Hurricane Sandy and adaptation pathways in New York: Lessons from a first-responder city     

《Global Environmental Change》2014

Two central issues of climate change have become increasingly evident: Climate change will significantly affect cities; and rapid global urbanization will increase dramatically the number of individuals, amount of critical infrastructure, and means of economic production that are exposed and vulnerable to dynamic climate risks. Simultaneously, cities in many settings have begun to emerge as early adopters of climate change action strategies including greenhouse gas mitigation and adaptation. The objective of this paper is to examine and analyze how officials of one city – the City of New York – have integrated a flexible adaptation pathways approach into the municipality's climate action strategy. This approach has been connected with the City's ongoing response to Hurricane Sandy, which struck in the October 2012 and resulted in damages worth more than US$19 billion. A case study narrative methodology utilizing the Wise et al. conceptual framework (see this volume) is used to evaluate the effectiveness of the flexible adaptation pathways approach in New York City. The paper finds that Hurricane Sandy serves as a “tipping point” leading to transformative adaptation due to the explicit inclusion of increasing climate change risks in the rebuilding effort. The potential for transferability of the approach to cities varying in size and development stage is discussed, with elements useful across cities including the overall concept of flexible adaptation pathways, the inclusion of the full metropolitan region in the planning process, and the co-generation of climate-risk information by stakeholders and scientists.  相似文献   

Analyzing forest effects on runoff and sediment production using leaf area index     

WU Xiao-Xia  GU Zhu-Jun  LUO Hao  SHI Xue-Zheng  YU Dong-Sheng 《山地科学学报》2014,11(1):119-130

Quantifying the effects of forests on water and soil conservation helps further understanding of ecological functions and improving vegetation reconstruction in water-eroded areas.Studies on the effects of vegetation on water and soil conservation have generally focused on vegetation types or vegetation horizontal distribution densities.However,only a few studies have used indicators that consider the vegetation vertical distribution.This study used the leaf area index(LAI) to investigate the relationship between forests and water and soil conservation in experimental plots.From 2007 to 2010,rainfall characteristics,LAI,and water and soil loss in 144 natural erosive rainfall events were measured from five pure tree plots(Pinus massoniana).These tree plots were located in Hetian Town,Changting County,Fujian Province,which is a typical water-eroded area in Southern China.Quadratic polynomial regression models for LAI and water/soil conservation effects(RE/SE) were established for each plot.The RE and SE corresponded to the ratios of the runoff depth(RD) and the soil loss(SL) of each pure tree plot to those of the control plot under each rainfall event.The transformation LAIs of the LAI–RE and LAI–SE curves,as well as the rainfall characteristics for the different water/soil conservation effects,were computed.The increasing LAI resulted in descending,descending–ascending,ascending–descending,and ascending trends in the LAI–RE and LAI–SE curves.The rainfall frequencies corresponding to each trend of LAI–RE and LAI–SE were different,and the rainfall distributions were not uniform per year.The effects of soil conservation in the plots were superior to those of water conservation.Most of the RE and SE values presented a positive effect on water and soil conservation.The main factor that caused different effects was rainfall intensity.During heavy rains(e.g.,rainfall erosivity R = 145 MJ mm/ha h and maximum 30 min intensity I30 = 13 mm/h),the main effects were positive,whereas light rains(e.g.,R = 70 MJ mm/ha h and I30 = 8 mm/h) generally led to negative effects.When the rainfall erosivity was lower than that of the positive or the negative effects to a threshold and the tree LAI reached a transformation value,the relationships between LAI and RE or SE notably transformed.Results showed that the plottransformation LAIs for water and soil conservation during rainfall events were both approximately 1.0 in our study.These results could be used to come up with a more efficient way to alleviate water and soil loss in water-eroded areas.  相似文献   

嫦娥一号DEM数据月表撞击坑自动检测     

骆磊  王心源  郭华东  李超  吉玮 《遥感学报》2014,18(1):105-116

基于嫦娥一号数字高程模型(DEM)数据,利用地形信息参数来描述月表撞击坑的边缘轮廓特征,采用Hough变换检测方法提取了月表撞击坑。将该方法应用于克拉维乌斯(Klavius)撞击坑的周围区域,在DEM数据500 m空间分辨率下,不考虑退化严重的撞击坑时,检测百分比D=90%,分支系数B=0.30,质量百分比Q=71%,在考虑退化严重的撞击坑时,D=71%,B=0.30,Q=58%;研究表明该算法对没有退化或轻微退化的撞击坑有很好检测效果。与基于影像数据月表撞击坑自动检测的研究进行比较,本文给出的算法具有更高的检测精度,同时虚假检测较少。证明该方法用于月表撞击坑的自动检测是可行的。  相似文献   

Transformations and hydraulic captures of petrochemical contaminants in a karst-fractured aquifer   总被引：2，自引：0，他引：2  

Yudao Chen  Xueyu Zhu  Xueshun Zhu  Yaping Jiang  Qinglin Xie 《Environmental Geology》2000,39(11):1304-1308

 The development of a petrochemical industry may be responsible for petrochemical contamination of karst-fractured aquifers in an urban water supply system. In the Dawu Well Field, a karst-fractured aquifer in Zibo City, in the east of China, has been seriously polluted by petrochemicals from the operation of petrochemical plants. More than 60 species of organic contaminants have been detected in the water supply wells of the Liuhang-Hougao zone, in the west part of Dawu Well Field. Investigations indicate that contaminants are transported from the petrochemical plants to the karst-fractured aquifer along karst fractures and the Jinling Fault. In the groundwater, concentrations of pollutants vary with depth. Concentrations are greater with depth because of the transmissibility of the Jinling fault. The local convective flow field has a significant influence on transportation of contaminants. Hydraulic barriers can prevent the transportation of contaminants and they can be removed by extraction. Received: 22 October 1999 · Accepted: 14 February 2000  相似文献