Should We Sample More than Required by the European Water Framework Directive? Case study: Emscher Catchment

Abstract

Measurement of restoration success is a challenge, especially in multiple-stressed urban systems. Standard indicators for ecological assessment may be too robust to indicate small but continuous improvements. Thus, a standardized method of the European Water Framework Directive (EU WFD) is extended by additional samplings of macroinvertebrates in the urban Emscher catchment. The aim is to prove whether additional sampling adds value to interpretate restoration success. According to the EU WFD, the Emscher's ecological status and potential are mainly identified as good to moderate regarding biological components of macrophytes and macroinvertebrates, whereas bad regarding fish communities. The additional sampling improves the quality of the biological dataset, because twice as many species of macroinvertebrates are found compared to the WFD method. Hence, the additional sampling allows a stronger indication for community ordination, and community metrics describing diversity, dispersal, and feeding preferences as well as by disentangling the roles of environmental variables. Nevertheless, it is concluded that the standardized and simple WFD method is sufficient to capture the most relevant effects. However, if the budget is allowed and information on the species pool, nature conservation, or aspects of early indication are needed, it may be useful to implement an additional sampling of macroinvertebrates.

Wastes in Underground Coal Mines and Their Behavior during Mine Water Level Rebound—A Review

“…Vogt [10] estimate that between 1964 and 1984, roughly 5-7 thousand tons of PCB were deposited in underground mines only in the western part of the Ruhr area. In [6], a detailed description of PCB mobilization modeling at the Lohberg site is presented.…”

“…In order to demonstrate the complexity of the spatial and temporal mine water evolution during rebound and how mine water management can be optimized, the feasibility study for the Central Water Province of the Ruhr area is used [6]. The Central Water Province has a surface extent of 1155 km 2 .…”

“…The very complex flow paths have been simplified here into the main flow paths, which indicate the direction of flow from the individual mine areas to the pumping stations. At the beginning of 2023, the plans of the feasibility study [6] were implemented, and the pumping operations at Zollverein, Carolinenglück and Amalie were halted. As a result, the water level is now rising in these subprovinces.…”

“…Further, the importance of water management concepts in the water rebound phase is highlighted, which effectively prevents harmful environmental effects. Notably, the quality of surface water in the Ruhr area has significantly improved over recent decades [6]. Achieving these outcomes requires an in-depth understanding of several pivotal aspects:…”