How to assess hydromorphology? A comparison of Ukrainian and German approaches

Abstract

Recently, the Ukrainian Western Bug water authorities developed a national field survey to assess the quality of river habitats. The Ukrainian government already cooperates with EU member states along transboundary rivers and also orientates itself towards the European Water Framework Directive (WFD). As a future application for EU membership is feasible, the water authorities started to implement WFD criteria into their national survey schemes including the assessment of rivers' hydromorphology. This article compares two different hydromorphological survey methods to identify similarities and differences of the classification approaches with regard to the conformity of obtained outputs with the WFD demands. The field surveys, the Ukrainian (UA-FS) and the German (LAWA-FS), were applied in parallel on 14 river sections along the Western Bug River and parts of its tributaries. Results show a wide range of conformity, but also several differences between and gaps within all methods. The UA-FS generally lacks the idea of reference condition in rivers' hydromorphology and the definition of different stream types or near-natural land uses. The UA-FS and the LAWA-FS approaches are similar with respect to their incorporated compartments and most main parameters, but differ in definition and interpretation of specific functional units and single parameters. Greatest similarities down to single parameters exist in aspects of land use, bank vegetation, currents diversity, and within-stream variation of water depths. Differences include the assessment and interpretation of lateral erosion, sinuosity, type and depth of profile, substrate diversity, as well as special structures of bank and riverbed. Overall, the LAWA-FS is more conservative in its rating than the UA-FS. Still, UA-FS can be regarded as an important improvement for a systematic and reliable monitoring of river hydromorphology in the Ukraine that will help to successfully engage with both the integrated water resources management and the WFD harmonisation process in the future.

Quantifying the Effect of Aerial Imagery Resolution in Automated Hydromorphological River Characterisation

“…This work demonstrates that for consistent and unbiased aerial imagery based hydromorphological assessment across EU Member States it is paramount to standardise the support used to obtain comparable ecological quality parameter estimates. Failure to do so could imply consequences in the management practice of water authorities (e.g., penalty payment) in terms of measures and efforts undertaken to accomplish the WFD [10]. In addition, results from the intercalibration process [4] identify as inadequate the spatial scale (few 100 m) of physical-habitat based hydromorphological methods and highlights the need for remote sensing based methods that enable detailed site-specific data collection to expand their application to a large number of water bodies.…”

“…The overall quantity disagreement (C) and allocation disagreement (Q) can therefore be derived as shown in Equations (9) and (10). For both C and Q, a larger value of disagreement indicates a larger mismatch between maps.…”

“…Belletti et al [4] compared over 100 EU hydromorphological assessment methods and classified them in four broad categories based on the key features surveyed: physical habitat, riparian habitat, morphological and hydrological regime alteration. The majority of methods compared rely on physical habitat identification and require the recognition of in-channel features that define homogenous areas of flow, vegetation and substrate [8] from either aerial imagery (e.g., [9]) or extensive field based work (e.g., [10,11]). An example is the UK assessment of flow types describing the lentic-lotic character of a reach that is routinely used at a National scale to assess river quality [7,8,12].…”

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

“…Consequently, a number of assessment methods were developed in particular countries to enable systematic evaluation of river hydromorphological quality (Rinaldi et al 2013a). Attempts at the standardization of these procedures brought about reviews (Belletti et al 2015) and comparisons of the methods used in different countries (Raven et al 2002;Scheifhacken et al 2012), and the European Committee for Standardization published two standards with the nomenclature and framework for hydromorphological evaluation of rivers (Boon et al 2010). However, many of the applied methods have one or more limitations: (1) they had been developed before the introduction of the Water Framework Directive and even though they provided the basis for its hydromorphological guidelines, they are not fully adjusted to its regulations; (2) they consist in static inventory of river habitat features and as such do not allow recognition of the ongoing hydrological and geomorphological processes; (3) they are general and involve little or no field surveys.…”

Visual data exploration for hydrological analysis

“…These well-selected model regions include the Ukraine Delfs et al 2011;Ertel et al 2011;Pavlik et al 2011;Scheifhacken et al 2011;Tavares et al 2011); the Middle East, with focus on Saudi Arabia (Petschinger et al 2011) and Oman (Grundmann et al 2011;Schütze et al 2011); Brazil (Lorz et al 2011;Vasyukova et al 2011) and Mongolia (Hartwig et al 2011;Vetter et al 2011). Cross-cutting activities are focussing on integrated modelling , socio-economic aspects (Horlemann et al 2011;Schanze et al 2011;Sigel et al 2011) as well as capacity building (Leidel et al 2011).…”