Mapping wetlands in the Lower Mekong Basin for wetland resource and conservation management using Landsat ETM images and field survey data

The Mekong River Basin is considered to be the second most species rich river basin in the world. The 795,000 km(2) catchment encompasses several ecoregions, incorporating biodiverse and productive wetland systems. Eighty percent of the rapidly expanding population of the Lower Mekong Basin (LMB), made up in part by Lao PDR, Thailand, Cambodia and Viet Nam, live in rural areas and are heavily reliant on wetland resources. As the populations of Cambodia and Lao PDR will double in the next 20 years, pressure on natural resources and particularly wetlands can only increase. For development planning, resource and conservation management to incorporate wetland issues, information on the distribution and character of Mekong wetlands is essential. The existing but outdated wetland maps were compiled from secondary landuse-landcover data, have limited coverage, poor thematic accuracy and no meta-data. Therefore the Mekong River Commission (MRC) undertook to produce new wetland coverage for the LMB. As resources, funding and regional capacity are limited, it was determined that the method applied should use existing facilities, be easily adaptable, and replicable locally. For the product to be useful it must be accepted by local governments and decision makers. The results must be of acceptable accuracy (>75%) and the methodology should be relatively understandable to non-experts. In the first stage of this exercise, field survey was conducted at five pilot sites covering a range of typical wetland habitats (MRC wetland classification) to supply data for a supervised classification of Landsat ETM images from the existing MRC archive. Images were analysed using ERDAS IMAGINE and applying Maximum Likelihood Classification. Field data were reserved to apply formal accuracy assessment to the final wetland habitat maps, with resulting accuracy ranging from 77 to 94%. The maps produced are now in use at a Provincial and National level in three countries for resource and conservation planning and management applications, including designation of a Ramsar wetland site of international importance.     

13种花卉植物受硫氧化物混合气体污染的伤害症状及其抗性表现

通过熏气的方法,比较了在硫氧化物混合污染气体的作用下,木本花卉（月季Rosa chinensis,杜鹃Rhododendron simsii,一品红Euphorbia pulcherrima,茉莉花Jasminum sambac）,一、二年生花卉（一串红Salvia splendens,凤仙花Impatiens balsamina）,宿根花卉（君子兰Clivia miniata）,室内观叶植物（文竹Asparagus setacens,吊兰Chlorophytum comosum,沿阶草Ophiopogon bodinieri,朱蕉Cordyline fruticosa,吊竹梅Zebrina pendula,白斑万年青Dieffenbachia bowmannii）中13种花卉植物的叶片伤害症状及植物抗性表现,并对植物受害后的恢复情况进行了追踪观察。发现在同种污染气体的作用下,不同种类的植物表现出不同的伤害症状。植株不同叶龄的叶片对污染气体的敏感性存在一定的差异,幼龄叶不一定比中老龄叶敏感性强。当污染浓度不超过一定阈值时,花卉植物都有不同程度的恢复能力。利用“花卉植物叶片伤害评价系统”对试验植物叶片伤害症状进行了评价,依据评价结果,对试验植物进行了抗性分级。为保证对植物抗性等级划分的准确性,建议制定统一的熏气浓度标准和评价标准。     

企业职业危害综合评价和风险分级系统及其应用

我国企业职业危害形势依然十分严峻,2007年共诊断各类职业病14296例,较2006年增加了24．11％。由于国家在一段时期内不太可能大幅度增加监管人员数量,因此,实施企业职业危害分级监管成为职业危害监管工作的一个紧迫需求。本文从提高企业监管信息化水平角度出发,开发企业职业危害综合评价和风险分级系统。系统即可为政府实施职业危害分级监管提供强有力的技术支撑,也可应用在企业的作业场所职业危害管理工作中,从而提高政府和企业职业危害管理工作技术水平和效率。     

长江中游大型通江湖泊湿地景观格局演变特征

鄱阳湖和洞庭湖湿地是长江中游仅有的两个天然通江湖泊湿地,具有不可替代自然和人文价值。近年来,尤其是三峡工程运行以后两湖湿地景观格局发生改变,对区域生态系统平衡和社会经济发展产生重要影响。以Landsat 7为数据源,通过决策树分类及高斯回归的方法定量评估了三峡工程运行前后两湖湿地景观格局的演变特征及其差异性,旨在正确认识大型水利工程的生态效应,为湿地保护与重建提供科学依据。结果表明:2000~2014年,洞庭湖枯水期水位变化不明显。从历史演变特征来看,虽然有少部分植被挤占泥滩和水体,但总体上3种湿地景观类型面积变化不大。相比之下,三峡工程运行后鄱阳湖枯水期水位显著下降,水体面积萎缩近14%,植被面积增加约8%。与2000年相比,2014年鄱阳湖植被分布高程下降了1 m多。不同程度的干旱胁迫是形成两湖湿地景观格局差异性演变特征的主要原因。     

