A contrast of two typical LUCC processes and their driving forces in oases of arid areas: A case study of Sangong River Watershed at the northern foot of Tianshan Mountains

Aerial photographs taken in 1978 and 1987, Landsat TM images in 1998 as well as soil, hydrology and socio-economic data for the oases in Sangong River Watershed were processed by Remote Sensing (RS) and Geographic Information System (GIS). There are two typical agricultural land uses in oases, Farm-based Land Use with large-scale intensified agricultural activities (FLU) and Household Responsibility-based Land Use with small-scale activities (HRLU). The Index Model of Land Use/Land Cover Change (LUCC), Weighted Index Sum (WIS) and logistic stepwise regression model were established to contrast the two typical LUCC processes and their driving forces. The land use patterns were dominated by cropland and grassland for the entire region, and cropland, residential and industrial land were increasing stably. In the HRLU areas, woodland and grassland declined dramatically, but in the FLU areas, grassland decreased only by 12.0%, whereas woodland increased by 13.7%. LUCC was stronger in the earlier stage (1978–1987) than in the later stage (1987–1998) for the entire region. LUCC was more intense in the HRLU areas than in the FLU areas during the entire period (1978–1998). Policy was a key factor in the land use change, and water resources were a precondition in land use. Under the control of policy and water resources, the main human driving factors included population and economy, and the main natural restrictions were soil fertility and groundwater depth. Human driving factors controlled the land change in the HRLU areas, but natural restriction factors dominated in the FLU areas. In the mean time, intensification of LUCC in the region had some spatiotemporal implications with a fluctuation of impact factors.     

采用扁铲侧胀试验估算土的侧向基床系数的探讨

根据双曲线拟合压缩试验和载荷试验形态，拟合扁铲侧胀试验形态，从小应变的扁铲侧胀试验推导出在工程上实用的大应变的土的侧向基床系数。     

中子活化分析在公路交通燧洞水文地质调查中的应用

利用中子活化测试结果 ,对岩石及泉水干涸残余物中常量及微量元素的进行分析对比 ,以了解深层岩体有关的地质与水文地质信息     

宝兴县城堤防工程灌注桩施工中的几个问题

介绍在宝兴县城堤防灌注桩工程施工中，如何解决孔轴线倾斜、卡钻、坍孔、导管堵塞等技术难题。     

长白山天池火山区电性结构和岩浆系统

在长白山火山区及其附近 ,沿 5条伞状测线和 1条北西向测线进行了 6 1个大地电磁测深点的观测。用Robust等方法对观测资料进行了处理 ;应用阻抗张量分解方法消除了局部不均匀体的影响 ;计算了反映地下横向不均匀性的地磁感应矢量。利用RRI二维自动反演等技术对资料进行了解释。结果表明 :在近地表存在低阻体 ,并分别与长白山天池水体、聚龙泉温泉、锦江温泉及长白山山门附近的地下水相对应。在长白山天池及其以北和以东地区 ,约 12km深处存在电阻率很低的地质体 ,电阻率为 10到几十Ω·m ,可能是地壳岩浆囊。在测区范围内 ,地壳电性结构在南北方向存在着明显的横向变化 ,而东西方向相对均匀 ,变化比较平缓     

白令海和楚科奇海水文特征和水团结构的初步分析

根据我国首次北极科学考察所获 CTD资料 ,分析了白令海和楚科奇海的水文特征和水团结构。研究表明 :(1 )该两海域温、盐度的分布有着明显的区域性差异。楚科奇海的温、盐度普遍低于白令海。 (2 )夏季 ,白令海大部分水域温度垂直分布的突出特点是 :在 2 0 m和 2 5 0 m间存在温度低于 3°C的中层冷水。 (3 )在楚科奇海北纬 70°以北海域 ,不论是水温或盐度皆明显减小 ,从而在此区域形成强的温、盐度锋带。 (4)在白令海存在三种水团 ,而楚科奇海的水团则大致分为两类     

The impact of resolution on the accuracy of hydrologic data derived from DEMs

1 Introduction Automated extraction of drainage features from DEMs is an effective alternative to the tedious manual mapping from topographic maps. The derived hydrologic characteristics include stream-channel networks, delineation of catchment boundaries, catchment area, catchment length, stream-channel long profiles and stream order etc. Other important characteristics of river catchments, such as the stream-channel density, stream-channel bifurcation ratios, stream-channel order, number…     

PROTEM-37瞬变电磁测深系统及应用实例

PROTEM - 37仪器具有分辨率高、动态范围大、抗干扰能力强、探测深度较大等优良性能。简要介绍了该仪器的测深原理、工作装置、野外施工步骤以及资料的处理解释。对TEM和MT资料的联合反演作了有益的尝试。介绍了该仪器在探测地下洞穴、勘察金属矿以及煤田水文地质调查等方面     

滇西泥盆纪——三叠纪盆—山转换过程与特提斯构造演化

滇西地区以昌宁－连缝合带为古特提斯主洋闭合的位置。晚古生代－中生代时期古特提斯经历了一次盆转山和山控盆演变序列的全过程，可大致划分为4个发展阶段：（1）洋盆扩张阶段（D－C2）。古特提斯洋西侧的保山地块属冈瓦纳古陆的东缘，为非火山型被动大陆边缘；东侧的思茅地块属扬子地块的西缘部分，为火山型被动大陆边缘。（2）洋－陆汇阶段（C3－P2）。昌宁－孟连洋向东俯冲消减，思茅地区转化为弧后扩张盆地；墨江一带形成弧后扩张洋盆，思茅地块从扬子西缘分离。（3）弧－陆碰撞阶段（T1－T3），古特提斯主洋及分支洋盆相继关闭，全区发生大规模的造山升隆，前期的盆转山过程转入山控盆阶段，在哀牢山两侧分别形成了受造山作用控制的兰坪－思茅弧后前陆盆地和楚雄周缘前陆盆地。（4）陆－陆碰撞阶段（J1－K），滇西前陆盆地向陆内拗陷盆地转变，造山带的控盆作用结束。     

Copper accumulation by Polygonum microcephalum D. Don and Rumex hastatus D. Don from copper mining spoils in Yunnan Province, P.R. China

A survey was made of copper mining spoils in Yunnan Province, southwest China. Polygonum microcephalum and Rumex hastatus were found to grow extensively on copper mining spoils in Yunnan Province as representatives of typical high-elevation copper flowers. Plants and their associated soil samples collected from several copper mines in the Province were analyzed for copper. It is found that both plant species can grow well on mining spoils rich in copper but with medium nutrient supply. P. microcephalum accumulated more copper in its organs than R. hastatus. The copper concentration in the roots of both species tended to increase with copper increase in the substrates. However, the tendency for the levels of copper in the leaves of both species to increase linearly with soil copper increase is not clear. This study suggests that both species may have some potential for phytostabilization of metal-contaminated soils and for biogeochemical prospecting.