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31.
Georgios D. Gikas Trisevgeni Yiannakopoulou Vassilios A. Tsihrintzis 《Environmental Modeling and Assessment》2006,11(3):219-233
SWAT ver. 2000 was used to predict hydrographs, and sediment, nitrate and total phosphorus loadings from a 1349 km2 mountainous/agricultural watershed in Northern Greece. The model was calibrated and verified using continuous meteorological
data from eight stations within the drainage area, and runoff, sediment and nutrient concentrations measured at nine stations
located within the main tributaries of the watershed, for the time period from May 1st, 1998 to January 31st, 2000. Model
validation methodology and resulting input parameters appropriate for Mediterranean drainage basins are presented. Predicted
by the model hydrographs, sedimentographs and pollutographs are plotted against observed values and show good agreement. Model
performance is evaluated using the root mean square error computation and scattergrams of predicted versus observed data.
The validated model is also used to test the effectiveness of three alternative cropping scenarios in reducing nutrient loadings
from the agricultural part of the watershed. The study showed that this model, if properly validated, can be used effectively
in testing management scenarios in Mediterranean drainage basins. 相似文献
32.
本文讨论了水环境数学模型的选择及在水质管理规划中的使用方法,达到实用的目的.具有广泛的通用性和实用性. 相似文献
33.
IMPACTS OF VISITORS ON SOIL AND VEGETATION OF THE RECREATIONAL AREA “NACIMIENTO DEL RÍO MUNDO” (CASTILLA-LA MANCHA, SPAIN) 总被引:1,自引:0,他引:1
Andrés-Abellán M Del Alamo JB Landete-Castillejos T López-Serrano FR García-Morote FA Del Cerro-Barja A 《Environmental monitoring and assessment》2005,101(1-3):55-67
This study examines the effects of recreational use on the soil and vegetation at a site of ecological importance (Nacimiento del Río Mundo, Albacete, Spain). The most visited sites showed increased soil compaction of approximately 50%, bare ground increase to 61 ± 10% and a decrease in richness (from 25 ± 2 to 15 ± 2 species), diversity (from 4.0 ± 0.1 to 2.7 ± 0.4) and stratification of plant species (from 80 ± 11 to 21 ± 4%). The most visited sites had 90% less plant species as compared to the least visited. Intense use was associated with the presence of nitrophilous plant and vegetal species with a morphology adapted to heavy trampling. The recreational areas showed a distribution pattern of impact radiating outwards from the most used and degraded point. At the most visited point, Los Chorros (the spring of the river), the impact radiated outwards for about 20 m. A pilot experiment examining the effects of one-year restriction to visitors for access to a formerly impacted area showed a plant cover increase by anthropic and not by native species of 57 percent units. 相似文献
34.
Combating desertification in natural rangelands has recently become a priority in large parts of southern Africa. Rangeland
managers, farmers, scientists, conservationists and land users have been applying a variety of restoration technologies to
address this problem. Bush encroachment, as part of the desertification process, involves the natural replacement of the herbaceous
plant cover by undesirable problem woody species. The active and passive restoration technologies that are applied, are mainly
based on indigenous knowledge and include the chemical, mechanical or manual reclamation of unproductive rangelands, as well
as the combating of woody and alien species encroachment. Indigenous practices and knowledge play a major role in the effectiveness
and success rate of these technologies. This project faces the challenge of bringing together both local and scientific knowledge
in a single user-friendly, computerised Decision Support System (DSS) which is directly accessible by land users to support
them in the process of decision making, concerning the combating of desertification. Case studies from central and northern
Namibia were used to combine qualitative and quantitative data to develop this Decision Support System. The DSS currently
consists of two databases and an expert system, which evaluates the results of land users’ management practices, and provides
easily accessible information and advice for participants in the system, based on the incorporated data. The DSS is also linked
to national and international web sites and databases to offer a wider range of information on technologies concerning agricultural
and conservation practices. 相似文献
35.
