Occurrence of Cryptosporidium in agricultural surface waters during an annual farming cycle in lowland UK

A 17-month survey based on weekly testing for Cryptosporidium oocysts in surface waters draining a livestock farm on a Warwickshire (UK) estate has shown that the parasite is present throughout the year, with the highest frequency of occurrence and maximum concentrations during the autumn and winter. The 190 ha farm is managed as an exemplar for a teaching institution. There were up to 800 livestock present at peak times of year in the catchment of the stream draining the estate. Oocysts were concentrated from grab samples by a flocculation procedure, stained with monoclonal antibody and detected by fluorescence microscopy. Overall, 274/418 (66%) of samples were positive for Cryptosporidium. Where the stream passed from the estate, the occurrence was 79%, with mean and median oocysts/l of 0.48 and 0.2, respectively. Highest oocyst levels coincided with calving and increased wild animal numbers following breeding. There was no correlation of oocyst levels with rainfall or slurry spreading. Cryptosporidium was also frequently found in a pond on arable land (no livestock) indicating that wild animals alone contributed oocysts to surface waters. These results from a well managed livestock farm may represent a typical natural baseline for levels of occurrence and concentration of Cryptosporidium oocysts in surface waters of the lowland agricultural environment of the UK.     

Net changes in nutrient concentrations below a point source input in two streams draining catchments with contrasting land uses

We examined net changes in ammonium-Nitrogen (NH(4)(+)-N), nitrate-Nitrogen (NO(3)(-)-N), dissolved inorganic nitrogen (DIN), soluble reactive phosphorus (SRP), and dissolved organic carbon (DOC) chloride-corrected ambient concentrations along a reach located below a wastewater treatment plant (WWTP) input in a non-agricultural (12 dates) and an agricultural (6 dates) stream. Based on those net changes, we estimated processing length (Snet) and mass transfer coefficient (Vf) of the cited nutrients. In the agricultural stream, results suggest that diffuse nutrient inputs from adjacent agricultural fields had a greater effect on water chemistry than the WWTP input, and probably overwhelmed the stream capacity to retain and transform nutrients. In the non-agricultural stream we observed consistent longitudinal trends below the WWTP input only for NH(4)(+)-N and NO(3)(-)-N. The tight coupling between longitudinal NH(4)(+)-N decreases and NO(3)(-)-N increases in the non-agricultural stream, and lack of longitudinal trends of DIN on most dates suggest that NH(4)(+)-N from the WWTP input was being nitrified along the reach. These results suggest that WWTP inputs favor conditions to support hot spots for chemoautotrophic activity.     

Predicting microbial pollution concentrations in UK rivers in response to land use change

The Water Framework Directive has caused a paradigm shift towards the integrated management of recreational water quality through the development of drainage basin-wide programmes of measures. This has increased the need for a cost-effective diagnostic tool capable of accurately predicting riverine faecal indicator organism (FIO) concentrations. This paper outlines the application of models developed to fulfil this need, which represent the first transferrable generic FIO models to be developed for the UK to incorporate direct measures of key FIO sources (namely human and livestock population data) as predictor variables.We apply a recently developed transfer methodology, which enables the quantification of geometric mean presumptive faecal coliforms and presumptive intestinal enterococci concentrations for base- and high-flow during the summer bathing season in unmonitored UK watercourses, to predict FIO concentrations in the Humber river basin district.Because the FIO models incorporate explanatory variables which allow the effects of policy measures which influence livestock stocking rates to be assessed, we carry out empirical analysis of the differential effects of seven land use management and policy instruments (fiscal constraint, production constraint, cost intervention, area intervention, demand-side constraint, input constraint, and micro-level land use management) all of which can be used to reduce riverine FIO concentrations.This research provides insights into FIO source apportionment, explores a selection of pollution remediation strategies and the spatial differentiation of land use policies which could be implemented to deliver river quality improvements.All of the policy tools we model reduce FIO concentrations in rivers but our research suggests that the installation of streamside fencing in intensive milk producing areas may be the single most effective land management strategy to reduce riverine microbial pollution.     

