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The variability in global oceanic evaporation data sets was examined for the period 1988-2000. These data sets are satellite estimates based on bulk aerodynamic formulations and include the NASA/Goddard Space Flight Center Satellite-based Surface Turbulent Flux version 2 （ GSSTF2）, the Japanese-ocean flux using remote sensing observations （J-OFURO）, and the Hamburg Ocean-Atmosphere Parameters and Fluxes from Satellite version 2 （HOAPS2）. The National Center for Environmental Prediction （NCEP） reanalysis is also included for comparison. An increase in global average surface latent heat flux （SLHF） can be observed in all the data sets. Empirical mode decomposition （EMD） shows long-term increases that started around 1990 for all remote sensing data sets. The effect of Mt. Pinatubo eruption in 1991 is clearly evident in HOAPS2 but is independent of the longterm increase. Linear regression analyses show increases of 9.4%, 13.0%, 7. 3%, and 3.9% for GSSTF2, J-OFURO, HOAPS2 and NCEP, for the periods of the data sets. Empirical orthogonal function （EOF） analyses show that the pattern of the first EOF of all data sets is consistent with a decadal variation associated with the enhancement of the tropical Hadley circulation, which is supported by other satellite observations. The second EOF of all four data sets is an ENSO mode, and the correlations between their time series and an SO1 are 0.74, 0.71,0.59, and 0.61 for GSSTF2, J-OFURO, HOAPS2, and NCEP in that order. When the Hadley modes are removed from the remote sensing data, the residue global increases are reduced to 2.2% , 7. 3%, and 〈 1% for GSSTF2, J-OFURO and HOAPS, respectively. If the ENSO mode is used as a calibration standard for the data sets, the Hadley mode is at least comparable to, if not larger than, the ENSO mode during our study period. 相似文献
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在城区化过程中,由于人口快速成长且集中,随之而来的建筑物、道路等不透水面密度增加,导致地下水补给减少及破坏水文循环。为了解土地利用方式改变对长期水文量影响,建立一个适宜的城区水循环模式是非常重要的。选定台湾台北的六馆抽水站集水区进行分析,模式参数经过敏感度分析、率定与验证。采用改变不同透水铺面设置比例的方案,评估其对径流量、入渗量、蒸发散量的改变。并分析设置不同比例屋顶雨水贮集系统对地表径流量及供水量的改变。所建立的城区水循环模式是评估土地利用改变造成水文量的改变的一个有效工具,并可提供决策者做为城区土地利用决策的参考。 相似文献
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台湾有将近80%的人口居住于城市地区,使得供水系统负荷增加、脆弱度提升,而城市化也导致径流量增加使得洪灾风险提高。拟整合供水、灾备用水和雨洪消减,并对雨洪滞蓄系统进行雨洪利用策略及容量分析研究。以台湾新北市秀峰国小为基地,规划雨水储留供水系统、渗透侧沟系统、生态池系统串联的雨洪滞蓄系统,建立多目标替代方案进行分析评估。采用绿色建筑设计方法结合合理化公式进行降雨径流演算。结果表明,在各替代方案下,系统需设置容量55~185m3,径流量削减率为26.5%~100%、洪峰削减率为15%~100%、供水率为5%~7.5%、灾备用水天数则从3d提升至19d。所提出的规划方法可以较小的设置容量达到雨洪滞蓄多目标利用效果。 相似文献
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Yung-Tan LEE Ju-Chin CHEN Jyh-Yi SHIH Kung-Suan HO Huai-Jen YANG Meng-Lung LIN Yen-Tsui HU Ching-Hsing CHIU 《《地质学报》英文版》2013,87(1):102-117
Cenozoic（Miocene to Pleistocene） basaltic rocks in Jiangsu province of eastern China include olivine tholeiite and alkali basalt.We present major,trace element and Sr-Nd isotopic data as well as Ar-Ar dating of these basalts to discuss the petrogenesis of the basalts and identify the geological processes beneath the study area.On the basis of chemical compisitions and Ar-Ar dating of Cenonoic basaltic rocks from Jiangsu province,we suggest that these basalts may belong to the same magmatic system.The alkali basalts found in Jiangsu province have higherΣFeO,MgO,CaO,Na2O, TiO2 and