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1.
Environmental Modeling & Assessment - Dairy farms are systems with multiple dependent variables whose practices influence their economic and environmental performances. Decisions made and...  相似文献   

2.
胶州湾大型底栖动物的次级生产力   总被引:1,自引:0,他引:1  
基于国外大型底栖动物次级生产力的评估方法,结合国内研究现状,选取了3种Brey模型对胶州湾大型底栖动物的次级生产力进行估算,通过2015—2017年连续3个季度对胶州湾海域大型底栖动物的调查,最终结果表明:胶州湾大型底栖动物的次级生产力与其他海域相比具备较高的水平,次级生产力的季节性变化明显,其中夏季为最高;湾内高值区位于湾顶中部红岛以南到向西偏移至大沽河口和红石崖附近。分析发现历年来大型底栖动物群落的物种组成基本保持稳定,菲律宾蛤仔(Ruditapes philippinarum)资源的变化是造成次级生产力变化的最主要因素。研究推荐使用Brey(2012)模型来估算胶州湾大型底栖动物次级生产力,春、夏、秋季的估算结果分别为880.17、1 537.64、458.33 kJ/(m~2·a)。  相似文献   

3.
Well-known mathematical models related to blending problem are extended and adjusted to the specific blending problem in copper production. Certain constraints are deduced from the process of making copper as well as from the ecological aspects of the production process. The models are applied to the production experience at the copper-smelting plant RTB Bor. The implementation of introduced models was made in the programming package MATHEMATICA. Numerical results corresponding to the introduced mathematical model were compared with results obtained by implementing the classical mathematical models.  相似文献   

4.
Impact of Pollution Caused by Uranium Production on Soil Macrofauna   总被引:1,自引:0,他引:1  
Thirty years of mining and milling activities of the Priargunsky Mining-Chemical Production Company (South-Eastern Siberia, Russia) have resulted in an enrichment of uranium in adjacent steppe soils by a factor of up to 600. A number of attendant pollutants (thorium, arsenic and heavy metals) also have high concentrations in the soil. To estimate the effects of this pollution on soil-living macroinvertebrates, pitfall trapping and core sampling were applied. The element composition of four beetle species was analysed. Soil macroinvertebrates had 3–37 times lower abundance and biodiversity at the contaminated sites compared with the control. Ground beetle communities at the contaminated sites were reduced compared to the control site. The concentrations of uranium and arsenic in beetles collected at the contaminated sites were 2–41 and 2–26 times higher, respectively, than at the control site. There is strong evidence that the contamination caused by uranium production has severe negative biological effects on important groups of the soil food web.  相似文献   

5.
The U.S. Environmental Protection Agency has released a report entitled Condition of the Mid-Atlantic Estuaries. That report summarizes the findings of several studies conducted by federal and state agencies and academic institutions in Chesapeake Bay, Delaware Estuary, and the coastal bays of Delaware, Maryland, and Virginia, and simultaneously addresses two distinct audiences: environmental managers and the general public. This paper documents the process of preparing the Estuaries Report, emphasizing the lessons learned in merging information from a wide-variety of sources and in reporting the results to multiple audiences. The major difficulties in preparing the report included: 1) choosing a format and topics that adequately addressed both environmental managers and the public, 2) resolving spatial and temporal disparities in the assembled data sets, and 3) establishing threshold values that distinguished between acceptable and unacceptable conditions in indicators. Our solutions to these challenges and alternatives are discussed. We conclude that a small team of knowledgeable scientists can effectively merge the information of diverse sources into a document that is useful to both environmental managers and the interested public. However, considerable interaction between the team and other scientists was necessary to resolve ambiguities and assure relevancy and accuracy. These findings support the proposition that the vast sources of existing environmental information can be easily and effectively used to assess the ecological condition across large regions.  相似文献   

