首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 78 毫秒
1.
Energy analysis of nonmarket values of the Mississippi Delta   总被引:1,自引:0,他引:1  
An energy analysis was used to estimate nonmarket values under various land cover scenarios in the Mississippi Delta. Land loss since 1900 has led to a decline in nonmarket values from $3.1 billion/year in 1900 to $2.5 billion in 1990, resulting in a total loss of $29.4 billion. This loss is concentrated in the Barataria-Terrebonne basins, where nonmarket value has dropped from $1.6 billion/year in 1956 to $1.3 billion/year in 1988. Although values are projected to increase in the Atchafalaya basin (from $723 million/year in 1988 to $756 million/year in 2058), total nonmarket value for the Louisiana coast is projected to decrease to $2.1 billion/year under currently approved levels of restoration.  相似文献   

2.
Logging has been a much maligned feature of frontier development in the Amazon. Most discussions ignore the fact that logging can be part of a renewable, environmentally benign, and broadly equitable economic activity in these remote places. We estimate there to be some 4.5 ± 1.35 billion m3 of commercial timber volume in the Brazilian Amazon today, of which 1.2 billion m3 is currently profitable to harvest, with a total potential stumpage value of $15.4 billion. A successful forest sector in the Brazilian Amazon will integrate timber harvesting on private lands and on unprotected and unsettled government lands with timber concessions on public lands. If a legal, productive, timber industry can be established outside of protected areas, it will deliver environmental benefits in synergy with those provided by the region’s network of protected areas, the latter of which we estimate to have an opportunity cost from lost timber revenues of $2.3 billion over 30 years. Indeed, on all land accessible to harvesting, the timber industry could produce an average of more than 16 million m3 per year over a 30-year harvest cycle—entirely outside of current protected areas—providing $4.8 billion in returns to landowners and generating $1.8 billion in sawnwood sales tax revenue. This level of harvest could be profitably complemented with an additional 10% from logging concessions on National Forests. This advance, however, should be realized only through widespread adoption of reduced impact logging techniques.  相似文献   

3.
This study employs a benefit-cost analysis framework to estimate market and non-market benefits and costs of controlling future spruce budworm (Choristoneura fumiferana) outbreaks on Crown forest lands in New Brunswick, Canada. We used: (i) an advanced timber supply model to project potential timber volume saved, timber value benefits, and costs of pest control efforts; and (ii) a recent contingent valuation method analysis that evaluated non-market benefits (i.e., changes in recreation opportunities and existence values) of controlling future spruce budworm outbreaks in the Province. A total of six alternative scenarios were evaluated, including two uncontrolled future budworm outbreak severities (moderate vs. severe) and, for each severity, three control program levels (protecting 10%, 20%, or 40% of the susceptible Crown land forest area). The economic criteria used to evaluate each scenario included benefit-cost ratios and net present values. Under severe outbreak conditions, results indicated that the highest benefit-cost ratio (4.04) occurred when protecting 10% (284,000 ha) of the susceptible area, and the highest net present value ($111 M) occurred when protecting 20% (568,000 ha) of the susceptible area. Under moderate outbreak conditions, the highest benefit-cost ratio (3.24) and net present value ($58.7 M) occurred when protecting 10% (284,000 ha) of the susceptible area. Inclusion of non-market values generally increased the benefit-cost ratios and net present values of the control programs, and in some cases, led to higher levels of control being supported. Results of this study highlight the importance of including non-market values into the decision making process of forest pest management.  相似文献   

4.
The National Park Service (NPS) currently manages a large and diverse system of park units nationwide which received an estimated 279 million recreational visits in 2011. This article uses park visitor data collected by the NPS Visitor Services Project to estimate a consistent set of count data travel cost models of park visitor willingness to pay (WTP). Models were estimated using 58 different park unit survey datasets. WTP estimates for these 58 park surveys were used within a meta-regression analysis model to predict average and total WTP for NPS recreational visitation system-wide. Estimated WTP per NPS visit in 2011 averaged $102 system-wide, and ranged across park units from $67 to $288. Total 2011 visitor WTP for the NPS system is estimated at $28.5 billion with a 95% confidence interval of $19.7–$43.1 billion. The estimation of a meta-regression model using consistently collected data and identical specification of visitor WTP models greatly reduces problems common to meta-regression models, including sample selection bias, primary data heterogeneity, and heteroskedasticity, as well as some aspects of panel effects. The article provides the first estimate of total annual NPS visitor WTP within the literature directly based on NPS visitor survey data.  相似文献   

