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1.
本文以陕北安塞纸坊沟为例,阐述了地块的概念和在地块尺度基础上,研究土地可持续利用的意义。从农业技术因子出发,在地块尺度上评价土地可持续利用发展,强调了人类认识程度、利用因素以及农业技术因子的重要性。从生态的角度,评价地块的土地自然适宜性,与土地利用现状结合评价土地的人为利用适宜性。从生态和经济效益评价两方面进行地块尺度土地可持续性发展评价,并初步建立了评价方法与模型  相似文献   

2.
将海岸带复合生态系统作为一个整体,充分考虑海岸带生态风险形成机制和生态环境保护要求,识别影响海岸带生态安全的主要因素。基于驱动力-压力-状态-影响-响应(DPSIR)模型,将海岸带生态安全归纳为驱动力、压力、状态、影响、响应5个准则层,选取26个能够反映生态安全状况的因子来构建海岸带生态安全评价指标体系。对粤港澳大湾区惠州岸段两个沿海县(区)2007、2010、2013、2015、2016年的海岸带生态安全状况进行评价分析,结果表明:(1)惠东县这5年海岸带生态安全等级分别为预警(Ⅲ)、较安全(Ⅱ)、较危险(Ⅳ)、较安全(Ⅱ)、较安全(Ⅱ);大亚湾区海岸带生态安全等级分别为预警(Ⅲ)、预警(Ⅲ)、预警(Ⅲ)、较安全(Ⅱ)、较安全(Ⅱ)。(2)"十二五"规划所采取的环境保护和生态建设措施对惠州海岸带生态环境的改善发挥了重要作用。海岸带生态安全状况于2013年有明显恶化,说明生态环境保护应对措施及力度仍不足以抵消这一时期持续增加的生态环境压力,同时,海岸带生态环境对于响应措施的反应具有一定程度的滞后性。(3)影响惠州海岸带生态安全的主要原因有工业的发展及污染物排放、人类活动密集及人类对海洋区域的大规模开发利用、政府响应措施实施力度、自然和人为原因所造成的海洋灾害和损失。  相似文献   

3.
自然灾害、城镇扩展及人类活动干扰在很大程度上影响着海岸带生态安全。归纳了国内外海岸带生态安全的研究热点,国内主要集中在生态安全管理、评估、格局规划3个方面,国外学者侧重于研究海岸带综合管理、环境演化及灾害预测、生态系统健康评价、风险评价等方面。生态安全评估是实施生态环境管理与保护行动的基础工作,但国内外现有研究中对海岸带生态安全的评估还没有统一的标准。针对海岸带生态安全的特点,对比相关概念模型、评价方法的优缺点,采用指标重要值的方法确定了海岸带生态安全评估指标的重要性程度。最后,基于"驱动力—压力—状态—响应"概念框架模型,提出海岸带生态安全评估的指标体系框架,以期为海岸带生态安全评估提供参考。  相似文献   

4.
中国一些城市正大力推动低效工业用地减量化复垦工作,部分地块复垦后实施农业利用,但针对工业用地复垦的相关环境监管体系尚未建立,存在一定农产品质量安全风险。为给国内低效工业用地复垦土地的污染风险管控工作提供有益借鉴,分析总结了北美地区废弃工业场地复垦土地土壤环境质量等级划分标准、复垦风险分级管控流程与方法,以及暴露途径安全阻控措施、低成本生态修复措施、选种低累积型农产品等最佳管理实践。结合中国低效工业用地减量化工作实际情况,提出制定本地化复垦土地土壤环境质量分级标准,研发轻、中度污染土壤生态修复技术,研究构建复垦土地全生命周期风险管控体系等对策建议。  相似文献   

5.
参考国家相关指南并结合南京市实际,以区级行政区为评价单元对南京市进行资源环境承载力评价。基于预警视角从资源、环境、生态等维度选取典型指标构建评价指标体系,分别进行针对资源、环境与生态的基础评价和针对农产品主产区的专项评价。采取"短板效应",结合基础、专项评价结果进行南京市资源环境承载力集成评价,为南京市资源环境承载力评价预警工作提供基础数据支撑,并从水资源、土地资源、大气环境、水环境、生态系统等方面进行超载因子识别与分析,提出相应的管控对策建议。  相似文献   

