Exploring the Relations Between Riverbank Erosion and Geomorphological Controls Using Geographically Weighted Logistic Regression

The relations between riverbank erosion and geomorphological variables that are thought to control or influence erosion are commonly modelled using regression. For a given river, a single regression model might befitted to data on erosion and its geomorphological controls obtained along the river's length. However, it is likely that the influence of some variables may vary with geographical location (i.e., distance upstream). For this reason, the spatially stationary regression model should be replaced with a non‐stationary equivalent. Geographically weighted regression (GWR) is a suitable choice. In this paper, GWR is extended to predict the binary presence or absence of erosion via the logistic model. This extended model was applied to data obtained from historical archives and a spatially intensive field survey of a length of 42 km of the Afon Dyfi in West Wales. The model parameters and the residual deviance of the model varied greatly with distance upstream. The practical implication of the result is that different management practices should be implemented at different locations along the river. Thus, the approach presented allowed inference of spatially varying management practice as a consequence of spatially varying geomorphological process.     

A River Runs Through It: Morphological and Landowner Sensitivities Along the Upper Missouri River, Montana, USA

Landowners along the Missouri River in Montana believe that the operation of Fort Peck Dam has initiated bank erosion, thus threatening agricultural development within the region. Their concerns have been heightened by proposals to increase discharge in order to enhance fisheries and wildlife interests. Geomorphological evaluation indicates that bed degradation and bank erosion have declined since construction of the dam, and the channel is now approaching dynamic equilibrium; public sensitivity to the proposed change is greater than the morphological sensitivity of the river. Sustainable management of the Missouri is now based on strategies that place more emphasis on partnership with local citizens.     

The Oral Tradition,Environmental Change and River Basin Management: Case Studies from Queensland and Victoria

River basin management activities are often carried out in the context of real or perceived environmental change. Views of environmental change provided by the oral tradition are compared with histories of change reconstructed from the historical documentary record for the Nogoa River, Queensland, and the Avon River, Victoria. Quite different perspectives on the nature and causes of river channel change are provided by the two types of sources. River basin managers appear to have generally adopted the views provided by the more easily accessible oral tradition, leading to management strategies that are not necessarily justifiable in the light of the documentary history.     

The need for river management and stream restoration practices to integrate hydrogeomorphology

There is growing support amongst scientists worldwide about the need for a shift in river management approaches to include hydrogeomorphic processes. However, the degree to which these concepts are transferred to governmental agencies and practitioners varies widely. In Quebec, for example, many stream restoration projects are based on the (incorrect) assumption that river mobility and its inevitable consequences (bank erosion of meanders, presence of woody debris in the channel) are problematic for salmonids. This paper presents examples drawn from current guidelines on stream restoration for fish habitat in Quebec to demonstrate the need to improve the knowledge exchange among scientists and decision makers about the positive impact of river mobility and large wood dynamics on biodiversity. Our observations reveal that existing guidelines for stream restoration in Quebec need to be revised to better integrate hydrogeomorphic concepts and to no longer assume that maintaining rivers in a static state is beneficial for fish. Adopting the “freedom space for rivers” approach would likely result in improved habitat as it combines natural processes related to mobility, flooding, and riparian wetland connectivity to determine the minimal space around rivers where development should not be allowed, thus allowing river processes to be restored.     

Reconstruction of local environments of ancient population in a changeable river valley landscape (The Middle Vychegda River,Northern Russia)

In river valleys, both human occupation and subsequent preservation of archaeological sites are affected by active landscape transformation caused by river lateral migration, incision/aggradation cycles and changes of river hydrological regime. In the middle Vychegda River valley (Northern Russia), there are numerous traces of human presence since the Mesolithic. We exploit multi-disciplinary archaeological, geomorphological and geochronological approach to elucidate the environmental preferences of settlements positioning during different epochs of the Holocene. High resolution space image supplemented with data on alluvial stratigraphy derived from bank exposures and hand cores, as well as 51 radiocarbon dates were used to make the geomorphic map showing ages of floodplain/terrace segments and palaeochannels. Using this map together with sediment facial interpretation, position of archaeological sites was analysed in the context of local geomorphic and hydrologic situation. The majority of archaeological sites and modern settlements are found on terraces at river banks or at oxbow lakes which were well connected to the river. Few exceptions from this rule may be explained by seasonal character of dwelling functioning, ritual burial practice or specialization of settlements. Geomorphic situation was used as a background for planning further prospection of different-age archaeological objects.     

