乌鲁木齐河流域柴窝堡盆地与河谷区地下水流模拟   总被引：4，自引：3，他引：1       下载免费PDF全文

李宁  周仰效  李文鹏 《水文地质工程地质》2009,36(3):1-7

乌鲁木齐河流域柴窝堡盆地与河谷区是乌鲁木齐市的重要供水水源地。为了更好地为地下水资源的可持续开发提供依据,本文尝试将几何形状及含水层厚度差异悬殊的柴窝堡盆地与河谷区联合起来,运用GMS模型系统建立了区域地下水稳定流和非稳定流数值模型。通过对观测孔地下水位过程线和地下水流场进行拟合,校正了研究区的渗透系数、给水度和储水率等水文地质参数。并运用模型分析了研究区的地下水流系统、地下水均衡量、地下水位变化趋势及地下水位监测网的设计。结果表明研究区地下水流主要存在两个径流排泄区:沿乌鲁木齐主河道的径流排泄区和以柴窝堡湖和大小盐湖为排泄中心的径流区;地下水储存量相对较大,能够调节季节性变化与地下水开采的影响;应加强主要河流洪积扇补给区和山前侧向补给带地下水位的监测与排泄区泉水流量的观测。  相似文献   

福建永安白垩纪红层盆地丹霞地貌及特征   总被引：2，自引：1，他引：1  

梁诗经 《福建地质》2009,28(1):1-9

永安白垩纪红层盆地位于福建省中部永安市东隅,大地构造处于华夏古陆武夷隆起的西南部,盆地内晚白垩世崇安组紫红色厚层一巨厚层砾岩、砂砾岩经内、外动力地质作用,发育峰丛、石峰、石堡、石墙、石柱等正地貌和线谷、巷谷、峡谷、峡谷曲流等负地貌,构成风光旖旎的丹霞地貌景观。永安红层盆地丹霞地貌于上新世开始发育,现已处于中年期发展演化阶段,是开展中年期丹霞地貌旅游和科考的宝贵地质遗迹。  相似文献   

不确定区域间拓扑关系定性推理   总被引：1，自引：0，他引：1  

杜世宏  秦其明  王桥  杨一鹏 《测绘学报》2005,34(4):349-354

提出不确定区域间拓扑关系的组合描述法,它对拓扑关系的描述能力与扩展九交完全相同.但组合描述模型的优点在于用已有的5种面/面基本拓扑关系的组合来表示44种不确定区域间的复杂拓扑关系,可以把44种复杂拓扑关系的推理转化为5种基本拓扑关系推理的组合,从而实现不确定区域间拓扑关系的推理.  相似文献   

Research on the algorithm of extracting ridge and valley lines from contour data     

JIN Hailiang GAO Jingxiang 《地球空间信息科学学报》2005,8(4):282-286

IntroductionSince middle period of the eighties ,howto ex-tract ridge and mountain valley lines automati-cally from digitized contour data and DEMdatahas al ways been an i mportant research in geo-matics field. In past documents , Chinese andforeign scholars have proposed many methodsfor auto-extracting terrain feature informationsuitable for different research purposes . For ex-ample ,Fei Lifan uses ridge and valley lines ex-tracted from digitized contour to group contourline generalization…  相似文献   

城区与郊区不同地形地貌下云地闪分布规律初步研究   总被引：2，自引：0，他引：2  

高磊  潘解祥 《气象科技》2009,37(6):729-733

利用上海3台SAFIR3000闪电定位仪的测量数据、计算机软件技术和数据统计方法对上海地区云地闪的分布规律进行了研究,得出了以下结论：①受地形地貌及高大建筑的影响,上海地区的云地闪分布规律是南北多,东西少,城区多,郊区少;②在郊区发生的云地闪密度虽然低于城区,但是其雷电流的平均强度要高于城区;③上海地区14：00-21：00是云地闪发生最为频繁的时间段。雷暴日是用于表征某地雷电活动的频繁程度并据此进行风险评估及确定雷电防护等级的一个重要参数,但此参数在实际应用过程中存在着一些问题,文章提出了用＂闪电密度＂或者＂地闪密度＂代替雷暴日的设想。  相似文献   

Model Simulations of the Boundary-Layer Evolution over an Arid Andes Valley   总被引：1，自引：1，他引：0  

Inge Bischoff-Gauß  Norbert Kalthoff  Samiro Khodayar  Melitta Fiebig-Wittmaack  Sonia Montecinos 《Boundary-Layer Meteorology》2008,128(3):357-379