Significance of urban and agricultural land use for biocide and pesticide dynamics in surface waters

Biocides and pesticides are designed to control the occurrence of unwanted organisms. From their point of application, these substances can be mobilized and transported to surface waters posing a threat to the aquatic environment. Historically, agricultural pesticides have received substantially more attention than biocidal compounds from urban use, despite being used in similar quantities.This study aims at improving our understanding of the influence of mixed urban and agricultural land use on the overall concentration dynamics of biocides and pesticides during rain events throughout the year. A comprehensive field study was conducted in a catchment within the Swiss plateau (25 km²). Four surface water sampling sites represented varying combinations of urban and agricultural sources. Additionally, the urban drainage system was studied by sampling the only wastewater treatment plant (WWTP) in the catchment, a combined sewer overflow (CSO), and a storm sewer (SS). High temporal resolution sampling was carried out during rain events from March to November 2007.The results, based on more than 600 samples analyzed for 23 substances, revealed distinct and complex concentration patterns for different compounds and sources. Five types of concentration patterns can be distinguished: a) compounds that showed elevated background concentrations throughout the year (e.g. diazinon >50 ng L⁻¹), indicating a constant household source; b) compounds that showed elevated concentrations driven by rain events throughout the year (e.g. diuron 100-300 ng L⁻¹), indicating a constant urban outdoor source such as facades; c) compounds with seasonal peak concentrations driven by rain events from urban and agricultural areas (e.g. mecoprop 1600 ng L⁻¹ and atrazine 2500 ng L⁻¹ respectively); d) compounds that showed unpredictably sharp peaks (e.g. atrazine 10,000 ng L⁻¹, diazinon 2500 ng L⁻¹), which were most probably due to improper handling or even disposal of products; and finally, e) compounds that were used in high amounts but were not detected in surface waters (e.g. isothiazolinones).It can be safely concluded that in catchments of mixed land use, the contributions of biocide and pesticide inputs into surface waters from urban areas are at least as important as those from agricultural areas.     

Evaluating river water quality through land use analysis and N budget approaches in livestock farming areas

This study was carried out to evaluate the quality of river water by analysis of land use in drainage basins and by estimating the N budgets. The drainage basins of Shibetsu River (Shibetsu area) and Bekkanbeushi River (Akkeshi area) in eastern Hokkaido, Japan were selected for a case study, and the evaluation of water quality was up-scaled to the regional level in Hokkaido by using the Arcview/GIS and statistical information. Water sampling was carried out in August 2001 and May 2002 in the Shibetsu and Akkeshi areas, respectively. The proportions of major land uses in drainage basins such as upland field, forest, urban area, wetland and wasteland for each sampling site were estimated by using topographic maps scaled at 1:25,000. The linear regression results showed that the correlation between NO3-N concentration and the proportion of upland in the drainage basins was highly and positively significant for both the Shibetsu area (r = 0.84, n = 57) and the Akkeshi area (r = 0.71, n = 73) at < 0.001 significance level. The regression coefficients or impact factors of river water quality were 0.015 and 0.0052 for the Shibetsu and Akkeshi areas, respectively. A comparison of these results with that of the previous study results in Hokkaido indicated that the impact factors were highest for intensive livestock farming areas (0.040), medium for mixed agriculture and livestock farming (0.020-0.030), and the lowest for grassland-based dairy cattle and horse farming areas (0.0052-0.015). The results of a simple regression analysis showed that the impact factors had a significant positive correlation with the cropland surplus N (r = 0.93, P < 0.01), chemical fertilizer N (r = 0.82, P < 0.05), and manure fertilizer N (r = 0.76, P < 0.05), which were estimated by using the N budget approach. Using the best-correlated regression model, impact factors for all cities, towns and villages of the Hokkaido region were estimated. The NO3-N concentrations for all major rivers in Hokkaido were predicted by multiplying the estimated impact factors by the proportion of uplands. The regression analysis indicated that the predicted NO3-N concentrations were significantly correlated (r = 0.62, P < 0.001, n = 203) with the measured NO3-N concentrations, reported previously. It can be concluded that estimating the proportions of upland fields in drainage basins, and calculating cropland surplus N enables us to predict river water quality with respect to NO3-N concentration.     

Examining spatially varying relationships between land use and water quality using geographically weighted regression I: model design and evaluation

Traditional regression techniques such as ordinary least squares (OLS) can hide important local variations in the model parameters, and are not able to deal with spatial autocorrelations existing in the variables. A recently developed technique, geographically weighted regression (GWR), is used to examine the relationships between land use and water quality in eastern Massachusetts, USA. GWR models make great improvements of model performance over OLS models, which is proved by F-test and comparisons of model R² and corrected Akaike Information Criterion (AIC_c) from both GWR and OLS. GWR models also improve the reliabilities of the relationships by reducing spatial autocorrelations. The application of GWR models finds that the relationships between land use and water quality are not constant over space but show great spatial non-stationarity. GWR models are able to reveal the information previously ignored by OLS models on the local causes of water pollution, and so improve the model ability to explain local situation of water quality. The results of this study suggest that GWR technique has the potential to serve as a useful tool for environmental research and management at watershed, regional, national and even global scales.     

