基于降水气候强迫的一种地表径流估计方法   总被引：2，自引：0，他引：2  

刘晶淼  丁裕国  周秀骥  李云 《气象学报》2004,62(3):285-293

文中从地表水分平衡的物理机制出发 ,引进降水概率统计分布理论 ,推导出一种由降水气候强迫形成的次网格尺度非均匀径流率计算方法。应用于mosaic方案 ,可进一步计算区域平均径流及产流和汇流。试验证明 ,对于不同物理性质的地表而言 ,由于其土壤入渗能力的差异 ,相同降水气候强迫所能生成的径流量及其相对比值是不同的 ,例如干旱区与湿润区就有很大差异。同时 ,不同空间分布概率的降水量 ,不同站点的地表性质、土壤水力学条件等物理因素的千变万化 ,可使径流特征的空间分布具有很大变异性。因上述各种因素的综合影响 ,由降水气候强迫所形成的地表径流具有特定的非均匀分布是必然的。文中用实测资料验证了其可靠性与可行性  相似文献   

NUMERICAL SIMULATION OF EXTREMELY HEAVY RAIN AND MESO-β SCALE LOW VORTEX IN INVERTED TYPHOON TROUGH^*          下载免费PDF全文

JIANG Yongqiang  WANG Changyu  ZHANG Weihuan  CHEN Zhongyi 《Acta Meteorologica Sinica》2004,18(2):195-210

Large-scale and mesoscale analyses are made for extremely heavy rain(EHR) and meso-β scale low vortex(MSLV) in Jiading District of Shanghai Municipality during 6-7 July 2001.It is shown that the EHR forms in the situation of northern westerly trough linking together with southern inverted typhoon trough at northwest side of the West Pacific Ocean subtropical high. Numerical simulation is made using a 21-layer improved REM(regional η coordinate model) for this course.The results show that the precipitation forms earlier than MSLV.and the strong convergence in wind velocity mate(WVM) triggers the strong precipitation.The formative reasons of WVM.especially the weak wind velocity center are discussed,and the formative mechanisms of the MSLV and EHR are discussed using high spatial and temporal resolution modeloutput physical fields.The results show that the heavy rain releases latent heat and warms the air column,and enhances the low level positive vorticity that existed before.Then it causes the formation of MSLV.There is a positive feedback mechanism between low vortex and precipitation,so CISK must be an important mechanism.  相似文献   

空间尺度基础性问题研究   总被引：11，自引：0，他引：11  

李霖  应申 《武汉大学学报(信息科学版)》2005,30(3):199-203

论述了地理信息科学领域中空间尺度的研究意义．介绍了空间尺度的具体内涵和定义．分析了空间尺度各内涵之间的内在联系和制约关系。  相似文献   

面向变化监控的动态电子地图设计   总被引：4，自引：0，他引：4  

艾廷华  朱熀  王洪 《武汉大学学报(信息科学版)》2005,30(10):858-861

以动态现象的表达、监控为主要任务的电子地图,具有四个功能:过程再现、实时跟踪、变化推演和变化模拟,分别对应时态特征上的过去式、进行式、将来式和虚拟语气。其设计原理与其他电子地图的差别表现为:地理背景底图的动态性,比例尺设计与时间有关,符号设计需扩充Bertin参量体系而引入动态参量,要顾及用户对变化过程的交互式控制。本文从地图设计角度讨论了这类地图的设计原理与方法,并应用到面向水路航务管理的电子航道图设计中,实现航标位置、工作状态的全天候远程监控。  相似文献   

Landslide hazard and risk mapping at catchment scale in the Arno River basin   总被引：6，自引：2，他引：6  

