Unintended consequences of biofuels production?The effects of large-scale crop conversion on water quality and quantity

Author(s):  
Heather L. Welch ◽  
Christopher T. Green ◽  
Richard A. Rebich ◽  
Jeannie R.B. Barlow ◽  
Matthew B. Hicks
Author(s):  
Dmitry Porshnov ◽  
Maris Klavins

Abstract. Water quality changes of surface waters can be used to assess human impact intensity, but of importance is to consider also impacts of climate change/variability and naturally occurring changes of environmental quality. In Latvia, during the recent decades a major reduction of anthropogenic pressure has happened due to restructuring of economy and industrial production, resulting in major decrease of loading of many groups of pollutants. However, trends and driving factors for other groups of substances have not been much studied. Long term (1980–2012) results of hydrochemical monitoring, performed in rivers of Latvia, are analysed during this study in connection with long-term sets of hydrological and heliophysical data, using standard statistical approaches. Our results indicate that variation of some hydrochemical values, for example COD and total Fe, show clearly visible decadal oscillated character, while variation of some other values, for example phosphate P and total P, show some individual characteristics of decadal oscillations. These results indicate the presence of a large scale, geochemical and geophysical significant process: multiannual pulse of catchment, driven by variation of solar irradiance through complex interactions between global atmospheric circulation, groundwater and surface waterbodies. The process described in our study is significant from a geochemical point of view and must be taken into account in prediction of water quality and quantity. Impacts of natural processes should be considered in the planning of environmental policy.


2011 ◽  
Vol 11 (4) ◽  
pp. 481-489
Author(s):  
S. Krause ◽  
A. Obermayer

The public drinking water supply of southern Germany is characterized by a rather decentralized network. Due to the hydrogeological setting in these parts of Germany many of the small water works with an average capacity of 50 m3/h have to treat raw water extracted from karstic or cliffy aquifers. These raw waters tend to be contaminated with particles and pathogens acquired during snowmelt or after strong rainfalls. In the last decade ultrafiltration has become the technology of choice for the removal of the aforementioned contaminants. Flux decline caused by unanticipated membrane fouling is the main limitation for the application of ultrafiltration membranes. This paper describes how membrane fouling phenomena can be predicted by using a statistical approach based on data from large scale filtration systems in combination with field and lab experiments on raw water quality and membrane performance. The data defines water quality and respective fouling phenomena both in technical scale filtration plants and in lab experiments of eleven different raw waters. The method described here is more economically feasible for small water works when compared to typical pilot experiments that are used for high capacity water works.


1995 ◽  
Vol 31 (8) ◽  
pp. 197-205 ◽  
Author(s):  
L. L. Bijlmakers ◽  
E. O. A. M. de Swart

For the area of the Ronde Venen a plan for large-scale wetland-restoration and improvement of the water quality was developed. Major elements of the developed spatial strategy are the optimal use of the specific hydrological and ecological characteristics of the area. Based on regional hydrological characteristics within the study area hydrological sub-units were distinguished by connecting discharge and recharge areas. In this way the intake of polluted surface water from outside the area could be minimized, with an optimal use of specific local differences in water quality. Two scenarios were developed and evaluated using hydrological, hydrochemical and ecological models. The scenarios differed in spatial composition and the way the water level was manipulated. In order to optimize water quality, natural and artificial pollution control mechanisms were implemented as well. An important criterion for the evaluation was the extent to which the scenarios succeeded in optimizing conditions for the realization of the ecological goals. The most promising and acceptable scenario has been worked out in further detail.


2015 ◽  
Vol 2015 (9) ◽  
pp. 2861-2876
Author(s):  
Hamidreza Kazemi ◽  
Sam Abdollahian ◽  
Thomas D Rockaway ◽  
Joshua Rivard

2021 ◽  
Author(s):  
Russell Adams ◽  
Donnacha Doody

<p>Northern Ireland has been somewhat overlooked in terms of water quality modelling in the past. Many of its catchments have consistently failed to meet Water Framework Directive targets especially due to high levels of dissolved nutrients and poor ecological status. A catchment based modelling study to address this issue has not been undertaken here previously and the approach described here uses two water quality models to achieve this aim. The objectives of the modelling were firstly to identify the total load reductions (in terms of Phosphorus (P)) required to reduce in-stream loadings sufficiently for concentrations of soluble reactive P (SRP) to be reduced to achieve the WFD “Good” status levels, and secondly to split these loadings into diffuse and point components. The third objective was to identify the most likely flow pathways for the transport of the diffuse component of P to the watercourses particularly for the agricultural (mostly intensive grassland farming) land use which dominates in almost all NI catchments.</p><p>The first model applied is the Source Load Apportionment Model (SLAM) developed by the Irish EPA. This model provides a large-scale assessment of the point and diffuse load components across catchments where multiple pressures are occurring. The second model us the Catchment Runoff Flux Assessment Tool (CRAFT) which is able to back-calculate nutrient loads associated with three major flow pathways. SLAM is a static model which uses averaged loadings from diffuse agriculture and non-agricultural land uses, and point sources (where information can be obtained from various sources) to calculate N and P exports. For P, the agricultural diffuse load component uses an enhanced version of the export coefficient approach based on combining the sources of P from applied nutrients (slurry and fertiliser) and soil P. A modelling tool allows the user to evaluate load reduction scenarios where one or several components of P (both point and diffuse) are adjusted downwards to achieve the catchment’s required load reduction. The CRAFT model works on a dynamic (daily) modelling scale and has simulated sub-catchments where the SLAM model has identified the need for significant load reductions. It identifies the different reductions (P export) that are required for each flow pathway, which will then inform on the type of additional measures (e.g. sediment traps, riparian buffer strips and wetlands) that may also be required.</p><p>The initial aim of this study is to complete a pilot application to the trans-border (UK and ROI) Blackwater catchment (1360 km<sup>2</sup>). Through a review of alternative modelling options for the whole area of NI, an assessment of whether this approach is suitable for application to the entire territory can be made.</p>


Sign in / Sign up

Export Citation Format

Share Document