Salt Marsh Accretion and Storm Tide Variation: an Example from a Barrier Island in the North Sea

We reconstruct past accretion rates of a salt marsh on the island of Sylt, Germany, using measurements of the radioisotopes 210Pb and 137Cs, as well as historical aerial photographs. Results from three cores indicate accretion rates varying between 1 and 16 mm year−1. Comparisons with tide gauge data show that high accretion rates during the 1980s and 1990s coincide with periods of increased storm activity. We identify a critical inundation height of 18 cm below which the strength of a storm seems to positively influence salt marsh accretion rates and above which the frequency of storms becomes the major factor. In addition to sea level rise, we conclude that in low marsh zones subject to higher inundation levels, mean storm strength is the major factor affecting marsh accretion, whereas in high marsh zones with lower inundation levels, it is storm frequency that impacts marsh accretion

Networks of cooperation: Water policy in Germany

German water policy-making defies easy categorisation. Policy processes are highly complex, fragmented, and diverse. Concentrating on the areas of drinking water supply and water pollution, the most important feature is the enormous importance of regional government in both the formulation and implementation of policy. The role of local government, and of municipal water utilities, is also crucial. The various forms of horizontal cooperation between individual municipalities and between the Lander are important, the latter having become particularly important as the Lander try to preserve their strong influence in the face of increasing policy activism by the EU. Historically, cooperative solutions have dominated much of policy development since the nineteenth century. In the face of powerful agricultural and industrial interests, the creation of networks of cooperation is still at the heart of policy, but the state relies less on authority or common interest than on exchange, with financial policy instruments coming to dominate. While water policy has been thoroughly reframed as part of environmental policy, environmental groups have played a relatively marginal role, although conflicts conceived in terms of local versus centralised water supply have gained some prominence in particular region

A systematic review of enhanced (or engineered) geothermal systems: past, present and future

Enhanced (or engineered) geothermal systems (EGS) have evolved from the hot dry rock concept, implemented for the first time at Fenton Hill in 1977. This paper systematically reviews all of the EGS projects worldwide, based on the information available in the public domain. The projects are classified by country, reservoir type, depth, reservoir temperature, stimulation methods, associated seismicity, plant capacity and current status. Thirty five years on from the first EGS implementation, the geothermal community can benefit from the lessons learnt and take a more objective approach to the pros and cons of ‘conventional’ EGS systems