Influence of catchment quality and altitude on the water and sediment composition of 68 small lakes in Central Europe

Abstract

68 lakes (63 Swiss, 2 French and 3 Italian) located in an altitudinal range between 334 and 2339 m spanning a wide range of land-use have been investigated. The aim of the study was to discuss influences of geographic location, vegetation and land-use in the catchment area on the water and sediment chemistry of small lakes. Detailed quantitative description of land-use, vegetation, and climate in the watershed of all lakes was established. Surface and bottom water samples collected from each lake were analyzed for major ions and nutrients. Correlations were interpreted using linear regression analysis. Chemical parameters of water and sediment reflect the characteristics of the catchment areas. All lakes were alkaline since they were situated on calcareous bedrock. Concentrations of nitrogen and phosphorus strongly increase with increasing agricultural land-use. Na and K, however, are positively correlated with the amount of urbanization within the catchment area. These elements as well as dissolved organic carbon (DOC), Mg, Ca, and alkalinity, increase when the catchment is urbanized or used for agriculture. Total nitrogen and organic carbon in the sediments decrease distinctly if large parts of the catchment consist of bare land. No correlations between sediment composition and maximum water depth or altitude of the lakes were found.Striking differences in the water compositions of lakes above and below approximately 700 m of altitude were observed. Concentrations of total nitrogen and nitrate, total phosphorus, DOC, Na, K, Mg, Ca, and alkalinity are distinctly higher in most lakes below 700 m than above, and the pH of the bottom waters of these lakes is generally lower. Estimates of total nitrogen concentrations, even in remote areas, indicate that precipitation is responsible for increased background concentrations. At lower altitudes nitrogen concentrations in lakes is explained by the nitrogen loaded rain from urban areas deposited on the catchment, and with high percentages of agricultural land-use in the watershed.

The effect of catchment area management on biogenic element concentrations in the water of small ponds

“…Land use affected the concentrations of ammonia nitrogen and nitrates, which were found to be the highest in a small pond whose catchment area represented the AL/FA type. The above tendencies correspond to the view that agricultural land use constitutes a major threat to water quality (Koc 2000;Koc et al 1997;Müller et al 1998;Rhazi et al 2001;Szpakowska, Karlik 1997). Statistically significant differences between particular catchment types were noted for nitrate nitrogen content only.…”

Pan-Eurasian Experiment (PEEX): towards a holistic understanding of the feedbacks and interactions in the land–atmosphere–ocean–society continuum in the northern Eurasian region

“…It is important to understand the future role of Arctic-boreal lakes, wetlands, and large river systems, including thermokarst lakes and running waters of all size, in biogeochemical cycles, and how these changes affect livelihoods, agriculture, forestry, and industry. The water chemistry of lakes without any direct pollution sources in the catchment area can be expected to reflect regional characteristics of water chemistry, as well as global anthropogenic processes, such as climate change and long-range air pollution (Müller et al, 1998;Moiseenko et al, 2001;Battarbee et al, 2005). The current ground-based streamflow-gauging network over the northern Eurasian region does not provide adequate spatial coverage for many scientific and water management applications, including the verification of the land-surface run-off contribution to the recipients of intra-continental run-off.…”

A 600-year sedimentary record of flood events from two sub-alpine lakes (Schwendiseen, Northeastern Switzerland)

“…They are partly surrounded by moraines from different glacial stages (Keller 1988). The theoretical hydrological catchment covers approximately 5 km 2 (Müller et al 1998, Schwab 1992. Over 75% of the drainage area consists of Cretaceous limestone (i.e.…”