Predicting the long-term variations in stream and lake inorganic aluminium concentrations for acidic and acid sensitive catchments

A modification to the one-box version of the MAGIC model of stream and lake acidification is given which presents a new hypothesis for describing inorganic aluminium controls in streams draining acidic catchments. This modification entails the removal of any assumption of Al(OH)₃ solubility control in the stream. Success of this modification is demonstrated for data collected from a regional survey of Welsh streams and lakes. The modified model is used with data from the acidic and acid impacted Dargall Lane catchment of the Galloway region of South West Scotland to provide an example of the long-term changes in stream acidity and inorganic aluminium concentration.     

Faecal indicator organism concentrations and catchment export coefficients in the UK

Characterisation of faecal indicator organism (FIO) concentrations and export coefficients for catchments with particular combinations of land use and under specific climatic regimes is critical in developing models to predict daily loads and apportion sources of the microbial parameters used to regulate water quality. Accordingly, this paper presents a synthesis of FIO concentration and export coefficient data for the summer bathing season, with some comparative winter data, for 205 river/stream sampling points widely distributed across mainland UK. In terms of both geometric mean (GM) FIO concentrations and export coefficients (expressed as cfu km(-2) h(-1)), the results reveal (1) statistically significant elevations at high flow compared with base flow, with concentrations typically increasing by more than an order of magnitude and export coefficients by about two orders; (2) significantly higher values in summer than in winter under high-flow conditions; and (3) extremely wide variability between the catchments (e.g. four orders of magnitude range for GM faecal coliform concentrations), which closely reflects land use-with urban areas and improved pastures identified as key FIO sources. Generally, these two most polluting land uses are concentrated in lowland areas where runoff (m3 km(-2) h(-1)) is low compared with upland areas, which in the UK are dominated by rough grazing and forestry. Consequently, contrasts in export coefficients between land use types are less than for FIO concentrations. The GMs reported for most land use categories are based on 13 sites and exhibit quite narrow confidence intervals. They may therefore be applied with some confidence to other catchments in the UK and similar geographical regions elsewhere. Examples are presented to illustrate how the results can be used to estimate daily summer base- and high-flow FIO loads for catchments with different land use types, and to assess the likely effectiveness of certain strategies for reducing FIO pollutant loadings in areas with extensive areas of lowland improved pasture.     

Nitrate concentrations in river waters of the upper Thames and its tributaries

The spatial and temporal patterns of in-stream nitrate concentrations for the upper Thames and selected tributaries are described in relation to point and diffuse sources for these rural catchments. The rivers associated with catchments dominated by permeable (Cretaceous Chalk) bedrock show a smaller range in nitrate concentrations than those associated with clay and mixed sedimentary bedrock of lower permeability. The differences reflect the contrasting nature of water storage within the catchments and the influence of point and diffuse sources of nitrate. Nitrate concentrations often increase in a gradual way as a function of flow for the rivers draining the permeable catchments, although there is usually a minor dip in nitrate concentrations at low to intermediate flow due to (1) within-river uptake of nitrate during the spring and the summer when biological activity is particularly high and (2) a seasonal fall in the water table and a change in preferential flow-pathway in the Chalk. There is also a decrease in the average nitrate concentration downstream for the Kennet where average concentrations decrease from around 35 to 25 mg NO(3) l(-1). For the lower permeability catchments, when point source inputs are not of major significance, nitrate concentrations in the rivers increase strongly with increasing flow and level off and in some cases then decline at higher flows. When point source inputs are important, the initial increase in nitrate concentrations do not always occur and there can even be an initial dilution, since the dilution of point sources of nitrate will be lowest under low-flow conditions. For the only two tributaries of the Thames which we have monitored for over 5 years (the Pang and the Kennet), nitrate concentrations have increased over time. For the main stem of the Thames, which was also monitored for over 5 years, there is no clear increase over time. As the Pang and the Kennet river water is mainly supplied from the Chalk, the increasing nitrate concentrations over time clearly reflect increasing nitrate concentrations within the groundwater. It primarily reflects long-term trends for agricultural fertilizer inputs and significant aquifer storage and long water residence times. The results are discussed in terms of hydrogeochemical processes and the Water Framework Directive and are compared with data from other eastern UK rivers. The importance of diffuse sources of nitrate contamination is highlighted. On a flow weighted basis, the average diffuse component of nitrate is around 95% for the Thames Basin rivers draining Chalk and for the corresponding rivers draining less permeable strata, there is a more significant but not major point source component (at least in terms of flux); the average diffuse component is 79% in this case. These data fit well with earlier assessments of agricultural sources to UK surface waters. Under baseflow conditions the diffuse sources remain dominant for the Chalk fed Thames Basin rivers, but point sources can be dominant for the low permeability cases. On a proportionate basis, the Thames Basin rivers are similar to the rural rivers of the Tweed and Humber Basins in terms of percentage diffuse components although the lower intensity agriculture occurring for the rivers monitored means that the average nitrate concentrations are lower for the rural rivers of central and northern England and the borders with Scotland: the Humber and Tweed.     

