TY - JOUR A1 - Morandi, Bertrand A1 - Kail, Jochem A1 - Tödter, Anne A1 - Wolter, Christian A1 - Piegay, Herve T1 - Diverse Approaches to Implement and Monitor River Restoration BT - a Comparative Perspective in France and Germany JF - Environmental Management N2 - River restoration is a main emphasis of river management in European countries. Cross-national comparisons of its implementation are still rare in scientific literature. Based on French and German national censuses, this study compares river restoration practices and monitoring by analysing 102 French and 270 German projects. This comparison aims to draw a spatial and temporal framework of restoration practices in both countries to identify potential drivers of cross-national similarities and differences. The results underline four major trends: (1) a lag of almost 15 years in river restoration implementation between France and Germany, with a consequently higher share of projects in Germany than in France, (2) substantial similarities in restored reach characteristics, short reach length, small rivers, and in "agricultural" areas, (3) good correspondences between stressors identified and restoration measures implemented. Morphological alterations were the most important highlighted stressors. River morphology enhancement, especially instream enhancements, were the most frequently implemented restoration measures. Some differences exist in specific restoration practices, as river continuity restoration were most frequently implemented in French projects, while large wood introduction or channel re-braiding were most frequently implemented in German projects, and (4) some quantitative and qualitative differences in monitoring practices and a significant lack of project monitoring, especially in Germany compared to France. These similarities and differences between Germany and France in restoration application and monitoring possibly result from a complex set of drivers that might be difficult to untangle (e.g., environmental, technical, political, cultural). KW - River restoration KW - Project monitoring KW - Hydromorphologic alteration KW - Mitigation measures KW - France KW - Germany Y1 - 2017 U6 - https://doi.org/10.1007/s00267-017-0923-3 SN - 0364-152X SN - 1432-1009 VL - 60 SP - 931 EP - 946 PB - Springer CY - New York ER - TY - JOUR A1 - Munz, Matthias A1 - Oswald, Sascha A1 - Schmidt, Christian T1 - Analysis of riverbed temperatures to determine the geometry of subsurface water flow around in-stream geomorphological structures JF - Journal of hydrology N2 - The analytical evaluation of diurnal temperature variation in riverbed sediments provides detailed information on exchange fluxes between rivers and groundwater. The underlying assumption of the stationary, one-dimensional vertical flow field is frequently violated in natural systems where subsurface water flow often has a significant horizontal component. In this paper, we present a new methodology for identifying the geometry of the subsurface flow field using vertical temperature profiles. The statistical analyses are based on model optimisation and selection and are used to evaluate the shape of vertical amplitude ratio profiles. The method was applied to multiple profiles measured around in-stream geomorphological structures in a losing reach of a gravel bed river. The predominant subsurface flow field was systematically categorised in purely vertical and horizontal (hyporheic, parafluvial) components. The results highlight that river groundwater exchange flux at the head, crest and tail of geomorphological structures significantly deviated from the one-dimensional vertical flow, due to a significant horizontal component. The geometry of the subsurface water flow depended on the position around the geomorphological structures and on the river level. The methodology presented in this paper features great potential for characterising the spatial patterns and temporal dynamics of complex subsurface flow geometries by using measured temperature time series in vertical profiles. (C) 2016 Elsevier B.V. All rights reserved. KW - Temperature time series KW - Amplitude ratio KW - River-groundwater exchange KW - Hyporheic zone KW - In-stream geomorphological structures KW - River restoration Y1 - 2016 U6 - https://doi.org/10.1016/j.jhydrol.2016.05.012 SN - 0022-1694 SN - 1879-2707 VL - 539 SP - 74 EP - 87 PB - Elsevier CY - Amsterdam ER -