Abstract

In an empirical/statistical approach to the interaction between watershed characteristics and lake water quality, the inter-lake variance of 87 chemically monitored dimictic glacial/boreal lakes is correlated to the distributed properties of catchment descriptors. In a total, 33 classes of land cover, soils and bedrock are identified and described with respect to element morphology and hydrology. Together with descriptors of catchment/lake morphology, hydrology and climate, they serve as explanatory variables in the construction of statistical regression models that assess the chemical lake water constituents: conductivity, hardness, Secchi depth, color, alkalinity, total phosphorus and pH. As a result, the four former variables (cond, H, Secc, col) are simulated with precision enough for quantitatively predictive purposes, whereas the three latter (alk, TP, pH) provide a rather qualitative - although highly significant - estimate. Using normalized regression coefficients, catchment descriptors are ranked with respect to their general importance. It is found that only fifteen landscape elements - out of the 33 totally identified - and seven other catchment/lake descriptors occur as significantly correlated to the inter-lake variance of water quality. The ranking of element descriptors provide a basis for decisions regarding the location of projects that affect the properties of landscape elements (e.g. damming, irrigation, mining). When applied in watershed management, projects that intend to conserve lake water quality should be located within as low ranked elements as possible, whereas the location of projects that strive to manipulate lake water quality may be calculated as a function of the chemical alteration desired. With the analyzed database being large enough to encompass a wide population of typical lakes, the results should be applicable in many dimictic glacial/boreal lakes throughout the world. (C) 1999 Elsevier Science B.V. All rights reserved.

Keywords

modeling lake water quality; catchment characteristics; watershed management

Published in

Journal of Hydrology
1999, Volume: 220, number: 3-4, pages: 186-208
Publisher: ELSEVIER SCIENCE BV

Associated SLU-program

Lakes and watercourses


UKÄ Subject classification

Oceanography, Hydrology, Water Resources


Publication identifier

DOI: https://doi.org/10.1016/S0022-1694(99)00070-0

Permanent link to this page (URI)

https://res.slu.se/id/publ/44180