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Notes: A river-corridor survey (RCS), routinely undertaken on behalf of the National Rivers Authority (NRA), provides a consistent national approach to gathering and recording environmental information on 500-m stretches of river corridor. The development of RCS is reviewed and the methodology which is currently applied within the NRA is described. A research programme, sponsored by the NRA, to develop scientifically-valid methods for extracting quantitative information from RCS maps is outlined. The methodology allows for spatial distortions and operator variance in mapping the 500-m stretches. It is based on an abundance scale and therefore provides data which can be quantitatively combined and analysed (a) to highlight different properties of the river corridor and (b) to summarize those properties over different corridor lengths. The results of an example application of these methods of information extraction to a 14.5-km length of river corridor are presented.

Notes: 1. Large wood forms an important component of woodland river ecosystems. The relationship between large wood and the physical characteristics of river systems varies greatly with changes in the tree species of the marginal woodland, the climatic and hydrological regime, the fluvial geomorphological setting and the river and woodland management context.2. Research on large wood and fluvial processes over the last 25 years has focussed on three main themes: the effects of wood on flow hydraulics; on the transfer of mineral and organic sediment; and on the geomorphology of river channels.3. Analogies between wood and mineral sediment transfer processes (supply, mobility and river characteristics that affect retention) are found useful as a framework for synthesising current knowledge on large wood in rivers.4. An important property of wood is its size when scaled to the size of the river channel. ′Small′ channels are defined as those whose width is less than the majority of wood pieces (e.g. width 〈 median wood piece length). `Medium' channels have widths greater than the size of most wood pieces (e.g. width 〈 upper quartile wood piece length), and `Large' channels are wider than the length of all of the wood pieces delivered to them.5. A conceptual framework defined here for evaluating the storage and dynamics of wood in rivers ranks the relative importance of hydrological characteristics (flow regime, sediment transport regime), wood characteristics (piece size, buoyancy, morphological complexity) and geomorphological characteristics (channel width, geomorphological style) in `Small', `Medium' and `Large' rivers.6. Wood pieces are large in comparison with river size in `small' rivers, therefore they tend to remain close to where they are delivered to the river and provide important structures in the stream, controlling rather than responding to the hydrological and sediment transfer characteristics of the river.7. For `Medium' rivers, the combination of wood length and form becomes critical to the stability of wood within the channel. Wood accumulations form as a result of smaller or more mobile wood pieces accumulating behind key pieces. Wood transport is governed mainly by the flow regime and the buoyancy of the wood. Even quite large wood pieces may require partial burial to give them stability, so enhancing the importance of the sediment transport regime.8. Wood dynamics in `Large' rivers vary with the geometry of the channel (slope and channel pattern), which controls the delivery, mobility and breakage of wood, and also the characteristics of the riparian zone, from where the greatest volume of wood is introduced. Wood retention depends on the channel pattern and the distribution of flow velocity. A large amount is stored at the channel margins. The greater the contact between the active channel and the forested floodplain and islands, the greater the quantity of wood that is stored.

Notes: 1. The landscapes of large floodplain rivers are characterised by heterogeneous environments related to the interplay of flood flows, sediment transport and vegetation dynamics.2. The large rivers of Europe, and probably most rivers throughout the forest biomes, were characterised by islands but over the period of major human interference, many have become dominated by incision and narrowing so that they are now characterised by single-thread and relatively simple channel forms.3. Vegetation plays an active role in developing heterogeneous channel forms through (a) biotic processes such as seed dispersal, vegetative regeneration and succession and (b) abiotic effects such as increasing flow resistance inducing sedimentation, and decreasing bank erodibility.4. In particular, accumulations of living driftwood (cf. dead driftwood accumulations and dispersed seedlings) accelerate sedimentation and island development.5. River reaches with vegetated islands have a high habitat diversity.6. The natural influences of flood disturbance, wood accumulation, vegetation growth, island development and tree die-off, cause island-dominated reaches to undergo cycles of island growth and decay that are related to cycles of aquatic habitat diversification and simplification.

Notes: Experience and knowledge of river-restoration schemes are generally available at the reach scale. However, there are problems with the application of this knowledge at the scale of large urbanised catchments which relate to understanding the system and predicting the impact of management strategies. This paper considers problems of developing a perceptive and efficient rehabilitation strategy for a large urbanised catchment, with specific reference to the River Tame in the West Midlands. Consideration is given to (a) rainfall-runoff relationships, (b) assessment of water quality and ecological status, and (c) predicting the impact of various management strategies.