5.
Historically, thermoelectric water withdrawal has been estimated by the Energy Information Administration (EIA) and the U.S. Geological Survey's (USGS) water‐use compilations. Recently, the USGS developed models for estimating withdrawal at thermoelectric plants to provide estimates independent from plant operator‐reported withdrawal data. This article compares three federal datasets of thermoelectric withdrawals for the United States in 2010: one based on the USGS water‐use compilation, another based on EIA data, and the third based on USGS model‐estimated data. The withdrawal data varied widely. Many plants had three different withdrawal values, and for approximately 54% of the plants the largest withdrawal value was twice the smallest, or larger. The causes of discrepancies among withdrawal estimates included definitional differences, definitional noise, and various nondefinitional causes. The uncertainty in national totals can be characterized by the range among the three datasets, from 5,640 m3/s (129 billion gallons per day [bgd]) to 6,954 m3/s (158 bgd), or by the aggregate difference between the smallest and largest values at each plant, from 4,014 m3/s (92 bgd) to 8,590 m3/s (196 bgd). When used to assess the accuracy of reported values, the USGS model estimates identify plants that need to be reviewed.  相似文献   

6.
/ The travel cost method was used to estimate the economic value of seven major power boating resources in Pennsylvania. A significant relationship between number of visitor trips and cost per visitor trip existed for five of the seven water bodies. The annual total value for those five resources was $396 million, which was 2.5 times greater than the total out-of-pocket expenditures of approximately $157 million visitors spent to visit them. Research results can help resource managers plan and craft programs and policies that are founded on economic values of the natural resources involved.  相似文献   

7.
Abstract: This study evaluates the economic value of riparian buffers and open space in a suburban watershed through two nonmarket valuation methods. A contingent valuation survey was implemented in the Dardenne Creek watershed, a suburban watershed of the St. Louis metropolitan area in Missouri, to evaluate the residents' perceptions of and willingness to pay (WTP) for adopting riparian buffers and preserving farmland in a hypothetical real estate market. A hedonic pricing model based on actual sale prices of homes in the watershed was applied to estimate the market value of open space and other environmental conditions such as flood zone and stream proximity in the study area. The results showed that residents' WTP was consistent with the economic values of open space and proximity to streams embedded in existing home prices. Through a better understanding of residents' perceptions and values, riparian buffer and open space programs can be designed and promoted to achieve greater implementation success and environmental benefit.  相似文献   

8.
Changes in the coastal landscape of Southern Sinaloa (Mexico), between 2000 and 2010, were analyzed to relate spatial variations in wetlands extent with the provision and economic value of the ecosystem services (ES). Remote sensing techniques applied to Landsat TM imagery were used to evaluate land use/land cover changes while the value transfer method was used to assess the value of ES by land cover category. Five wetland types and other four land covers were found as representative of the coastal landscape. Findings reveal a 14 % decrease in the saltmarsh/forested mangrove area and a 12 % increase in the area of shrimp pond aquaculture (artificial wetland) during the study period. ES valuation shows that the total value flow increased by 9 % from $215 to $233 million (2007 USD) during the 10-year period. This increase is explained as result of the high value worldwide assigned to saltmarsh. We recognize limitations in the transfer-based approach in quantifying and mapping ES values in the region, but this method provides with value estimates spatially defined, and also provides some guidance in the preliminary screening of policies and projected development in the context of data-scarce regions.  相似文献   

9.
Land use since 1935 was quantified for Georgia, USA, and for a sample of 20 counties from the major physiographic regions within the state. Statistical data on crop production, pasture productivity, and forest growth were used to estimate net primary production. Appropriate harvest indices (ratio of crop yield to total plant production) were used to correct crop yield data for different decades. Net primary production (NPP) of the Georgia landscape increased from 2.5 to 6.4 tonnes/ha from 1935 to 1982, but varied considerably among land uses and physiographic regions. NPP in the piedmont and mountains reached a plateau between 1960 and 1982, but the upper and lower coastal plains showed a continued linear increase in NPP. In all regions, NPP rose most between 1960 and 1982, coinciding with increases in inputs such as fertilizer and irrigation. Natural ecosystem NPP for Georgia is approximately 16–18 tonnes/ha, and the estimated actual NPP is thus considerably less than the potential. Spatial and temporal patterns of NPP may be a useful basis for evaluating the biological performance of a landscape.  相似文献   

