1. introduction

1. Introduction

1.1. Background

Water regulates life and as such is of fundamental importance to human, other animal and plant life. Because of the interaction between atmosphere, lithosphere, hydrosphere and biosphere and the consistency of the global water cycle, every change or modification in one of these spheres will consequently lead to a modification of the water cycle and water balance.

In this context humankind plays a special role. As part of the biosphere it massively influences other spheres, especially through water consumption influencing the global hydrosphere. Because of the complex physical and chemical properties of water it does not only serve humans as a source of food but also as a means of production in agriculture, aquaculture, forestry, industry, energy and as a means of transport.

Artificial alterations to the natural cycle of water has produced massive changes in agricultural landscape and in aquatic, riparian, wetland and other floodplain habitats. These interventions have had both positive and negative impacts on the problems that they were intended to solve. Some of these activities have greatly constrained the degree of interactions between the river channel and the associated floodplain with catastrophic effects on biodiversity.

1.2. Tasks

According to the European Environment Agency’s Topic Centre of Inland Waters’ (ETC/IW) Technical Work Programme for the 1995 Subvention (Feb. 1996), the main task is to determine, on a pan-European scale, the significance of and key issues arising from human interventions in the hydrological cycle.

The first step of defining a strategy on this issue will be the collation of readily available information on past and on-going activities relating to such physical impacts on the hydrological cycle throughout some countries in the EEA area. The basis of the information is the knowledge and experience of the ETC-IW partners. Contributors to the project (AWW-Austria, INAG-Portugal, IOW-France, NERI-Denmark and NIVA-Norway) have reported on the situation in their own countries and from other countries if information is available.

1.3. Structure of the Report

This report comprises four main parts and two Appendices:

Part 1 describes the background, tasks and investigation methods of the project. Hydrological data from different sources are also compared.

Part 2 deals with the Biogeographic Regions defined by the European Commission for the Natura 2000 process and the country-specific descriptions and adaptations on the biogeographic map.

Part 3 (sections 4 to 6) gives a brief overview of the main human interventions in the hydrological cycle selected by the contributing partners.

Part 4 (sections 7 and 8) gives the main conclusions from this scoping study and makes recommendations on how the study should proceed in the next phase during the 1996 subvention period.

Appendix A contains a list of possible human interventions in the hydrological cycle.

Appendix B presents the detailed description of the selected human interventions by the contributing partners.

1.4. Investigation Method

AWW provided a draft list of possible human interventions in the hydrological cycle. This draft was sent out to the relevant ETC-Partners contributing to this project for comment and completion (deadline: 18 March 96).

The final working paper including the list of "Human interventions in the hydrological cycle", complete with definitions and including an annex of proposed key words/figures to describe the human inventions was distributed to ETC/IW partners WRc, AWW, INAG, IOW, NERI and NIVA. Contributors had to select the most significant interventions up to a maximum of six, with up to three from each main category and for each biogeographic region (deadline for contribution: 19 April 96). The complete list of selected human interventions is attached in Annex 1.

The main categories for human interventions are:

A. River, lake and estuary regulation

B. Water abstraction

C. Activities in the catchment

The selection is based on the significance of the physical intervention and the importance of its effects. The significance of an intervention has been interpreted as being in terms of water volumes involved, economic aspects, population and surface area concerned and the frequency of an intervention in the region.

The importance of the effects, positive and negative, was assessed in terms of the number of people affected from the intervention, economic aspects, direct and indirect impacts on the environment, fauna and flora, aesthetic impacts and the significance of habitat modification.

The contributors were invited to give a short description and an explanation of the intervention, the extent, the benefits and both positive and negative effects. Added examples complete the contributions.

Note:

The following selection of significant human interventions in the hydrological cycle is based on a consultation of experts at AWW (Austria), INAG (Portugal), IOW (France), NERI (Denmark) and NIVA (Norway) and the results refer only to country specific experiences and cannot be extrapolated to the whole Europe without further work. These contributions do not represent official statements of the countries involved.