Jesper Persson

The hydraulic performance of ponds of various layouts

This study analyses how the hydraulic performance differs between 13 ponds with hypothetically different layouts. The paper also includes a discussion of short-circuiting, hydraulic efficiency and suitable parameters for measuring hydraulic performance. The ponds were studied by using a 2-D vertically integrated numerical model. Tracer studies were simulated and then evaluated and compared. The results confirm that length-to-width ratio, location of in- and outlets, and subsurface berm have a large impact on pond hydraulic performance. There is also an indication that an island placed in front of the inlet improves the hydraulic performance, and that a curved pond or an island placed near the side does not decrease the performance.

Perceptions of environmental compensation in different scientific fields

Environmental compensation is used worldwide, but remains a concept under development in many countries. The underlying idea is to maintain the overall quality of the environment in cases where environmental assets are damaged, for example, by residential or industrial development or by road construction. This study aimed to investigate how environmental compensation is perceived in a number of scientific fields and what the differences, if any, are between those fields. The results showed that the respondents took a positive view of environmental compensation in general, of the inclusion of social aspects and of the role of NGOs, but that they also (implicitly) questioned the mitigation hierarchy. The study also revealed several differences between the scientific disciplines, though mainly in the differing strengths of the groups’ convictions.

The Concept and Practices of Environmental Compensation in European Union

This article discusses the concept of environmental compensation and provides the examples of environmental compensation practices in various European Union countries. The principle of environmental compensation is to avoid, minimize, restore or compensate the damage to the biodiversity due to human activities, however in practice it is almost impossible to achieve no net loss to the biodiversity. European Union has issued Directive that established the principles of environmental compensation already in 2004, however until now the practices of environmental compensation in European Union countries are very fragmented. The implementation of environmental compensation principles in urban development is constrained mainly by factors such as lack of space, and the complexity of environments that are affected. There is a lack of integrated approach towards the strategies how environmental compensation should be implemented in the planning of various projects that have impact upon biodiversity. Furthermore, there is a lack of holistic approach towards the nature in legislation and practices of environmental compensation, as usually focus of instruments is on specific parts of natural environment. Ideally, the principles of environmental compensation should be an integral part of national strategies of sustainable development. DOI: http://dx.doi.org/10.5755/j01.ppaa.15.3.16616