6.
The rates of oxygen production and respiration of the colonial zoanthid of the genus Palythoa were measured in situ at a depth of 3.4m (reef-edge) using an automated respirometer. The respirometer recorded changes in oxygen concentration of four samples of Palythoa enclosed in separate perspex chambers concurrently with light intensity (irradiance) readings every 20 seconds for 24 hours. Photosynthetic parameters (Pm(gross), Rd and Ik) were estimated from photosynthesis-irradiance (PI) curves generated for each of the four samples. Average instantaneous maximum gross photosynthetic (Pm(gross)) and respiration (Rd) rates obtained for Palythoa were 12.50µmo2l cm-2h-1 and - 4.24µmolO2cm-2h-1, giving a Pm(gross)/(-Rd) ratio of 2.92. The net 24 hour production (Pn24) at 3.4m, estimated by integrating the photokinetic parameters over 7 days of light data, was negative, resulting in a daily gross photosynthesis to respiration [Pg24/(-Rd24)] ratio of 0.77, while estimated 24 hour productivity at 1.4m gave a ratio of 1.13. This suggests that Palythoa would be able to sustain positive production at 1.4m but not at 3.4m.  相似文献   

7.
就新疆推进清洁生产的过程进行了回顾,并结合清洁生产的推进工作及现状进行了初步分析,找出了新疆推进清洁生产过程中存在的问题,提出了解决对策和方法。  相似文献   

8.
A hydrodynamic-oyster population dynamics model was developed to assess the effect of a change in ship channel configuration under different freshwater inflow regimes and different future hydrologies on oyster (Crassostrea virginica) populations in Galveston Bay, Texas. The population dynamics model includes the effects of environmental conditions, predators, and the oyster parasite Perkinsus marinus on oyster populations. The hydrodynamic model includes the effects of wind stress, river runoff, tides, and oceanic exchange on the circulation of the Bay. Simulations were run for low, mean, and high freshwater inflow conditions under the present (1993) hydrology and predicted hydrologies for 2024 and 2049 that include anticipated water diversion projects to satisfy the freshwater demands of population growth in metropolitan Houston, Texas. Simulation results show that oyster biomass was predicted to increase after enlargement of the ship channel. Oyster biomass is expected to increase on about 53% of total reef acreage when averaged over a 50-yr time span. Oyster reef acreage characterized by increased biomass after channel enlargement increases moderately under the present hydrology and the 2049 hydrology, but decreases slightly in 2024. Lower biomass in 2024 is due to reduced freshwater inflow and increased saltwater intrusion that pushes the optimal areas for oyster growth somewhat farther upbay than in 2049. Declines in oyster biomass, noted in most simulations in downbay reaches, were more than balanced by increased oyster biomass upbay. The differential between upbay and downbay reefs can be explained by an increase in mortality from Perkinsus marinus downbay and saltwater intrusion upbay that expands the area characterized by moderate salinities. The 20th century history of Galveston Bay is one of expansion of isohaline structure and increased oyster production as a result of anthropogenic modification of bay physiography. The salinity gradient of the 1990s, however, is not in equilibrium with the distribution of hard substrate required for oyster growth, that reflects an earlier equilibrium with the pre-1900s hydrodynamics. Increased saltwater intrusion is normally disadvantageous to oyster populations; but, in this case, channel enlargement further expands the salinity gradient upbay and outward (east and west) from the channel. As a result, in most years, oyster biomass is increased because moderate salinities cover more of the pre-1900s reef tracts where hard substrate is plentiful.  相似文献   

9.
Recent articles have investigated with integrated assessment models the possibility that climate damage bears on productivity (TFP) growth and not on production. Here, we compare the impact of these alternative representations of damage on the social cost of carbon (SCC). We ask whether damage on TFP growth leads to higher SCC than damage on production ceteris paribus. To make possible a controlled comparison, we introduce a measure of aggregate damage, or damage strength, based on welfare variations. With a simple climate-economy model, we compare three damage structures: quadratic damage on production, linear damage on growth and quadratic damage on growth. We show that when damage strength is the same, the ranking of SCC between a model with damage on production and a model with damage on TFP growth is not unequivocal. It depends on welfare parameters such as the utility discount rate or the elasticity of marginal social utility of consumption.  相似文献   