6.
京津冀地区生态环境保护一体化是推动京津冀协同发展的重要保障.基于DPSIR模型和障碍度模型对北京市 、天津市和河北省进行了生态安全评价和障碍因子诊断.结果显示:(1)2008—2017年,京津冀地区的生态安全水平整体呈现向好的趋势;(2)北京市影响生态安全的主要障碍因子为国内生产总值增长率、SO2排放量和每万人拥有公共...  相似文献   

7.
水资源可持续利用评价是水资源可持续管理的重要手段。在分析水资源生态足迹和生态承载力时空变化的基础上,结合水资源生态足迹指标,以压力-状态-响应(PSR)模型为框架构建了水资源可持续利用评价指标体系,运用熵权法和综合指数法对四川省2010—2019年水资源利用水平进行综合评价。结果表明:2010—2019年,四川省人均水资源生态承载力呈“W”型变化,人均水资源生态盈余在时间上呈波动变化,空间上存在明显差异,呈西高东低分布。综合评价中压力指数、状态指数、响应指数分别呈下降、上升、上升趋势,综合评价指数在2015年最低(0.109 6),2019年最高(0.212 1)。研究显示,四川省水资源可持续利用状况有所改善,仍需提高生产、生活、生态环境用水账户的用水效率,进一步推进水资源可持续利用。  相似文献   

8.
提出了评价对象、评价目标和评价方法三位一体的城镇生态承载力综合评价方法,构建了递阶多层生态承载力评价指标体系和面向应用对象的、融合多指标评语信息的生态承载力综合评价模型.以浙江省义乌市为例,对2000-2007年义乌市的生态承载力状况进行了评价与分析.结果表明,义乌市2000 2007年的生态承载力得分在60~70分,且呈逐年增加的趋势,说明其承载力状况良好;各支持力要素中,环境支持力得分一般,虽然随时间呈现一定波动但基本保持不变.资源支持力得分最差,人类支持力得分最高,且随时间逐年增加.结合研究区域实际情况对其生态承载力影响因素进行了剖析,并提出了生态承载力提高措施,为其可持续发展提供理论指导.  相似文献   

9.
模糊综合评价法在矿区塌陷土地复垦潜力评估中的应用   总被引:6,自引:0,他引:6  
为了合理利用土地、提高土地生产率、改善矿区及其周围的生态环境,对矿区塌陷土地复垦潜力进行了研究。阐述了模糊综合评价法的基本原理,并以南票矿区为例,选择了塌陷土地复垦潜力评价的二层树状结构因子,确定了隶属度函数、评价指标权重和评价集,得出了塌陷土地复垦潜力的评价结果。为其他矿区塌陷土地复垦潜力评价提供了理论依据。  相似文献   

10.
工业城市污染土壤评估技术应用研究   总被引:3,自引:0,他引:3  
利用生态毒理指标与传统化学指标相结合的方法,对沈阳市部分潜在污染企业进行了凋查与评估,并根据土地再利用要求进行初步分级。结果表明,大多数潜在场地的土壤污染状况都比较严重,必须修复后才能再利用。此外,生态毒性测试结果与环境质量现状评价结果并非完全相一致,说明了把生态毒理指标与化学指标结合起来,衡量土壤污染程度的方法是比较科学的。  相似文献   

11.
Concentrations of different chlorinated compounds were measured in mussels incubated in two polluted watercourses, a river (the River Kymijoki) and a lake (Lake Vanaja) for four weeks in summer 1995. The sum concentrations of polychlorinated phenols (PCP) and biphenyls (PCB) were both about 1 μg/g lipid weight (lw) in Lake Vanaja mussels, while in the River Kymijoki mussels PCPs were non-detectable and PCBs were measured 120 ng/g lIw. The concentrations of toxic polychlorinated dibenzo-p-dioxin (PCDD) and dibenzofuran (PCDF) congeners ranged between <17 and 370 pg/g Iw in Lake Vanaja mussels and between <38 and 11,000 pg/g lw in the River Kymijoki mussels. Polychlorinated diphenyl ethers (PCDE) were detected in the mussels incubated in the River Kymijoki (0.4–1.1 ng/g Iw), but not in those incubated in Lake Vanaja. Polychlorinated phenoxyanisoles (PCPA) were measured 33 ng/g lw and polychlorinated phenoxyphenols (PCPP) 300 ng/g lw in the mussels incubated in the River Kymijoki. PCPAs were also detected in reference samples, which were sediment and pike from the River Kymijoki and Baltic salmon, seal and white-tailed sea eagle.  相似文献   

