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751.
基于Landsat土地利用类型分类资料、夜间灯光影像资料、自动气象站资料以及大气边界层探测资料,划分出城市、郊区以及湖区代表站,分析了苏州2015年1月城市热岛日变化、昼夜差异特征以及城、湖温度差日变化特征,并对苏州城市热岛分布特征以及城、湖大气边界层结构差异进行分析。结果显示:(1)白天热岛强度小,09~17时热岛强度均小于1℃,最小值仅为02℃;夜间热岛强度大,19~05时热岛强度维持在12℃以上,最大值为17℃。(2)城、湖温差白天为正,夜间为负,市区变温速率比湖区快约02℃/h。(3) 苏州白天热中心形状不规则,范围大,城郊温差小,夜间形成单一封闭稳定热中心,热中心形状与市区有较好对应,城、郊温差维持在15℃左右。冬季地面盛行西北风,太湖湖陆风现象显著,湖陆风和盛行风向共同影响城市热羽向西南方向发展。(4)城、湖虚位温廓线在白天差异小,均有不稳定边界层形成,夜间市区仍维持不稳定边界层,而湖区有稳定边界层发展,近地层内干岛效应显著。(5)城市热岛影响范围有明显日变化特征,白天城市热岛影响范围小于40 m,夜间大于200 m。 相似文献
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选取典型工业区,汇总了恶臭污染的突发性、排放不规律、夜间高值显著等特征,分析了由化学特性、物质种类和监控要求等带来的恶臭污染监测难点。根据信访投诉、地理特点和大气扩散规律,提出构建工业区恶臭污染自动监控体系。在恶臭污染排放特征分析基础上,筛选优控污染物,优选适用在线监测技术,建设边界监控为主、园区监测为辅的专业化、自动化大气特征污染监测系统,通过统一联网和平台,统一质控和规范,建立预警监测信息平台。在实际构建与应用的过程中,探索了分级管理、多方合作的运行机制,为工业区恶臭污染分析评估、污染溯源和控制提供了技术支持。 相似文献
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Hanzhong Jia Yafang Shi Xiaofeng Nie Song Zhao Tiecheng Wang Virender K. Sharma 《Frontiers of Environmental Science & Engineering》2020,14(4):73
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基于2017—2019年上海市环境检验检测行业资源统计数据,分析了第三方环境检测机构的发展现状及细分领域的营收情况,发现了以大气环境、土壤环境和污染源检测为增长热点等特征。基于对机构改革与市场准入情况、行业集中度与市场竞争关系、机构规模与营收关系等方面的分析,提出第三方环境检测领域存在着诚信机制缺位、机构资质能力薄弱、管理体系运行乏力等风险,提出了提升质量管理和资质建设两大核心竞争力、掌握行业监管动向和重点、参与行业协会建设构建诚信自治模式等对策。 相似文献
758.
在自动扶梯(人行道)的检验过程中,关于安全距离和尺寸的测量项目众多,特别是针对防夹装置、防护挡板以及扶手带周围距离等项目的检验,烦琐复杂且费时费力.本文简要讨论了国内自动扶梯典型事故、自动扶梯(人行道)安全距离和尺寸的检验难点以及目前市场上的解决方案,开发出专用工具箱,从而有效提高检验准确率和效率. 相似文献
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Effects of Land Use Changes on the Ecosystem Service Values of a Reclamation Farm in Northeast China 总被引:3,自引:0,他引:3
Fanghua Hao Xuehui Lai Wei Ouyang Yiming Xu Xinfeng Wei Kaiyu Song 《Environmental management》2012,50(5):888-899
Intensive agricultural development can change land use, which can further affect regional ecosystem services and functions. With the rapid growth of the population and the national demand for food, the northeast of China, which is located in the high latitudes, has experienced four agricultural developments since the 1950s. The original wetlands of this area were developed for farmland. The evaluation of ecosystem services is conducted to reveal the ecosystem status and variable trends caused by land reclamation. The aim of this study is to provide scientific basis for environmental management and for the sustainable development of agriculture in Northeast China. With GIS-RS technology, a typical farm was chosen to analyze variations in the ecosystem service value in response to land use changes during the study period. The total ecosystem service value of the farm decreased from 7523.10 million Yuan in 1979 to 4023.59 million Yuan in 2009 with an annual rate of ?1.6?% due to the decreasing areas of woodland and wetland. The increased areas of cropland, water area and grassland partly offset the loss of the total value, but the loss was still greater than the compensation. Waste treatment and climate regulation were the top two service functions with high service values, contributing to approximately 50?% of the total service value. The spatial difference of the ecosystem service value also was analyzed. The wetlands located in the central and northeastern sections of the farm changed significantly. From the aspect of ecosystem service value, the wetland and water area should be conserved, as they have the highest value coefficients. The accuracy of the value coefficient, however, needs to be studied further in future research. 相似文献
760.
The extensive reclamation of marshland into cropland has tremendously impacted the ecological environment of the Sanjiang Plain in northeast China. To understand the impacts of marshland reclamation and restoration on soil properties, we investigated the labile organic carbon fractions and the soil enzyme activities in an undisturbed marshland, a cultivated marshland and three marshlands that had been restored for 3, 6 and 12?years. Soil samples collected from the different management systems at a depth of 0-20?cm in July 2009 were analyzed for soil organic carbon (SOC), dissolved organic carbon (DOC), microbial biomass carbon (MBC) and easily degradable organic carbon. In addition, the activities of the invertase, β-glucosidase, urease and acid phosphatase were determined. These enzymes are involved in C, N and P cycling, respectively. Long-term cultivation resulted in decreased SOC, DOC, MBC, microbial quotient and C (invertase, β-glucosidase) and N-transforming (urease) enzyme activities compared with undisturbed marshland. After marshland restoration, the MBC and DOC concentrations and the soil invertase, β-glucosidase and urease activities increased. Soil DOC and MBC concentrations are probably the main factors responsible for the different invertase, β-glucosidase and urease activities. In addition, marshland restoration caused a significant increase in the microbial quotient, which reflects enhanced efficiency of organic substrate use by microbial biomass. Our observations demonstrated that soil quality recovered following marshland restoration. DOC, MBC and invertase, β-glucosidase and urease activities were sensitive for discriminating soil ecosystems under the different types of land use. Thus, these parameters should be considered to be indicators for detecting changes in soil quality and environmental impacts in marshlands. 相似文献