Marek Giełczewski

Contrasting the roles of section length and instream habitat enhancement for river restoration success: a field study of 20 European restoration projects

Restoration of river hydromorphology often has limited detected effects on river biota. One frequently discussed reason is that the restored river length is insufficient to allow populations to develop and give the room for geomorphological processes to occur. We investigated ten pairs of restored river sections of which one was a large project involving a long, intensively restored river section and one represented a smaller restoration effort. The restoration effect was quantified by comparing each restored river section to an upstream non-restored section. We sampled the following response variables: habitat composition in the river and its floodplain, three aquatic organism groups (aquatic macrophytes, benthic invertebrates and fish), two floodplain-inhabiting organism groups (floodplain vegetation, ground beetles), as well as food web composition and land-water interactions reflected by stable isotopes. For each response variable, we compared the difference in dissimilarity of the restored and nearby non-restored section between the larger and the smaller restoration projects. In a second step, we regrouped the pairs and compared restored sections with large changes in substrate composition to those with small changes. When comparing all restored to all non-restored sections, ground beetles were most strongly responding to restoration, followed by fish, floodplain vegetation, benthic invertebrates and aquatic macrophytes. Aquatic habitats and stable isotope signatures responded less strongly. When grouping the restored sections by project size, there was no difference in the response to restoration between the projects targeting long and short river sections with regard to any of the measured response variables except nitrogen isotopic composition. In contrast, when grouping the restored sections by substrate composition, the responses of fish, benthic invertebrates, aquatic macrophytes, floodplain vegetation and nitrogen isotopic composition were greater in sections with larger changes in substrate composition as compared to those with smaller changes. Synthesis and applications. The effects of hydromorphological restoration measures on aquatic and floodplain biota strongly depend on the creation of habitat for aquatic organisms, which were limited or not present prior to restoration. These positive effects on habitats are not necessarily related to the restored river length. Therefore, we recommend a focus on habitat enhancement in river restoration projects. The effects of hydromorphological restoration measures on aquatic and floodplain biota strongly depend on the creation of habitat for aquatic organisms, which were limited or not present prior to restoration. These positive effects on habitats are not necessarily related to the restored river length. Therefore, we recommend a focus on habitat enhancement in river restoration projects.

Assessing restoration effects on hydromorphology in European mid-sized rivers by key hydromorphological parameters

The effects of river restoration on hydromorphological conditions and variability are often documented immediately following the restoration, but rarely properly monitored in the long term. This study assesses outcomes of 20 restoration projects undertaken across central and northern Europe for a comprehensive set of hydromorphological parameters, quantified at both larger and smaller spatial scales. For each project, we compared a restored river section to an upstream degraded section. Ten pairs of large projects were contrasted to ten similar but less extensive projects, to address the importance of restoration extent for the success of each project. Overall, river restoration increased habitat diversity through changes in channel morphology. Our results indicated that restoration particularly improved macro- and mesohabitat diversity, but had a limited effect on microhabitat conditions, including the diversity of substrates. We found no significant difference in effects between large and small restoration projects. Our results reveal the need to assess hydromorphological parameters which reflect processes occurring at different spatial scales, including indicators of larger-scale hydromorphological processes such as bank erosion, to monitor restoration effects effectively and accurately. Additionally, our results demonstrate the importance of developing terrestrial parameters, to assess the lateral dimension of river restoration.

Modelling of discharge, nitrate and phosphate loads from the Reda catchment to the Puck Lagoon using SWAT

Abstract Modelling of discharge, nitrate and phosphate loads from the Reda catchment to the Puck Lagoon using SWAT. This study presents an application of the SWAT model (Soil and Water Assessment Tool) in an agricultural, coastal catchment situated in northern Poland, draining an area of 482 km2 (the Reda catchment). The main objective of this study was calibration and validation of the model against daily discharge and water quality parameters (bi-monthly total suspended solids [TSS], nitrate nitrogen [N-NO3] and phosphate phosphorus [P-PO4] loads). Calibration and validation were conducted using the SWAT-CUP program and SUFI-2 (Sequential Uncertainty Fitting Version 2) algorithm. The Nash- -Sutcliffe efficiency, which was set as an objective function in calibration of all variables, was equal for discharge to 0.75 and 0.61 for calibration and validation periods, respectively. For TSS, N-NO3 and P-PO4 loads NSE was equal to 0.56, 0.62 and 0.53 in calibration period, and 0.22, 0.64 and -1.78 in validation period, respectively. For the calibration period all the results are satisfactory or good, while for the validation period the results for TSS and P-PO4 loads are rather poor, which is related mainly to the lack of homogeneity between calibration and validation periods. These results demonstrate that SWAT is an appropriate tool for quantification of nutrient loads in Polish agricultural catchments, in particular for N-NO3. The model can therefore be applied for water resources management, for quantification of scenarios of climate and land use change, and for estimation of the Best Management Practices efficiency

Assessing Restoration Effects on River Hydromorphology Using the Process-based Morphological Quality Index in Eight European River Reaches

The Morphological Quality Index (MQI) and the Morphological Quality Index for monitoring (MQIm) have been applied to eight case studies across Europe with the objective of analyzing the hydromorphological response to various restoration measures and of comparing the results of the MQI and MQIm as a morphological assessment applied at the reach scale, with a conventional site scale physical-habitat assessment method. For each restored reach, the two indices were applied to the pre-restoration and post-restoration conditions. The restored reach was also compared to an adjacent, degraded reach. Results show that in all cases the restoration measures improved the morphological quality of the reach, but that the degree of improvement depends on many factors, including the initial morphological conditions, the length of the restored portion in relation to the reach length, and on the type of intervention. The comparison with a conventional site scale physical-habitat assessment method shows that the MQI and MQIm are best suited for the evaluation of restoration effects on river hydromorphology at the geomorphologically-relevant scale of the river reach.

The Narew River Basin Management Problems – Integrated Approach

An integrated approach to river basin management seems to be the most appropriate and promising way to achieve sustainable development of the large river catchment. Such approach is especially essential in the areas where economical activities are occurring together with great needs for nature protection due to its unique values and, local and global importance for ecological completeness. The Narew River Basin is a perfect example of such area. The main water management problems (key pressures and impacts) of the basin were identified. The present state of components of the integrated water management was recognized. Finally, the main directions for achieving integrated management, with their strengths, weaknesses, threats and opportunities, were elaborated.

Application of SWAT for modeling management scenarios in a large lowland watershed in Poland

Through many years man is managing rivers to compensate for droughts, floods or intensification of agricultural and industrial production. Due to presence of diverse factors (changes in land use and production intensification, climatic changes) various management practises may have positive or negative influence on water quality. Existing monitoring programmes are often not sufficient to estimate impact of many investments/measures that are widely used in Poland, like retention reservoirs, subsoil irrigation systems, or changes in land use and agricultural practises, on water quality because of low frequency, irregularity or limited extent of the measurements. This is especially the case in the large lowland rivers, such as the Narew river located in North-East Poland, draining a 28,000 km2 watershed, where this case study was performed. The aim of this study was to apply the watershed model, Soil & Water Assessment Tool for impact assessment of management scenarios developed with active stakeholders participation on water quality in a large river basin. An intermediate aim was development of these scenarios, describing future changes in land use, agriculture and water management, by formal linking of key river basin stakeholders with modellers. This case study demonstrates that parameters representing the driving forces used to quantify the scenarios are sensitive with respect to water quality constituents. Preliminary results of modeling showed that under a “greener” Sustainability Eventually scenario an improvement of water quality can be expected, in contrast to worsening of water quality under a market-oriented Economy First scenario.