Real-life energy use in the UK: How occupancy and dwelling characteristics affect domestic electricity use

The patterns of electricity consumption were studied for 27 representative dwellings in Northern Ireland. The type of dwelling, its location, ownership and size, household appliances, attributes of the occupants including number of occupants, income, age and occupancy patterns have differing but significant impacts on electricity consumption. A clear correlation was found between average annual electricity consumption and floor area. The monthly consumption of detached houses is between 3.57 and 5.17 kWh m⁻²; semi-detached between 3.44 and 4.59 kWh m⁻² and terraced houses between 2.5 and 3.9 kWh m⁻². The average winter consumption exceeded the average summer consumption by 1.59 kWh m⁻² for detached, by 1.16 kWh m⁻² for semi-detached and by 1.78 kWh m⁻² for terraced houses. The difference in the annual demand on the grid between detached and terraced houses is between 24 and 30%. The electricity consumption per person decreases as the number of occupants increases. This is particularly significant in large dwellings but smaller numbers of occupants.     

Spatial dynamics of farming practices in the Seine basin: methods for agronomic approaches on a regional scale

A research procedure is proposed which aims to analyse the agricultural spatial dynamics during the last thirty years using two levels of organisation of farming activity: the agricultural production system and the cropping system. Based on methods of statistical mapping and data mining, this procedure involves modelling the diversity of production systems and cropping systems (crop successions and sequences of cultural practices for each crop) in the form of classes independently of their localisation within the basin. It identifies homogeneous regions made up of groups of contiguous agricultural districts which exhibit similar combinations of production systems, crop successions or cultural practices during a given period of time. The results show a major increase in arable farms since 1970 at the expense of dairy farms and mixed cropping/livestock. This trend however appeared to be greatly spatially differentiated according to the agricultural districts, since livestock remained important on the edges of the basin, whereas it practically disappeared in its centre. The crop successions practiced in the basin and the cultural practices used on them also appear to be spatially differentiated, although the link to the production systems is not always clear. Thus it appears pertinent to combine the analysis of the two levels of organisation of the agriculture (methods of land use described by the concept of cropping system, and also the production systems into which the cropping systems fit) in the context of an environmental problem.     

Antifouling paint booster biocides in UK coastal waters: inputs,occurrence and environmental fate

This study considered the inputs of antifouling paint booster biocides into the aquatic environment directly from painted hulls and high pressure hosing operations, the occurrence of booster biocides in marinas, harbours and docks, and the influence of degradation and water-sediment partition on their environmental fate. Irgarol 1051, the Irgarol 1051 degradation product GS26575, diuron, and the diuron degradation products 1-(3-chlorophenyl)-3,1-dimethylurea (CPDU), 1-(3,4-dichlorophenyl)-3-methylurea (DCPMU) and 1-(3,4-dichlorophenyl)urea (DCPU) were all detected at measurable concentrations in surface waters. Irgarol 1051, GS26575 and diuron were also detected in bottom sediments. A preliminary study of biocide input during both normal use and foreshore hull hosing showed that hosing may be a significant point source input and also be a cause for future concern since much of this input is in the form of paint particles. Field based measurements and laboratory experiments showed that Irgarol 1051 and diuron persist in the water column, due to a low affinity to partition onto sedimentary material and high resistance to degradation. Other biocides such as chlorothalonil, dichlofluanid, and Sea-Nine 211 were all found to be rapidly removed from the water column and be less persistent.     

Without zoning: Urban development and land use controls in Houston

Houston is the only major city in North America without zoning. The growth of Houston illustrates a traditional free market philosophy in which land use zoning is seen as a violation of private property and personal liberty. This paper explores how the lack of zoning has an impact on land use controls and urban development in Houston. Using a theoretical framework derived from institutional economics and public choice theories for institutional analyses of land development controls, it explores how local land use policies made by both the local government and non-governmental sectors shape urban development in Houston. The study results show that despite the city’s lack of zoning, local land use regulatory policies made by the municipality have significant influence on urban development. Additionally, civic and private organizations such as super neighborhoods and homeowner associations fill the gaps left by the lack of land use zoning. These two aspects contribute to land use controls and urban development of the city. The study finds that land use controls by private contract and by government legislative intervention are not mutually exclusive or immutable; that equity goals are not met in market approaches, and public planning intervention is necessary; and that deed restrictions might be better at facilitating property sales and maintenance than at improving neighborhood welfare and governance.     

