Mitigation Of Water Pollution Research Articles

Quantifying the spatial variability of soil physical and chemical properties in relation to mitigation of diffuse water pollution

Understanding spatial variability of soil properties in response to land-use impacts is essential for evaluating the effectiveness of measures taken to address diffuse water pollution from agriculture. However, despite the growing emphasis on integrated catchment-scale implementation of land-use mitigation measures, the baseline landscape-scale evaluation of the spatial variability of key soil nutrients remains scarce. This study employs a high resolution geostatistical approach to characterise the spatial variability of parameters, including soil bulk density (BD), total soil carbon (TC), nitrogen (TN), phosphorus (TP), inorganic phosphorus (IP), organic phosphorus (OP), stable nitrogen isotope ratio (δ15N), C:N ratio, carbon storage and nitrogen storage in two study catchments with contrasting land uses (agricultural and semi-natural) that are subject to targeted management interventions to reduce flood risk and improve water quality. We found a stronger degree of spatial dependence of all soil properties in the agricultural than the semi-natural catchment, except for bulk density and δ15N. Furthermore, bulk density, TP, IP, OP, C:N ratio, δ15N and carbon storage showed a longer range or spatial auto-correlation in the agricultural catchment. The central tendency (median and mean) of all soil properties was also significantly different between the two catchments, with the exception of IP and δ15N. The spatial correlations between the soil properties pointed to the mechanisms that were responsible for the observed differences, whilst the krigged surfaces of soil variables identified most likely critical source areas for targeted land management interventions to improve water quality. Arable and intensive grasslands were identified as ‘high-impact’ land uses, associated with negative alteration of soil properties and increased diffuse water pollution, whilst moorland was a ‘low impact’ land use associated with improved water quality. A comparison with the national soil survey dataset shows that whilst it can be relied upon for the broad characterisation of carbon and TP stocks in the two study catchments, it underestimates the spatial variability of key soil properties in certain soil types and land uses. As the restoration of soil spatial heterogeneity may take several decades, a high resolution geostatistical approach should be included in the future design of catchment-scale monitoring schemes to inform catchment management strategies and elucidate the time frame over which landscape scale improvements in soil properties and corresponding ecosystem services can be achieved.

Water Quality Management in Japan: Recent Developments and Challenges for Integration

ABSTRACTJapanese water quality management is evolving toward the more integrated management of water resources by adapting to the changes in society, such as changes in public perceptions on water and the environment; diversification of water usage; and the state of water quality itself. Mitigation of water pollution and conservation of the watershed environment and ecosystem services have begun to be recognized as important elements of water quality management. In that sense, water quality management in Japan is now transforming from management of water quality to management of the wider water environment. Although there have been signs of integration of the quantity and quality aspects of water management, this paper concludes that opportunities to promote integrated management should be further explored in Japan and that local governments must play a key role in the promotion of integrated water resources management. Copyright © 2011 John Wiley & Sons, Ltd and ERP Environment.

Vegetated ditches for treatment of surface water with highly fluctuating water regime

Vegetated drainage ditches (VDD) as a type of constructed wetland primarily serve to remove and store excess water associated with irrigation and storm events. Current research suggests using a VDD as an additional practice in the mitigation of surface water pollution. The VDD for water treatment of the Glinscica River was constructed in 2006. The efficiency of the system was evaluated in 2008 and 2009 regarding the reduction of SS, COD, BOD5, NH4-N, NO3-N, NO2-N, TN, ON and TP. The microbiological association developed in the VDD was analyzed with a focus on the identification and quantification of the narG gene as a denitrification indicator. This paper discusses the efficiency of pollution removal and the distribution of the narG gene within the VDD. The results showed that the highly fluctuating water regime was the main reason for the even distribution and abundance of the narG gene throughout the system, regardless of oxygen saturation or the nutrient status of the wastewater. With the exception of SS, pollutant concentrations met the permitted outflow levels.

