Application of the Mesohabitat Simulation System (MesoHABSIM) for Assessing Impact of River Maintenance and Restoration Measures

Katarzyna Suska,Piotr Parasiewicz

doi:10.3390/w12123356

Abstract

Maintenance and restoration activities alter the river morphology and hydrology, and in consequence, alter fish habitats. The aim of this research was to investigate the change of habitat availability for fish guilds after carrying out maintenance works, commonly used river restoration measures and a restoration derived from fish habitat requirements. The selected study site is located at a close to natural condition section of Swider River in central Poland. The MesoHABSIM model was used to assess the area of suitable habitats in this site and predict habitat distribution at all planning scenarios. The affinity index which is a measure of similarity of two distributions showed that the likely distribution of habitats for fish resulting from simulated maintenance is 76.5% similar to that under measured conditions. The distribution of habitats caused by river restoration is also similar to that of the baseline in 73.2%. The resemblance between the restoration scenario focusing on fish habitat requirements and the reference conditions is 93.1%. It is beneficial to define the river restoration measures based on habitat availability for fish community. Modelling is a useful tool to simulate the changes and predict which guilds there is abundance of suitable habitats, and for which there are too few. It allows for more effective use of resources according to quantitative target states.

Highlights

All Member States of the EU must comply with the requirements of the Council Directive concerning the protection of waters against pollution, caused by nitrates from agricultural sources [1]and Water Framework Directive [2]
The analyzed Swider river section was divided into eighteen HMUs for reference conditions, five HMUs for maintenance works simulation and fifteen HMUs for river restoration simulation
Under reference conditions in the analyzed section of the river, the four guilds had suitable habitats, while the midwater guild most probably did not exist under these hydrological conditions (100% of the area of the habitat is unsuitable)

Summary

Introduction

All Member States of the EU must comply with the requirements of the Council Directive concerning the protection of waters against pollution, caused by nitrates from agricultural sources [1]and Water Framework Directive [2]. All Member States of the EU must comply with the requirements of the Council Directive concerning the protection of waters against pollution, caused by nitrates from agricultural sources [1]. Basin Management Plans 60% of the surface water bodies in EU did not achieve good ecological status and 46% did not achieve good chemical status (the status of 16% is unknown). Hydromorphological modifications are caused by the construction of dams, embankments, carrying out channelization and flow regulation [3]. In Poland in 2018, 87% of rivers and dammed reservoirs did not achieve good ecological status. Assessment of the hydromorphological status carried out in 2018 for 998 out of 4586 river water bodies showed that 31% of the evaluated waters have high status [4].

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