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971.
Environmental impact assessment of a proposed info-tech complex in East Calcutta wetlands 总被引:1,自引:0,他引:1
An info-tech complex is proposed for 286 acres (116 ha) of land within the East Calcutta wetlands. The proposed site is 15 km east of Kolkata city and only 8 km south of Dum Dum airport. The site is vacant, with pockets of agricultural land and a few degrading water-logged areas. In order to assess the likely impact of the proposed development on the environment, a rapid environmental impact assessment of an area of 10 km radius from the centre of the project site was carried out. The present status of the environment with respect to ambient air, surface water, groundwater, soil, landuse, noise, and socio-economics of the core and buffer zone has been documented and correlated with 24 project activities during construction, development and operational phases. The frequency of adverse impacts is greater than that of beneficial impacts. Out of the total adverse impacts 20 are short term, reversible and have a low magnitude. The total impact score for the proposed project is (–)468.75 and as per the Assessment Value Index Scale the environmental impact of the proposed project activities is no appreciable impact. But there are certain sectors where the environment will be adversely impacted. Therefore, appropriate measures have been suggested to ameliorate the adverse impacts. It is envisaged that if these measures are implemented then there will be an improvement in the quality of the environment, as well as life, by 687.5 units. 相似文献
972.
Post-irrigation impact of domestic sewage effluent on composition of soils,crops and ground water--a case study 总被引:18,自引:0,他引:18
Long-term irrigation with sewage water adds large amounts of carbon, major and micro- nutrients to the soil. We compared the spatial distribution of N, P, K and other micronutrients and toxic elements in the top 0.6 m of an alluvial soil along with their associated effects on the composition of crops and ground waters after about three decades of irrigation with domestic sewage effluent as a function of distance from the disposal point. Use of sewage for irrigation in various proportions improved the organic matter to 1.24-1.78% and fertility status of soils especially down to a distance of 1 km along the disposal channel. Build up in total N was up to 2908 kg ha(-1), available P (58 kg ha(-1)), total P (2115 kg ha(-1)), available K (305 kg ha(-1)) and total K (4712 kg ha(-1)) in surface 0.15 m soil. Vertical distribution of these parameters also varied, with most accumulations occurring in surface 0.3 m. Traces of NO3-N (up to 2.8 mg l(-1)), Pb (up to 0.35 mg l(-1)) and Mn (up to 0.23 mg l(-1)) could also be observed in well waters near the disposal point thus indicating initiation of ground water contamination. However, the contents of heavy metals in crops sampled from the area were below the permissible critical levels. Though the study confirms that the domestic sewage can effectively increase water resource for irrigation but there is a need for continuous monitoring of the concentrations of potentially toxic elements in soil, plants and ground water. 相似文献
973.
Environmental radiological impact associated with non-uranium mining industries: a proposal for screening criteria 总被引:1,自引:0,他引:1
Pires do Rio MA Amaral EC Fernandes HM Rochedo ER 《Journal of environmental radioactivity》2002,59(1):1-17
Niobium, phosphate, coal and gold mining facilities have been selected as case studies with the aim of identifying possible sources of radiological impact during and after cessation of industrial operations. The results have shown that acid drainage, as well as chemical processing of mineral ores, constitute relevant impact indicators for present-day and future scenarios. The possible use of solid wastes abandoned at the end of the operations represents a long-term radiological concern. Therefore, it is necessary that Brazilian legislation for environmental licensing be revised taking into account the potential environmental and radiological impacts caused by these industries and establishing remedial procedures for waste storage areas in the existing sites. The indicators developed and procedures carried out can be used in screening for decisions on the adoption of regulatory requirements for practices at such types of installations. 相似文献
974.
After the Aznalcóllar mining spill (25th April 1998), considerable social concern arose amongst the inhabitants of the SW Iberian Peninsula concerning the consumption of local seafood. Squilla mantis was collected in four regions of the Gulf of Cádiz with a dual objective: to analyze the heavy metal levels for human consumption and as part of biomonitoring program. Heavy metal concentrations (Fe, Mn, Zn, Cu, Cd and Pb) were analyzed in soft tissues and cuticle. The highest values were found in the soft tissues for zinc, copper and cadmium and in the cuticle for iron, manganese and lead. The mean copper concentration in the soft tissue, corresponding to the edible part, was 27.1 microg x g(-1) wet weight. Approximately 80% of stations showed values higher than 20 microg x g(-1) wet weight of copper, the Spanish legal limit for the concentration of this metal in the crustacean for human consumption. For Zn and Cu no significant differences were found between regions, probably related with the capacity for regulation of S. mantis. The highest values found for copper in the Gulf of Cádiz compared to other areas is likely to be related with contamination from terrestrial mining activities (copper and pyrites) in the region, dating back to the times of Tartessians and Romans, rather than the effects of mining spill which was shown not to create any significant increases in heavy metal concentrations of organisms of the Guadalquivir River or the adjacent coastal area. 相似文献
975.
