Geomorphic Processes In Environments with Strong Seasonal Contrasts

The sixteen papers which comprise this volume have been arranged according to the emphasis given to measurement, theory, or application. Six papers present results from ongoing research in Spain. The first three from Catalonia refer to work in forested ecosystems where high amounts of winter precipitation make seasonal contrasts relatively high. The paper by Avila & Roda deals with chemical denudation, in the same area that SALA has measured mechanical erosion. Sevink considers how processes in these areas are influenced by organic soil horizons. The next four papers by Brown, Burt, Rogner and Mietton present the results of measurements from studies in respectively England, California, Israel and Burkina Faso. Brown demonstrates how studies of magnetic susceptibility can increase our insight into processes in Mediterranean environments; Rogner describes measurements of Cavernous weathering in the Negev; Burt draws attention to the seasonality of nitrate leaching in the relatively less seasonal environment of southwest England; and Mietton addresses the technical problems of measuring temperature in the hot dry environment of Burkina Faso. The last two papers, dealing mainly with method both by La Roca & Calvo Cases, describe measurements from marls in Valencia. The role of extreme events in this region in influencing process and morphological development is one of the points stressed. In two papers Poesen & Torri describe how cup size influences splash transport and detachment. This is followed by I Meson & Verstraten who consider how rill initiation is related to physico-chemically controlled soil properties that influence the dynamic response of material to wetting. Three of the final four papers concerned with application deal with soil erosion based on different approaches. Lewis, working in Rwanda using simple measurements and the USLE, looks mainly at the effect of groundcover on soil loss; Zanchi in Central Italy uses the USLE with plot measurements of soil loss to draw attention to the importance of seasonal variations in soil erodibility. Plot measurements also form the basis of the paper by Goczan & Kertesz who present the result of measurements from Hungary. Finally Lavee shows how geomorphic principles can be applied to locate sites for toxic waste disposal. Two papers presented during the symposium are not included because of space but will be published elsewhere. These are by Haigh on the Environmental correlates of landslide frequency along new highways in the Central Himalaya and by Gerits on the implications of chemical thresholds and physical-chemical processes for modelling erosion in Spain.