Communities in Catchments: Implications for Natural Resource Management

Economic and social considerations in natural resource management include the need for community participation and a greater appreciation of social and economic processes in understanding environmental problems. It is anticipated that new frameworks will guide these inclusions and redirect planning and management activities to achieve environmental sustainability. This paper examines issues of participation and the nature of ‘community’ through an analysis of relevant natural resource management policy documents and a case study of a public drinking water supply catchment in Western Australia. The findings indicate that if NRM strategies are to be successful, then a much wider and more inclusive view of community is needed, one that fully captures the different stakeholder groups beyond farmers, such as town residents, indigenous people, and those involved in other land uses. We need strategies that can accommodate differences within and between communities.     

Bank Erosion in the Bellinger Valley,New South Wales: Definition and Management

Lateral channel migration is normal or autogenic, with bank erosion often on concave and accretion on convex banks. Where bank erosion occurs, particularly at an accelerated rate through land abuse and an increase in flood magnitude and frequency or allogenic, it threatens human use of the flood plain. There is a demand for protection, often with very little understanding of the erosion hazard. Measurements based on photogrammetry were used to define bank erosion and accretion, as well as width changes, in eight meander arcs (11 sections in each) over 41 years. It was concluded that, if this rate continued over the next century, 82 ha of alluvial land, 6.2 km of roads, two bridges, 9 homes and 51 home sites could be lost. Various management options, costs and benefits are given in order to show how future planning and protection can be more rational.     

Development of Trigger Levels to Assess Catchment Disturbance on Stream Suspended Sediment Loads in the Magela Creek Catchment,Northern Territory,Australia

Trigger levels for fine suspended sediment (FSS) load in streams are required to identify rainfall-runoff events that have significantly elevated FSS loads, compared with expected background loads, as a result of catchment disturbance. Stream FSS load data collected in the mine-impacted Magela Creek catchment in the wet-dry tropics were used to derive water quality management trigger levels for two approaches – a Before-After-Control-Impact Paired difference design (BACIP) and a regression relationship between observed FSS load and corresponding event discharge characteristics. The results indicate that both the BACIP and regression relationship approaches behave similarly, with similar FSS load events elevated above trigger levels. Notwithstanding this, it is recommended that in order to reliably assess the location and magnitude of a catchment disturbance on FSS load, a combination of BACIP and regression relationship approaches must be adopted. In this study, an event with a FSS load above trigger levels associated with both BACIP and the regression relationship fitted for the downstream site is considered to be significantly elevated as a result of a disturbance within the mine-impacted region. While this technique cannot conclusively determine whether the cause of the disturbance is mine-related or natural (such as fire or bank erosion), it is an efficient statistical method of identifying events that warrant further investigation and management action, if required.     

Paleochannel Studies in Archaeology: The Case of The Vychegda River,Northeastern European Russia

Geological and geomorphological settings are often taken into account when choosing strategy in archaeological studies. In the Vychegda River valley (Archangelsk Province, Komi Republic), at the end of the Late Pleistocene and in the Holocene, lateral channel migrations were the dominant process of riverine landscape changes and hence directly influenced human occupation of the valley. Therefore, to assess the physical settings of archaeological sites we employed paleochannel analysis, a geomorphological technique aimed at reconstructing river channel transformations in the historical and geological past. The potential application of paleochannel analysis in archaeology includes designing archaeological surveys and predicting destructive river actions at archaeological sites located in river valleys.     

Citizenship and the production of landscape and knowledge in contemporary Canadian nuclear fuel waste management

This article considers the relationship between Aboriginal peoples in Canada and the nuclear industry in the contemporary geography of Canadian Nuclear Fuel Waste management. It explores the ways in which the knowledge produced by the Canadian nuclear industry, through the work of the Nuclear Waste Management Organization about nuclear waste, its management and its effects, gains primacy over the knowledge and experience of the Serpent River First Nation (SRFN). I identify a discourse of citizenship as instrumental to pursuing and maintaining industry control over knowledge produced about this policy issue. Of particular interest is the manner in which this discourse operates to disqualify and subjugate the alternative experiences of, and knowledge about, nuclear waste and radioactivity contained in the oral histories and testimonies of the SRFN. I suggest that the discourse marginalizes the knowledge of the SRFN through the use of scaled representations of identity and place, to create a particular 'Canadian' account of the fuel chain and its effects.     

Highlighting the Need and Potential for Use of Interdisciplinary Science in Adaptive Environmental Management: The Case of Endangered Upland Swamps in the Blue Mountains,NSW, Australia

The Blue Mountains region of New South Wales, including the World Heritage listed Blue Mountains National Park, is arguably one of Australia's most highly valued and iconic wilderness areas. Common to this region are upland swamps (formally ‘temperate highland peat swamps on sandstone’), which play a vital hydrological role at the headwaters of the river catchments, as well as providing the habitat for an array of flora and fauna species. This paper involves an interdisciplinary examination into the need and potential for adaptive management in the Blue Mountains. It uses geomorphic (physical) knowledge of swamp condition and social data about the volunteers who rehabilitate them. Research involved using the River Styles river condition framework across 47 swamps and questionnaires and interviews with local rehabilitation volunteers. It is proposed that there is a need and a potential to combine geomorphic understanding with further engagement of community volunteers in order to enable an interdisciplinary approach to adaptive management. Such an approach could result in the effective environmental management of upland swamps in the Blue Mountains.     

