国家级格点化定量降水预报系统   总被引：10，自引：7，他引：3  

曹勇  刘凑华  宗志平  谌芸  代刊  陈涛  杨寅 《气象》2016,42(12):1476-1482

利用主客观融合降水反演、降水统计降尺度、降水时间拆分等技术构建了国家级格点化定量降水预报系统。该系统结构合理,模块功能明确,于2014年6月在国家气象中心投入业务使用,生成0~168 h时效,10 km分辨率,逐3 h的格点化定量降水预报产品。通过对2015年第13号热带气旋苏迪罗的格点化降水预报个例检验,结果显示,相比欧洲中期数值预报中心的确定性模式预报和预报员主观预报,该产品能更好地体现台风降水的时空精细化分布特点,对福建东北部和浙江东南部的特大暴雨中心位置表现更准确细致。通过对2015年4—9月的格点化产品整体效果检验,结果显示,相比欧洲中期数值预报中心的确定性模式预报和由反距离客观分析后的预报员主观预报,该产品既能保持和预报员主观预报相同的准确率,同时也能较明显地提高降水预报的时空精细化程度。  相似文献   

武威市初、终霜日气候特征   总被引：2，自引：0，他引：2  

丁文魁  杨晓玲  殷玉春  马玉山 《气象科技》2016,44(4):647-652

为了因地制宜,合理调整种植结构和布局,有效利用农业气候资源。利用1961—2014年武威市4个气象站点初、终霜日(最低地温≤0℃)观测资料,采用现代气候诊断分析方法,系统分析了该市年初、终霜日的时空变化特征。结果表明:受海拔高度、地形地势以及植被覆盖情况的影响,在空间分布上,武威市初霜日为山区早于荒漠区早于绿洲平原区,终霜日为山区晚于荒漠区晚于绿洲平原区,各地初、终霜日存在一定的异常性,正常初、终霜日均在60%左右,对农业生产造成危害的偏早和特早初霜日、偏晚和特晚终霜日的概率均在20%左右。在时间变化上,武威市初霜日呈显著推迟趋势,终霜日呈显著提早趋势,霜期呈显著缩短趋势,终霜日提早的幅度比初霜日推迟的幅度更大。初霜日和终霜日的时间序列均分别存在着8~10年和9~11年的准周期变化。初霜日在1998年发生了气候突变,终霜日在1996年发生了气候突变。  相似文献   

Risk management study on impulse waves generated by Hongyanzi landslide in Three Gorges Reservoir of China on June 24, 2015   总被引：3，自引：1，他引：2  

Bolin Huang  Yueping Yin  Chunlan Du 《Landslides》2016,13(3):603-616

On June 24, 2015, Hongyanzi slope located in Wushan County of the Three Gorges Reservoir collapsed, generating 5–6-m-high impulse waves, which overturned 13 boats, killed 2 persons, and injured 4 persons. It is the second incident of landslide-generated impulse waves since the 175-m experimental impoundment in 2008. The emergency investigation shows that Hongyanzi landslide is a bedding soil landslide with a volume of 23?×?10⁴ m³ induced by a series of triggering factors such as rainfall, flooding upstream, and reservoir drawdown. The nonlinear Boussinesq water wave model is used to reproduce the impulse waves generated by the landslide of June 24th. The numerical simulation results suggest that the wave propagation process was influenced by the T-shaped geomorphic conditions of river valley, and the coastal areas in the county seat were the major wave-affected areas, which is opposite to the landslide. The numerical wave process accord well with the observed incident, and the investigation values were in good agreement with the calculated values. Moreover, the worst-case scenario of the 7?×?10⁴ m³ deformation mass beside Hongyanzi landslide is potential to generate impulse waves, which was predicted with the same numerical model. This adjacent deformation mass will probably generate impulse waves with maximum height and run-up of 2.2 and 2.0 m, respectively, and only a very few areas in the water course had waves rising to a height of 1 m or above. The research results provide a technical basis for emergency disposal to Hongyanzi landslide and navigation restriction in Wushan waterway. More importantly, it pushes the risk management of the navigation based on the impulse wave generated by landslide. It is advised that the Three Gorges Reservoir and other reservoirs around the world should put more efforts in performing special surveys and studies on the potential hazards associated with landslide-generated impulse waves.  相似文献   

Microbial dechlorination of HCB,PCP, PCB180, HCH and PCE in a Yangtze Three Gorges Reservoir enrichment culture,China     

Irene Kranzioch-Seipel  Ulrike Beckert  Chaofeng Shen  Daqiang Yin  Andreas Tiehm 《Environmental Earth Sciences》2016,75(10):928

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Assessment on characteristics of LUCC process based on complex network in Modern Yellow River Delta,Shandong Province of China     

Baolei Zhang  Le Yin  Shumin Zhang  Chaoyang Feng 《Earth Science Informatics》2016,9(1):83-93

Research on land use cover change (LUCC) has reached a mature stage and has formed a relatively complete scientific system. However, most studies analyzed the LUCC process from the view of land use types ignoring the integrality and systematicness of the land use system, which brought certain constraints to understanding the complexity and systematicness of land use process scientifically. Using the Modern Yellow River Delta (MYRD) of China as the study area, this research introduced the complex network analysis method to the study of the LUCC process by using 9 periods of land use data between 1976 and 2014 to build 8 stages of complex networks. The values of node degree, betweenness, changing proportions, and average shortest path in the networks were calculated to identify the key land use types, changing models of land use types, and the stability of land use system. Additionally, main parts of complex networks of the period from 1976 to 1995 and the period from 1995 to 2014 were selected to evaluate the changing characteristics of the LUCC process. The results indicated the area and proportion of natural wetland kept reducing, but the area and proportion of artificial wetland or non-wetland continued rising. The bare land, reed, bush, and cultivated land were the key land use types of the LUCC process. In the past 38 years, beach, bare land, reed and bush had been the output types, and the building land and salt pan had been the input types. The LUCC process has been a transfer process of natural wetland to artificial wetland and non-wetland in the past 38 years, which could be divided into land accretion process (1976 to 1995) and construction process (1995 to 2014). The land ecosystem was unstable for the period from 1990 to 2006.  相似文献   

