黑龙江省近50年干旱发展事实及分析

应用实测的降水、气温和土壤湿度资料，分析黑龙江省近50年干旱化的发展趋势。结果表明，用月平均气温、降水量距平和均方差所构造的“干旱指数”以及土壤湿度显示近50年来黑龙江省是向干旱发展的。1990年以来这种干旱化趋势尤为明显，西部亚干旱地区的干旱化相对更严重。在气温和降水两个要素中，气温的升高对干旱化的作用可能更重要。利用CNEP／NCAR的容积式土壤湿度计算了全球50年来干旱的发展趋势，结果表明：黑龙江省近50年干旱的发展是全球气候异常的重要组成部分。这显然与全球气候变暖的大背景有关。为探讨东北区干旱的发展对全球气候变暖的响应，利用Jones等的1951－2000年全球平均气温资料和黑龙江省10个站的干旱指数进行线性回归分析。结果表明：在全球平均温度上升1℃的情况下，黑龙江省的干旱化程度要增加10％左右。这种形势应该引起我们的关注。     

Tomographic investigation of the upper crustal structure and seismotectonic envi—ronments in Yunnan Province

Investigation has been made for the upper crust structure and seismotectionic environments in Yunnan Province using the plentiful DSS data of the four profiles.The derived velocity model has a good relationship with the ex-posed basins,uplifts and faults.The low velocity anomaly corresponding to the volcano also has been revealed.There exits a prominent lateral inhomogeneity within the upper crust of Yunnan region.The depth of crystalline basement generally ranges from 0km to 5km,and the bedrocks are exposed on the ground directly in some places,nevertheless the thickness of sedimentary cover also can reack to 8km or even 12km at some targe depressions.Although the Changning-Shuangjiang fault is a boundary between two first class tectonic units,its incision depth within the crust maybe shallow.On the other hand,known as the plates‘seam,the Honghe fault has a distinct evi-dence of extending into the mid-lower crust.The widely spread activity of the volcanoes in the geological era has a close relationship with the earthquake‘s occurrence nowadays.Despite of the ceasing of the volcanoes in some places on the ground,the material in the mid-lower crst is still active,and there still exists strong upward stress-As the ceasing of the volcanoes on the surface,most parts of the power from the lower crust and the upper mantle cannot be released;therefore it accumulates at some appropriate tectonic locations.Moreover,the saturation of the water from the basin,the action of other fluids,and the effects of the outer stress maybe another direct reason ac-count for the strong earthquakes‘occurrence in Yunnan region.     

云南地区上部地壳结构和地震构造环境的层析成像研究

利用4条DSS丰富的测深资料，对云南地区上部地壳结构和地震构造环境进行了层析成像研究．成像结果显示，得到的速度模型与地表盆地、隆起与断裂有很好的对应关系，显示了与地表火山岩系相应的低速异常体．云南地区上部地壳横向不均匀性显著．结晶基底的深度一般为0~5 km．局部基底高于海平面，基岩直接出露地表，同时在一些大的坳陷处沉积厚度可达8~12 km．作为一级构造单元的昌宁-双江断裂可能切割不深，而红河断裂作为板块缝合线切割较深，有延伸到中下地壳的迹象．云南地区历史上的广泛的火山活动与现今中强地震的发生有紧密联系．有的地方尽管现今地表已不再有火山活动，但中下地壳活动并未停止，存在较大的应力作用．由于地表火山活动停止，来自中下地壳和上地幔的大部分能量得不到释放，而在有利的构造部位积聚，以及盆地水的渗透、其它流体的作用和外动力作用，可能是云南地区经常诱发中强地震的重要原因．      

319国道涪陵至彭水沿线滑坡发育特征

在涪陵至彭水长约140km范围内，319国道沿线发育有滑坡32处，发育密度约为0．23个/km，发育形式以堆积层滑坡和岩石顺层滑坡为主。在现场调查的基础上，总结和分析了沿线滑坡发育的地质环境和人为环境，结果表明，沿线的地质构造、地形地貌以及地层岩性组合是滑坡发育的主要原因，河流的侧向切蚀作用、暴雨以及人类的工程活动是滑坡形成的重要诱发因素。     

