Use and management
Freshwaters are used in many ways: as a drinking water supply, for industrial transportation and for recreation. All these functions, also referred to as ecosystem services, can only be ensured if rivers and lakes are in a good ecological state. Since its introduction in 2002, the Water Framework Directive has called for just that. And yet water is a scarce resource in many regions of the world. The growing pressure caused by mining, industry, hydroelectric power production and agriculture affects water quality and the passage of freshwaters. At IGB, we develop concepts for the future-oriented management of freshwater resources for the welfare of humans and nature. We investigate how anthropogenic influences affect freshwaters, and how lakes, flowing waters and wetlands can be used sustainably and revitalised efficiently.
A review of hydropower plants in Romania: distribution, current knowledge, and their effects on fish in headwater streams
Hydropower is renewable, but mostly not environmentally friendly. The study shows for Romania how the expansion of hydropower runs counter to the goals of EU environmental policy. Hydropower conflicts with the requirements of the Flora-Fauna-Habitat Directive and the European Water Framework Directive: around half of the hydropower plants in Romania are located in nature conservation areas.
How much habitat does a river need?: a spatially-explicit population dynamics model to assess ratios of ontogenetical habitat needs
The authors used a spatially explicit population dynamics model for the barbel to investigate the functional dependencies of sub-habitats. They showed that revitalising only spawning or only juvenile habitats is not effective; the functional unit and a minimum size of habitats are essential. The model helps to predict the revitalisation success on the basis of the size.
The study shows: Europe has some of the most fragmented rivers in the world. On average, there is about one barrier per 1.4 kilometres of stream, in Germany even two barriers per kilometre. Small transverse structures with an impoundment height of less than two metres account for the lion's share. The study also shows opportunities for reconnecting streams and rivers.
Spatial and temporal variability of methane emissions from cascading reservoirs in the Upper Mekong River
Potential sediment methane production rates increase along the reservoir cascade in the Upper Mekong River. Ebullition is an important but previously overlooked pathway for methane emission. Both diffusive and ebullitive fluxes show high intra and inter reservoir variability. Fluxes fall into the low-to-mid range of global estimates for hydropower reservoirs.
The authors reviewed ecological studies in historic canal systems, examined the potential of historic canals to contribute to aquatic biodiversity conservation, and provided suggestions to promote biodiversity conservation given the opportunities and challenges in canal management (e.g., nature conservation vs historic preservation).