Protection of neighbour buildings due to construction of shield tunnel in mixed ground with sand over weathered granite     

Qing-Long Cui  Huai-Na Wu  Shui-Long Shen  Zhen-Yu Yin  Suksun Horpibulsuk 《Environmental Earth Sciences》2016,75(6):458

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Characteristics of groundwater flow field after land creation engineering in the hilly and gully area of the Loess Plateau   总被引：1，自引：0，他引：1  

Xiaoxi Yin  Luwang Chen  Jiandong He  Xiaoqing Feng  Wen Zeng 《Arabian Journal of Geosciences》2016,9(14):646

In order to study the degree of influence and control mechanism to groundwater flow field caused by land creation engineering in the hilly and gully area of the Loess Plateau, based on the geological and engineering conditions of the first stage project of Yan’an new district in China, numerical simulation of groundwater flow is carried out by the Feflow and GIS technologies. From the simulation, punning measure relatively reduces infiltration recharge and artificial gravel drain increases groundwater seepage. The basic characteristics of groundwater flow field is controlled by the old and new topographies in the whole study area, and artificial gravel drain plays an auxiliary role in accelerating groundwater drawdown upstream and promotes groundwater rise downstream. According to differences of groundwater level and declining percentages of hydraulic gradient in the main and secondary gullies, dewatering of artificial gravel drain in the secondary gully is more effective than that in the main gully, which will yet play an important role in the future. The study results will make contributions to understand groundwater response to land creation engineering and will be beneficial to take necessary measures to prevent collapse of loess and failure of building foundation in the hilly and gully area of the Loess Plateau.  相似文献   

Evaluation of Effective Depth of PVD Improvement in Soft Clay Deposit: A Field Case Study     

Jun Chen  Zhen-Yu Yin  Ye-Shuang Xu  Suksun Horpibulsuk 《Marine Georesources & Geotechnology》2016,34(5):420-430

This article presents a case history of determination of effective depth of prefabricated vertical drains (PVDs) under embankment loading on a very soft clay deposit in central China, near Jiujiang, Jiangxi Province. The height of the embankment was 5.3 m and construction time was about one year. The PVDs were installed to a depth of 8.5 m at a spacing of 1.5 m in a triangular pattern. Field observations and the finite element method (FEM) were employed to analyze the performance of the soft deposit during embankment construction. The influential depth of the embankment loading was evaluated based on settlement, excess pore pressure, and stress increase in subsoil, both from the observed data and FEM analysis. The effective PVD depth was determined in the following ways: (1) the depth of 5% subsoil settlement of surface settlement; (2) vertical stress increase in subsoil of 25% in-situ stress; and (3) consolidation time/PVD depth relation by FEM. Based on the analysis, the effective depth of PVDs was determined to be between 10 and 12.8 m for this field case.  相似文献   

西太平洋暖池热盐结构盐度场变异的主模态          下载免费PDF全文

秦思思  张启龙  尹宝树 《应用海洋学学报》2016,35(3):303-310

基于1950~2011年间的月平均温、盐度资料,以28℃等温线作为西太平洋暖池的定义标准,并取ΔT=-0.4℃,分别计算了暖池区(20°N~15°S,120°E~140°W)各格点混合层、障碍层和深层的平均盐度,构成了暖池热盐结构的盐度场.据此,运用EOF分解法分析了暖池热盐结构盐度距平场主要模态的变化特征及其与ENSO间的关系,并探讨了主要模态的年际变异机理.结果表明,暖池热盐结构盐度场第一模态揭示了盐度场变异的关键区位于暖池中部;该模态具有2~4a的年际变化和准10a的年代际变化,并在1977年前后经历了一次气候跃变(此外,深层盐度场第一模态还在1999年前后发生了一次气候跃变),且在跃变前后与不同类型的ENSO事件有较密切的联系.暖池中部混合层和障碍层盐度的变化比较一致,即在跃变前盐度为偏高期,而在跃变后则变为偏低期.暖池中部深层盐度在1977年以前和1999年之后皆处于偏高期,而在1978~1999年间则处于偏低期.而且,从混合层至深层,盐度的变化幅度逐渐变小.进一步分析表明,暖池中部混合层和障碍层盐度的年际变化主要是由纬向风、南赤道流(SEC)和降水共同引起的,即当东风增强(减弱)时,强(弱)SEC将携带更多(少)的高盐水进入混合层或潜沉至障碍层,同时局地降水的减少(增多),也使得混合层和障碍层的盐度增加(减少);深层盐度的年际变化主要是由SEC和赤道潜流(EUC)导致的,即当SEC增强(减弱)时,将有更多(少)的高盐水进入暖池,而当EUC增强(减弱)时则有更多(少)的低盐水流出暖池,从而使得暖池的深层盐度升高(降低).  相似文献   

Slow earthquakes,tectonic tremors,and rheology of the lower continental crust     

An Yin 《《地质学报》英文版》2018,92(Z1):3-3

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