12.
Book review     
The Pesticide Manual ‐ A World Compendium, 8th Edition, C.R. Worthing, Editor and S.B. Walker, Assistant Editor, British Crop Protection Council, BCPC Publications Sales, Bear Farm, Binfield, Bracknell, Berkshire RG12 5QE, England. 1987, 1100 pp., UK £50; Overseas £56. ISBN 0–948404–01–9.  相似文献   

13.
Organochlorine compounds in a three-step terrestrial food chain   总被引:1,自引:0,他引:1  
The concentrations of 15 organochlorine chemicals (PCBs and pesticides) were studied in a Central European oak wood food chain system: Great tit (Parus major), caterpillars (Tortrix viridana, Operophtera brumata, Erannis defoliaria), and oak-leaves (Quercus robur). Juvenile tits receive organochlorines from the mother via egg transfer and, eventually to a greater extent, from the caterpillar food source during nestling period. The concentrations of PCB 153 (2,2′,4,4′,5,5′-hexachlorobiphenyl, the most abundant in this study) was found in leaf material at ca. 1 ng/g, in caterpillars 10 ng/g, and in bird eggs 170 ng/g on an average and on a dry mass basis.  相似文献   

14.
Abstract

The active ingredients in commercial formulations of malathion, oxamyl, carbaryl, diazinon, and chlorpyrifos diluted to “spray tank”; concentrations with buffered distilled or natural water of pH 4–9 were stable for at least 24 hr. Formulations of trichlorfon were not stable at pH 7 or above but disappearance rates were slower than for the pure chemical in homogeneous solution. Cupric ion was observed to be an effective catalyst for the hydrolysis of a variety of pure organophosphorus insecticides but did not catalyze hydrolysis of the active ingredients of the formulations examined. Increasing the dilution of the formulation increased the susceptibility of malathion, oxamyl, and carbaryl to hydrolysis.  相似文献   

15.
Abstract

One of the dominant tree species growing within and around the eastern portion of Los Alamos National Laboratory (LANL), Los Alamos, NM, lands is the pinon pine (Pinus edulis). Pinon pine is used for firewood, fence posts, and building materials and is a source of nuts for food—the seeds are consumed by a wide variety of animals and are also gathered by people in the area and eaten raw or roasted. This study investigated the (1) concentration of 3H, 137Cs, 90Sr, totU, 238Pu, 239, 240Pu, and241 Am in soils (0‐ to 12‐in. [31 cm] depth underneath the tree), pinon pine shoots (PPS), and pinon pine nuts (PPN) collected from LANL lands and regional background (BG) locations, (2) committed effective dose equivalent (CEDE) from the ingestion of nuts, and (3) soil to PPS to PPN concentration ratios (CRs). Most radionuclides, with the exception of 3H in soils, were not significantly higher (p < 0.10) in soils, PPS, and PPN collected from LANL as compared to BG locations, and concentrations of most radionuclides in PPN from LANL have decreased over time. The maximum net CEDE (the CEDE plus two sigma minus BG) at the most conservative ingestion rate (10 lb [4.5 kg]) was 0.0018 mrem (0.018 μSv); this is far below the International Commission on Radiological Protection (all pathway) permissible dose limit of 100 mrem (1000 μSv). Soil‐to‐nut CRs for most radionuclides were within the range of default values in the literature for common fruits and vegetables.  相似文献   

