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  • 1979—2017年青藏高原色林错流域气候变化分析

    Subjects: Environmental Sciences, Resource Sciences >> Basic Disciplines of Environmental Science and Technology submitted time 2020-06-21 Cooperative journals: 《干旱区研究》

    Abstract:利用中国区域地面气象要素数据集(CMFD) 和GLDAS数据集的1979—2017年格点气温(2 m)、降水、比湿、风速(10m)、太阳辐射资料,运用线性回归、累积距平、滑动平均及Mann-Kendall突变检验方法,研究了近39 a来色林错流域气候特征和时空变化规律。结果表明:色林错流域多年平均气温为-1.8℃,降水量为389.4mm,比湿为3.2g·kg-1,太阳辐射为236.2W·m-2,风速为3.7m·s-1。色林错流域的月平均气温仅在5—9月高于0℃,流域平均气温以0.049℃·a-1的速率呈显著升高之势。流域降水集中在6—9月,占全年降水量的80%以上,流域平均年降水量以4.65mm·a-1的速率显著增大。气温的升高和降水的增加暗示了色林错流域在近几十年来呈现显著的暖湿气候背景。1979—2017年,流域年均风速变化在空间上表现为南部增大、北部减小,减小速率以流域东北部最大。多年平均太阳辐射空间分布整体呈自东向西逐渐增大的趋势,时间变化以-0.29W·m-2·a-1的速率显著减小,1980s中期至2000s中期减小尤为明显。流域的年均比湿变化趋势并不显著,但2006年开始呈显著减小之势。本研究结果对该流域的湖泊扩张机制、生态系统对气候变化的响应以及物候变化等研究具有指示意义。

  • 精细化交叉口数据模型的建模方法

    Subjects: Computer Science >> Integration Theory of Computer Science submitted time 2019-01-28 Cooperative journals: 《计算机应用研究》

    Abstract: Aiming at the deficiency of physical geometry and traffic organization canalization description in traffic network data model at present, this paper presented a road network data model oriented to refined intersections. And the model described logical topology and rule of markings of intersections from physical, logical and geometric levels. It could also support the calculation requirements of traffic analysis. At the same time, based on physical topology and logical topology, the paper presented a modeling method of intersection geometry topology by using linear reference technology based on elements. The results show that this method can effectively realize the automatic generation of precise intersection models.