Exploring the linkages between river water chemistry and watershed characteristics using GIS-based catchment and locality analyses

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• 作者：Helen P. Jarvie ; Takashi Oguchi and Colin Neal
• 关键词：Water quality GIS River Catchment Land use Humber Land– ; Ocean Interaction Study (LOIS) LOICZ Nutrients Trace elements Metals
• 刊名：Regional Environmental Change
• 出版时间：December 2002
• 出版年：2002
• 期刊代码：125_1436-3798
• 类别：ear
• 卷：3
• 期：1-3
• 页码：36-50
• 数据来源：sp

摘要

A typology of land characteristics for the Humber catchment in central/eastern England is identified in relation to land use, hydrology and demographic, topographic and geological characteristics, using GIS and statistical analyses. Empirical relationships between land characteristics and water quality were examined in relation to the spatial variability in water quality across the Humber catchment. Analyses of relationships between land characteristics and water quality were undertaken at two hierarchical scales: (1) individual catchments and (2) localities of 10 km radius draining to each sampling site. The importance of urban and agricultural sources was identified, together with a hydrological component linked to dilution of point source inputs and mobilisation of specific sediment-associated contaminants in higher-energy (higher-flow) environments. High-solubility (dissolved) chemical determinands (such as B, Cl and SO₄), which undergo conservative transport through the river network, show the strongest linkages with land characteristics at the catchment scale. Cr, Zn and Ca show stronger correlations with land characteristics at the locality rather than the catchment scale, indicating that the concentrations of these determinands are more closely linked to the availability of localised sources. This work provides a starting point for investigating how changes in land use and management of drainage basins might impact river water quality at the regional scale and fluxes to the coastal zone, by providing a mechanism for examining linkages between regional-scale land characteristics and river water quality. The next step requires development of the approach within a more rigorous statistical framework and the extension of the regional analysis within a wider national and international context.