Your search found 2 records
1 Imholt, C.; Soulsby, C.; Malcolm, I. A.; Hrachowitz, M.; Gibbins, C. N.; Langan, S.; Tetzlaff, D. 2011. Influence of scale on thermal characteristics in a large Montane River Basin. River Research and Applications, 17p. (Online first). [doi: https://doi.org/10.1002/rra.1608]
River basins ; Streams ; Temperature ; Regression analysis ; Models ; GIS ; Monitoring ; Catchment areas ; Riparian zones ; Vegetation / UK / Scotland / River Dee Catchment
(Location: IWMI HQ Call no: e-copy only Record No: H044701)
(4.69 MB)
This study monitored stream temperatures over two hydrological years at various nested scales within the large, unregulated river Dee catchment (North East Scotland). These scales were (i) the whole catchment (11 sites along main stem Dee); (ii) the tributary (single sites in main tributaries); (iii) the Girnock (five sites in one subcatchment); and (iv) the reach (26 points across single reach). The aim was to characterize the thermal regime of all locations and compare the magnitude of variation between each scale. The controls on this variation were assessed via a multiple linear regression model using Geographic Information System-derived catchment data. Temperatures were collected at 15-min resolution and for further analysis and discussion combined to daily means. At the catchment and subcatchment scales, a west to east gradient in mean and minimum temperatures was observed, largely paralleling changes in altitude. Temperature differences between subcatchments were generally greater than between the sites along the main stem of the Dee. Differences between tributaries reflected differences in their morphology and land use. However, some tributaries had similar thermal regimes, despite different catchment and riparian characteristics. Subcatchment differences in thermal regimes of one of the tributaries corresponded to riparian vegetation reduced diurnal variability in sections dominated by broadleaf woodland. Compared with the larger scales, reach differences in thermal regime were small (e.g. mean temperatures of riffle, pool and margin habitats were within 0.3C). The most noticeable difference was in relation to the point samples within the backwater area, which has a more constant thermal regime, most probably reflecting its groundwater source. The regression analysis indicated that monthly mean temperatures can be predicted well using elevation and catchment area. Forest cover was a significant explanatory variable during the summer months. However, some of the empirical temperature data from the Dee indicate that similar thermal regimes can result from different physical controls and processes that have important implications for the extrapolation of such predictive models.
2 Balana, Bedru B.; Jackson-Blake, L.; Martin-Ortega, J.; Dunn, S. 2015. Integrated cost-effectiveness analysis of agri-environmental measures for water quality. Journal of Environmental Management, 161:163-172. [doi: https://doi.org/10.1016/j.jenvman.2015.06.035]
Cost benefit analysis ; Agriculture ; Environmental management ; Hydrology ; Chemicals ; Water quality ; Water management ; Wastewater treatment ; Land management ; Nitrates ; Phosphorus ; Pollutants ; Case studies / Scotland / River Dee catchment
(Location: IWMI HQ Call no: e-copy only Record No: H047103)
(1.20 MB)
This paper presents an application of integrated methodological approach for identifying cost-effective combinations of agri-environmental measures to achieve water quality targets. The methodological approach involves linking hydro-chemical modelling with economic costs of mitigation measures. The utility of the approach was explored for the River Dee catchment in North East Scotland, examining the cost-effectiveness of mitigation measures for nitrogen (N) and phosphorus (P) pollutants. In-stream nitrate concentration was modelled using the STREAM-N and phosphorus using INCA-P model. Both models were first run for baseline conditions and then their effectiveness for changes in land management was simulated. Costs were based on farm income foregone, capital and operational expenditures. The costs and effects data were integrated using ‘Risk Solver Platform’ optimization in excel to produce the most cost-effective combination of measures by which target nutrient reductions could be attained at a minimum economic cost. The analysis identified different combination of measures as most costeffective for the two pollutants. An important aspect of this paper is integration of model-based effectiveness estimates with economic cost of measures for cost-effectiveness analysis of land and water management options. The methodological approach developed is not limited to the two pollutants and the selected agri-environmental measures considered in the paper; the approach can be adapted to the cost-effectiveness analysis of any catchment-scale environmental management options.
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