The historical impacts of hydroelectric power development on traditional mountain irrigation in the Valais, Switzerland

Your use of this PDF, the BioOne Web site, and all posted and associated content indicates your acceptance of BioOne’s Terms of Use, available at www.bioone.org/page/terms_of_use. Usage of BioOne content is strictly limited to personal, educational, and non-commercial use. Commercial inquiries or rights and permissions requests should be directed to the individual publisher as copyright holderIn many Western European mountains, ancient irrigation practices have been the basis for sustainable subsistence-based mountain agriculture, especially up to the beginning of the 20th century. These mountain zones have proved popular sites for the development of hydroelectric power (HEP). Few attempts have been made to measure the impact of HEP on traditional indigenous irrigation systems dependent on the same resource base. This article examines the physical and socioeconomic impact of HEP development on the bisse irrigation system in the Valais, Switzerland, and discusses new water resource issues, conflicts, adaptations, and innovative responses. The study shows that a two- to three-tier consultation process has led to communes and autonomous collective irrigation institutions (consortages) signing and ratifying long-term conventions that ceded water to HEP companies at the scale of watersheds. Water supplies for irrigation are protected by these conventions at the same time as changed hydrological regimes improve water security in economically viable bisses. Conventions also improved the economic security of some consortages, while at the level of individual households, HEP development allowed diversification of income generation strategies.Peer reviewe

Investigation of the superstructure of polymers during deformation by synchrotron radiation

Firstly a short review of some frequently used models for fibre structures is given. Then a model, based on a three-dimensional monoclinic paracrystalline macrolattice is described. This model allows the calculation of the two-dimensional intensity distribution for the small-angle scattering from semicrystalline polymers with different orientational states. The parameters of the model result from comparison with the measured intensity. The method of analysis is applied to low-density polyethylene deformed uniaxially at different temperatures. The use of synchrotron radiation makes it possible to follow the destruction and rebuilding of the superstructure. A reversible change of the superstructure during stretching and relaxing was found for different draw ratios for very high-molecular-weight polyethylene samples

Investigation of the superstructure of polymers during deformation by synchrotron radiation

Firstly a short review of some frequently used models for fibre structures is given. Then a model, based on a three-dimensional monoclinic paracrystalline macrolattice is described. This model allows the calculation of the two-dimensional intensity distribution for the small-angle scattering from semicrystalline polymers with different orientational states. The parameters of the model result from comparison with the measured intensity. The method of analysis is applied to low-density polyethylene deformed uniaxially at different temperatures. The use of synchrotron radiation makes it possible to follow the destruction and rebuilding of the superstructure. A reversible change of the superstructure during stretching and relaxing was found for different draw ratios for very high-molecular-weight polyethylene samples

The change of the superstructure of semicrystalline polymers during deformation: results from small-angle scattering with synchrotron radiation

The change of the superstructure of different polyethylenes during uniaxial deformation is investigated. The method used is small-angle scattering with synchrotron radiation. For branched polyethylene (Lupolen 1840D) the whole deformation range is analyzed. Beginning with superstructure of the lamellar cluster type, the superstructure partly disappears on a time scale of a few minutes and the fibrillar structure is built up. The degree of destruction and rebuilding depends on the drawing temperature. For very high molecular weight polyethylene (GUR) a reversible change of the superstructure at higher deformation ratios and at different temperatures is observed. The superstructure of (ethylene—hexene) copolymers (TIPELIN) at high draw ratios depends on the drawing temperature and is almost independent of the side group content. Interfibrillar microcracks parallel to the draw direction are produced in samples with a low side group content for draw ratios λ ≥ 1.5

Green Hydropower: The contribution of aquatic science research to the promotion of sustainable electricity

Hydropower use is responsible for a wide range of environmental disturbances to river systems. Over the past decades, aquatic science research has been successful in identifying a considerable number of relationships that exist between plant operation and ecosystem quality. This increase in scientific knowledge was, however, not matched by a corresponding reduction in environmental impacts stemming from hydropower. In the present paper, we show how aquatic science projects may be defined and implemented to better link scientific knowledge with the resolution of environmental problems. We base our analysis on a major aquatic science research project in which an eco-label for "sustainable hydropower" (Green Hydropower) was developed for Switzerland. We first assess the state of aquatic science research on alpine river systems. The Swiss history of hydropower shows that the limited adoption of this knowledge was due to a severe coordination and action problem. The Green Hydropower project aimed at establishing an environmental product label for hydropower plant operation, which should help overcome these problems. It had to deal with two major challenges: the integration of widely differing knowledge stocks and the management of a network of diverse stakeholders operating in a conflict-laden political environment. By carefully dealing with these two problem areas, the project was finally able to define a scientifically-based and broadly-accepted standard for Green Hydropower operation. We conclude by discussing lessons for the improvement of problem-oriented aquatic science research, in general