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1.
Suburban Areas in Developing Countries and Their Relationship to Groundwater Pollution: A Case Study of Mar del Plata, Argentina 总被引:1,自引:0,他引:1
Hector E. Massone Daniel E. Martinez Jose L. Cionchi Emilia Bocanegra 《Environmental management》1998,22(2):245-254
2 were sampled in order to verify the impact of these problems on groundwater. All samples were analyzed for major ions, and
about 30 of them for fecal coliforms and heavy metals. Nineteen samples were selected for pesticide analyses. The average
nitrate content was 80 mg/liter, eight times the regional background value. Fecal coliforms were detected in 60% of the analyzed
samples. Zinc content and a high Cl−/HCO3
− ratio were observed in the surroundings of the solid waste disposal area. Moreover, lindane and heptachlor pesticides were
detected in ten samples. 相似文献
2.
Comparing Landslide Maps: A Case Study in the Upper Tiber River Basin, Central Italy 总被引:17,自引:0,他引:17
/ The preparation of landslide maps is an important step in any landslide hazard assessment. Landslides maps are prepared around the world, but little effort is made to assess their reliability, outline their main characteristics, and pinpoint their limitations. In order to redress this imbalance, the results of a long-term research project in the Upper Tiber River basin in central Italy are used to compare reconnaissance and detailed landslide inventory maps, statistical and geomorphologically based density maps, and landslide hazard maps obtained by multivariate statistical modeling. An attempt is made to discuss advantages and limitations of the available maps, outlining possible applications for decision-makers, land developers, and environmental and civil defence agencies. The Tiber experiment has confirmed that landslides can be cost-effectively mapped by interpreting aerial photographs coupled with field surveys and that errors and uncertainties associated with the inventory can be quantified. The experiment has shown that GIS makes it easy to prepare landslide density maps and facilitates the production of statistically based landslide hazard models. The former supply an overview of the distribution of landslides that is easily comprehended but do not provide insight on the causes of instability. The latter, giving insight into the causes of instability, are diagnostically powerful, but are difficult to prepare and exploit. 相似文献
3.
/ Land use/land cover classifications for 1973 and 1991, derived from the interpretation of satellite imagery, are quantified on the basis of biophysical land units in a study area in southeastern Australia. Nutrient export potentials are estimated for each land unit based on their composition of land use/land cover classes. Spatial and temporal comparisons are made of the land units based on the calculated pollution hazard indicators to provide an insight into changes in the state of the environment and the regional significance of land use changes. For example, one ecosystem, unique to the study, showed a large increase in pollution hazard over the study period as a manifestation of an 11-fold rise in cleared area and an expansion of cropping activities. The benefits to environmental management in general are discussed.KEY WORDS: Land cover change; Nutrient export; Environmental condition; Pollution hazard; Agricultural pollution; Nonpoint source pollution; Diffuse pollution; Environmental degradation 相似文献
4.
Three mathematical models, the runoff curve number equation, the universal soil loss equation, and the mass response functions,
were evaluated for predicting nonpoint source nutrient loading from agricultural watersheds of the Mediterranean region. These
methodologies were applied to a catchment, the gulf of Gera Basin, that is a typical terrestrial ecosystem of the islands
of the Aegean archipelago. The calibration of the model parameters was based on data from experimental plots from which edge-of-field
losses of sediment, water runoff, and nutrients were measured. Special emphasis was given to the transport of dissolved and
solid-phase nutrients from their sources in the farmers' fields to the outlet of the watershed in order to estimate respective
attenuation rates. It was found that nonpoint nutrient loading due to surface losses was high during winter, the contribution
being between 50% and 80% of the total annual nutrient losses from the terrestrial ecosystem. The good fit between simulated
and experimental data supports the view that these modeling procedures should be considered as reliable and effective methodological
tools in Mediterranean areas for evaluating potential control measures, such as management practices for soil and water conservation
and changes in land uses, aimed at diminishing soil loss and nutrient delivery to surface waters. Furthermore, the modifications
of the general mathematical formulations and the experimental values of the model parameters provided by the study can be
used in further application of these methodologies in watersheds with similar characteristics. 相似文献
5.
