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1.
以石葵河生态河道治理为例,将工程扰动区划分为河道工程区(Q1)、临时施工道路区(Q2)、弃渣场区(Q3)、取土区(Q4)、临时表土堆场区(Q5)等5个分区。采用层次分析法和CVOR模型,构建山区河道整治工程扰动区植被恢复综合评价模型。结果表明:Q1区植被恢复潜力最强,生态健康等级为健康,属容易恢复区,Q4区、Q5区、Q2区生态健康等级为不健康,植被恢复潜力较弱,生态修复中须加大投资;植被恢复潜力与生态系统健康评价结果基本保持一致,基况条件对植被恢复潜力影响较大,可通过人工干扰提高扰动区植被恢复潜力,提升植被恢复效果。  相似文献   

2.
新疆北部沙漠边缘植被恢复可能性初探   总被引:2,自引:0,他引:2  
古尔班通古特沙漠边缘植被破坏严重,沙丘活化明显,是新疆干旱植被恢复的重点地区之一,一般缺乏地表水补充,其沙丘的水分状况便成为植被生存和恢复过程的关键条件,为探究古尔班通古特沙漠边缘植被恢复的可能性,在植物生长期内对流动沙丘和固定沙丘不同部位的水分状况进行了连续监测,结果表明:沙丘大多数层次含水量月变化与月降水量分布相一致;流动沙丘含水量从上部到下部依次升高;流动沙丘中部和下部稳定湿沙层处在距沙丘表面60 cm以下,且厚度超过100 cm,固定沙丘稳定湿沙层只存在于沙丘中部距沙丘表面60~150 cm内,其厚度不超过100 cm,在一般年份,该地区利用本地种进行植被恢复是可行的.  相似文献   

3.
采用归一化植被指数、景观多样性指数、景观均匀度指数等技术指标,评价那棱格勒河下游绿洲的生态环境现状。结果表明:那棱格勒河下游绿洲区主要为中植被覆盖(覆盖度30%~60%)区域,占绿洲区总面积的42.83%;低植被覆盖类型(覆盖度10%~30%)和高植被覆盖类型(覆盖度60%)次之。极低植被覆盖(覆盖度10%)区域最少,占绿洲区总面积的3.96%。稀疏草地和荒漠为该区域的优势景观,自然生产力等级低,生态系统受外界干扰后难以恢复,极易发生退化与沙化,系统的恢复稳定性与阻抗稳定性都较弱。  相似文献   

4.
基于遥感和像元二分模型的新疆植被覆盖度格局动态监测   总被引:1,自引:0,他引:1  
利用MODIS归一化植被指数(NDVI)资料反演了2006—2015年新疆植被覆盖状况,获取不同时期的植被覆盖度图,并进一步分析了植被覆盖度变化的原因。结果表明:新疆植被覆盖度呈现北部高于南部、西部高于东部的分布特征,其中西部和西北部的山地森林、草地以及天山北坡绿洲农作物、草地区域植被覆盖情况最好。过去10年间,新疆植被覆盖度总体呈上升趋势,2015年植被覆盖度达到最高,为16.68%。生态恢复工程、降水和气温等是影响植被覆盖度变化的主要因素。  相似文献   

5.
亢河流域是大巴山自然保护区的重要组成部分,亢河沿岸植被因城巫公路建设和居民伐薪等而受到强烈的干扰。为更有效地保护亢河流域植被及其生态系统的稳定性,通过样方和线路勘察的方法对亢河沿岸的植被现状进行调查,调查结果表明:该地区常见植物有23科32属53种,并有国家I级和2级保护植物;地带性植被类型为针阔叶混交林,共有植被型5个,群系7个;植被多样性的分布与人类干扰强度密切相关。为了从根本上解决对植被多样性的强干扰问题,除加强自然保护区的管理外,还应采取积极、科学的发展方式提高当地居民的生活水平.  相似文献   

