of 7142 pieces along 210 km of the Barwon–Darling River, SE Australia. The majority of pieces (72%) were 50% were complex in character. Most pieces (98%) were attached to the bank, distributed relatively uniformly and correlated to the riparian zone. Pieces were either completely (25.9%) or partially aligned (36.4%) to the flow suggesting passive realignment. The primary driver of wood alignment was related to its size, secondary influences were height above the river bed (a correlate of str...

Assessment of variable source area hydrological models in humid tropical watersheds

Abstract: The objective of this study was to compare the performances of hydrological models that incorporate the Variable Source Area (VSA) mechanism of runoff generation with that of the Soil and Water Assessment Tool (SWAT), which uses the infiltration-excess mechanism. One of the VSA-based model used, SWAT–VSA, has been proposed as a re-conceptualization of the SWAT and uses a topography-based wetness index to identify source areas. In this study, the topography-based wetness index was replaced with a Modified Normalized Difference Water Index (MNDWI) derived from satellite imagery resulting in the SWAT–MNDWI model. Model performances were evaluated through their application in two humid tropical watersheds (Hemavathi – 2974 km2; Harangi – 538.8 km2) located in the Upper Cauvery River Basin, India. Using relevant data inputs, the three models were applied separately to both watersheds. Models were calibrated for the historical period 2000–2003 and validated for the period 2004–2006 using observed daily ...

Lessons learned from the 2016 Yangtze River flood in Anhui province, China

Abstract: During the flood season of 2016, the middle and lower reaches of the Yangtze River suffered the worst flooding since 1999, involving Hunan, Hubei, Anhui, Jiangxi and Jiangsu provinces and the Taihu...

Evaluating the impacts of dredging and saline water intrusion on rural livelihoods in the Volta Estuary

Abstract: Many communities around the world are directly dependent on rivers. In Ghana the damming of the Volta River for hydro-electric power led to the development of a sandbar at the estuary, which disrup...

Nationwide investigation of citizen-based river groups in Japan: their potential for sustainable river management

Abstract: This is the first quantitative study investigating citizen-based river groups throughout Japan. Recently, river management faces multiple challenges, such as increased risk of disasters, the ageing of existing river protection facilities, and the growing awareness of environmental issues. However, funding for river management has been reduced because of a rapidly ageing and declining population. In this context, citizen-based river groups may be expected to cooperate with river managers to sustainably manage rivers. There are hundreds of river groups in Japan, but there are few reports detailing their information at a national level. The purpose of this study is to quantitatively investigate citizen-based river groups in Japan by analysing the following: (1) the number of people and amount of time they invest in river-related activities; (2) what kind of activities they do; and (3) when and where these activities occur. We investigated 207 river groups using questionnaires and interviews. Our resu...

River basin management and community : the Great Ouse Basin, 1850–present

Abstract: River basins are difficult units to manage. Society is generally not organized on the basis of river basins, yet river basins are important units for society and vice versa. This paper discusses the development and effectiveness of river basin management, using the Great Ouse Basin in the east of England as an example. Because of conflicting interests between upstream and downstream areas in this basin, it took some 70 years, from 1850 to 1920, to establish the first basin-wide management body, and because of these interests this body was initially not very effective. Over the years management was scaled up until in 1989 a national rivers authority was established. A fundamental issue was the lack of a sense of community at the basin scale. This could have mitigated the conflicts of interests and facilitated better cooperation. The paper recommends more research on the role of community in river basin management and suggests to extend the notions of ‘institutional’ and ‘socio-ecological fit’ to in...