Fluorimetric determination of inorganic selenium in waters with the use of anion-exchange sorbents

We have investigated a possibility of sorption concentration concurrently with fractionation of different valence forms of inorganic selenium during fluorimetric determination of its mass concentration in natural and drinking waters. We have also studied sorption of anions of tetra- and hexavalent selenium from the aqueous medium on the surface of anion-exchange sorbents. We have found optimal conditions of sorption and desorption of selenate- and selenite-anions on the strong-base anion-exchanger AV-17.     

浅析土地利用规划中的生态规划与设计

分析了土地生态规划在国内外的发展现状,阐述了生态规划的发展与含义,提出了土地生态规划设计应着重遵循的原则,以使人类活动与自然资源保护相协调,从而促进生态系统的良性循环和社会经济的持续发展。     

西部地区的土地利用与城镇开发

探索和研究西部城镇土地开发 ,必然涉及到西部地区的土地资源、特征、耕地保护与政策调整。文章重点研究西部地区土地资源的利用及其政策调整和西部地区城镇开发的重点及其城镇开发的资金筹措 ,以及如何建立城市建设资金的良性循环机制问题。     

Stream cation concentrations and losses from drainage basins with contrasting land uses in Southern Ontario

The concentration and loss of major cations from 22 watersheds near Toronto, Ontario, was measured over a 27-month period. Calcium and potassium concentrations exhibited a positive relationship with crop area and a negative correlation with abandoned farm land + forest and areas of sand + sandy loam soil. The influence of soil properties and farming activities on streám cation levels could not be separated because of multicollinearity between land use and soils. An absence of correlation between crop area and annual losses of calcium and potassium can be attributed to lower annual stream discharges in agricultural watersheds in comparison to watersheds containing extensive areas of forest and abandoned farm land. Stream concentrations and losses of potassium and sodium were positively correlated with urban land use. Detailed water sampling in the vicinity of urban centres confirmed that these areas are important contributors of sodium, and to a lesser extent, of potassium to streams. Magnesium concentration was influenced mainly by differences in watershed hydrology and no correlation was evident with urban or agricultural land use.     

Landscape diversity and land use planning: a case study in Bavaria

A maximum of landscape diversity is to be regarded as a helpful target as well as an analytical tool to detect actual planning deficits. First of all, specific indicators and targets for ecosystem and landscape levels will be defined. Ecosystem types are derived from landscape ecological site conditions, and are combined with the demands of minimal areas related to present and potential ecosystem types.The suitability of management practices for the site conditions, and the requirements mentioned above, will together form the basis on which a target landscape in its pattern, and the management practices suggested can be mapped. In comparison with the present use of the landscape, measures are derived which indicate that the target of a high landscape diversity has real practical meaning: conversion of about 15% of the arable land into forests and grasslands as one result of this study fits into the political and administrative programmes already established. In addition, four modification categories of the actual usage are mapped and described in size and number in this case study. The basic assumptions of this approach will be explained, to provide further working hypotheses for an interdisciplinary and integrative research into landscape ecology in rural landscapes.     

Relationships between microbial water quality and environmental conditions in coastal recreational waters: the Fylde coast, UK.

This paper explores ways in which the analysis of microbial data from routine compliance monitoring, in combination with basic environmental data, can provide insight into the factors affecting faecal-indicator organism concentrations in coastal waters. In the case study presented, eight designated bathing waters on the Fylde coast are continuing to exhibit unreliable compliance with the Imperative standards for total coliform (TC) and faecal coliform (FC) concentrations specified in the EU Bathing Water Directive (76/160/EEC), despite significant reductions in geometric mean concentrations following recent major investment in the sewerage infrastructure. Faecal streptococci (FS) concentrations have remained high and have not been improved by the new sewerage schemes. The results suggest that, prior to the schemes, higher bacterial concentrations were strongly associated with rainfall; and sewage sources were important for TC and FC, but less important for FS, which may have been more strongly affected by diffuse catchment sources. In the post-schemes period, catchment sources appear to be of greater significance; rainfall remains as a significant, though less important, predictor; and tide height at time of sampling, together with variables such as sunshine and the proportion of onshore winds (which affect the survival and movement of bacteria that have already entered the coastal waters), assume greater significance. The approach used here provides a cost-effective management tool for the exploratory investigation of any monitoring point that is failing to meet recreational water quality standards.