This thesis provides a survey of the research results of the relationship between on the one hand the construction, management and maintenance of civil engineering works, and on the other hand the environment, nature and landscape, with the main focus on motorways and coastal protection. The growing number and increase in size of civil engineering works and the growing need for protection measures of the sandy coasts have led to an ever increasing risk of adverse effects on the nature and landscape of the Netherlands, as well as to an increase in the degree of the impact of these effects. Consequently, such institutions as the Road and Hydraulic Engineering Institute (Dienst Weg- en Waterbouwkunde - DWW -) of the Directorate General of Public Works and Water Management (Rijkswaterstaat) of the Ministry of Transport, Public Works and Water Management have carried out extensive studies of possible adverse effects. Based on these studies were carried out of measures intended to prevent adverse effects, to avoid their impact and to mitigate and/or to compensate for them (i.e. to take measures elsewhere in order to bring about a no net loss of nature values), apart from measures that can produce positive effects.
From a scientific point of view as well as of the interest of society it is important to pay attention to the possibilities for better inserting civil engineering work (e.g. construction and use of infrastructure and such activities as coastal management) into ecosystems in order to conserve and develop biodiversity.
In this thesis the results of conducted research as well as outsources studies are presented in the form of a synthesis. In this context, the focus has been on integrating knowledge concerning the understanding, use and control of patterns and processes of ecosystems into the planning, the design, construction and maintenance of civil engineering works. Special attention was paid to roads, waterways, road verges, slopes, banks and bridges and viaducts related to the main infrastructure. Much attention is paid not only to the results of the research, but also to integrating the knowledge and understanding developed, in combination with other studies in the same field carried out under the responsibility of the Regional Directorates of Rijkswaterstaat.
This thesis was realized in the authors capacity as head (later, former head) of the research section of the environment department of the Road and Hydraulic Engineering Institute and nowadays as coordinator of research into environmental measures for infrastructure; as part-time staff member at the Delft Interfaculty Research Centre for the Sustainable Constructed Environment, especially the research programme 'The Ecological City'; and later as part-time researcher/lecturer at the Faculty of Civil Engineering and Geosciences of the Delft University of Technology.
This thesis discusses applied research, which incorporated original research work intended to extend the available knowledge and especially to solve clearly defined practical problems, which in this thesis are considered in their integral context as much as possible.
The main research questions, which have been subdivided into subquestions, were in which fields and by which means contributions can be made to reduce adverse effects or to increase the ecological significance of civil engineering works, both existing ones and those to be constructed. Studies have also been made whether it would be possible to formulate on the basis of the research results a set of ecological engineering principles to be used in actual practice.
In addition to the systematic collection, analysis and evaluation of data using the available methods and technology in the relevant research fields, research was carried out into the possibilities of creating a synthesis - a combination of not only monofunctional but also multifunctional (interdisciplinary) solutions, since the latter are expected to lead to a larger degree of sustainable development of our actions. Ecological engineering can play an important role in this context. This thesis includes a summary of the knowledge and understanding of the application of ecological engineering in the field of the integration of roads and road systems and natural patterns and processes, the significance of road verges as habitats for plants and animals, the fragmenting effect of roads and the possibilities to adopt mitigating measures, the insertion of roads into the landscape and the management of sandy coasts.
The thesis gives also insight into the way the responsibility for environmental and ecological issues in relation to the primary tasks of Rijkswaterstaat has developed within the organisation. This thesis highlights some of the important aspects referred to above concerning motorways and nature, environment and landscape. For aspects about environmental impact assessments (EIA) and motorways, reference is made to the thesis by dr. E.J.J.M. Arts, productgroup leader tracÃ© at the Road and Hydraulic Engineering Institute and as far as the subject compensation is concerned, to the soon to be published thesis written by drs. R. Cuperus, productgroup leader nature and landscape at the Road and Hydraulic Engineering Institute. For the fields of noise and roads and air and roads, reference is made to both existing literature and to upcoming publications within the scope of the ongoing 'Noise Innovation Programme' contracted to the DWW and the recently launched 'Airquality Innovation Programme'.