Work Package 6 of REFORM focuses on monitoring protocols, survey methods, assessment procedures, guidelines and other tools for characterising the consequences of physical degradation and restoration, and for planning and designing successful river restoration and mitigation measures and programmes. Deliverable 6.2 of Work Package 6 is the final report on methods, models and tools to assess the hydromorphology of rivers.
This report summarises the outputs of Tasks 6.1 (Selection of indicators for cost-effective monitoring and development of monitoring protocols to assess river degradation and restoration), 6.2 (Improve existing methods to survey and assess the hydromorphology of river ecosystems), and 6.3 (Identification and selection of existing hydromorphological and ecological models and tools suitable to plan and evaluate river restoration).
The deliverable is structured in five parts. Part 1 (this volume) provides an overall framework for hydromorphological assessment. Part 2 includes thematic annexes on protocols for monitoring indicators and models. Part 3 is a detailed guidebook for the application of the Morphological Quality Index (MQI). Part 4 describes the Geomorphic Units survey and classification System. Part 5 includes a series of applications to several case studies of several tools and methods reported in the previous parts.
Summary of Deliverable 6.2 Part 1
The aim of this Deliverable is to provide a flexible, open-ended framework of procedures and tools through which practitioners can summarise river conditions, set monitoring activities, support the selection of appropriate and sustainable restoration actions.
Methods and Results
The overall assessment framework presented in this Deliverable is a more prescriptive version of the open-ended REFORM hydromorphological framework developed in Deliverable 2.1. Therefore, it provides a more formal set of methods and tools with which to practically assess and monitor hydromorphological conditions. Some of the key features of the REFORM hydromorphological framework presented here are the following: (i) it provides a flexible set of procedures such that member states can incorporate their own data sets and methods; (ii) it is organised in a sequence of stages, each one containing a series of procedural steps that support the assessment of river conditions in a consistent manner; (iii) its application allows representative reaches or sites to be selected for monitoring river conditions, and for appropriate upscaling or downscaling of information; (iv) it can be used to classify and understand current conditions, to assess the potential for morphological changes, and to support prioritisation of actions and selection of sustainable management strategies.
This report (D6.2 Part 1) describes the succession of logical stages required to implement the framework and its assessments as follows.
(1) Catchment-wide delineation and spatial characterization of the fluvial system. This phase provides a delineation, characterization and analysis of the river system in its current conditions, according to the framework developed in D2.1.
(2) Assessment of temporal changes and current conditions. This phase involves reconstructing the history and evolutionary trajectories of morphological changes and assessing river conditions in its present state.
(3) Assessment of scenario-based future trends. This phase is aimed to identify possible scenarios of hydromorphological modification.
(4) Identification of management actions. This last phase is aimed to identify possible hydromorphological restoration or management actions, and strongly interacts with the identification of restoration potential and strategies developed in REFORM WP5.
The methods and tools developed or revised in this Deliverable have relevance for hydromorphological assessment and monitoring aimed at implementing the WFD. Concerning the definition of WFD water bodies, the REFORM framework uses a more standard geomorphological terminology for the spatial units and the procedures recommended include a more comprehensive and explicitly process-based set of criteria. Application of the REFORM framework to delineate segments often generates boundaries that correspond to WFD water body boundaries, which can be further subdivided into ‘reaches’ using additional geomorphological criteria such as the classification of river typologies.
This Deliverable also suggests suitable methods for the evaluation of the different components of an overall ‘river condition assessment’, such as for hydrological assessment (IARI, IAHRIS), morphological assessment (MQI, Rivers-MImAS, SYRAH), and riparian vegetation assessment (RQI). Specifically, the Morphological Quality Index (MQI) has been extended and tested during the project and is the recommended method from REFORM for the assessment of morphological conditions.
Conclusions and recommendations
In order to characterise, assess, and monitor hydromorphological conditions of rivers, an overall analysis of different components (hydrology, morphology, riparian vegetation) is required. The analysis must be based on appropriate spatial and temporal scales.
For sustainable solutions to river management problems, it is crucial to develop understanding of the functioning of a river reach in the context of the character and changes in the spatial units (segment, landscape unit, catchment, biogeographical region) within which the reach is located.
Knowledge of past hydromorphological changes which have occurred at different spatial scales, their causes, and reconstruction of the river evolutionary trajectory in response to those changes is a fundamental component of the analysis.
We provide the following key recommendations for stakeholders:
• We recommend using two linked process-based approaches to achieve a comprehensive and synergic hydromorphological assessment: (i) a multi-scale, open-ended framework to develop an understanding of river reach hydromorphology; (ii) a more prescriptive approach based on the integration of more specific assessment tools.
• The delineation of WFD water body boundaries can be integrated into the REFORM framework at the segment scale, and then the water bodies can be further sub-divided into ‘reaches’ using additional geomorphological criteria such as the identification of river (morphological) types.
• The Morphological Quality Index (MQI) is recommended to assess river conditions, i.e. for analysing and interpreting critical problems and causes of alteration. The method should be implemented for the entire gradient of morphological conditions (not only for high status water bodies) for supporting interpretation of BQEs, and should be integrated with a characterization of the assemblage of geomorphic units (GUS) that determine the morphology at reach scale.