10.
Climate change has serious effects on the setting up and the operation of natural ecosystems. Small increase in temperature could cause rise in the amount of some species or potential disappearance of others. During our researches, the dispersion of the species and biomass production of a theoretical ecosystem were examined on the effect of the temperature–climate change. The answers of the ecosystems which are given to the climate change could be described by means of global climate modelling and dynamic vegetation models. The examination of the operation of the ecosystems is only possible in huge centres on supercomputers because of the number and the complexity of the calculation. The number of the calculation could be decreased to the level of a PC by considering the temperature and the reproduction during modelling a theoretical ecosystem, and several important theoretical questions could be answered.  相似文献   

11.
农村生活垃圾产生特征及分类收集模式   总被引:3,自引:0,他引:3  
以南京市高淳县的一个村为研究对象,依托新建的农村生活垃圾分类收集系统,对该区域生活垃圾的产生量、组成成分及其动态变化进行了调查研究,从垃圾分类收集模式的运行效果和经济可行性对其进行了分析。结果表明,该地区农村人均垃圾产生量为0.4 kg/d ,但随季节有一定的波动,这主要是由食品类消费的季节性变动而引起。垃圾组成以有机垃圾为主,约占55%,可回收垃圾、其他垃圾和有害垃圾所占比例分别为30.5%、14.2%和0.34%。通过认真的宣传和指导,村民在较短的时间内基本都可以做到正确分类;垃圾分类收集系统的户均建设成本为21元,运行费用比分类收集前每户每月增加3.2元 。  相似文献   

12.
阐述了清洁生产是可持续局长战略思想的具体体现,是实现可持续发展战略的必由之路。并提出了推行清洁生产的一些建议和设想。  相似文献   

13.
Around the Mediterranean basin, climate change is one of the major phenomena affecting agriculture. Therefore, the mode of production and crop management will have to change radically. Our objective in this article is to examine the long-run effects of climate change on date production in Tunisia using panel cointegration covering the period from 1980 to 2014 in 24 regions. The climate of Tunisia differs in our study because we find a Saharan climate in the south and a European climate in the north. The central regions are characterized by a Mediterranean climate. Our empirical results show that the effects of climate and weather variability on date production must be considered a serious threat in Tunisia. In addition, we estimate relatively negative and variable long-run effects of temperature increase and rainfall shortages across regions on date output over the last three decades.  相似文献   

14.
生产单元是企业内部环境风险防控的最小节点。生产企业内部存在风险节点数量繁多、属性差异大且互相存在联级放大效应等问题,使得企业环境风险一直存在较大的不确定性,给企业环境风险事故源头防控带来很大困难。传统的企业环境风险量化评估方法侧重整体的环境风险评估,精细度不足,缺乏对生产单元间相互影响等复杂情况的考量,评估结果准确性较低,且评估成本高、效率低。针对企业内部生产单元层级事故风险难以厘清的问题,梳理了上万条环境风险重点关注行业的历史环境事故,创新性地构建了考量“群发/链发”情况的事故情景与概率矩阵;考量企业生产单元与风险物质复杂属性、事故情景特性、周边扩散条件、环境风险受体等多维因素,集成设计了一套企业环境风险事故全过程模拟模型。通过从事故情景构建到事故损害结果分析的全链路自动化模拟,实现对企业生产单元环境风险的量化评估,达到精准识别企业内高风险节点,提升企业风险防控能力的目的;最后,研究通过对比真实历史环境事故调查结果,验证模型模拟具有较高准确性。  相似文献   

15.
借鉴欧盟、经济合作与发展组织、美国提出的固体废物加工产物属于产品需要满足的条件,结合《固体废物鉴别导则(试行)》中鉴别固体废物加工产物不属于固体废物而属于产品时最常用的因素,提出固体废物加工产物属于产品需要同时满足的3个条件,即符合国家、地方或行业通用的产品质量标准,符合国家污染控制标准,以及生产工艺过程和相应设施通过环境影响评价及建设项目竣工环境保护验收,为固体废物加工产物的固体废物监管和鉴别提供参考。  相似文献   

