湖南省雷电特征及闪电数据分析

湖南是雷暴多发区,雷暴分布是南多北少,西多东少。近35年地面雷暴观测数据显示,全省年平均雷暴数呈下降趋势。湖南闪电以负地闪为主,占总地闪的94．59％,平均闪电强度随着海拔高度的增加而加大,长沙、韶山为闪电强度低值中心。一天中13～20时是闪电高发期,正地闪的平均能量要大于负地闪。     

Assessment of the red-crowned crane habitat in the Yellow River Delta Nature Reserve, East China

As wildlife habitat is in constant evolution, periodic monitoring is essential to assess its quality. In this study, the change to the red-crowned crane habitat in the Yellow River Delta Nature Reserve was detected from multi-temporal remote sensing data from 1992 to 2008 in a geographic information system. Habitat fragmentation was derived from both physical constraints and human disturbance. The changing habitat quality was assessed against five landscape indices. The results obtained from Landsat TM images indicate that potential habitat shrank 37.9 % during 1992–2001, but recovered 99.4 % by 2008. Suitable habitat shrank by 4,329 ha to a level below that of 1992 despite an increase of 4,747 ha in potential habitat due to an increase of 9,075 ha in fragmented areas. Both landscape indices and the red-crowned crane population reveal that suitable habitat was the most fragmented in 2001, but the least fragmented in 1992. Therefore, it is inadequate to just restore wetland through artificial diversion of channel flow to the Reserve to preserve the crane habitat. Commensurate efforts should also be directed at improving habitat quality by minimizing human activities and spatially juxtaposing water and reed marshes harmoniously inside the Reserve.     

Opportunities and challenges for development of urbanization in Western China

Urban and rural dual structure in Western China is obvious.The economic development of the central cities is relatively quick while that of the rural areas is lagging behind.The speeding up of urbanization contributes to the intensively uncoordinated development of urban and rural areas.Besides,the eco-fragile environment,shortage of available water resources,adverse geographic location,and relatively backward social economy restrict the development of urbanization in Western China.However,Western China also has the advantages of backwardness.This paper analyzes the present situation and development trend of urbanization in Western China.The results show that Western China has basically formed a development pattern with"industry promotes agriculture and urban leads to village".Therefore,combined with the present situation of Western China,this paper describes and analyzes the opportunities and challenges that may appear in the process of urbanization in Western China,puts forward the development pattern in which urban and rural areas can gain mutual support and co-development,and provides related recommendations.     

Restorating marine coastal ecosystem health as a new goad for integrated catchment management in Tolo Harbour,Hong Kong,China

Abstract

The paper demonstrates why it is necessary to take the restoration of marine coastal ecosystem health as a new goal for integrated catchment management, in coastal area of the Tolo Harbour. The present goal of integrated catchment management (ICM) in the Tolo Harbour is to meet with Water Quality Objectives. The performance of an ICM plan, Tolo Harbour Action Plan (THAP), is evaluated by using marine coastal ecosystem health indicators including stress indicators and responses indicators. Since the implementation of THAP in 1988, some significant reduction in pollution loading has been observed—reduction of 83% of BOD load and 82% of TN between 1988 and 1999. There has been an improvement in the health state of Tolo Harbour marine coastal ecosystem as evidenced in the trends of the physical, chemical and biological indicators, although some reverse fluctuations in some periods exist. However, this can only be considered as the first sign of the ecosystem health restoration, since ecosystem health covers not only physical, chemical and biological aspects of an ecosystem, but also ecosystem-service-function aspect. It is recommended to take the restoration and protection of marine coastal ecosystem health as a new goal, instead of water quality objective management, for integrated catchment management in Tolo Harbour catchment. Steps to further improve the marine coastal ecosystem health of Tolo harbour are discussed in the paper.     