The Eppalock Soil Conservation Project,Victoria, Australia: The Prevention of Resevoir Sedementation and the Politics of Catchment Management

The Eppalock Soil Conservation Project (ESCP) is a celebrated ‘whole-of-catchment’ management project implemented upstream of Lake Eppalock reservoir in Victoria, Australia. In 1959, a Victorian Parliamentary Public Works Committee (PPWC) found that the enlarged reservoir would be endangered by sedimentation as a result of severe erosion in the catchment. One of the main objectives of the ESCP was therefore to minimise the amount of sediment entering Lake Eppalock. The reservoir has not subsequently filled with sediment, and this fact has been used to suggest that the catchment scheme was successful in preventing reservoir sedimentation. It is argued here, however, that the estimate of sedimentation presented by the PPWC was inflated and that, even in the absence of a catchment management scheme, Lake Eppalock was not in danger of losing a significant proportion of its capacity to sedimentation. The proponents of the ESCP may have overstated the sedimentation threat to provide justification for what has become an outstanding catchment management project. Prior to the ESCP and despite overpowering evidence, successive governments had failed to respond to the threat of soil erosion. The immediate threat to a large public asset provided the politically powerful lever that was required to justify a total catchment approach to erosion control. Given the circumstances leading up to the 1959 PPWC Inquiry, the actions of the ESCP proponents cannot be criticised. However, this study provides a timely reminder that we cannot accept the apparent achievements of natural resource management projects without first examining the science and politics driving the project.     

Transboundary river governance and climate vulnerability: Community perspectives in Nepal’s Koshi river basin

Frequent floods in the Koshi River have left the Nepalese vulnerable to erosion and recurring inundation—especially those living on the floodplains. The situation is worsening because water flow in the river is highly uncertain, affected by rainfall in the mountains and by climate change, and influenced by the Koshi barrage, which is governed by the Koshi River Agreement, a bilateral river agreement with India. This study addresses how Koshi River governance contributes to the vulnerability of riverine communities in Nepal by drawing upon ideas about vulnerability and vulnerability mapping. A household survey and interviews were conducted in 2015 for a comparative study of people living on two river islands located upstream and downstream of the barrage. Findings remain relevant because of persistent governance challenges and growing climate change effects, escalating islanders’ vulnerability to recurrent floods. The islanders’ vulnerability was produced locally and also shaped by historical, social, economic, political, geographical, and ecological processes occurring at multiple scales. That insight highlights the need to study the broader political economy of hazard production to understand vulnerability in the context of governance.     

Water,Wind, Wood,and Trees: Interactions,Spatial Variations,Temporal Dynamics,and their Potential Role in River Rehabilitation

Recent Australian research has quantified the role of large wood (wood of any origin and length with a diameter greater than 0.1 m) in dissipating stream energy, forming pool habitats by local bed scour, protecting river banks from erosion, and damming rivers with long rafts causing avulsions. Large wood in Australian streams is sourced by a range of processes from the nearby riparian zone which has usually been degraded by post‐European settlement vegetation clearing. Large wood loadings within the bankfull channel are dependent not only on the type and quality of the riparian plant community but also on bankfull specific stream power, channel width, and the processes of large wood delivery to the stream. While bank erosion and floodplain stripping by catastrophic floods are obvious and important delivery mechanisms, treefall and trunk and branch breakage by strong winds during tropical cyclones and severe storms are also significant in the tropics. Furthermore, wood decay and downstream transport produce temporally dynamic large wood distributions. The longevity of natural large wood structures in rivers, such as rafts, debris dams, and log steps, requires determination. River rehabilitation programs need to not only include the reintroduction of large wood, but also carefully plan the spatial distribution of that wood, the most appropriate type and range of large wood structures, and, most importantly, the revegetation of the riparian zone to ensure a natural long‐term source of large wood. Exotic species management is an essential part of river rehabilitation.     

Fluvial Geomorphology and River Management

Australian river landscapes offer many challenges for management. Much Australian river research is novel, but practical concerns have always had an influence on the research agenda. Australia’s distinctive contributions to fluvial geomorphology include recognition of the great age of many fluvially eroded landscapes; understanding complex levee, terrace and valley fill sequences; analysing the impacts of rare major floods; interpreting the effects of impoundment, mining and urbanisation; and understanding the great anastomosing inland river systems. River restoration is now a major theme in the literature of river engineering, fluvial geomorphology and landscape design. Great achievements are occurring in geo‐ecological river management and engineering. Changing people’s thinking is becoming at least as important as gaining new scientific knowledge. The existing understanding needs to be more widely shared and enhanced by greater involvement with Asian countries where river management issues daily affect the lives of millions of people.     