10.
The impacts of strategically located contour prairie strips on sediment and nutrient runoff export from watersheds maintained under an annual row crop production system have been studied at a long-term research site in central Iowa. Data from 2007 to 2011 indicate that the contour prairie strips utilized within row crop-dominated landscapes have greater than proportionate and positive effects on the functioning of biophysical systems. Crop producers and land management agencies require comprehensive information about the Best Management Practices with regard to performance efficacy, operational/management parameters, and the full range of financial parameters. Here, a farm-level financial model assesses the establishment, management, and opportunity costs of contour prairie strips within cropped fields. Annualized, depending on variable opportunity costs the 15-year present value cost of utilizing contour prairie strips ranges from $590 to $865 ha?1 year?1 ($240–$350 ac?1 year?1). Expressed in the context of “treatment area” (e.g., in this study 1 ha of prairie treats 10 ha of crops), the costs of contour prairie strips can also be viewed as $59 to about $87 per treated hectare ($24–$35 ac?1). If prairie strips were under a 15-year CRP contract, total per acre cost to farmers would be reduced by over 85 %. Based on sediment, phosphorus, and nitrogen export data from the related field studies and across low, medium, and high land rent scenarios, a megagram (Mg) of soil retained within the watershed costs between $7.79 and $11.46 mg?1, phosphorus retained costs between $6.97 and $10.25 kg?1, and nitrogen retained costs between $1.59 and $2.34 kg?1. Based on overall project results, contour prairie strips may well become one of the key conservation practices used to sustain US Corn Belt agriculture in the decades to come.  相似文献   

11.
ABSTRACT: Since nitrogen is a nutrient frequently in short supply in coastal ecosystems, an estimate of the nitrogen input via rain was made for the Georgia coast. Water samples collected in 34 separate storms during a 12 month period were analysed for concentrations of ammonia, nitrate plus nitrite, and dissolved organic nitrogen (DON). The range and average concentration in micromoles of nitrogen per liter was 0.0 to 137 (6.3) for ammonia, 1.0 to 21 (7.9) for nitrate plus nitrite, and 0.0 to 13.6 (4.0) for DON. DON, not usually measured in rain, comprised up to 62% of the total nitrogen content. The annual amount of nitrogen contributed by rain to the coast was about 0.3 g N/m2. This value is a small fraction of the calculated nitrogen requirements of coastal plants. More than half the rain samples had pH values less than the CO2 equilibrium pH of 5.6. Values as low as 4.2 were in the range of pH values reported for acid rain in Europe and the northeastern U.S. Total titratable acidity was measured for 12 summer rainwater samples. The results fox 7 individual storms showed a highly linear relation between hydrogen ion concentration and total acidity. However, the elope of the regression line indicated that increases in acidity were not a result of addition of strong acid alone.  相似文献   

12.
ABSTRACT. The Bureau of Reclamation was created to implement the Reclamation Act of 1902 and subsequent legislation to conserve and develop the water resources of the western states for maximum efficient use. This has been accomplished by the planning and construction of major multiple use projects which now supply water to approximately eight million acres of land which annually produce 52 million tons of food and fiber with a gross crop value of approximately $2 billion. Fifteen million people are served with municipal and industrial water supplies and hydroelectric power from Bureau projects now returns $160 million annually to the Treasury. Flood control, recreation, and fish and wildlife enhancement are other major benefits. The Bureau of Reclamation is now undertaking a Westwide Survey of water resources and of the needs of the future which is more far-reaching than anything heretofore accomplished. The information accumulated during this ten-year survey will determine whether there is a necessity for consideration of major interbasin transfer of water supply.  相似文献   

