Investigating the impact of climate change on New York City’s primary water supply     

Adão H. Matonse  Donald C. Pierson  Allan Frei  Mark S. Zion  Aavudai Anandhi  Elliot Schneiderman  Ben Wright 《Climatic change》2013,116(3-4):437-456

Future climate scenarios projected by three different General Circulation Models and a delta-change methodology are used as input to the Generalized Watershed Loading Functions – Variable Source Area (GWLF-VSA) watershed model to simulate future inflows to reservoirs that are part of the New York City water supply system (NYCWSS). These inflows are in turn used as part of the NYC OASIS model designed to simulate operations for the NYCWSS. In this study future demands and operation rules are assumed stationary and future climate variability is based on historical data to which change factors were applied in order to develop the future scenarios. Our results for the West of Hudson portion of the NYCWSS suggest that future climate change will impact regional hydrology on a seasonal basis. The combined effect of projected increases in winter air temperatures, increased winter rain, and earlier snowmelt results in more runoff occurring during winter and slightly less runoff in early spring, increased spring and summer evapotranspiration, and reduction in number of days the system is under drought conditions. At subsystem level reservoir storages, water releases and spills appear to be higher and less variable during the winter months and are slightly reduced during summer. Under the projected future climate and assumptions in this study the NYC reservoir system continues to show high resilience, high annual reliability and relatively low vulnerability.  相似文献   

The Variability of Spring Sand-Dust Storm Frequency in Northeast Asia from 1980 to 2011   总被引：1，自引：0，他引：1       下载免费PDF全文

YANG Yuanqin  WANG Jizhi  NIU Tao  ZHOU Chunhong  CHEN Miao  LIU Jiyan 《Acta Meteorologica Sinica》2013,27(1):119-127

The characteristic distributions of regional sand-dust storm(SDS) weather processes over Northeast Asia from 1980 to 2011 were investigated using the shared WMO surface station meteorological data,atmospheric sounding data,China high density weather data,NCEP/NCAR reanalysis data,as well as the archived original weather maps of China.The concentration-weighted trajectory(CWT) method was used to calculate the SDS frequency from the discrete station data and to track the large-scale regional SDS weather processes in Northeast Asia.A spline trend analysis method was employed to investigate the variability of the SDS weather systems.The results show that during 1980-2011,the SDS weather processes exhibit both a historical persistence and abrupt transitions with an approximate 10-yr high-low occurrence oscillation.Through composite analysis of atmospheric circulation during high and low SDS years,it is found that the SDS occurrences are closely related to the anomalies of arctic vortex and midlatitude westerly,and the circulation patterns around the Lake Baikal.During the high frequency years,the meridianal flows in the upper and mid troposphere above the high SDS corridor in East Asia(from the Lake Balkhash along Northwest and North China,Korean Peninsula,and Japan Islands) are apparently stronger than the meridianal flows during the low SDS frequency years,favoring the development and transport of SDSs in the midlatitude regions.  相似文献   

Regional Climate Effects of Internally and Externally Mixed Aerosols over China          下载免费PDF全文

YU Yong  NIU Shengjie  ZHANG Hu  WU Ziyue 《Acta Meteorologica Sinica》2013,27(1):110-118

A regional climate model is employed to simulate the aerosols(dust,sulfate,black carbon,and organic carbon) and their direct effect on the climate over China.The emphasis is on the direct radiative forcing due to the change in mixing state of aerosols.The results show that direct radiative forcing is significantly different between externally and internally mixed aerosols.At the top of the atmosphere(TOA),the radiative forcing of externally mixed aerosols is larger than that of internally mixed ones,especially in the Tarim desert region where the difference is about 0.7 W m 2.At the surface,however,the situation becomes opposite,especially in the Sichuan basin where the difference is about-1.4 W m 2.Nonetheless,either externally or internally mixed aerosols in China can result in a significant cooling effect,except for the warming in South China in winter and the slight warming in North China in February.The cooling effect induced by externally mixed aerosols is weaker than that induced by internally mixed aerosols,and this is more obvious in spring and winter than in summer and autumn.In spring and summer,the inhibiting effect of externally mixed aerosols on precipitation is less than that of internally mixed aerosols,whereas in autumn and winter the difference is not obvious.  相似文献   

台风对四川暴雨影响的环境场对比分析   总被引：5，自引：1，他引：4  

康岚  牛俊丽  徐琳娜  肖红茹  陈莹 《气象》2013,39(4):427-435

通过统计2000-2010年5-9月在15°～35°N、103°～130°E区域内活动的台风与相应时段四川逐日降水量之间的关系,指出与四川暴雨统计关系最密切的台风路径分别为偏西路径、转向路径和西北路径.对比相似台风路径背景下四川有无明显暴雨出现的环境场特征,指出西风带低槽在40°N以北活动,中亚地区为高脊,中纬度大陆高压控制西藏东部到四川大部或我国中东部为宽广低槽是不利四川产生明显暴雨的环境场特征;巴尔克什湖到贝加尔湖为宽广低槽,副热带锋区密集,到达36°N附近,中纬度带状高压脊线位于30°N以南以及我国中高纬度呈现出东高西低的态势,西部为经向度大的斜压性低槽是有利四川产生暴雨的环境场特征.分析指出:台风对四川天气的影响主要有三方面,一是通过影响副热带高压(大陆高压)产生间接影响;二是台风低压外围环流直接影响;三是作为载体向四川输送暖湿空气,与中高纬低值系统及副热带高压相互作用共同影响.  相似文献   