6.
基于神东中心区植被覆盖变化的多时相遥感监测   总被引:1,自引:1,他引:0       下载免费PDF全文
准确、快速地获取植被覆盖信息是矿区生态恢复和建设的关键与重点。以神东中心区为研究对象,利用2002、2005、2007、2010、2012年Landsat TM/ETM+和HJ1A-CCD1五景同期遥感数据,采用像元二分模型法,归一化植被指数(NDVI)值反演植被覆盖度,对研究区生态环境变化规律进行分析。结果表明,神东中心区平均植被覆盖度整体呈上升趋势,区内绝大部分地表覆盖程度得到改善,改善区面积达64.01%,退化区面积只有15.34%。该方法快速、定量地反映矿区植被覆盖及变化情况,为矿区生态环境动态监测和治理提供技术支持。  相似文献   

7.
水生植被在湖库生态系统中发挥稳定沉积物、净化水质、平衡水生生态系统等作用,监测水生植被变化对湖库生态环境的监测具有重要意义。梳理了国内外利用高光谱、多光谱光学卫星遥感数据提取湖库水生植被的方法,尤其是针对其中涉及的阈值确定问题进行总结分析,介绍了典型研究区水生植被时空分布和变化以及与水质的关系,最后给出一些水生植被遥感监测的展望。  相似文献   

8.
利用多星遥感影像动态监测了2015年春季太湖北部湖湾沉水植被分布的变化过程,并对水生植被遥感监测中的几个关键问题展开了探讨。决策树方法获取的水生植被分布结果表明,2015年4月28日太湖北部湖湾发现明显沉水植被分布面积约11.2 km~2,与2014年同期相比,新出现的较大面积沉水植被分布区域主要集中在田鸡山西和锡东水厂附近。提出应及时清理打捞,避免水生植被死亡腐烂,威胁水质安全。  相似文献   

9.
通过对2011年常州地区各类植物VOC排放因子,以及各类植被分布面积等数据统计分析,采用BEIS模型为参考的估算方法,建立起常州地区植被VOC的排放清单。结果表明,植被所排放VOC的变化规律既与植物本身有关又与气温和太阳辐射有关,区域内年植被VOC的总排放量为1.13×104 t。  相似文献   

10.
利用MODIS数据建立近7年和静县NDVI时间序列,通过采用均值法、最大合成法和一元线性回归法,分析了该区不同植被类型年内变化、年际变化趋势.结果表明,和静县植被季相变化明显,不同植被类型变化幅度差异显著;近7年大部分地区植被存在退化趋势,局部区域植被有所改善;不同植被类型退化程度从大到小为荒漠草原>荒漠植被>草原>高山垫状植被>高寒草原>草甸 沼泽>落叶阔叶林>耕地;平原区植被NDVI的变化主要受人为活动的影响.山区植被NDVI除受季节性放牧影响外,更多的受气候变化的影响.  相似文献   

11.
研究了用超声波萃取城市污水处理厂污泥中动植物油和矿物油的方法,并与索氏提取法进行比较.结果表明,超声波萃取法对污泥中矿物油和动植物油测定操作简单快速,标样回收率高,精密度好.  相似文献   

12.
王斌 《中国环境监测》2016,32(5):116-119
免疫磁性微球(SMPPA)应用于水样中吲哚美辛的分离富集,并应用高效液相色谱法对吲哚美辛进行测定。在优化的淋洗和洗脱条件下,70%甲醇和10%甲醇分别作为洗脱液和淋洗液,其回收率能达到90%。选择了湖水、河水、自来水、污水厂进口水以及医院排水为真实样品进行测定,其中湖水、河水、自来水3种真实水样中未能检测出吲哚美辛,污水厂进口水以及医院排水中吲哚美辛的含量分别为0.762、35.4 ng/m L。对这5种水进行加标回收吲哚美辛,加标回收率为92.7%~113%,RSD为1.09%~7.73%。该方法具有简便、快速、特异性等特点,能有效地分离富集水样中的目标物,对其他目标物具有广泛的实际应用价值。  相似文献   