江淮气旋发生发展中尺度系统特征数值模拟研究

本文应用中尺度模式MM5对发生在江淮流域的气旋进行了数值模拟，并用模式输出的高时空分辨率、动力协调资料、HUBEX试验期间的加密观测资料进行江淮气旋的中尺度诊断研究。结果表明：从大尺度角度看，江淮气旋的生成可分为静止锋上的波动和倒槽锋生两种类型，但从中尺度角度分析，它们具有如下共同特点：（1）它们的生成源地均在大别山西侧，大别山地形均使得气旋发展增强，移速减慢。（2）在发展阶段，700hPa层以下的温压场的斜压结构是气旋发展的重要因素，当冷平流与暖平流呈现西北－东南的偶极子型时，气旋发展；当冷暖平流偶极子呈东西型时，气旋发展进入成熟期。（3）气旋中的中尺度雨带与Wave-CISK湿条件对称不稳定区有密切关系，辐合上升区出现在气旋暖锋前部和冷锋后部50－100km范围内。     

NUMERICAL SIMULATIONS AND DOPPLER RADAR DATA ANALYSIS OF A HAIL PROCESS IN HUAIHE RIVER BASIN

A hail process in Huaihe River Basin observed by CINRAD Doppler radar on 12May 2000 hasbeen simulated by using nonhydrostatic mesoscale numerical model MM5.The simulated wind fieldis analyzed and compared with Doppler radar wind data,both of them show that there was ameso-β cyclone around the hail region.Results show that this meso-β cyclone existed below 3 kmin the troposphere and its cyclonic circulation was very obvious below 1 km.The temperature andmoisture fields from the simulation are also analyzed.Furthermore,the storm-relativeenvironmental helicity and CAPE(convective available potential energy)are discussed.     

腾冲火山地热区地壳结构的地震学研究

根据腾冲火山地热区实施的人工地震测深剖面资料 ,用有限差分反演和正向走时拟合方法确定了地壳二维 P波速度结构 .地壳模型显示 ,在腾冲的热海热田附近上地壳存在低速异常体 ,它与火山地热活动可能有关 .测线的二维地壳结构上显示出两条地壳断裂 :龙陵—瑞丽断裂和腾冲断裂 ,其中腾冲断裂可能切穿莫霍界面 .同时 ,根据远震波形资料反演腾冲热海热田地区的 S波速度结构 ,也显示出该地区上地壳存在 S波的低速异常 .本文从深部结构方面探讨腾冲火山的成因 .腾冲火山地热区地壳具有低 P波和 S波速度、低电阻率、高热流值和低 Q值 ,以及上地幔也具有低 P波速度的特点 .由此推测地壳内岩浆来源于上地幔 ,腾冲附近地区存在的上地壳低速度异常可与岩浆的分异作用相联系 .与地球上大多数的活动火山一样 ,腾冲火山位于移动板块之间的边界附近 ,属于“板块边界”火山     

狼山—武威—共和断裂带和地热分布

狼山—武威—共和断裂带是近年来根据重力、航磁资料解释发现的规模仅次于郯庐断裂的大型走滑隐伏断裂带。该断裂带沿狼山—武威—共和一线呈NEE向延伸 ,横切了北大山、龙首山、祁连山和西秦岭造山带 ,使蒙甘青地区在地球物理场和区域构造格架上具有EW分块的基本格局。沿该断裂 ,温泉、地热异常成群、成带分布 ,与其南段亚东—羊八井—那曲走滑断裂 ,构成中国西部一条近SN向导热、控震断裂构造。     

Critical Sensitivity and Trans-scale Fluctuations in Catastrophic Rupture

-- Rupture in the heterogeneous crust appears to be a catastrophe transition. Catastrophic rupture sensitively depends on the details of heterogeneity and stress transfer on multiple scales. These are difficult to identify and deal with. As a result, the threshold of earthquake-like rupture presents uncertainty. This may be the root of the difficulty of earthquake prediction. Based on a coupled pattern mapping model, we represent critical sensitivity and trans-scale fluctuations associated with catastrophic rupture. Critical sensitivity means that a system may become significantly sensitive near catastrophe transition. Trans-scale fluctuations mean that the level of stress fluctuations increases strongly and the spatial scale of stress and damage fluctuations evolves from the mesoscopic heterogeneity scale to the macroscopic scale as the catastrophe regime is approached. The underlying mechanism behind critical sensitivity and trans-scale fluctuations is the coupling effect between heterogeneity and dynamical nonlinearity. Such features may provide clues for prediction of catastrophic rupture, like material failure and great earthquakes. Critical sensitivity may be the physical mechanism underlying a promising earthquake forecasting method, the load-unload response ratio (LURR).     

永登县药水沟—红门寺地热资源综合勘查评价

药水沟—红门寺地热田位于兰州—民和盆地西缘 ,由药水沟、龙王沟温泉和红门寺地热孔组成。利用物化探指标对该地热勘查靶区筛选 ,对地热条件较好的药水沟进行地、物、化和水文综合勘查 ,查明了控制地热的地质构造背景和热水通道 ,提出下步开发建议