太湖鱼类产量、组成的变动规律及与环境的关系   总被引：30，自引：3，他引：27  

刘恩生  刘正文  陈伟民  陈开宁 《湖泊科学》2005,17(3):251-255

湖泊生态系统健康包含两个方面的内涵:满足人类社会合理要求的能力和湖泊生态系统自我维持与更新的能力.获知湖泊生态系统健康状况及其区域分异特征,对于湖泊管理具有重要意义.本文基于对太湖的野外调查,计算了表征湖泊生态系统健康的系统能、系统能结构、生态缓冲容量和湖泊营养状态指数.聚类分析结果表明,太湖不同湖区生态系统健康状况存在一定差异,东部湖区较好,西部湖区较差,呈现由东南部湖区向西北部湖区递减的趋势.该结果对进一步研究湖泊生态系统健康评价指标阈值具有重要的参考意义.  相似文献   

江河源区生态系统服务价值评估初探——以江西东江源区为例   总被引：4，自引：0，他引：4  

刘青  胡振鹏 《湖泊科学》2007,19(3):351-356

应用生态学、生态经济学、福利经济学方法和前人的研究成果,在研究江河源区生态系统价值评估流程和评估方法的基础上,以江西东江源区为研究案例,初步估算出东江源区生态系统服务功能经济总价值为81.0亿元,约为东江源区2004年国内生产总值(GDP)的4.11倍,单位面积生态系统服务功能价值为23121元/hm2,并对估算结果进行了分析.  相似文献   

Shaking table tests on a masonry building monitored using smart bricks: Damage detection and localization     

Andrea Meoni  Antonella D'Alessandro  Nicola Cavalagli  Massimiliano Gioffré  Filippo Ubertini 《地震工程与结构动力学》2019,48(8):910-928

The seismic behavior of unreinforced masonry buildings is typically characterized by premature brittle collapse mechanisms that can cause serious consequences for the protection of human lives and for the preservation of historical and cultural heritage. Structural health monitoring can be a powerful tool enabling a quick post-earthquake assessment of the structure's performance, but its applications are still scarce as a consequence of the severe limitations affecting off-the-shelf sensing technologies, in terms of local nature of the measurements, costs, as well as long-term behavior, installation, and maintenance. To overcome some of these limitations, the authors have recently proposed a new sensing technology, called “smart brick,” that is a durable clay brick doped with stainless steel microfibers, working as a smart strain sensor for masonry buildings. This paper presents the first full-scale application of smart bricks, used for detecting and localizing progressive earthquake-induced damage in an unreinforced masonry building subjected to shaking table tests. Smart bricks are employed to detect changes in load paths on masonry walls, comparing strain measurements acquired after each step of the seismic sequence with those referring to the undamaged structure. Experimental results are interpreted using a 3D finite element model built to reproduce the shaking table tests. Overall, the results demonstrate that the smart bricks can effectively reveal local permanent changes in structural conditions following a progressive damage, therefore being apt for earthquake-induced damage detection and localization.  相似文献   

洞庭湖主要河口区表层沉积物与河蚬中砷的污染特征及风险评价     

李滨  王健  李德亮  张婷 《湖泊科学》2019,31(3):667-676

水体砷污染及其健康危害已成为一个备受关注的环境问题.本研究通过测定洞庭湖主要河口区表层沉积物砷含量、河蚬砷及砷形态（亚砷酸盐As（Ⅲ）、砷酸盐As（Ⅴ）、甲基砷酸MMA、二甲基砷酸DMA和砷甜菜碱AsB）含量,对表层沉积物砷的潜在生态风险和河蚬食用健康风险进行评价.结果表明,洞庭湖主要河口区表层沉积物砷含量在11.47~61.20 mg/kg之间,其水平分布规律表现为：南洞庭湖>东洞庭湖>西洞庭湖.河蚬砷含量范围为6.36~11.15 mg/kg,各砷形态含量排序为：AsB > As（Ⅴ） > DMA > As（Ⅲ） > MMA,各样地间不存在显著性差异.应用潜在生态风险指数法对表层沉积物中砷的潜在生态风险进行评价,各样地的潜在生态风险指数均值为23.09,潜在生态风险程度属于轻微级别.同时,利用致癌风险指数（CR）和危熵系数（HQ）评价经河蚬摄入无机砷给人体带来的潜在健康风险.洞庭湖主要河口区河蚬中无机砷的致癌风险CR_iAs值达到了1.36×10^-3~3.43×10^-3（平均值为2.24×10^-3）,均显著超过USEPA推荐的可接受风险水平上限值（1×10^-4）,其危熵系数HQ_iAs值达到3.01~7.61（平均值为4.98,约为标准值的5倍）,说明长期食用当地河蚬具有较高的致癌和非致癌健康风险.本研究结果对于了解洞庭湖沉积物和底栖动物的砷污染现状和风险水平具有重要意义,为该流域的砷污染控制及治理提供科学依据.  相似文献   