16.
Degradation and sorption/desorption are important processes affecting the leaching of pesticides through soil. This research characterized the degradation and sorption of imidacloprid (1-[(6-chloro-3-pyridinyl)-methyl]-N-nitro-2-imidazolidinimine) in Drummer (silty clay loam) and Exeter (sandy loam) surface soils and their corresponding subsurface soils using sequential extraction methods over 400 days. By the end of the incubation, approximately 55% of imidacloprid applied at a rate of 1.0 mg kg?1 degraded in the Exeter sandy loam surface and subsurface soils, compared to 40% of applied imidacloprid within 300 days in Drummer surface and subsurface soils. At the 0.1 mg kg?1 application rate, dissipation was slower for all four soils. Water-extractable imidacloprid in Exeter surface soil decreased from 98% of applied at day 1 to > 70% of the imidacloprid remaining after 400 d, as compared to 55% in the Drummer surface soil at day 1 and 12% at day 400. These data suggest that imidacloprid was bioavailable to degrading soil microorganisms and sorption/desorption was not the limiting factor for biodegradation. In subsurface soils > 40% of 14C-benzoic acid was mineralized over 21 days, demonstrating an active microbial community. In contrast, cumulative 14CO2 was less than 1.5% of applied 14C-imidacloprid in all soils over 400 d. Qualitative differences in the microbial communities appear to limit the degradation of imidacloprid in the subsurface soils.  相似文献   

17.
Abstract

Five organophosphorous insecticides: Leptophos, EPN, Cyano‐fenphos, trichloronate and salithion proved to cause irreversible ataxia not only to chicken but also to mice and sheep. TOCP was included as a reference. Cyanofenphos blocked the catecholamine B‐receptor binding activity with 3H‐norepinephrine at a level similar to that of the specific inhibitor propranolol in the mouse heart preparation. In the lamb heart preparation, the B‐receptor was more sensitive to Leptophos, salithion and TOCP than to propranolol. The six compounds and their oxons were screened for their in‐vitro inhibition to monamine oxidase (MAO), acetyl cholinesterase (AChE) and neurotoxic esterase (NTE) in the brain of either mouse, lamb or chicken. It is believed that their AChE inhibition stands for their acute toxicity, while NTE inhibition is responsible for their paralytic ataxia.  相似文献   

18.
土壤中砷的化学平衡   总被引:2,自引:0,他引:2  
本文比较详细地综述了砷的化学特性,环境背景值及来源和循环,土壤中砷的三大化学平衡即沉淀溶解平衡,氧化还原平衡,吸附解吸平衡,以及微生物对砷的转化。  相似文献   

19.
The total concentration of toxic elements (aluminum, cadmium, chromium and lead) and selected macro and micro elements (iron, manganese, copper and zinc) are reported in six leafy edible vegetation species, namely lettuce, spinach, cabbage, chards and green and red types of Amaranth herbs. Although spinach and chards had greater than 125 mv of iron, both the amaranthus herbs recorded > than 320 μ g g? 1 dry weight. In both the spinach and chard species, the Mn and Zn levels were appreciable recording > 225 μ g g? 1 and 150 μ g g? 1 dry weight, respectively. Aluminum concentrations were (in μ g g? 1 dry weight) lettuce (10), cabbage (11), spinach (167), chards (65), amaranthus green (293) and amaranthus red (233). All the micro and macro elements and the toxic elements (Ni, Cr, Cd and Pb) elements analyzed, were below the recommended maximum permitted levels (RMI) in vegetables. Further the elemental uptake and distribution of the nine elements, at three growth stages of the lettuce plant grown on soil bed under controlled conditions are detailed. In the soil, except for iron (16%), greater than 33% of the other cations were in exchangeable form. Generally in the lettuce plant, roots retained much of the iron (> 224 μ g g? 1) and aluminum (> 360 μ g g? 1), while leaves had less than 200 μ g g? 1 of iron and 165 μ g g? 1 of Al. Although the concentrations of elements marginally decreased with growth, the lettuce leaves had significant amounts of Mn (30 μ g g? 1), Zn (50 μ g g? 1) and Cu (3.6 μ g g? 1). Some presence of lead in leaves (2.0 μ g g? 1) was noticed, but all the toxic and other elements analyzed were well below the RMI values for the vegetables.  相似文献   

20.
Abstract

The dissipation of 1.0 ppm nonylphenol in stream and pond water, incubated in flasks at 16°C under simulated field conditions up to 44 days indicated that the half‐life was 2.5 days if the flasks were open, and 16 days if they were closed. A transformed product was detected in the closed flasks.

Translocation of nonylphenol in water occurred when treated water samples were incubated in the presence of sediment. After 10 days, nonylphenol was detected only in the sediment, but not in water (detection limit = 10 ppb). About 80% of the nonylphenol was degraded in 71 days, but no degradation occurred if the water and the sediment were autoclaved prior to incubation.  相似文献   

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