A Methodology Framework for Regional Land-use Change Studies based on Landsat TM images: A Case Study in Northeast China

Abstract

Land-use change is an important aspect of global environment change. It is, in a sense, the direct result of human activities influencing our physical environment. This paper analyzed the land- use change in Northeast China during 1985–2000 based on Landsat TM images. It divides Northeast China into five land-use zones based on the dynamic degree model of land-use: woodland/grassland-arable land conversion zone, dry land-paddy field conversion zone; urban expansion zone, interlocked zone of farming and pasturing and reclamation and abandon zone. The findings include the obvious increase of cropland area, paddy field and dry land increased by 75 and 276 thousand hm² respectively; urban areas expanded rapidly, areas of town and rural residence increased by 76.8 thousand hm²; areas of forests and grassland decreased sharply with the amounts of 1399 and 1521 thousand hm² respectively; areas of water body and unused land increased by 148 and 514 thousand hm² respectively. This paper also discusses the driving forces in each land-use dynamic zone and finds that some key biophysical factors affect conspicuously the conversion of different land-use types. The relation between land-use conversion and DEM, accumulated temperature (≤10°C) and precipitation was analyzed and represented. The land-use changes In Northeast China resulted from the changing macro social and economic factors and local physical elements. Rapid population growth and management changes can explain the shaping of woodland/grassland-cropland conversion zone. The conversion from dry land to paddy field in the dry land-paddy field conversion zone, apart from the change of physical elements promoting the expansion of paddy field, results from two reasons: one is that the implementation of market economy in China has given farmers the right to decide what and how they plant their crops, the other factor is originated partially from the change of the dietary habit along with the social and economic development. The conversion from paddy field to dry land is caused primarily by the shortfall of irrigation water, which in turn is caused by poor water allocation managed by local governments. The shaping of the reclamation and abandon zone is partially due to the lack of environment protection consciousness among pioneer settlers. The reason for the conversion from grassland to cropland is the relatively higher profits of farming than that of pasturing in the interlocked zone of farming and pasturing. In Northeast China, the rapid expansion of built-up areas results from two factors: the existence of a small number of towns and the huge potential for expansion of the existing towns and cities. The urban land expanded mainly in areas with a gentle topographic relief and low population density.     

中国西部城镇化可持续发展路径的探讨

基于对中国西部地区城镇化进程的调研,本文探讨了西部地区城镇化可持续发展的路径,结合西部地区的现状与西部地区城镇发展的历史趋势,分析了中国西部地区城镇化发展的需求,阐析了其城镇化进程中的环境压力与阻力,提出了促进中国西部城镇化可持续发展的政策建议.目前,西部地区整体城镇化水平滞后,各省(区)间的城镇化发展水平极不均衡.而社会经济发展水平对于城镇化具有很大的促进作用,故未来相当一段时间内,西部地区社会经济发展是其区域城镇化进程的主要动力,同时西部地区尚处于城镇化与工业化发展的正相关期,工业化水平的提升对西部地区城镇化进程的推动作用不容小觑.城镇化进程的不断加快和工业化的快速推进过程中,西部地区本就脆弱的生态环境存在进一步遭受损失与破坏的威胁.这些将会导致西部地区生态环境状况的恶化转而成为其城市化的严重制约,给当地经济可持续发展造成一定程度的影响.据此,文中提出建议,未来西部城镇化建设过程中,应推行“二元”城镇化发展战略,增强中心城镇的辐射带动作用,培育中小城市和特色鲜明的小城镇;进一步完善西部城镇基础设施水平,以各级政府支持管理为先导和主导,尝试采用“公私营合作”(PPP)融资模式,重点推进交通及通讯设施建设;构建长期稳定的绿色城镇发展战略,推进城市绿色文化、建设绿色城市,筹措西部地区绿色城镇发展基金、发展城市绿色产业;立足功能分区并结合城镇化战略格局优化城镇化发展,依托国家主体功能区划优化城镇化发展格局,结合“两横三纵”城镇化战略格局推进城市群建设.     