13.
Long-distance pipeline construction results in marked human disturbance of the regional ecosystem and brings into question the safety of pipeline construction with respect to the environment. Thus, the direct environmental impact and proper handling of such large projects have received much attention. The potential environmental effects, however, have not been fully addressed, particularly for large linear pipeline projects, and the threshold of such effects is unclear. In this study, two typical eco-fragile areas in western China, where large linear construction projects have been conducted, were chosen as the case study areas. Soil quality indices (SQI) and vegetation indices (VI), representing the most important potential effects, were used to analyze the scope of the effect of large pipeline construction on the surrounding environment. These two indices in different buffer zones along the pipeline were compared against the background values. The analysis resulted in three main findings. First, pipeline construction continues to influence the nearby eco-environment even after a 4-year recovery period. During this period, the effect on vegetation due to pipeline construction reaches 300 m beyond the working area, and is much larger in distance than the effect on soil, which is mainly confined to within 30 m either side of the pipeline, indicating that vegetation is more sensitive than soil to this type of human disturbance. However, the effect may not reach beyond 500 m from the pipeline. Second, the scope of the effect in terms of distance on vegetation may also be determined by the frequency of disturbance and the intensity of the pipeline construction. The greater the number of pipelines in an area, the higher the construction intensity and the more frequent the disturbance. Frequent disturbance may expand the effect on vegetation on both sides of the pipeline, but not on soil quality. Third, the construction may eliminate the stable, resident plant community. During the recovery period, the plant community in the work area of the pipeline is replaced by some species that are rare or uncommon in the resident plant community because of human disturbance, thereby increasing the plant diversity in the work area. In terms of plant succession, the duration of the recovery period has a direct effect on the composition and structure of the plant community. The findings provide a theoretical basis and scientific foundation for improving the environmental impact assessment (EIA) of oil and gas pipeline construction as it pertains to the desert steppe ecosystem, and provide a reference point for recovery and management of the eco-environment during the pipeline construction period.  相似文献   

14.
建立电子制冷预浓缩仪-气相色谱-质谱法测定空气中10种含硫化合物的方法。经考察不同采样容器、优化预处理条件、研究样品保存等获得了最佳实验条件,并通过实际样品的测定,考察了方法的适用性。结果表明:硫化氢、甲硫醇和乙硫醇3种高活性含硫化合物校准曲线线性回归系数在0.990以上,另外7种含硫化合物在0.995以上;高、中、低空白加标样品相对标准偏差均为9.5%以内,乙硫醇由于具有高活性和吸附性,低浓度空白加标回收率为63%,其余组分回收率范围为83%~110%;当进样体积为400 mL时,各目标化合物的方法检出限为0.2×10-3~1.1×10-3 mg/m3。分析污水处理厂无组织排放监控点的空气结果显示,该方法具有较低的检出限及较强的抗干扰能力,能较好地满足目前监测工作的要求。  相似文献   

15.
污水污泥是城市废水处理后的终端产物,既是一种生物质原料,可以被有效地资源化和能源化,同时又含有大量有毒有害物质,如何妥善地处理处置污水污泥,已成为全社会关注的课题。浅析了污水污泥的处理处置方法以及当前的研究热点和新技术。污泥处理处置的发展方向为减量化、稳定化,以及在无害化前提下的资源化、能源化。  相似文献   

16.
微库仑法测水样中可吸附有机卤素(AOX)受多种因素影响,其中溶解性有机碳(DOC)的影响非常显著。DOC对微库仑法2种前处理方法(双柱法和振荡法)的影响差异很大。双柱法受DOC影响较小,当DOC浓度小于1 000 mg/L时,AOX加标回收率范围为94.0%~104%。振荡法受DOC影响较明显,随着DOC浓度的升高,AOX回收率持续下降,当DOC浓度达到1 000 mg/L时,AOX加标回收率下降至72.1%,但DOC浓度小于100 mg/L时,AOX加标回收满足方法要求。进一步研究发现,DOC对振荡法的影响主要由于竞争吸附降低了活性炭对AOX的吸附容量,而非吸附速率,虽然增大活性炭用量可在一定程度上减小DOC对AOX测定的影响,但对样品进行稀释是减少DOC影响的最简单高效的办法。同时,DOC对不同类型的有机卤代物影响不同,有机溴受DOC影响程度小于有机氯。  相似文献   