The boundary layer of the Elqui valley in the arid north of Chile exhibits several interesting phenomena, such as a very shallow convective boundary layer (CBL) during the day. In the morning, warming is observed in and above the CBL, while the humidity decreases in the CBL. At midday, in and above the CBL of the valley, the temperature stagnates. In the afternoon in the CBL the temperature decreases and humidity increases, although the latent heat flux is very low. Because the characteristic features of the valley atmosphere are hard to interpret from observations alone, model simulations were applied. The simulations indicate that all components of the budget equations, i.e. the turbulent flux divergences, advection via the sea breeze, the upvalley and upslope wind systems, as well as subsidence, contribute to the evolution of the valley atmosphere.  相似文献   

淮河流域一次MCC的环境流场及动力分析   总被引：1，自引：1，他引：0  

井喜  井宇  李明娟  王明学  杜继稳  李栋梁 《高原气象》2008,27(2):349-357

利用卫星云图和高空风等各种天气学资料,对2006年7月2日淮河流域发生的一次中尺度对流复合体(MCC)和淮河流域暴雨天气过程进行了大尺度环境场和物理量的诊断分析。结果表明:MCC是造成暴雨的直接影响系统,对流层中层来自北方的干侵入对MCC的生成发展起着重要作用;对流层低层华北冷空气的南下锋生、对流层中低层西南气流沿锋面爬升,为MCC的生成提供了触发机制;高低空急流耦合、天气尺度经向间接次级环流圈的形成,为MCC的生成、发展和维持提供了动力条件;对流层低层能量场特征、风速风向垂直切变特征、总指数及云图弓状回波后部干侵入区的变化等,对MCC的生成和发展有指示意义。  相似文献   

Late Quaternary glaciation of the Tianshan, Central Asia, using cosmogenic Be surface exposure dating     

Ping Kong  David Fink  Chunguang Na  Feixin Huang 《Quaternary Research》2009,72(2):229-233

Glacial deposits are present at the head of the Ürümqi River valley, Tianshan, Central Asia. ¹⁰Be surface exposure ages of 15 boulders from three sites along a 12 km valley transect range from 9 to 21 ka suggesting emplacement by glacial retreat and advance commencing at the global last glacial maximum (LGM) and most likely abating in the early Holocene. Although the age spread for a given locality is not small, perhaps indicating post-depositional reworking, maximum ages per site are either coeval with or are post-LGM and inconsistent with previous pre-LGM electron spin resonance ages.  相似文献   

Tectonic Landform of Quaternary Lakes and Its Implications for Deformation in the Northern Qinghai‐Tibet Plateau   总被引：1，自引：1，他引：0  

WANG An  WANG Guocan  LI Dewei  XIE Defan  LIU Demin 《《地质学报》英文版》2009,83(1):121-129

The Hohxil region in the northern Qinghai-Tibet Plateau is occupied by numerous plateau lakes, which have long been inferred as being tectonic products. However, so far little evidence has been found to support this tentative inference. Field survey and morphotectonic analysis of TM satellite images in the eastern segment of the Hohxil region revealed that Kusai Lake and Yelusu Lake are S-shaped pull-apart basins, which were dominated by left strike-slip master faults trending WNW–ESE. The pull-apart distances of the two lakes are analyzed to be <15-20 km and 15 km respectively. Based on studies of the faulting rate, the initiation ages of the pull-apart basins are suggested to be approximately in the Early Pleistocene. The pull-apart basin tectonics is further regarded as a common mechanism for the widely distributed large lake basins in the northern Qinghai-Tibet Plateau. Regional distribution of these pull-apart basins and their substantial intra-block slip suggest that a sinistral shear stress, which is independent of the distinguished strike-slip faults, has been imposed on across the northern Qinghai-Tibet Plateau. Thus, the intra-block slip may be an important expression of the eastward extrusion of the Plateau crustal material in accommodating the ongoing continent–continent convergence between India and Eurasia. The revelation of pull-apart tectonics within the Plateau hinterland provides field evidence and a possible style of deformation for the newly proposed continuous deformation by the global positioning system (GPS) measurement across the northern Qinghai-Tibet Plateau. A model, with respect to systematic tectonic landform development, for pull-apart basins is finally proposed.  相似文献   

城郊型流域治理优化模式设计研究——以兰州市南郊西果园流域为例     

陈建荣 《冰川冻土》2009,31(2)

以兰州市边缘的城郊型小流域为研究对象,使用多目标决策方法,进行城郊型流域治理优化模式设计研究.结果表明:小流域优化结构模式使经济林果业得到发展,提高了草地的产量,为工业用地的发展预留了空间.水土保持方面,综合保水率、保土牢达到80%以上,年径流模数和土壤侵蚀模数显著降低,减少侵蚀量15.73×104t,减少径流255×104m3.优化结构模式实施后,经济、生态和社会效益明显,使小流域年人均农业收入可由原来的1 303元增至2 646元;减轻了市区的洪灾威胁,有效地控制了泥沙下泄进入市区,起到净化市区空气、水源污染;增强了人们的水土保持生态环境建设意识,激发了群众城郊型小流域水土保持建设的积极性.  相似文献