吉林省敦化市乡村人群气候变化感知的偏差及群体分异研究   总被引：2，自引：0，他引：2       下载免费PDF全文

田青  姚冬萍  苏桂武  刘健  谢今范 《气候变化研究进展》2011,7(3):217-223

通过问卷调查,具体分析了吉林省敦化市乡村人群对气候变化趋势和极端冷暖年的感知偏差及人群分异.发现乡村人群对气候变化趋势的感知与科学事实比较符合,由于对变暖转折年代更敏感,因而对变暖的确认度在一些时段与科学事实在变化程度或幅度上存在比较大的偏差.乡村人群对极端冷暖年不如对趋势感知的准确度高.经验积累影响乡村人群对气候变化...  相似文献   

Phytoplankton biomass and primary production responses to physico-chemical forcing across the northeastern New Zealand continental shelf     

Mark Gall  John Zeldis 《Continental Shelf Research》2011,31(17):1799-1810

Phytoplankton biomass and primary production were monitored in the Hauraki Gulf and on the northeastern continental shelf, New Zealand - using ship surveys, moored instruments and satellite observations (1998-2001) - capturing variability across a range of space and time scales. A depth-integrated primary production model (DIM) was used to predict integrated productivity from surface parameters, enabling regional-specific estimates from satellite data. The shelf site was dominated by pico-phytoplankton, with low chlorophyll-a (<1 mg m⁻³) and annual production (136 g C m⁻² yr⁻¹). In contrast, the gulf contained a micro/nano-phytoplankton-dominated community, with relatively high chlorophyll-a (>1 mg m⁻³) and annual production (178 g C m⁻² yr⁻¹). Biomass and productivity responded to physico-chemical factors; a combination of light, critical mixing depths and/or nutrient limitation—particularly new nitrate-N. Relatively low biomass and production was observed during 1999. This coincided with inter-annual variability in the timing and extent of upwelling- and downwelling-favourable along-shelf wind-stress, influencing the fluxes of new nitrate-N to the shelf and gulf. Relationships with the Southern Oscillation Index are also discussed. Our multi-scaled sampling highlighted details associated with stratification and de-stratification events, and deep sub-surface chlorophyll-a not visible to satellite sensors. This study demonstrates the importance of multi-scaled sampling in gaining estimates of regional production and its responses to physico-chemical forcing.  相似文献   

Application of snowmelt runoff model for water resource management   总被引：1，自引：0，他引：1  

Mohsin Jamil Butt  Muhammad Bilal 《水文研究》2011,25(24):3735-3747

Snow‐covered areas (SCAs) are the fundamental source of water for the hydrological cycle for some region. Accurate measurements of river discharge from snowmelt can help manage much needed water required for hydropower generation and irrigation purposes. This study aims to apply the snowmelt runoff model (SRM) in the Upper Indus basin by the Astore River in northern Pakistan for the years 2000 to 2006. The Shuttle Radar Topographic Mission (SRTM) data are used to generate the Digital Elevation Model (DEM) of the region. Various variables (snow cover depletion curves (SCDCs), temperature and precipitation) and parameters (degree‐day factor, recession coefficient, runoff coefficients, time lag, critical temperature and temperature lapse rate) are used as input in the SRM. However, snow cover data are direct and an important input to the SRM. Satellite data from the Moderate Resolution Imaging Spectroradiometer (MODIS) are used to estimate the SCA. Normalized difference snow index (NDSI) algorithm is applied for snow cover mapping and to differentiate snow from other land features. Nash–Sutcliffe coefficient of determination (R²) and volume difference (D_V) are used for quality assessment of the SRM. The results of the current research show that for the study years (2000–2006), the average value of R² is 0·87 and average volume difference D_V is 1·18%. The correlation coefficient between measured and computed runoff is 0·95. The results of the study further show that a high level of accuracy can be achieved during the snowmelt season. The simulation results endorse that the SRM in conjunction with MODIS snow cover product is very useful for water resource management in the Astore River and can be used for runoff forecasts in the Indus River basin in northern Pakistan. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

分级加载时超固结粘土的一维非线性固结分析     

官志  刘洋  张秀凤 《地震工程学报》2011,33(Z1)

采用土层孔隙比与固结压力和渗透系数之间的非线性经验模型,考虑天然饱和粘土的应力历史影响以及施工荷载分级加载的情况,建立了超固结饱和粘土的一维非线性固结控制方程,采用有限差分法离散求解了该方程,并编制了相应的计算程序;最后对考虑与不考虑超固结特性的饱和粘土一维非线性固结和线性固结的结果进行了比较分析。  相似文献   