The Significance of Coastal Processes for Management of the River Murray Estuary

The tidal prism in the River Murray estuary has been reduced by over 85 percent since completion of the barrages in 1940 and regulation has diminished the rate and size of river flows through the estuary. Reduced fluvial flushing has emphasised the dominance of coastal processes at the river mouth. These are expressed in the accretion and stabilisation of a flood-tidal delta, the migration of the mouth, the erosion of Sir Richard Peninsula and the accumulation of new flood-tidal deltaic deposits. Inconclusive studies relating river flow to mouth migration indicate the importance of coastal processes such as littoral drift, tidal flux and sea state, particularly at times of low river flow, in explaining the position and morphology of the mouth. Previous management strategies have failed to consider coastal processes adequately.     

The Geography of the Anthropocene in New Zealand: Differential River Catchment Response to Human Impact

New Zealand provides a useful environment to test the notion that the Anthropocene is a new geological epoch. There are two well‐dated anthropogenic impact ‘events’: Polynesian settlement c. AD 1280, and European colonisation c. AD 1800. Little attention, however, has been given to regional catchment response to these, although it has been assumed that both Polynesian and European farming and land use management practices significantly increased erosion rates across most of New Zealand. This paper addresses the nature and timing of human impacts on river systems using meta‐analysis of a recently compiled nationwide database of radiocarbon‐dated fluvial deposits. This shows highly variable human impacts on erosion and sedimentation in river systems, which are often difficult to separate from naturally driven river activity. Catchment‐scale data with high resolution dating control record clearer evidence of human disturbance. In Northland, anthropogenic alluviation is recorded from c. AD 1300 linked to early Polynesian settlement, enhanced further in the late 19th and 20th centuries by European land clearance, when sedimentation rates exceeded 25 mm year^?1. This study demonstrates significant geographical variability in the timing of human impact on river dynamics in New Zealand, despite two synchronous phases of human settlement, and highlights the difficulty of formally designating a simple and single ‘Anthropocene Epoch/Age’.     

Planning Cultures and Histories: Influences on the Evolution of Planning Systems and Spatial Development Patterns

Abstract

This special issue addresses the influences of planning cultures and histories on the evolution of planning systems and spatial development. As well as providing an international comparative perspective on these issues, the collection of articles also engages in a search for new conceptual frameworks and alternative points of view to better understand and explain these differences. The articles focus on three main aspects: the change in planning systems and its impact on spatial development patterns; the interrelationship between planning cultures and histories from a path-dependency perspective; and the variations in physical development patterns resulting from different planning cultures and histories. Papers from different parts of the European continent present evidence at different scales to illustrate these aspects. In all cases, the specific combinations of political, ideological, social, economic and technological factors are important in determining urban and regional planning trajectories as well as spatial development patterns.     

Gendering Border Studies

Scholars working in (post)colonial settings have called for more-than-human (MTH) and post-human geographies to shift their gaze beyond Anglo-European ways of knowing the world. In this paper I explore the opportunities for an MTH political project that works in solidarity with and learns from Indigenous communities. I begin by examining the considerable synergies between MTH theorists’ understandings of nonhuman agency and kinship, and the worldviews of Ngāi Tahu (a Māori tribe). I then examine how Ngāi Tahu have worked within a new water management regime in the Canterbury region of Aotearoa New Zealand to articulate a relational ethics with the Hurunui River. In navigating multiple tensions and advocating for the lively river, the political space of the new catchment committee was expanded to (begin to) include the river. However, non-Māori who attempted to describe an understanding of a river-kin were less successful. This unevenness, I argue, highlights the complementary contributions to be made by expanded theoretical engagements. In particular there are generative possibilities for MTH theorists to work alongside Indigenous communities, and carve political space for more people to advocate for a relational ethics.     

The Fortifications of Hull between 1321 and 1864

As one of the most important ports on the east coast of England, Hull had a major strategic role as a supply base for English armies, particularly in their campaigns against Scotland. Consequently, its defence was a major consideration for the English Crown. The medieval and later town defences of Hull were amongst the strongest in Yorkshire. From 1321-4 until 1776 the town was surrounded on three sides by a substantial Town Ditch and bank, later fronted by a circuit of brick walls incorporating numerous gates and towers; the fourth side, opening onto the River Hull and the town’s waterfronts, was protected by a boom chain slung across the entrance to the river. This paper summarizes the historical and archaeological evidence not only for the defences on the west bank of the River Hull, surrounding the Old Town, but also the better-known Henrician and Stuart military defences on the east bank of the river.