Use of Soil and Water Protection Practices Among Farmers in Three Midwest Watersheds 总被引:1,自引:0,他引:1
Data were collected from 1011 farmers in three Midwestern watersheds (Ohio, Iowa, and Minnesota) to assess factors that influence
the use of conservation production systems at the farm level. The “vested interests” perspective used to guide the investigation
was derived from elements of social learning and social exchange theories. Respondents were asked to indicate their frequency
of use for 18 agricultural production practices that could be adopted on Midwestern farms at the time of the study. Responses
to the 18 items were summed to form a composite variable, termed “conservation production index,” for use as the dependent
variable in multivariate analysis. Eleven independent variables were identified from the theory as likely predictors of conservation
adoption, including respondents' perceptions about production costs, output and risks, and perceived importance of access
to subsidies, technical assistance, and informational/educational programs. Regression analysis was used to assess the performance
of the independent variables in explaining variance in the conservation production index. Explained variance in the three
regression models ranged from 2% in the Minnesota watershed to 19% in the Ohio watershed. The researchers concluded that the
model had limited utility in predicting adoption of conservation production systems within the three study watersheds. Findings
are discussed in the context of conservation programs within the three areas. 相似文献
6.
Setting Priorities for Research on Pollution Reduction Functions of Agricultural Buffers 总被引:4,自引:0,他引:4
Dosskey MG 《Environmental management》2002,30(5):0641-0650
The success of buffer installation initiatives and programs to reduce nonpoint source pollution of streams on agricultural
lands will depend the ability of local planners to locate and design buffers for specific circumstances with substantial and
predictable results. Current predictive capabilities are inadequate, and major sources of uncertainty remain. An assessment
of these uncertainties cautions that there is greater risk of overestimating buffer impact than underestimating it.
Priorities for future research are proposed that will lead more quickly to major advances in predictive capabilities. Highest
priority is given for work on the surface runoff filtration function, which is almost universally important to the amount
of pollution reduction expected from buffer installation and for which there remain major sources of uncertainty for predicting
level of impact. Foremost uncertainties surround the extent and consequences of runoff flow concentration and pollutant accumulation.
Other buffer functions, including filtration of groundwater nitrate and stabilization of channel erosion sources of sediments,
may be important in some regions. However, uncertainty surrounds our ability to identify and quantify the extent of site conditions
where buffer installation can substantially reduce stream pollution in these ways.
Deficiencies in predictive models reflect gaps in experimental information as well as technology to account for spatial heterogeneity
of pollutant sources, pathways, and buffer capabilities across watersheds. Since completion of a comprehensive watershed-scale
buffer model is probably far off, immediate needs call for simpler techniques to gage the probable impacts of buffer installation
at local scales. 相似文献
7.
干旱河谷地区农业产业结构的调整对环境及经济的影响分析--以汉源地区为例 总被引:1,自引:1,他引:1
中国农业产业结构的调整,是中国改革开放、市场化发展的集中体现。本文以汉源地区为例,总结分析了典型的干旱河谷地带农业产业结构的调整情况,不仅促进了当地农村发展方式的根本转变、改善了农村经济、提高了农民收入,同时还解决了当地剩余劳动力的就地消化问题。本文指出了农业产业结构的调整可能对当地生态环境造成的影响,其中诸如不舍理用药用肥造成的水污染、土壤和农产品的硝酸盐污染以及土壤退化、大气污染等环境问题。需要在实践中更加审慎地调整农业产业结构。 相似文献
8.
The U.S. Environmental Protection Agency (USEPA) and the U.S. Department of Agriculture (USDA) are promoting point/nonpoint trading as a way of reducing the costs of meeting water quality goals. Farms can create offsets by implementing management practices such as conservation tillage, nutrient management and buffer strips. To be eligible to sell offsets or credits, farmers must first comply with baseline requirements. USEPA guidance recommends that the baseline for nonpoint sources be management practices that are consistent with the water quality goal. A farmer would not be able to create offsets until the minimum practice standards are met. An alternative baseline is those practices being implemented at the time the trading program starts, or when the farmer enters the program. The selection of the baseline affects the efficiency and equity of the trading program. It has major implications for which farmers benefit from trading, the cost of nonpoint source offsets, and ultimately the number of offsets that nonpoint sources can sell to regulated point sources. We use a simple model of the average profit-maximizing dairy farmer operating in the Conestoga watershed in Pennsylvania to evaluate the implications of baseline requirements on the cost and quantity of offsets that can be produced for sale in a water quality trading market, and which farmers benefit most from trading. 相似文献
9.