17.
高锰酸盐指数分析一般不进行加标回收实验,因为加标回收率的实施对一个综合指标来说不易找到现成的标准物质,且容量法做加标回收存在一定困难,为加强高锰酸盐指数分析时准确度的控制,文章在加标回收率的测定方面做了积极的探索。  相似文献   

18.
Some health important enteric viruses are considered to be emerging waterborne pathogens and so the improvement of detection of these viruses in the aquatic environment is one of the most important steps in dealing with these pathogens. Since these viruses may be present in low numbers in water, it is necessary to concentrate water samples before viral detection. Although there are several methods to concentrate viruses in environmental waters, all present some drawbacks and consequently the method should be chosen that, despite its limitations, is adequate to achieve the aim of each study. As the effectiveness of the concentration methods is evaluated by determining the efficiency of viral recovery after concentration, it is important to use a simple and effective approach to evaluate their recovery efficiency. In this work ultracentrifugation, usually used as a secondary step for virus concentration, was evaluated as the main method to concentrate directly viruses in environmental water samples, using the microscopic enumeration of virus-like particles (VLP) as a new approach to estimate the efficiency of recovery. As the flocculation method is currently employed to concentrate viruses in environmental waters, it was also used in this study to assess the efficiency of the ultracentrifugation as the main viral concentration method in environmental waters. The results of this study indicate that ultracentrifugation is an adequate approach to concentrate viruses directly from environmental waters (recovery percentages between 66 and 72% in wastewaters and between 66 and 76% in recreational waters) and that the determination of VLP by epifluorescence microscopy is a simple, fast and cheap alternative approach to determine the recovery efficiency of the viral concentration methods.  相似文献   

19.
A recently developed method for the determination of arsenic species (arsenite, arsenate, monomethylarsonate, MMAA, and dimethylarsinate, DMAA) has been applied to the study of arsenic speciation in plants. This method uses ion-exchange liquid chromatography coupled on-line to atomic fluorescence spectrometry through continuous hydride generation. Various extraction procedures have been studied in detail using three plant certified reference materials. None of the procedures tested revealed fully satisfying results with all kinds of plant samples; microwave assisted extraction with 0.3 mol dm-3 orthophosphoric acid was found to be the most convenient for dealing with terrestrial plants. Species stability appears good. This method was applied to real world cultivated plant parts. Arsenate appears to predominate in soils, roots and leaves; unidentified species (probably arsenosugars) play an important role (60%) in rice fruits. Carrot was found to be the most contaminated edible plant part, containing 1 mg kg-1 essentially as arsenate species. MMAA was detected in all soils and some plant parts especially shallots at low levels, whereas DMAA was found only in one soil sample and in hot pepper leaves. Arsenite is a minor component of all soils; it is also present in some plant parts at low levels. However, no evident relationships were found between As speciation in the various plant parts and much more detailed studies will be necessary to elucidate As behaviour in plants.  相似文献   

20.
A procedure using pre-column trimethylsilyl derivatization and gas chromatography/ mass spectrometry (GC/MS) was developed and applied in determining trace estrogens in complex matrix. Main conditions were optimized, including pH value, salinity of water sample, elution reagents, clean procedure, derivative solvent and temperature. The optimized method was used to determine steroid estrogens in surface water and effluents of wastewater treatment plant (WWTP). Low detection limits of 0.01, 0.03, 0.03, 0.07, 0.09 and 0.13 ng/l for DES, E1, E2, EE2, E3 and E(V), respectively were obtained under optimism condition. No apparent interferences appeared in chromatography in comparison with ultrapure water blank. Mean recovery ranged from 72.6% to 111.0% with relative standard deviation of 1.1-4.6% for spiked surface water, and from 66.6% to 121.1% with relative standard deviation of 1.5-4.7% for spiked effluent of WWTP. The results suggested that the optimized method provides a robust solution for the determination of trace steroid estrogens in complex matrix.  相似文献   

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