13.
In 1978 the USA used non-fuel processed mineral materials valued at over $200 billion (109). Non-fuel mineral imports caused a trade imbalance of $8 billion. Imports supplied more than half of US supplies of 20 important minerals. The US stockpile of strategic materials is valued at over $11 billion. While world reserves of most minerals are now deemed adequate until 2000, demand for high temperature and special property materials requires careful monitoring and anticipation of disruptions in vulnerable sources.  相似文献   

14.
Riparian buffers have the potential to improve stream water quality in agricultural landscapes. This potential may vary in response to landscape characteristics such as soils, topography, land use, and human activities, including legacies of historical land management. We built a predictive model to estimate the sediment and phosphorus load reduction that should be achievable following the implementation of riparian buffers; then we estimated load reduction potential for a set of 1598 watersheds (average 54 km2) in Wisconsin. Our results indicate that land cover is generally the most important driver of constituent loads in Wisconsin streams, but its influence varies among pollutants and according to the scale at which it is measured. Physiographic (drainage density) variation also influenced sediment and phosphorus loads. The effect of historical land use on present-day channel erosion and variation in soil texture are the most important sources of phosphorus and sediment that riparian buffers cannot attenuate. However, in most watersheds, a large proportion (approximately 70%) of these pollutants can be eliminated from streams with buffers. Cumulative frequency distributions of load reduction potential indicate that targeting pollution reduction in the highest 10% of Wisconsin watersheds would reduce total phosphorus and sediment loads in the entire state by approximately 20%. These results support our approach of geographically targeting nonpoint source pollution reduction at multiple scales, including the watershed scale.  相似文献   

15.
Abstract: Sediment oxygen demand (SOD) is believed to be an important process affecting dissolved oxygen (DO) concentrations in blackwater streams of the southeastern coastal plain. Because very few data on SOD are available, it is common for modelers to take SOD values from the literature for use with DO models. In this study, SOD was measured in seven blackwater streams of the Suwannee River Basin within the Georgia coastal plain for between August 2004 and April 2005. SOD was measured using four in situ chambers and was found to vary on average between 0.1 and 2.3 g O2/m/day across the seven study sites throughout the study period. SOD was found to vary significantly between the watersheds within the Suwannee River Basin. However, land use was not found to be the driving force behind SOD values. Statistical analyses did find significant interaction between land use and watersheds suggesting that an intrinsically different factor in each of the watersheds may be affecting SOD and the low DO concentrations. Further research is needed to identify the factors driving SOD dynamics in the blackwater streams of Georgia’s coastal plain. Results from this study will be used by the Georgia Department of Natural Resources – Environmental Protection Division as model input data for the development and evaluation of DO total maximum daily loads in the Georgia coastal plain.  相似文献   

16.
US Federal law mandates that mined land be returned by mine operators to a condition capable of supporting its pre-mining use or a higher use. Previously forested lands have commonly been reclaimed to hayland/pasture or wildlife habitat, and most of these lands have been abandoned from management and rendered non-productive. This situation has left landowners in the position of converting these reclaimed mined lands to forests at a later date, if they choose to make them economically productive. Such land-use conversion, however, comes with a substantial up-front cost to the landowner, which makes the financial viability of such a conversion questionable. We examine the financial viability of reforestation of these previously reclaimed mine lands by calculating land expectation value (LEV) under a range of conditions that include forest type, site quality, and reforestation intensity. We find that conversion to white pine is viable on higher quality sites under low to moderate interest rates with low or high timber prices, but conversion to mixed hardwoods is only profitable under the high price scenario with low interest rates, and only on higher quality sites. We also consider the implications of a shift in reforestation burden from the landowner to the mine operator, and results suggest that including costs of reforestation as part of the mining operation creates a financially viable forest enterprise for landowners under all scenarios for both white pine and mixed hardwoods. Two forms of carbon payments that could encourage reforestation of previously reclaimed mined lands also are examined: an annual payment based upon the total accumulated carbon found on-site in a given year, and an annual payment based on only the increment of carbon storage each year. Our carbon payment results indicate that annual values of up to $5.17 per ton of carbon stored in hardwoods and $9.39 per ton of carbon stored in pines would be required to make reforestation profitable under the poorest conditions (high interest rates, low prices, and poor quality site) when the payment is based on accumulated on-site carbon, although lower values are required under more favorable scenarios. Payments that are based upon the annual increment of carbon must fall in the range of $8.66–$71.88 per ton of carbon stored in hardwoods and $0–$83.29 per ton of carbon stored in pines to make reforestation financially viable.  相似文献   