Recovering the Good Earth: China’s Growing Organic Market

People whose impressions of Chinese food exports are colored by reports of contaminated pet food or pesticide-laced dumplings might not expect China to have much of an organic market. They would be wrong. According to “The Greening of China’s Food: Green Food, Organic Food, and Eco-labelling,” a paper presented at the May 2008 Sustainable Consumption and Alternative Agri-Food Systems Conference, 28% of China’s arable land—just over 34 million hectares—is devoted to “eco-foods,” a designation that includes organic certification as well as China’s unique “green” and “hazard-free” categories of food. In an increasingly global food market, unexpected opportunities for farmers around the world are opening in unlikely places, such as China’s experiments with organic food. The world market for organic foods has soared, with sales growing by more than US$5 billion annually and doubling between 2000 and 2006, according to the International Federation of Organic Agriculture Movements (IFOAM), an umbrella organization based in Bonn, Germany. That international trend explains why China and other countries—despite relatively little domestic demand for organic food—have become big players in the organic market. Organic farming in China is largely an export-oriented industry, with the main products for both export and import being cereals, soybeans, and tea, followed by some vegetables, fruits and meat. Yet, although China has instituted several eco-food certification systems, reports of lax inspections persist. “Regulation is an imperfect substitute for the accountability, and trust, built into a market in which food producers meet the gaze of eaters and vice versa,” author Michael Pollan writes in his 2008 book In Defense of Food: An Eater’s Manifesto. In situations where farmers and consumers can’t meet face-to-face at the farmer’s market, however, some form of inspection is all that’s left to serve the interest of public health. How, then, is China adapting to secure the safety of its exports and the health of its own citizens?

Modelling the impact and potential mitigation of cold water pollution on Murray cod populations downstream of Hume Dam, Australia

AbstractA one‐dimensional hydrodynamic reservoir model is coupled with a stochastic fish population model to examine the impacts of cold water pollution (CWP) on the Australian freshwater fish, Murray cod, downstream of Hume Dam, Australia. Mitigation of CWP through the introduction of selective withdrawal capabilities to access near‐surface water is predicted to increase discharge temperatures during the crucial spring‐early summer post‐spawning period by 4–6°C for normal operating conditions, that is, a full reservoir in early spring. No improvement in discharge temperature was predicted for drought conditions characterized by relatively low storage levels in early spring. The predicted temperature increase using selective withdrawal increased the predicted average minimum female population abundance by 30–300% depending on the assumed spawning behaviour. Increased discharge temperatures appear to be achievable and are expected to reduce the stress currently impacting Murray cod populations due to CWP during crucial post‐spawning periods. This provides evidence that mitigation of this problem may assist in rehabilitating Murray cod populations in the Murray River downstream of Hume Dam. Copyright © 2007 John Wiley & Sons, Ltd.

The effectiveness and feasibility of economic incentives of input control in the mitigation of agricultural water pollution

Agricultural water pollution in Finland is mainly caused by nutrient losses from fields. Nutrient losses can be mitigated, e.g., by changing management practices and by plant rotation. Adoption of the necessary measures may be voluntary, but economic incentives can also be used. Nutrient losses can be regulated, e.g., by incentives to decrease the use of fertilizers. Economic incentives include a change in product prices, an input tax or an input quota. So far an input tax has been applied in Finnish agriculture. The effectiveness and feasibility of these policy measures on the farm can be assessed by calculating the change in farm profit and nutrient losses. The input quota was found to be the least-cost measure at the farm level when the marginal abatement costs of measures were compared on a grain farm growing barley. Alternative policy measures caused bigger losses in profit on the farm and the reduction in nitrogen leakage was smaller.

Mitigation of Agricultural Water Pollution in Finland: An Evaluation of Management Practices

This paper summarizes the results of recent studies concerning the agricultural nutrient load to surface waters in Finland and possible management practices for reducing nutrient losses from agricultural land. Both the nitrogen and the phosphorus load exceed the loads from municipal and industrial sources together, thus being mainly responsible for the eutrophication of surface and coastal waters. 25% of the total agricultural phosphorus load is bioavailable dissolved reactive phosphorus, and 5% of the paniculate phosphorus load is available for algae. Reduced tillage, filter strips and permanent grassland on the set-aside land are means investigated for reducing erosion and nutrient losses. Based on experiments and model simulations, it is estimated that a wide adoption of all these practices would reduce total phosphorus load by about 40%. Soluble phosphorus and nitrogen losses can be reduced by adjusting the amount and timing of fertilization and manure application to the actual needs of plants. If the whole set-aside area was under permanent grassland, the nitrogen loss would decrease by about 17%, but the effect of cover or undersown crops in Finnish conditions is still unknown. More investigations are also needed of the effects of all these management practices on the soluble phosphorus load.