Comparative Analysis of New Zealand and US Approaches for Agricultural Nonpoint Source Pollution Management 总被引:1,自引:0,他引:1
Brian S. Caruso 《Environmental management》2000,25(1):9-22
The role of the central government in New Zealand is generally limited to research and policy development, and regional councils
are responsible for most monitoring and management of the problem. The role of the federal government in the United States
includes research and monitoring, policy development, and regulation. States also have a significant management role. Both
countries rely on voluntary approaches for NPS pollution management. Very few national water quality standards exist in New
Zealand, whereas standards are widely used in the United States. Loading estimates and modeling are often used in the United
States, but not in New Zealand. A wide range of best management practices (BMPs) are used in the United States, including
buffer strips and constructed/engineered wetlands. Buffer strips and riparian management have been emphasized and used widely
in New Zealand.
Many approaches are common to both countries, but management of the problem has only been partly successful. The primary barriers
are the inadequacy of the voluntary approach and the lack of scientific tools that are useful to decision-makers. More work
needs to be performed on the evaluation of approaches developed in both countries that could be applied in the other countries.
In addition, more cooperation and information/technology transfer between the two countries should be encouraged in the future. 相似文献
10.
Assessing Landscape Health: A Case Study from Northeastern Italy 总被引:17,自引:0,他引:17
Bertollo P 《Environmental management》2001,27(3):349-365
This article investigates the concept of biophysical landscape health for what are termed “highly governed landscapes.” It
proposes a definition of landscape health along with a preliminary diagnostic model and methods. The idea of landscape health
derives from the emerging integrative science of ecosystem health, which seeks to diagnose ecosystem condition as humans diagnose
human health. Highly governed landscapes, such as the reclaimed areas of coastal northeastern Italy, are landscapes that have
been subject to even greater degrees of human manipulation than normal cultural landscapes. These highly altered landscapes
are not easily served by existing environmental paradigms and concepts of health are seen to have numerous advantages. This
paper condenses a broader investigation of landscape health into three main sections. A brief review of the literature is
followed by a case study, which details two different phases of landscape transformation in the Lower Piave area of northeastern
Italy. A definition and general parameters of biophysical landscape health are then presented after this background stage.
Some key parameters of biophysical health include absence of distress and risk factors, sustainability, biodiversity, resilience,
and balance. For certain parameters, a preliminary landscape health diagnostic framework is presented that includes potential
diagnostic methods and thresholds based on findings from this case study. At the paper's conclusion, a summary diagnostic
model is presented, which suggests a process needed to implement landscape health assessment into practice. 相似文献
11.
Rockfall Hazard and Risk Assessment Along a Transportation Corridor in the Nera Valley,Central Italy 总被引:11,自引:0,他引:11
Rockfalls are a common type of fast-moving slope failures, and in many countries they represent the primary cause of landslide fatalities. We present a methodology to ascertain rockfall hazard and to determine the associated risk along transportation networks. The proposed methodology is based on the combined analysis of the recurrence of rockfall events, determined from historical information, the frequency-volume statistics of rockfalls, obtained from inventories of recent rockfall triggering events, and the results of a physically based, spatially distributed rockfall simulation model used to determine rockfall hazard. The available information on rockfall hazard is combined in a Geographic Information System with a map of the transportation network to identify the road sections potentially subject to rockfalls. Information on the location and type of rockfall defensive measures, including revetment nets, elastic fences, concrete walls, and artificial tunnels, is used to estimate the efficacy of the defensive structures and to determine the level of the residual rockfall risk along the roads. To illustrate the methodology, we discuss an application in a 48-km2 area in the Nera River valley, in the Umbria Region of central Italy, where rockfalls are abundant, and where considerable investments were recently made to mitigate rockfall risk.
Note: This version was published online in June 2005 with the cover date of August 2004. 相似文献
12.
Landscape Planning for Agricultural Nonpoint Source Pollution Reduction I: A Geographical Allocation Framework 总被引:1,自引:1,他引:0
Agricultural nonpoint source pollution remains a persistent environmental problem, despite the large amount of money that
has been spent on its abatement. At local scales, agricultural best management practices (BMPs) have been shown to be effective
at reducing nutrient and sediment inputs to surface waters. However, these effects have rarely been found to act in concert
to produce measurable, broad-scale improvements in water quality. We investigated potential causes for this failure through
an effort to develop recommendations for the use of riparian buffers in addressing nonpoint source pollution in Wisconsin.
