A method for the assessment and analysis of the hydromorphological condition of Italian streams: The Morphological Quality Index (MQI)

Abstract

A new index has been developed for the hydromorphological assessment of Italian rivers. The method was designed to comply with the EU Water Framework Directive requirements, but its use can be extended to other applications in river management. The evaluation of stream morphological quality is preceded by a phase of river segmentation, consisting of an initial division of the network into river reaches with homogeneous morphological characteristics. The evaluation procedure consists of a set of 28 indicators, which were defined to assess longitudinal and lateral continuity, channel pattern, cross section configuration, bed structure and substrate, and vegetation in the riparian corridor. These characteristics are analyzed in terms of geomorphological functionality, artificiality, and channel adjustments. Indicators, classes, and the scoring system were defined based on expert judgement. The scoring system leads to the definition of the Morphological Quality Index (MQI). Application of the method to 102 river reaches covering a wide range of physical conditions and human pressures of Italian streams enabled the testing of the overall methodology and the refinement of the indicators and scores. Limitations, strengths, and the applicability of the method are also discussed in the paper.

Evolución morfo-sedimentaria del tramo medio del río Segre

“…Aunque existen diversos métodos para el estudio del estado hidro-sedimentario en sistemas fluviales (por ej. Richter et al, 1996;Raven et al, 1997;Mathews y Richter, 2007;Ollero et al, 2008;Alber y Piégay, 2011;Rinaldi et al, 2013;Lobera et al, 2015), la integración que se ha realizado en este artículo se considera como novedosa y de gran interés en el campo de la geomorfología fluvial.…”

Assessment of river hydromorphological quality for restoration purposes: an example of the application of RHQ method to a Polish Carpathian river

“…-the assessment should aim to determine the degree of deviation from typical undisturbed conditions for a given river rather than the abundance of habitat features beneficial for river biota (CEN 2010) that may vary between different types of watercourses; -degree of modification of river hydromorphology is determined in relation to reference conditions that define the best attainable river state under contemporary environmental conditions in the catchment (Wy_ zga et al 2012b); -the assessment is largely based on field surveys to allow adequate recognition of the type, location and extent of the modification to river hydromorphology; -the methodology allows to recognize hydrological and geomorphological processes that control the state of the river ecosystem, including the processes of river adjustment to changing environmental conditions (Rinaldi et al 2013b). …”

“…These methods involve evaluation of the entire river corridor and both present and recent river change analysed on maps, aerial photos and orthophotos (Rinaldi et al 2013a;Belletti et al 2015). This group of methods includes, among others, the Australian River Styles Framework (Brierley and Fryirs 2005); IHG method in Spain (Ollero et al 2011), MQI in Italy (Rinaldi et al 2013b) and Polish method of river hydromorphological quality assessment RHQ (Wy_ zga et al 2009(Wy_ zga et al , 2010b(Wy_ zga et al , 2012b. Consideration of ongoing processes and field recognition of the river state make these methods most suitable for river restoration purposes.…”

“…As a consequence of the two latter limitations, these methods of assessment are of very limited use for the purposes of river restoration. The adequate assessment method should be based on detailed recognition of the extent and causes of degradation of river's hydromorphological conditions and allow the analysis of this state not only in the context of past human intervention in the river channel and corridor but also in the context of river adjustment to environmental changes (Wy_ zga et al 2012b;Rinaldi et al 2013b).…”

Long-term river trajectories to enhance restoration efficiency and sustainability on the Upper Rhine: an interdisciplinary study (Rohrschollen Island, France)

“…Historical hydromorphological adjustments should be evaluated on an accurate spatial scale and a high temporal resolution to identify past evolutionary processes and causal relationships (Bogen et al, 1992;Horowitz et al, 1999). 30 Interdisciplinary and retrospective studies, however, rarely combine different data sources to obtain a comprehensive view of functional changes (Bravard and Bethemont, 1989;Gurnell et al, 2003;James et al, 2009;Lawler, 1993;Lespez et al, 2015;Rinaldi et al, 2013;Trimble and Cooke, 1991). Furthermore, historical studies rarely consider sediment dating and pollution (Bogen et al, 1992;Garban et al, 1996;Horowitz et al, 1999;Woitke et al, 2003).…”