钢铁生产行业二英污染特征变化及其排放因子

对我国某省多家钢铁生产企业烧结工序和电炉工序排放烟气中二英（PCDD/Fs）污染水平、排放特征及其排放因子进行了初步研究.结果表明,烧结工序PCDD/Fs毒性当量浓度（以I-TEQ计,下同）为0.003~0.557 ng·m^-3,均值为0.165 ng·m^-3;电炉工序PCDD/Fs毒性当量浓度为0.006~0.057 ng·m^-3,均值为0.025 ng·m^-3.PCDD/Fs毒性当量浓度水平总体较低,较2005~2019年研究报道结果下降1~2个数量级.2005~2020年,钢铁生产行业排放PCDD/Fs毒性当量浓度水平先升高后降低,尤其是新的标准限值实施以及对烟尘等常规污染物进行超低排放控制后,呈现大幅下降.指纹谱图特征显示,所有烟气样品17种PCDD/Fs中最大浓度贡献单体为2,3,7,8-TCDF,与已有研究中以高氯代PCDFs和PCDDs为主不同,且低氯代PCDFs占比有所增加,表明PCDD/Fs生成主要来源有所变化.烧结工序和电炉工序PCDD/Fs同类物指纹分布特征相似,呈现典型的高温热过程特征,两个工序生产过程中PCDD/Fs的生成机制可能均为"从头合成".钢铁生产企业烧结工序PCDD/Fs废气排放因子（以I-TEQ计,下同）为0.003~0.5 μg·t^-1,排放因子平均值为（0.18±0.22）μg·t^-1;电炉工序PCDD/Fs废气排放因子为0.04~0.5 μg·t^-1,排放因子平均值为（0.27±0.23）μg·t^-1;低于UNEP于2013发布的"二英和呋喃排放识别和量化标准工具包"以及2004年我国二英排放清单中的排放因子,建议对我国钢铁生产行业PCDD/Fs排放状况开展调查,更新排放因子.     

风蚀扬尘抑尘剂效率测试方法与应用

风蚀扬尘抑尘剂是一种控制风蚀扬尘的有效措施,探讨使用便携式风洞(PI-SWERL)测试风蚀扬尘抑尘剂效率的方法,并对比国内外2种抑尘剂对风蚀扬尘PM2. 5的抑制效率,以研究喷洒方式、稀释倍数和风速对抑尘效率的影响.结果表明:①按照推荐的稀释倍数分别配置G和Enviroseal(ES)抑尘剂水溶液并测试,液滴喷洒方式对应的抑尘效率优于雾化喷洒方式,在17. 2 m·s~(-1)(相当于8级风)风速时G抑尘剂效率(99. 5%)优于ES抑尘剂(94. 0%)和水(77. 5%);②对稀释倍数为50、100、150、200和400倍的G抑尘剂进行测试,在17. 2 m·s~(-1)风速时,抑尘效率分别为99. 7%、99. 5%、99. 7%、98. 1%和95. 9%,可根据抑尘效率变化拐点确定抑尘剂最佳成本效益稀释倍数;在13. 1～17. 2 m·s~(-1)风速范围内,抑尘效率随风速增加而增加.③使用便携式风洞测试风蚀扬尘抑尘剂效率的方法,可以量化抑尘剂对风蚀扬尘PM2. 5的抑制效率,建议对风蚀扬尘抑尘剂开展抑尘有效期和环境友好性测试.     

Predicting future quantities of obsolete household appliances in Nanjing by a stock-based model

China has become one of the largest producers of obsolete household appliances (HAs) in the world. However, information on discarded HAs in China is deficient owing to the unavailability of reliable data. The estimation of future obsolete streams is a crucial issue for the establishment of efficient waste collection and recycling systems. The present study describes a prediction model to forecast future obsolete HAs on the basis of information of in-use stocks of HAs in households. The model was applied to a forecasting analysis of quantities of obsolete HAs from 2009 to 2050 in Nanjing, China. The results show that a total of about 76 million units (2.8 million tonnes) of obsolete HAs will be generated in Nanjing over the next 40 years. Discarded air conditioners, color TV sets, and personal computers will be the major contributors. The total discarded amount of major kinds of HAs will increase from nearly 1.0 million units in 2009 to a maximum of 2.1 million units in 2040, and then decrease slightly to 2.0 million units in 2050. Urban households will generate significantly more obsolete HAs (about 56 million units) than rural households, due to the difference in their HA possession levels. The results of this study should help the Nanjing municipality to develop the collection and recycling systems and facilities needed for the obsolete HAs generated in the future. From a methodological perspective, the stock-based model provides a suitable tool to predict the generation of discarded HAs in the future.     

有机废气治理技术的研究进展

有机废气治理问题是当前废气处理的难点问题之一。本文首先介绍了几类传统有机废气处理技术的发展现状,包括吸附法、吸收法、催化氧化法、生物处理法等。对这几类有机废气治理技术的应用机理、适用范围以及现存问题进行了综合地比较与分析。最后,对于近年来出现的几类新型有机废气处理技术,如膜分离法、光催化氧化法、综合处理法的发展前景进行了一定的展望并列举了几类新技术的工程应用实例。