Towards a more sustainable management of soil resources by redistribution of economic and ecological added and reduced values (SUMSOR)
Région d'Oberaargau (BE), agglomération de Lausanne (VD)
Our research project is dealing with the question of the role of economic and ecological added and reduced values and how its redistribution improves the sustainability of qualitative and quantitative soil management policies. It focuses on the following four objectives:
1) Understanding how various types of added/reduced economic and ecological values of land/soil are created and how they interact within three of the most problematical types of (functional) spaces in Switzerland: agglomerations, tourist areas, and rural periurban areas.
2) Comparing, in a theoretical and a methodological perspective, existing and innovative new policy instruments dealing with the question of land/soil added and reduced value redistribution under the aspect of their capacity to achieve the objective of a more ecological land use.
3) Testing - through three quasi experimental/scenarios based case studies - various (sets of) existing or new policy instruments that could strengthen the redistribution of land and soil property and use rights as well as of land/soil ecological and economic added/reduced values in a more sustainable way and at a functional space scale.
4) Formulating specific, innovative and applicable policy recommendations, based on the three quasi-experimental and scenario based case studies, concerning the way of developing new redistributive institutional and policy designs, compatible with the existing federal land, soil, and subsoil property rights regimes.
L’un des objectifs émergeant des politiques de gestion durable des sols consiste dans la coordination des politiques d’aménagement du territoire et de protection qualitative des sols (notamment intégration des instruments de la LAT avec les instruments de l’Osol). Or, nos résultats semblent montrer que les enjeux redistributifs se posent de manière différente dans le cas des plus et moins-values écologiques et économiques. Alors que la redistribution entre plus et moins-values économiques peut se faire de manière plus uniforme au travers de différentes catégories d’instruments à différentes échelles spatiales, les enjeux redistributifs ou même plus simplement de protection des valeurs écologiques (mesurées en termes de services écosystémiques) semblent devoir être traités de manière plus spécifique et plus différenciée localement.
Par ailleurs, l’analyse de la mise en œuvre des politiques de gestion des sols durant ces 30 dernières années montre une étonnante capacité des autorités publiques, notamment municipales, à développer des stratégies innovantes permettant de compenser leur position structurellement faible face aux propriétaires fonciers.
Finalement, l’étude prospective menée plus spécifiquement sur l’instrument (en voie de discussion et d’émergence) des syndicats d’améliorations foncières et d’aménagement du territoire multi-sites dans le canton de Vaud indique que la mise en œuvre d’un tel instrument pourrait être très prometteuse dans l’optique de transférer les droits à bâtir localisés dans les zones à bâtir surdimensionnées des communes péri-urbaines en direction des zones à densifier à l’intérieur des agglomérations.
The research designs and/or theoretical frames and/or methods and data used are the following for each of the four research objectives :
Objective and work package 1: The qualitative part of the research analysed the implementation of existing policy instruments – such as zoning, time limited property rights (or surface rights), tax on added land value (Mehrwertabschöpfung), land improvement syndicate, community facility tax, soil decontamination obligation, etc. - in the Bernese peri-urban communes of the Oberaargau region and sub-urban and urban communes in the agglomeration of Lausanne between 1990 and 2016. The data collected for the analysis involved the following elements: a screening of past and present public and private legislation, the study of various secondary sources such as documents from spatial planning offices as well as archives of the cantons of Berne and Vaud, conventions between actors (mainly landowners and political authorities), online documents and data from web sites of public authorities (federal, cantonal and communal) and the media, site interviews of actors representing various interests in the policy implementation process (cantonal, communal, target group, third parties) and site visits.
In regard to the methodology, the selection of the case studies involved an extensive press review and the interview of local, regional and/or cantonal actors with expertise on land use planning (representatives from environmental NGOs, administrative actors, journalists).
Objective and work package 2 : The writing of the handbook on redistributive policy instruments does not require specific theoretical and methodological insights. The selection of the 33 instruments which are compared is based on an extended literature knowledge and review from some of the co-authors that have been working on this topic for more than 10 to 15 years. The same applies for the selection of the comparison criteria.
Objective and work package 3: Two main methodological innovations were required for the development of the simulation methdology. First, we developed a modelling framework that allowed us to spatially explicit future urban growth resulting from both regulatory as well as market based instruments. Second, we developed a heuristic for multi-objective optimization based on a genetic algorithm to find optimal urban growth configurations and compared them to configurations resulting from a Business As Usual (BAU) urban growth dynamic. In both cases we focused on the development of residential areas as a large amount of urban growth is driven by the expansion of this land-use class.
The modelling framework for simulating future growth of residential areas consisted of four steps and was implemented in the canton of Bern. First, we estimated the suitability for new development of residential areas in a spatially explicit way. The regulatory policy instruments that we investigated was zoning, which has traditionally been the dominant planning instrument in Switzerland. To model zoning, we calibrated a logistic regression model using remote sensing data on the historic development of residential areas in Switzerland. As an indicator of the suitability of residential development under market mechanisms, we calibrated a hedonic model using data on prices of single-family homes. Secondly, we estimated future demand of new residential areas. Thirdly, we allocated new residential areas until the demand was met, based on the spatial suitability derived for the two different instruments.
To analyse the resulting urban form (e.g. compact development vs. sprawling development) we calculated certain landscape metrics. Urban form can be a good indicator for sustainable development. However, it does not explicitly capture the influence of urban configuration on different development goals. We therefore included an analysis of how the configurations resulting from market-driven and zoning-driven development influence ecosystem services.
The heuristic used to find a set of so-called Non-Dominated Solutions (NDSs) to a multi-objective optimization problem was based on the genetic algorithm NSGA II. Modifications of the NSGA II involved the introduction of a 2D-crossover as well as a biased mutation operator. To ease interpretation of our results we focused on only two objectives to be optimized: maximizing compactness of urban development and minimizing loss of fertile soils. The optimization framework was applied to different municipalities in the canton of Zürich.
Objective and work package 4 : We have investigated the different potential uses of the “Multisite Land Improvement Syndicate” (MLIS) instrument whose aim is to redistribute development rights on the intercommunal level. The issue at hand is the transfer of these rights between a sending area (typically a remote suburban commune) where the land is dezoned and a receiving area (typically an urban commune) where the land will be put to use. On the basis of several case studies and different scenario simulations, our work questions the territorial, land property and financial conditions for an effective implementation of the MLIS. Simultaneously, necessary legal modifications and socio-political conditions have also been evaluated.
|Ethical approval||No||Study type||
|Start - End date||01.04.2013 - 28.04.2016|