Drought and institutional adaptation in the Great Plains of Alberta and Saskatchewan, 1914–1939

Agriculture in the southern Great Plains of Canada has been particularly vulnerable to prolonged episodes of drought. Using climate data and a precipitation minus potential evapotranspiration index, the extent of the region’s exposure to drought is examined. Between 1914 and 1917, the Dry Belt was particularly vulnerable to drought, whereas after 1928, a much larger region known as the Palliser Triangle covering most of southern Alberta and Saskatchewan was much more exposed to drought. These droughts provoked major institutional adaptation, in particular the establishment of the Special Areas Board by the Government of Alberta, and the creation of the Prairie Farm Rehabilitation Administration by the Government of Canada. Both organizations have proved to be relatively permanent public adaptations to the natural hazard of drought in the region. Moreover, these earlier experiences with prolonged drought as well as institution-building may be of value in helping the residents of the Palliser Triangle adapt to predicted climate changes in the future as well as anticipate some of the barriers to effective institutional adaptation.     

喜马拉雅山脉的地质地貌特征:来自SRTM数字高程模型和降水量数据的约束

利用GTOPO30和SRTM3数字高程(DEM)数据,提取了喜马拉雅山脉(造山带)的数字高程模型并对其进行了地质地貌的初步分析。从SRTM3数字高程数据提取出坡度数据,初步分析了喜马拉雅山脉坡度和高程的特征。数字高程和坡度图清楚地展现了喜马拉雅大型断裂带(构造边界)的空间分布特征。分析了中国气象局下属的西藏、青海、四川和云南4省区气象观测台站55年来的年平均降水量观测数据、喜马拉雅山脉南坡的年平均降水量数据、喜马拉雅DEM和裂变径迹数据,发现喜马拉雅山脉从东至西,年平均降水量逐渐减少,地形起伏逐渐变小,而高程渐次升高,与此同时剥蚀速率降低;从北至南,年平均降水量逐渐增加,地形起伏增大,高程快速降低,而剥蚀速率则急剧升高。这充分说明了喜马拉雅年平均降水量大的地区,地表剥蚀作用相对较强,年平均降水量小的地区,地表剥蚀作用则较弱,即:在喜马拉雅地区,长周期的地表剥蚀过程(可长达数个百万年时间尺度)和短周期(仅仅50年)的降水量观测是耦合的。     

极化SAR目标相对最优极化研究

目标相对最优极化就是选取一种极化状态,使得研究目标和背景地物的接收功率对比达到最大。通过讨论了目标相对最优极化问题,提出了改进的模型和解算方法,利用实际数据对其模型和方法进行了实验,验证了其有效性和正确性。     

Artificial Upwelling of Deep Seawater Using the Perpetual Salt Fountain for Cultivation of Ocean Desert

Deep seawater in the ocean contains a great deal of nutrients. Stommel et al. have proposed the notion of a “perpetual salt fountain” (Stommel et al., 1956). They noted the possibility of a permanent upwelling of deep seawater with no additional external energy source. If we can cause deep seawater to upwell extensively, we can achieve an ocean farm. We have succeeded in measuring the upwelling velocity by an experiment in the Mariana Trench area using a special measurement system. A 0.3 m diameter, 280 m long soft pipe made of PVC sheet was used in the experiment. The measured data, a verification experiment, and numerical simulation results, gave an estimate of upwelling velocity of 212 m/day. This revised version was published online in July 2006 with corrections to the Cover Date.     

东海黑潮热输送及其与黄淮平原区汛期降水的关系

根据日本气象厅1956—1990年PN（G）断面观测资料分析东海黑潮热输送的变异特征，并探讨其冬季热输送与黄淮平原区汛期（6－8月）降水的关系。结果表明，黑潮通过PN（G）断面多年平均的热输送达15．74×1014W，其中冬季热输送的年际和长期变化特别明显；冬季热输送年际变化的周期主要为对．23.4a、3.5a、和2.6a，长期变化总趋势是70年代末以前各年热输送距平均为负值，对年代末接近多年平均值，进入80年代各年距平值不仅为正且逐年增大；东海黑潮冬季热输送与黄淮平原区汛期降水具有相近的长期变化趋势，两者间存在较好的负相关关系。     

长江中下游6月份降水的一个预报指标

根据１９６３－１９９２年嵊山海洋站２月海气感热输送和２２ａ太阳磁周期与降水的关系，提出了一个长江中下游６月降水的综合预报指标，用此指标，对１９９３年６月长江中下游降水进行回报，结果与实况一致。     

长江和长江口高含量无机氮的主要控制因素

根据1998－1998年长江和长江口河水和雨水的现场调查、历史资料以及相关文献，定量分析长江流域无机氮的主要来源和输送调查。估算表明，降水无机氮、农业非点源氮（化肥和土壤流失的氮）和点源污水氮的输入分别占长江口无机氮输出通量的62．3％、18．5％和14．4％。氮的降水输入是长江口高含量无机氮的主要来源，进入长江的降水氮仅仅大约占长江流域全部降水氮的36．8％。降水米要受控于化肥气态损失、化石燃料及动植物过程中释放的物质等。实际上，化肥N的气态损失和农业非点源流失大约占长江流域年化肥N使用量的60％，这是控制长江口高含量无机氮的关键因素。     

厄尔尼诺现象和浙江近海鲐鲹鱼渔获量变化关系──长江口ENSO渔场学问题之二

本文研究浙江近海1970年到1992年鲐鱼渔获量变化与Elnino现象的关系，结合捕捞强度，长江中下游汛期（4—9月）降水量距平年际变化综合分析，探讨浙江近海鲐鱼渔获量变动规律，为合理开发渔业资源提供科学依据。     

矿产预测中成矿信息的提取和强化

成矿信息的提取是矿产预测的重要手段,其方法的有效性直接影响到预测成果的可靠性。在成矿规律研究的基础上,有意识地干预模型的构成,突出与成矿有关的信息;抑制某些成矿意义不明显和属干扰的信息,有目的地使模型向反映成矿信息的方向逼近,提高模型与矿床实际赋存地质环境的吻合程度,均是成矿信息提取和强化的内涵。本文从研究实践中总结了先验约束模型和非先验约束模型的强化方法,在新疆阿勒泰地区的地质－找矿工作中已取得