We used frequency distributions of phosphorus pollution at two spatial scales (watershed and field), along with typical stream
phosphorus (P) concentration variability, to simulate benefit/cost curves for four approaches to geographically allocating
conservation effort. The approaches differ in two ways: (1) whether effort is aggregated within certain watersheds or distributed
without regard to watershed boundaries (dispersed), and (2) whether effort is targeted toward the most highly P-polluting
fields or is distributed randomly with regard to field-scale P pollution levels. In realistic implementation scenarios, the
aggregated and targeted approach most efficiently improves water quality. For example, with effort on only 10% of a model
landscape, 26% of the total P load is retained and 25% of watersheds significantly improve. Our results indicate that agricultural
conservation can be more efficient if it accounts for the uneven spatial distribution of potential pollution sources and the
cumulative aspects of environmental benefits. 相似文献
13.
On the choice of farm management practices after the reform of the Common Agricultural Policy in 2003 总被引:1,自引:0,他引:1
The Common Agricultural Policy (CAP) was fundamentally reformed in 2003. From 2005, farmers will receive decoupled income support payments instead of production premiums if basic standards for environment, food safety, animal health and welfare are met. Farmers are likely to adjust production and management practices to the new policy framework. We describe how this reform fits into the EU strategy of making agricultural production more environmentally friendly by concentrating on the financial aspects of the reforms. Using an agricultural sector model for Austria, we show that the reform will further decrease agricultural outputs, reduce farm inputs, lessen nitrogen surpluses and make environmentally friendly management practices more attractive for farmers. 相似文献
14.
Intrinsic vulnerability assessment of Sette Comuni Plateau aquifer (Veneto Region, Italy) 总被引:1,自引:0,他引:1
Maps illustrating the different degrees of vulnerability within a given area are integral to environmental protection and management policies. The assessment of the intrinsic vulnerability of karst areas is difficult since the type and stage of karst development and the related underground discharge behavior are difficult to determine and quantify. Geographic Information Systems techniques are applied to the evaluation of the vulnerability of an aquifer in the alpine karst area of the Sette Comuni Plateau, in the Veneto Region of northern Italy. The water resources of the studied aquifer are of particular importance to the local communities. This aquifer must therefore be protected from both inappropriate use as well as possible pollution. The SINTACS and SINTACS P(RO) K(ARST) vulnerability assessment methods have been utilized here to create the vulnerability map. SINTACS P(RO) K(ARST) is an adaptation of the parametric managerial model (SINTACS) to karst hydrostructures. The vulnerability map reveals vast zones (81% of the analyzed areas) with a high degree of vulnerability. The presence of well-developed karst structures in these highly vulnerable areas facilitate water percolation, thereby enhancing the groundwater vulnerability risk. Only 1.5 of the studied aquifer have extremely high-vulnerability levels, however these areas include all of the major springs utilized for human consumption. This vulnerability map of the Sette Comuni Plateau aquifer is an indispensable tool for both the effective management of water resources and as support to environmental planning in the Sette Comuni Plateau area. 相似文献
15.
16.
Little is known about the vulnerability to landslides, despite landslides causing frequent and widespread damage to the population
and the built-up environment in many areas of the world. Lack of information about vulnerability to landslides limits our
ability to determine landslide risk. This paper provides information on the vulnerability of buildings and roads to landslides
in Umbria, central Italy. Information on 103 landslides of the slide and slide-earth flow types that have resulted in damage
to buildings and roads at 90 sites in Umbria is used to establish dependencies between the area of the landslide and the vulnerability
to landslides. The dependencies obtained are applied in the hills surrounding the town of Collazzone, in central Umbria, an
area for which a detailed landslide inventory map is available. By exploiting the landslide inventory and the established
vulnerability curves, the geographical distribution of the vulnerability to landslides is mapped and statistics of the expected
damage are calculated. Reliability and limits of the vulnerability thresholds and of the obtained vulnerability assessment
are discussed. 相似文献
17.