17.
Phytophthora ramorum, cause of sudden oak death, is a quarantined, non-native, invasive forest pathogen resulting in substantial mortality in coastal live oak (Quercus agrifolia) and several other related tree species on the Pacific Coast of the United States. We estimate the discounted cost of oak treatment, removal, and replacement on developed land in California communities using simulations of P. ramorum spread and infection risk over the next decade (2010-2020). An estimated 734 thousand oak trees occur on developed land in communities in the analysis area. The simulations predict an expanding sudden oak death (SOD) infestation that will likely encompass most of northwestern California and warrant treatment, removal, and replacement of more than 10 thousand oak trees with discounted cost of $7.5 million. In addition, we estimate the discounted property losses to single family homes of $135 million. Expanding the land base to include developed land outside as well as inside communities doubles the estimates of the number of oak trees killed and the associated costs and losses. The predicted costs and property value losses are substantial, but many of the damages in urban areas (e.g. potential losses from increased fire and safety risks of the dead trees and the loss of ecosystem service values) are not included.  相似文献   

18.
Economic assessment of damage caused by invasive alien species provides useful information to consider when determining whether management programs should be established, modified, or discontinued. We estimate the baseline economic damage from an invasive alien pathogen, Ceratocystis fagacearum, a fungus that causes oak wilt, which is a significant disease of oaks (Quercus spp.) in the central United States. We focus on Anoka County, Minnesota, a 1,156 km2 mostly urban county in the Minneapolis-Saint Paul metropolitan region. We develop a landscape-level model of oak wilt spread that accounts for underground and overland pathogen transmission. We predict the economic damage of tree mortality from oak wilt spread in the absence of management during the period 2007–2016. Our metric of economic damage is removal cost, which is one component of the total economic loss from tree mortality. We estimate that Anoka County has 5.92 million oak trees and 885 active oak wilt pockets covering 5.47 km2 in 2007. The likelihood that landowners remove infected oaks varies by land use and ranges from 86% on developed land to 57% on forest land. Over the next decade, depending on the rates of oak wilt pocket establishment and expansion, 76–266 thousand trees will be infected with discounted removal cost of $18–60 million. Although our predictions of removal costs are substantial, they are lower bounds on the total economic loss from tree mortality because we do not estimate economic losses from reduced services and increased hazards. Our predictions suggest that there are significant economic benefits, in terms of damage reduction, from preventing new pocket establishment or slowing the radial growth of existing pockets.  相似文献   

19.
Economic amenity values of wildlife: Six case studies in Pennsylvania   总被引:1,自引:0,他引:1  
The travel clost method (TCM) and contingent valuation method (CVM) were used to evaluate the economic value of six different ecotourism activities involving observation of wildlife in Pennsylvania. The six activities were: catch-and-release trout fishing; catch-and-release trout fishing with fly-fishing equipment; viewing waterfowl; watching elk; observing migration flights of raptors; and seeing live wildlife in an environmental education setting. TCM results provided significant statistical relationships between level of use and travel costs for the two types of trout fishing activities. CVM provided estimates of consumer surplus for the other four sites. The consumers' surplus value (1988 dollars) of all six activities to participants amounted to a total of more than $1.28 million annually—twice the total out-of-pocket expenditures of approximately $640,000 spent to visit the sites. The economic amenity values of the six activities compare favorably with similarly derived values in other studies for hunting, fishing, hiking, and backpacking in dispersed recreation environments and wilderness areas in western states.  相似文献   

20.
The effects of ozone air pollution on the agricultural sector are an important environmental challenge facing policy makers. Most studies of the economic impact of air pollution on agriculture have found that a 25% reduction in ambient ozone would provide benefits of at least $1–2 billion annually in the United States. This paper extends existing research by estimating the benefits of a reduction in emissions from a major source of ozone formation: motor-vehicle emissions. An agricultural production model is combined with an analysis of motor-vehicle emissions and air quality to estimate the impacts of emissions from six different motor-vehicle classes, at both the regional and national level. The benefits to the agricultural sector from completely eliminating ozone precursor emissions from motor vehicles ranges between $3·5 and $6·1 billion annually.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号