A. Haurie J.J.E. Kübler A. Clappier H. van den Bergh 《Environmental Modeling and Assessment》2004,9(1):1-12
A method is proposed to build integrated models (also called Metamodels) aimed at quantifying the economic efficiency of air quality policies. This Metamodeling approach is based on the coupling of two complementary models, that operate at different scales in space and time, and which represent the economic and the physical and chemical processes, respectively. The joint consideration of the physico-chemical and techno-economic structure of the pollution control problems permits a comprehensive evaluation of air pollution abatement strategies. The motivating pollution control problems include urban-regional air quality management through efficient energy and traffic control policies. A pilot study, exploiting data collected in the Geneva canton (Switzerland), is used to demonstrate the potential of the approach. 相似文献
36.
Brock B. Bernstein Rainer Hoenicke Catherine Tyrell 《Environmental monitoring and assessment》1997,48(3):297-306
We present a planning framework that structures thelarge amount of interrelated information involved indeveloping regional monitoring programs. By regionalwe mean programs that recognize the importance ofprocesses that occur on larger geographic scales andthat cut across more than one ecosystem component. Theframework helps visualize functional relationshipsamong qualitative ingredients such as public concernsand more concrete details such as individual dataelements. It portrays the flow of information amongthe components of a regional program and ties eachaspect of the program to management decision-makingneeds. This makes it easier, during the planningprocess, to ensure that monitoring will actuallyproduce useful information. Further, the frameworksnovel, graphically oriented, and readily accessibleformat makes key information equally available to thewide range of participants (regulators, scientists,managers, public) whose input and support arenecessary for program success. 相似文献
37.
地震安全性评价工作在城市建设中起着非常重要的作用,为工程抗震提供精确的设计依据,提供科学合理的地震动参数,提出科学合理的设防要求,能够在一定程度上避免破坏性地震造成的损失,从而达到有效减灾的目的。 相似文献
38.
简要论述中小企业实施ISO 144001标准、建立 环境管理体系面临机遇和挑战,以及中小企业实施ISO 14001标准的对策。 相似文献
39.
Supplementing the nutrient requirement of crops through organic manures plays a key role in sustaining soil fertility, and crop productivity and reducing use of fossil fuels. Field experiments were conducted for 2 years at two different locations (i.e. Lucknow and Pantnagar) in Uttar Pradesh, India. The objectives of the study were to assess the herb and essential oil yields of Japanese mint (Mentha arvensis cv. Hy 77), and its nutrient accumulation under single and combined applications of organic manures and inorganic fertilizers (NPK). Changes in physical and chemical characteristics of the soils (Fluvisols, Mollisols) were also determined. Eight treatments comprising different combinations of NPK through inorganic fertilizers and farm yard manure (FYM) were compared. The distilled waste of mint after extraction of essential oil was recycled to soils in the plots to supplement the nutritional requirement of the succeeding mustard crop (Brassica juncea cv. Pusa Bold). Herb and essential oil yield of mint were significantly higher with combined application of organic and inorganic sources of nutrients as compared to single applications. Accumulation of N and P was at par under full inorganic and combined supply whereas, K accumulation was higher with the former. Soil organic C and pH after harvest of mint did not significantly differ among the treatments, but the level of mineralizable N, Olsen-P and NH4OAc extractable K were higher in soil with integrated supply of nutrients. Significant increase in soil water stable aggregates, organic C, available NPK and microbial biomass, and decrease in soil bulk density were observed with waste recycling over fertilizer application. These benefits were reflected in the seed and stubble yield of mustard which succeeded mint. This study indicates that combined application of inorganic fertilizers with organics helps in increasing the availability of nutrients and crop yield and provides a significant effect to the succeeding crop. Similarly, recycling crop residues reduces the need for fossil fuel based fertilizer, and helps in sustaining and restoring soil fertility in terms of available nutrients and major physical and chemical characteristics of the soil. 相似文献
40.
Anoveralldescriptionofindustrialwastewasgivenfromgeneration;treatment,disposalandemissionandcomprehensiveutilization.Inspiteo... 相似文献