地形对2011年9月华西致灾暴雨强迫作用的数值模拟研究   总被引：1，自引：0，他引：1  

刘冀彦  毛龙江  牛涛  陈淼  刘洪利  王继志 《气象》2013,39(8):975-987

运用GRAPES_Meso模式对2011年9月16-18日发生在陕西、四川的连续特大致洪暴雨过程进行数值模拟.通过对比3套敏感性试验结果,揭示了气流与地形相互作用对本次致灾暴雨的影响,结果如下:(1)16-18日在台风和蒙古高压共同影响下,850 hPa在黄、渤海形成偏东水汽通道,使大量水汽经华北平原输送至华西地区,气流被秦岭分割为南北两支,北支在秦岭北侧受到迎风坡阻挡,形成强迫抬升和水汽辐合中心;南支暖湿气流从东部灌入汉中平原,受到“喇叭口”地形挤压而辐合上升.(2)平原与高大山脉的交错相间地形导致条带状正负垂直运动带产生,在垂直方向上形成强烈的抽吸作用,加之该地区16-18日丰沛的水汽交汇,从而引发大范围强降水.(3)海拔高度与地表起伏度均对降雨有较大影响,在同样海拔情况下,地表起伏度越大,就越容易产生暴雨.  相似文献   

Livelihoods and the transformative potential of cities: Challenges of inclusive development in Rustenburg,North West Province,South Africa     

Ben Mosiane 《Singapore journal of tropical geography》2011,32(1):38-52

Urban geographers increasingly incorporate the potential of so‐called informal livelihood activities to provide resources that can be creatively managed in the transformation of urban space, particularly to the benefit of less well off and marginalized residents. This paper reports a case study in Rustenburg, North West Province, South Africa, where city managers began to promote inclusive development in the early 1990s, just prior to the formal dismantling of the apartheid system. The findings reveal that Rustenburg's urban transformation process, over a decade later, continued to reproduce repressive practices that limit the informal livelihood activities of the urban majority. Apparently efforts of well‐meaning city managers to implement a sustainable and inclusive development process are often rendered futile at the point of actually defining the constituents of urban socioeconomic transformation.  相似文献   

甘肃省县域经济发展水平空间差异评价   总被引：9，自引：4，他引：5  

马利邦  牛叔文  李怡欣  杨丽娜 《干旱区地理》2011,34(1):194-200

运用<省级主体功能区划分技术规程>中经济发展水平指标的计算方法,以GDP增长率和人均GDP计算出甘肃省1998-2007年各县区的经济发展水平,将其划分为经济发展水平高值区域、较高值区域、中值区域、较低值区域和低值区域,并对近10 a来经济发展时空差异分两个阶段进行了评价.结果表明,甘肃省县域经济发展水平的时空差异十分...  相似文献   

顾及语义差异的基础地理信息客户数据库更新实施模型     

王育红  牛亚辉  林艳 《地理与地理信息科学》2011,27(1):1-6

客户数据库更新就是利用新版基础地理数据库中更新变化的要素信息,对客户数据库进行相应的级联更新,以使其具有良好现势性的过程。现有研究大多侧重于基础地理数据库更新信息的分发与提供,而没有充分考虑语义差异环境下如何高效实施客户数据库更新的具体问题。针对此,该文概括了基础地理数据库与其客户数据库之间潜在的各种语义差异;从实施效率、数据完备性、一致性、正确性等方面,分析描述了语义差异给更新实施过程带来的不利影响;最后依据语义映射和转换理论,提出了由语义匹配、变化提取、更新集成3种基本操作组成的更新实施模型,并阐述了3种基本操作的执行策略和关键环节。  相似文献   

High‐resolution absorption spectroscopy of the circumgalactic medium of the Milky Way     

P. Richter  Aj. Fox  N. Ben Bekhti  M. T. Murphy  D. Bomans  S. Frank 《Astronomische Nachrichten》2014,335(1):92-98

In this article we discuss the importance of high‐resolution absorption spectroscopy for our understanding of the distribution and physical nature of the gaseous circumgalactic medium (CGM) that surrounds the Milky Way. Observational and theoretical studies indicate a high complexity of the gas kinematics and an extreme multi‐phase nature of the CGM in low‐redshift galaxies. High‐precision absorption‐line measurements of the Milky Way's gas environment thus are essential to explore fundamental parameters of circumgalactic gas in the local Universe, such as mass, chemical composition, and spatial distribution. We shortly review important characteristics of the Milky Way's CGM and discuss recent results from our multi‐wavelength observations of the Magellanic Stream. Finally, we discuss the potential of studying the warm‐hot phase of the Milky Way's CGM by searching for extremely weak [Fe X] λ 6374.5 Å and [Fe XIV] λ 5302.9 Å absorption in optical QSO spectra. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

A dearth of planetary transits in the direction of NGC 6940     

Ben Hood  rew Collier Cameron  Stephen R. Kane  D. M. Bramich  Keith Horne  Rachel A. Street  I. A. Bond  A. J. Penny  Y. Tsapras  A. Quirrenbach  N. Safizadeh  D. Mitchell  J. Cooke 《Monthly notices of the Royal Astronomical Society》2005,360(2):791-800

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