Agricultural landscapes illustrate the impact of human actions on physical settings, and differential human pressures cause
these landscapes to change with time. Our study explored changes in the terraced landscapes of Nisyros Island, Greece, focusing
on the socioeconomic aspects during two time periods using field data, cadastral research, local documents, and published
literature, as well as surveys of the islanders. Population increases during the late 19th to early 20th centuries marked a significant escalation of terrace and dry stone wall construction, which facilitated cultivation on 58.4%
of the island. By the mid-20th century, the economic collapse of agricultural activities and consequent emigration caused the abandonment of cultivated
land and traditional management practices, dramatically reducing farm and field numbers. Terrace abandonment continued in
recent decades, with increased livestock grazing becoming the main land management tool; as a result, both farm and pasture
sizes increased. Neglect and changing land use has led to deterioration and destruction of many terraces on the island. We
discuss the socioeconomic and political backgrounds responsible for the land-use change before World War II (annexation of
Nisyros Island by the Ottoman Empire, Italy, and Greece; overseas migration opportunities; and world transportation changes)
and after the war (social changes in peasant societies; worldwide changes in agricultural production practices). The adverse
landscape changes documented for Nisyros Island appear to be inevitable for modern Mediterranean rural societies, including
those on other islands in this region. The island’s unique terraced landscapes may qualify Nisyros to become an archive or
repository of old agricultural management techniques to be used by future generations and a living resource for sustainable
management. 相似文献
18.
California’s population increased 25% between 1980 and 1990, resulting in rapid and extensive urbanization. Of a total 123,000
ha urbanized in 42 of the state’s 58 counties between 1984 and 1990, an estimated 13% occurred on irrigated prime farmland,
and 48% on wildlands or fallow marginal farmlands. Sixty-six percent of all new irrigated farmland put into production between
1984 and 1990 was of lesser quality than the prime farmland taken out of production by urbanization. Factors dictating the
agricultural development of marginal farmlands include the availability and price of water and land, agricultural commodity
prices, and technical innovations such as drip irrigation systems that impact the feasibility and costs of production. The
increasing amount of marginal farmland being put into production could have significant water quality consequences because
marginal lands are generally steeper, have more erodible soils, poorer drainage, and require more fertilizer than prime farmlands.
Although no data exist to test our hypothesis, and numerous variables preclude definitive predictions, the evidence suggests
that new irrigated marginal lands can increase nonpoint source (NPS) pollution for a given size area by an order of magnitude
in some cases. 相似文献
19.
The Ala Wai Canal Watershed Model (ALAWAT) is a planning-level watershed model for approximating direct runoff, streamflow,
sediment loads, and loads for up to five pollutants. ALAWAT uses raster GIS data layers including land use, SCS soil hydrologic
groups, annual rainfall, and subwatershed delineations as direct model parameter inputs and can use daily total rainfall from
up to ten rain gauges and streamflow from up to ten stream gauges. ALAWAT uses a daily time step and can simulate flows for
up to ten-year periods and for up to 50 subwatersheds. Pollutant loads are approximated using a user-defined combination of
rating curve relationships, mean event concentrations, and loading/washoff parameters for specific subwatersheds, land uses,
and times of year. Using ALAWAT, annual average streamflow and baseflow relationships and urban suspended sediment loads were
approximated for the Ala Wai Canal watershed (about 10,400 acres) on the island of Oahu, Hawaii. Annual average urban suspended
sediments were approximated using two methods: mean event concentrations and pollutant loading and washoff. Parameters for
the pollutant loading and washoff method were then modified to simulate the effect of various street sweeping intervals on
sediment loads. 相似文献
20.
Applying Statistical Causal Analyses to Agricultural Conservation: A Case Study Examining P Loss Impacts 下载免费PDF全文
Song S. Qian R. Daren Harmel 《Journal of the American Water Resources Association》2016,52(1):198-208
Estimating the effect of agricultural conservation practices on reducing nutrient loss using observational data can be confounded by factors such as differing crop types and management practices. As we may not have the full knowledge of these confounding factors, conventional statistical meta‐analysis methods can be misleading. We discuss the use of two statistical causal analysis methods for quantifying the effects of water and soil conservation practices in reducing P loss from agricultural fields. With the propensity score method, a subset of data was used to form a treatment group and a control group with similar distributions of confounding factors. With the multilevel modeling method, data were stratified based on important confounding factors, and the conservation practice effect was evaluated for each stratum. Both methods resulted in similar estimates of the conservation practice effect (total P load reduction avg. ~70%). In addition, both methods show evidence of conservation practices reducing the incremental increase in total P export per unit increase in fertilizer application. These results are presented as examples of the types of outcomes provided by statistical causal analyses, not to provide definitive estimates of P loss reduction. The enhanced meta‐analysis methods presented within are applicable for improved assessment of agricultural practices and their effects and can be used for providing realistic parameter values for watershed‐scale modeling. 相似文献