水生态评价方法研究进展及展望          下载免费PDF全文

易雨君  叶敬旴  丁航  银森录 《湖泊科学》2024,36(3):657-669

水生态系统是人类赖以生存的基础,近年来气候变化和水资源开发、水体污染、过度捕捞等人类活动导致水生态系统严重受损,水生态系统的保护和修复已成为全球面临的重大挑战。科学合理的水生态评价方法是实现水生态系统稳定、健康和可持续管理的基本保障,也是目前我国各相关管理部门高度重视的关键问题,多个部门围绕水生态评价展开了积极探索与实践。本文系统回顾了水生态评价方法的发展历程并阐释了水生态评价的内涵,梳理了常用的水生态评价方法,明晰了各方法的基本理念和应用场景,分析了各方法的优点和不足,提出了基于生态完整性的水生态健康评价方法,最后对目前我国水生态评价需进一步完善的工作进行了展望。本文以期与相关领域研究者和管理者在水生态评价理论和方法方面进行探讨,为我国水生态考核工作提供理论支持。  相似文献   

全球环境变化与人类健康   总被引：9，自引：0，他引：9  

程杨  杨林生  李海蓉 《地理科学进展》2006,25(2):46-58

全球环境变化与人类健康研究是目前地球系统科学研究关注的热点问题之一,引起了越来越多机构和科学家的重视,并且已取得了一定的研究成果。本文介绍了全球环境变化研究的内容和意义及目前全球环境变化的研究体系;总结了在全球气候变化、臭氧层损耗、生物多样性的丧失、土地荒漠化和干旱、环境污染、全球化以及城市化等多方面给人类健康带来的影响;概括了目前关于全球环境变化与人类健康研究的热点领域以及我国开展全球环境变化与健康研究的主要问题。  相似文献   

黄河健康生命的指标体系     

刘晓燕  张原锋  张建中 《地理学报(英文版)》2006,16(3):259-270

  相似文献   

污染场地健康风险评价的理论和方法   总被引：62，自引：2，他引：60  

陈鸿汉  谌宏伟  何江涛  刘菲  沈照理  韩冰  孙静 《地学前缘》2006,13(1):216-223

综合国外研究进展介绍了污染场地健康风险评价的基础理论和评价方法,基础理论主要从人体摄取污染物质的方式和机制以及污染物摄取剂量和人体健康效应的关系两方面开展讨论。评价方法从数据收集、暴露评估、毒性评估和风险表征4方面进行探讨。在此基础上,对评价方法进行了探讨,提出了“叠加风险”和“多暴露途径同种污染物累计健康风险”的概念和计算方法,分析了中国开展污染场地健康风险评价的相关问题,指出构建中国污染场地健康风险评价体系应从制定法律入手,以典型污染场地风险评价为试点,逐渐建立和完善风险评价指南和技术细则,最终完成包括法律法规、评价指南和技术细则等在内的污染场地健康风险评价体系的建立。  相似文献   

大气生物气溶胶的源排放与源解析研究进展     

李彦鹏  马天峰  杜胜利  谢雯文  张皓月  谢铮胜 《地球科学与环境学报》2021,(2):315-331

2019年新冠肺炎(COVID-19)的全球爆发引起了公众对生物气溶胶的广泛关注.生物气溶胶是大气气溶胶的重要组成部分.生物气溶胶由于具有普通气溶胶的理化性质和本身特有的生物学特性,在全球生态系统、气候变化、空气质量和公共卫生等领域均扮演十分重要的角色.然而,目前学术界对生物气溶胶的研究主要集中在采样监测、消杀防护以及...  相似文献   

Assessing Worldview-3 multispectral imaging abilities to map the tree diversity in semi-arid parklands     

《International Journal of Applied Earth Observation and Geoinformation》2020

Semi-arid parkland agrosystems are strongly sensitive to climate change and anthropic pressure. In the context of sustainability research, trees are considered critical for various ecosystem services covering environment quality as well as food security and health. But their actual ecological impact on both cropland and natural vegetation is not well understood yet, and collecting spatial and structural information around agroforestry systems is becoming an important issue. Tree mapping in semi-arid parklands could be one of these prerequisites. While for obtaining an exhaustive inventory of individual trees and for analysing their spatial distribution, remote sensing is the ideal tool. However, it has been noted that depending on the spatial resolution and sensor spectral characteristics, tree species cannot be distinguished clearly, even in the sparsely vegetated semi-arid ecosystems of West Africa. Thus, this work focuses on assessing the capabilities of Worldview-3 imagery, acquired in 8 spectral bands, to detect, delineate, and identify certain key tree species in the Faidherbia albida parkland in Bambey, Senegal, based on a ground-truth database corresponding to 5000 trees. The tree crowns are delineated through NDVI thresholding and consecutive filtering to provide object-based radiometric signatures, radiometric indices, and textural information. A factorial discriminant analysis is then performed, which indicates that only four out of the seven most abundant species in the study area can be discriminated: “Faidherbia albida”,” Azadirachta indica”, “Balanites aegyptiaca” and “Tamarindus indica”. Next, random forest and support vector machine classifiers are employed to identify the optimal combination of classifier parameters to discriminate these classes with a high accuracy, robustness, and stability. The linear support vector machine with cost=1 and gamma=0.01 provides the optimal results with a global accuracy of 88 % and kappa of 0.71. This classifier is applied to the whole study area to map all the trees with crowns larger than 2 m, sorted in four identified species and a fifth common group of unidentified species. This map thus enables analysing the variability in tree density and the spatial distribution of different species. Such information can afterwards be correlated to the ecological functioning of the parkland and local practices, and offers promising opportunities to help future sustainability initiatives in different socio-ecological contexts.  相似文献