P2O5 and incompatible elements,but lower Al2O3 and compatible elements contents than olivine tholeiite which may be caused by fractional crystallization of olivine,pyroxene and minor plagioclase.In Jiangsu basaltic rocks the incompatible elements increase with decreasing MgO/ΣFeO ratios.The primitive mantle-normalized incompatible elements and chondrite-normalized REE patterns of basaltic rocks found in Jiangsu province are similar to those of OIB.Partial loss of the mantle lithosphere accompanied by rising of asthenospheric mantle may accelerate the generation of the basaltic magma.The 143Nd/144Nd vs.87Sr/86Sr plot indicates a mixing of a depleted asthenospheric mantle source and an EMI component in the study area.According to Shaw’s equation,the basalts from Jiangsu province may be formed by l%-5%partial melting of a depleted asthenospheric mantle source.On the basis of Ar-Ar ages of this study and the fractional crystallization model proposed by Brooks and Nielsen（1982）,we suggest that basalts from Jiangsu province may belong to a magmatic system with JF-2 as the primitive magma which has undergone fractional crystallization and evolved progressively to produce other types of basalts. 相似文献
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我国高校世界地理课程改革与发展再认识 总被引：1，自引：1，他引：1
本文简要回顾与反思我国高校世界地理课程发展历程以及全球化，信息化形势下课程改革与发展态势。从教育理念创新，课程结构创新，教材内容创新，教学方法创新等不同维度，探讨世界地理课程改革策略与方法，以其科学教育与人文教育的融合，以及自身丰富的科学。文化，生活内涵和个性化特色，推进课程教学创新与可持续发展。 相似文献
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COSMIC星座GPS无线电掩星探测利用GPS开环接收技术提高低层大气观测数据的质量和对上升掩星事件的跟踪能力.开环掩星观测数据受到GPS导航数据调制的影响,在其数据后处理中必须消除该影响以获得高质量的科学反演结果.利用GPS导航数据调制码数据和利用开环数据本身内在的关系等两种方法可以消除该影响.将上述方法应用于COSMIC的掩星事件个例反演,获得了修复的大气附加相位数据;并利用几何光学近似反演方法和全谱反演方法,获得了射线弯曲角. 全谱反演方法获得的弯曲角及其温度反演结果与COSMIC数据中心的结果一致,说明我们的算法是有效的. 相似文献
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Y. J. CHIU A. M. BORGHUIS H. Y. LEE K. T. CHANG J. H. CHAO 《国际泥沙研究》2007,22(4):304-317
Sedimentation from soil erosion is a critical reservoir watershed management issue. Due to the difficulty of field investigations, empirical formulas are commonly used to estimate the soil erosion rate. However, these estimations are often far from accurate. An effective alternative to estimating soil erosion is to analyze the spatial variation of 137Cs inventory in the soil. 137Cs can be adsorbed by the soil and is widely assumed to change its distribution only when disturbed by rainfall and human activities. Thus, 137Cs distributed in soils can be a useful environmental tracer to estimate soil erosion. In this study, the net soil loss estimate is 108,346 t/yr and the gross erosion and net erosion rates are 10.1 and 9 t/ha yr respectively. The sediment delivery ratio is therefore estimated to be 0.9 based on the two erosion rates. Because of the steep hillsides in the watershed, only 10% of the sediment yield stayed in the deposition sites and 90% was transported to the river as the sediment output. Soil erosion estimates from spatial variations of the 137Cs activity in the Baishi river watershed showed satisfactory accuracy when compared to sediment yield data. Using soil 137Cs concentrations is therefore a feasible method for estimating soil loss or deposition in Taiwan. Data sampling, analysis and result of this approach are given in this paper. 相似文献
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