Hydrologic Landscape Classification to Estimate Bristol Bay,Alaska Watershed Hydrology

Hydrologic landscapes (HLs) have proven to be a useful tool for broad scale assessment and classification of landscapes across the United States as they help organize larger geographical areas into areas of similar hydrologic characteristics. We developed a HL classification for the Bristol Bay watershed of southwest Alaska that incorporates indices of annual climate and seasonality, terrain, geology, and the influences of large lakes and glaciers. A HL classification is particularly useful in this large watershed because of its hydrologic and landscape variability, important salmon fishery, variety of environmental and potential anthropogenic stressors, and lack of widespread hydrologic data. Following creation of Bristol Bay basin‐wide HL classes, we compared the HL distributions within watersheds grouped by two calculated runoff parameters derived from available long‐term streamflow records and found HL distributions within these groups provided predictive insight on hydrologic behavior. Using these developed runoff groups, we estimated expected hydrologic behavior in watersheds across the larger Bristol Bay watershed that lacked gauged streamflow records. The HL approach provides a scientific basis for estimating the first‐order hydrologic behavior of watersheds and landscapes that lack detailed hydrologic information.     

基于灾度的亚洲巨灾划分标准研究

分析了灾害的双重属性:自然属性和社会属性。灾度是灾害社会属性的定量描述,论述了灾度在灾害分级中的应用。提出了灾度计算模型,该模型的影响因子包括:死亡人数、直接经济损失和受灾人数。收集了1954-2010之间的亚洲灾害,并应用灾度计算模型对收集到的资料进行了计算与分析。提出了亚洲巨灾标准:灾度大于8的灾害为亚洲巨灾。该标准具有计算简便、易于对不同灾害进行比较的特点。     

中国适应气候变化技术分类研究

近百年来,全球气候变化呈现出变暖的主要特征,气候变化所带来的影响日趋严重,其所造成的经济损失在全球范围内显著上升。适应气候变化是现阶段应对气候变化行动的重要方面,适应气候变化的技术分类研究是清晰认识适应气候变化的基础,是实现适应技术集成并构建合理有效的适应技术体系的手段。本文通过对适应气候变化技术分类问题的分析,提出了不同的适应气候变化技术分类方式,气候变化影响过程、区域、领域、适应目的、适应机制、适应时效、适应程度、适应层面等,针对气候变化及其影响梳理了中国不同区域与不同领域的适应气候变化技术清单。从气候变化影响过程来看,可以将适应气候变化技术分为气候变化影响发生前、发生过程中、发生后三类;从区域与领域气候变化影响来看,可以将适应气候变化技术分为八大区域与七大领域;本研究重点针对八大区域与农业、水资源、生态环境三大领域进行了分析。通过研究发现,现阶段适应气候变化技术分类研究尚存在一些问题,适应气候变化技术分类的导向不明确,造成对适应技术认识的不清晰;适应气候变化技术的分类往往与分层混淆在一起,导致人们对适应气候变化技术的认识和理解出现偏差;适应气候变化技术分类对适应行动的指导作用存在不足。综合来看,对适应气候变化技术进行精细分类,可以为适应气候变化技术的筛选、集成、效益评估奠定基础,推进适应气候变化行动高效有序开展,为适应气候变化技术体系构建提供支撑。     

氯代烃的相对危险性分级

选用分子结构拓朴指数,物理化学性质参数和毒性毒理指数共11种作为危险性分级参数。采用模糊聚类相似系数法,Q型系统聚类相似系数法和欧氏距离倒数法,以及平面投影对应变换法进行最终综合评判分析。将24种氯代烃的大气环境事故中的相对危险性分为轻度、中度、高度和极度四个等级。     

倍斜率聚类法在环境质量综合评价中的应用

倍斜率聚类法依据灰色系统理论和模糊数学理论的有关基本原则,以宽域式结构建立隶属函数,函数的左侧斜率小于右侧斜率,以大气环境质量评介为例说明了该法的具体应用,并与模糊综合评判法和灰色聚类法进行了比较,结果表明,该法更为合理,实用。     

B-P网络用于环境质量分类研究

用全国２５个湖泊的水质指标资料作为训练样本,应用人工神经Ｂ－Ｐ算法,分别建立了３参数和４参数的水质分类模型,并用所建立的模型对６个湖泊水质进行分类检验效果。结果表明Ｂ－Ｐ模型应用于环境质量分类是可行的,且由于Ｂ－Ｐ网络有学习,自适应的能力,因而与其它的环境质量分类法相比具有优越性。