Dauda S. Garuba 《Local Environment》2006,11(1):17-36
This paper examines the diverse strategies being adopted by rural dwellers to cope with the worsening economic crisis in Nigeria, in which they absorb a disproportionate burden as the most marginalized social category. While it draws from secondary materials, it nevertheless relies on the personal observations and experiences of the author's long contact with rural communities across the country. This contact, spanning over a decade, was also complemented with interviews and focus group discussions with rural dwellers. The findings reveal that rural dwellers in Nigeria—irrespective of geographical location and creed—are united by the poverty precipitated by the lingering and excruciating economic crisis that has enveloped the country since the 1980s. The paper concludes on the note that while the various strategies evolved by the people to actualize their survival may seem a creative response, given how they have enhanced their organizational dynamics and self-reliance, they are nevertheless mere survival mechanisms, not a long-term substitute for the development of a sound, healthy and robust economy that can effectively respond to the much-talked-about national rebirth. 相似文献
976.
Michael S. Carolan 《Local Environment》2006,11(4):421-431
After the last few decades in which the importance of 'local' knowledge has been emphasized, attention must now turn to better understanding how such knowledge is communicated to certified experts (scientists) and vice versa. This paper examines how expert knowledge is co-produced in agriculture by local and non-local experts for the benefit of both. The argument is informed by an empirical case study of sustainable farmers and agriculture professionals in Iowa. While much has been written about how the conventional and sustainable models of agriculture rest upon different epistemological orientations, little has yet been said about how those different experts (local and certified) interact with each other. Building upon the work of H. M. Collins and Robert Evans, and their tripartite model of expertise (of no, contributory, and interactional expertise), I investigate the different forms of expertise that exist within agriculture. In doing so, specific focus is placed upon interactional expertise for creating meaningful exchanges (or interactions) between scientists and non-scientists. 相似文献
977.
978.
Rameshwar S. Kanwar 《Journal of the American Water Resources Association》2006,42(6):1493-1501
Abstract: Diverse cropping systems can have significant impacts on nutrient losses through tile drain systems and to surface water bodies (rivers and streams). Increased transport of nitrogen to water bodies can reduce dissolved oxygen and enrich the supply of nutrients, resulting in hypoxic zones. With the objective of reducing the transport of nutrients from agricultural watersheds, long term studies (1990 to 1998) were conducted in Iowa to investigate the impact of tillage, crop rotation, and N-management practices on NO3 -N leaching losses to tile drain water. Results of these studies indicated that continuous corn production systems required higher input of nitrogen fertilizers and resulted in significantly higher NO3 -N leaching losses compared to rotated corn in plots either fertilized with manure or urea ammonium nitrate. Also, rotated corn gave higher corn yields, 8 megagrams per hectare (Mg/ha) versus 6 Mg/ha, than continuous corn. The higher N application rates resulted in increased NO3 -N concentrations in tile water. A strip cropping system with alfalfa lowered NO3 -N concentrations in tile water to less than 10 mg/l. These studies indicated that better land use practices can reduce NO3 -N leaching losses to surface and ground water systems and will help in mitigating environmental concerns of the production agriculture. 相似文献
979.
Knut Veisten Ståle Navrud Johnny S. Y. Valen 《Journal of Environmental Planning and Management》2006,49(2):167-180
Previous contingent valuation (CV) studies on biodiversity have indicated that as much as one-quarter of the respondents show lexicographic preferences when facing biodiversity-money trade-offs. This behaviour is incompatible with welfare theory underlying CV, and thus questions the validity and reliability of the outcome of CV of changes in biodiversity. However, it is difficult from CV responses to distinguish between strict and modified lexicographic preferences, and those attaching a high value to biodiversity. This paper adds to the empirical evidence showing that what at first hand seems to represent strict lexicographic preferences is at most representing modified lexicographic preferences, and probably rather represent just high valuation of biodiversity. Data on both hypothetical and actual willingness to pay (WTP) from a CV study on biodiversity were used to perform tests of inconsistent attitudes to estimate the maximum share of non-compensatory preferences for biodiversity. The results show that there are very few respondents in the group that consistently state high preference for biodiversity preservation and show clear reluctance to trade-off biodiversity with other goods. However, this group also had higher WTP, both hypothetical and actual, than the reference group. This is consistent with exchange preferences and steep indifference curves. Thus, people with lexicographic preferences for biodiversity are probably less numerous than previously indicated. 相似文献
980.
This study examines sources of fecal coliform in Segment 2302 of the Rio Grande, located south of the International Falcon Reservoir in southern Texas. The watershed is unique because the contributing drainage areas lie in Texas and Mexico. Additionally, the watershed is mostly rural, with populated communities known as “colonias.” The colonias lack sewered systems and discharge sanitary water directly to the ground surface, thus posing an increased health hazard from coliform bacteria. Monitoring data confirm that Segment 2302 is not safe for contact recreation due to elevated fecal coliform levels. The goal of the study was to simulate the observed exceedences in Segment 2302 and evaluate potential strategies for their elimination. Fecal coliform contributions from ranching and colonia discharges were modeled using the Hydrologic Simulation Program‐Fortran (HSPF). Model results indicated that the regulatory 30‐day geometric mean fecal coliform concentration of 200 colony forming units (cfu) per 100 milliliters is exceeded approximately three times per year for a total of 30 days. Ongoing initiatives to improve wastewater facilities will reduce this to approximately once per year for 14 days. Best management practices will be necessary to reduce cattle access to streams and eliminate all exceedences. The developed model was limited by the relatively sparse flow and fecal coliform data. 相似文献