16.
基于清洁生产、产业生态学和循环经济等可持续发展理论,结合产业园区现有指标体系、评价标准和相关文献资料,通过评价指标频度统计分析,筛选出重点关注指标,经专家咨询补充完善相关指标,构建了产业园区清洁生产水平评价指标体系(包含7项一级指标和26项二级指标)。通过层次分析法确定了各项指标权重,参考已发布相关标准及研究成果,确定了指标评价标准。以苏州国家环保高新技术产业园为例,应用该指标体系评价其清洁生产水平,结果为合格,与实际情况相符。指出,该指标体系能够合理反映产业园区清洁生产水平,判断其是否建成清洁生产园区,并在园区层面提出清洁生产审核重点及改进建议,从而进一步发掘产业园区清洁生产潜力。  相似文献   

17.
企业生产环保投诉案件的环境监测有别于委托监测和“三同时”验收监测。以杭州市某企业生产环保投诉案件为例,从案件内容、监测前期准备、现场踏勘、监测重点、规范性与准确性要求等方面对企业生产环保投诉案件的环境监测进行阐述与分析,重点是掌握监测前后企业和敏感目标的环境情况,制定必要的监测工作流程和技术规范,为环境管理正确处理该类案件提供科学依据。  相似文献   

18.
Rising populations and incomes throughout the world have boosted meat demand by over 75% in the last 20years, intensifying pressures on production systems and the natural resources to which they are linked. As a growing proportion of global meat production is traded, the environmental impacts of production become increasingly separated from where the meat is consumed. In this paper, we quantify the use of three important resources associated with industrial livestock production and trade—water, land, and nitrogen—using a country-specific model that combines trade, agronomic, biogeochemical, and hydrological data. Our model focuses on pigs and chickens, as these animals are raised predominantly in intensive systems using concentrated, compound feeds. The results describe the geographical patterns of environmental resource use due to meat production, trade, and consumption. We show that US feed, animal, and meat destined for export require almost as much nitrogen and land, and 20% more water, than products destined for domestic consumption. Model results also demonstrate that among various production factors, improvements in crop yields and animal feed conversion efficiencies result in the most significant reductions in environmental harm. By explicitly tracking the externalities of meat production, we hope to bolster suppliers’ accountability and provide better information to meat consumers.
Kirsten OlesonEmail:
  相似文献   

19.
在遥感与地理信息系统技术支持下,以兵团2000、2005、2010年3期TM影像和HJ1A-CCD1影像为主要数据源,研究了兵团景观空间格局变化特征。结果表明,兵团景观类型从2000—2010年发生了较大变化,农田和城镇面积显著增加,草地、灌丛和冰川(永久积雪)显著减少。城镇景观受人为活动干扰强度最大。分析认为,人口和农业机械化是影响农田景观的主要驱动因素,经济发展和小城镇建设是影响城镇景观格局的主要因素,而政策导向是调节兵团景观格局变化的有效途径。  相似文献   

20.
The Sahelo-Sudanian region of Cameroon extends over 10 million hectares. Varied flora and soil types, a complex mosaic of vegetation and plant communities and a diversified wild animal population are the major natural resources of this region. Desertification in the region can be related to two major known causes: a. short or long-term drought due to short-term or long-term climatic trends toward aridity; b. human activities which degrade the biological environment. Globally, humans generally have less effect on desertification than climatic change in the short run. The only strategy to fight against this situation particularly in the developing countries is to withdraw populations from the areas and to settle them elsewhere. However, most local or regional desertification processes in general, and in the Sahelo-Sudanian region in particular, are due to the misuse or unsound exploitation of natural resources by humans and their animals. Often, comprehension of the complexity of even small interactions between parameters affecting our local environment remains limited. Poor economic assessments of the long-term benefits of proper natural resource conservation and management increase the extent of the exploitation, in turn increasing the degradation process. Yet ecologically sound management of natural resources integrating indigenous knowledge and basic population interest and concern can secure restoration in several areas and sustained productivity of Sahelo-Sudanian lands.  相似文献   

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