小波分析在T梁结构损伤识别中的应用研究     

韩西  崔璟  钟厉  狄海波  杨科 《地震工程与工程振动》2011,31(1):101-105

为了提高结构损伤识别的精确度和适用性,将小波分析引入到结构损伤识别中.本文介绍了梁结构在完好状态与损伤状态下振动测试加速度差的理论分析,证明了小波分析加速度差应用于桥梁结构损伤检测的可行性.然后以小波分析为工具,在桥梁结构不同损伤状态下,以移动荷载作用下各节点的加速度时程曲线差为研究对象,来识别结构的损伤状态.并通过试...  相似文献   

温差对泉州四至井水氡测值的影响分析   总被引：1，自引：0，他引：1  

尤宇星 《华北地震科学》2011,29(3):57-60

温度变化是影响水氡观测值的主要因素之一.通过1986-2009年泉州台四至井观测数据资料的分析,说明:调整观测室室内温度使其超过采集水样的原始温度,在运输水样过程中对水样采取保温措施,减小取样水温和鼓泡后水温的温差,能够得到更真实、准确的观测值.  相似文献   

新04号泉溶解气CO2异常特征分析     

朱成英  高小其  李艳萍  李新勇 《地震地磁观测与研究》2011,32(3):95-99

运用Mapsis软件前兆异常分析中的差分和从属函数,对新04号泉溶解气CO2进行异常识别,结果认为:①差分和从属函数异常形态均为高值异常;②差分异常对近场中强震和远场强震的映震率均为71.4％(5/7);从属函数异常对近场中强震的映震率为66.7％,而对远场强震的映震率为83.3％(5/6);两者均出现异常时,对近场中...  相似文献   

中国区域经济发展的地区差异GIS分析   总被引：1，自引：0，他引：1  

陈浩  邓祥征 《地球信息科学学报》2011,13(5):586-593

本文主要针对我国改革开放以来地区间经济发展的差距究竟是扩大(发散)还是缩小(收敛)的问题开展了研究.首先,对全国各省(市)1980 - 2008年的人均名义GDP数据进行了空间自相关分析,探讨了全国区域经济发展的地区差异变化,揭示了1984年以后中国各地区之间的经济发展的正空间自相关关系,即全国区域经济发展差异在整体上...  相似文献   

Curious Indeed,or Curious in Deed? Some peculiarities of post-settlement relations with an antipodean river     

Stephanie Lavau 《The Australian geographer》2011,42(3):241-256

Prominent in many historical accounts of European first contact with Australian nature are stories of encounters between European curiosity and curious Australian biota, such as the platypus and the eucalyptus. In this paper, I argue that post-settlement relations with the Goulburn River, one of the largest rivers in south-east Australia, likewise attest to the centrality of curiosity in early European engagements with Australian landscape. In mapping several relational ontologies of the Goulburn River, I attend to the socio-material practices in which this river has been performed as different and as normal. My interest is in a specific form of difference, that of antipodean difference: the river as topsy-turvy, backwards, unusual, or inverted in relation to some presumed norm, whether that norm be rooted in memories and experiences of European rivers or imaginings of an original state of nature. This is a story of how an extraordinary river became ordinary, and of how we might understand antipodean difference as curious in deed (i.e. as performed), rather than as curious indeed (i.e. as an innate quality of Australian nature).  相似文献   

Changing climate affects vegetation growth in the arid region of the northwestern China   总被引：13，自引：0，他引：13  

X. Zhao  K. TanS. Zhao  J. Fang 《Journal of Arid Environments》2011,75(10):946-952

The northwestern China is a typical dry-land region of Inner Asia, where significant climate change has been observed over the past several decades. How the regional vegetation, particularly the grassland-oasis-desert complex, responds to such climatic change is poorly understood. To address this question, we investigated spatio-temporal changes in vegetation growth and their responses to a changing climate by biome and bioregion, using satellite-sensed Normalized Difference Vegetation Index (NDVI) data from 1982 to 2003, along with corresponding climate data. Over the past 22 years, about 30% of the total vegetated area showed an annual increase of 0.7% in growing season NDVI. This trend occurred in all biomes and all bioregions except Sawuer, a subregion of the study area with no significant climate change. Further analyses indicated that NDVI change was highly correlated with the current precipitation and evapotranspiration in growing season but was not associated with temperature. We also found that NDVI was positively correlated with the preceding winter precipitation. These findings suggest that precipitation may be the key cause of vegetation growth in this area, even for mountain forests and grasslands, whose growth are often regarded to be limited by low temperate in winter and early spring.  相似文献