Session I. Assessment and Rehabilitation of Hydromorphological Processes in Rivers
ثبت نشده
چکیده
Streams and their riparian zones provide typical examples of naturally speciesrich, dynamic habitats. Under natural conditions, spatial and temporal variation in flooding disturbance coincide with a strong hydrological gradient from the channel to the uplands, generating a heterogeneous environment with corresponding high plant and animal diversity. Yet, streams and their riparian zones are highly vulnerable freshwater systems which are increasingly threatened across the world by anthropogenic modifications, such as damming and channelization, as well as by projected increases in climate-induced droughts and flash floods. Severe losses of diversity along streams and their riparian zones, and the lack of ecological improvement after costly restoration programmes, call for detailed and mechanistic understanding of the regulation of species distributions and biodiversity in relation to the dynamic interactions of water flow, erosion and sedimentation. We present the results of a series of innovative hydromorphological stream restoration measures in The Netherlands, aimed at reconstructing the naturally dynamic and heterogeneous stream-riparian gradient of lowland sandy-substrate streams. These measures include re-meandering, channel excavation, narrowing of the stream profile and re-creation of a v-shaped stream valley with gently sloping riparian zones. We evaluate the achievements following these restoration measures in terms of vegetation rehabilitation and plant diversity and report on the mechanisms that contributed to successes. More specifically, we evaluate whether restoration of stream hydromorphology is sufficient, considering other abiotic limitations (water and soil quality) and biotic limitations (availability of nearby source populations to allow colonization of the restored sites).
منابع مشابه
Assessment of river hydromorphological quality for restoration purposes: an example of the application of RHQ method to a Polish Carpathian river
Planning and implementation of effective restoration projects require appropriate assessment of a river’s hydromorphological status. Two European standards on hydromorphological assessment of rivers and hydromorphological assessment methods used in Poland are reviewed in the context of their applicability for river restoration purposes. River Hydromorphological Quality assessment method is pres...
متن کاملNew tools for the hydromorphological assessment and monitoring of European streams.
Hydromorphological stream assessment has significantly expanded over the last years, but a need has emerged from recent reviews for more comprehensive, process-based methods that consider the character and dynamics of the river with greater accuracy. With this as a focus, a series of hydromorphological tools have been developed and/or further extended in Europe within the context of the REFORM ...
متن کاملAdapting and adopting River Habitat Survey: Problems and solutions for fluvial hydromorphological assessment in Portugal
Adapting and adopting River Habitat Survey: Problems and solutions for fluvial hydromorphological assessment in Portugal The Water Framework Directive (WFD), which established the use of hydromorphological quality elements to assess the ecological status of water bodies, has influenced the purpose and content of several European methods for characterizing physical structure and assessing habita...
متن کاملAssessment of hydromorphological conditions of the river using the MQI method (Case study area: JAJROOD River)
The destruction of the rivers and, consequently, the need to reconstruct them, is one of the known important problems in throughout the world. However, suitable methods for assessing the morphological changes (morphology) associated with this action, as well as the cognition of the effect of the morphological factors in order to intervention in the process of river reconstruction, are still bei...
متن کامل