F. Catani  N. Casagli  L. Ermini  G. Righini  G. Menduni 《Landslides》2005,2(4):329-342

We present the methodologies adopted and the outcomes obtained in the analysis of landslide risk in the basin of the Arno River (Central Italy) in the framework of a project sponsored by the Basin Authority of the Arno River, started in the year 2002 and completed at the beginning of 2005. In particular, a complete set of methods and applications for the assessment of landslide susceptibility and risk are described and discussed. A new landslide inventory of the whole area was realized, using conventional (aerial-photo interpretation and field surveys) and non-conventional methods (e.g. remote sensing techniques such as DInSAR and PS-InSAR). The great majority of the mapped mass movements are rotational slides (75%), solifluctions and other shallow slow movements (17%) and flows (5%), while soil slips, and other rapid landslides, seem less frequent everywhere within the basin. The relationships between landslide characteristics and environmental factors have been assessed through statistical analysis. As expected, the results show a strong control of land cover, lithology and morphology on landslide occurrence. The landslide frequency-size distribution shows a typical scaling behaviour already underlined in other landslide inventories worldwide. The assessment of landslide hazard in terms of probability of occurrence in a given time, based for mapped landslides on direct and indirect observations of the state of activity and recurrence time, has been extended to landslide-free areas through the application of statistical methods implemented in an artificial neural network (ANN). Unique conditions units (UCU) were defined by the map overlay of landslide preparatory factors (lithology, land cover, slope gradient, slope curvature and upslope contributing area) and afterwards used to construct a series of model vectors for the training and test of the ANN. Various different ANNs were selected throughout the basin, until each UCU was assigned a degree of membership to a susceptibility and a hazard class. Model validation confirms that prediction results are very good, with an average percentage of correctly recognized mass movements of about 85%. The analysis also revealed the existence of a large number of unmapped mass movements, thus contributing to the completeness of the final inventory. Temporal hazard was estimated via the translation of state of activity in recurrence time and hence probability of occurrence. The following intersection of hazard values with vulnerability and exposure figures, obtained by reclassification of digital vector mapping at 1:10,000 scale, lead to the definition of risk values for each terrain unit for different periods of time into the future. The final results of the research are now undergoing a process of integration and implementation within land planning and risk prevention policies and practices at local and national level.  相似文献   

Periodic pumping tests     

Jörg Renner  Mareike Messar 《Geophysical Journal International》2006,167(1):479-493

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热采锅炉结垢模拟及其成分、微形貌研究   总被引：1，自引：0，他引：1  

张英  蔡元峰  刘喜林  齐先有  孙涛  潘宇观  武俊宪  谢加才  徐夕生  郭涛 《矿物岩石地球化学通报》2006,25(2):121-128

为减少湿蒸汽热采锅炉结垢对油田生产造成的损失,设计了模拟湿蒸气发生器来模拟热采生产中的蒸汽产生过程,重点研究锅炉的结垢情况。对模拟油田产生蒸汽的模拟炉中水垢的粉末X射线衍射(XRD)、电子探针波谱成分分析(EP-MA)和扫描电子显微镜(SEM)的研究表明,辐射段水垢主要由蒙脱石、针钠钙石和锥辉石组成,它们形成于相近的水热条件。水垢的XRD研究表明,蒙脱石和针钠钙石垢遍布整个水管,而锥辉石垢主要出现在水管尾部。形成锥辉石中的铁主要来源于水管的腐蚀,当水管表面形成一层水垢后,进水中的微量Fe成为另外一个重要来源。  相似文献   

大比例尺城乡一体化土地调查综合技术的研究   总被引：2，自引：0，他引：2  

苏士虎  徐伟忠  赵晓敏  杨卫国  张斌  彭良勇 《现代测绘》2006,29(3):3-6,10

本研究项目根据国家法规、规程和规定,以江阴市”数字国土”工程为研究对象,依靠3S现代测绘高新技术手段,对江阴市城镇1∶500、农村1∶1000进行地籍、地形和土地利用现状调查技术研究,建立城乡一体化地籍管理信息系统和基础地理信息系统,探索城乡一体化建设和维护更新等管理模式。  相似文献   

边界层参数化方案对降水预报的影响   总被引：15，自引：1，他引：15       下载免费PDF全文

陈炯  王建捷 《应用气象学报》2006,17(Z1):11-17

利用新一代WRF模式模拟了2003年7月8—10日的江淮暴雨,就WRF模式中的MRF和MYJ边界层参数化方案进行了对比试验。发现分辨率为20 km时,WRF模式基本上能够模拟出中尺度降水的范围、位置和强度。采用边界层方案显然比不采用边界层方案的模拟效果好,但是MYJ方案与MRF方案相比并没有明显的优越性。另外发现边界层物理过程对格点尺度降水影响很小,模式主要通过边界层物理过程和积云对流过程之间的耦合,来改善对流性降水的模拟。  相似文献   

GIS assisted inverse geochemical modeling for plausible phase transfers in aquifers     

S. D. Dhiman  Ashok K. Keshari 《Environmental Geology》2006,50(8):1211-1219

A geographical information system (GIS) assisted approach that couples a groundwater flow model and an inverse geochemical model is presented to quantify the phase mole transfers between two points on the flow path within a groundwater system. It is used to investigate the plausible phase transfers in the unconfined aquifer of Mehsana district of Gujarat State, India. X-ray diffraction analysis of soil samples is carried out for mineral characterization. The groundwater flow field is simulated using MODFLOW and flow paths used for inverse geochemical modeling are traced using PMPATH, a particle tracking algorithm. The plausible phase mole transfers in the flow path are quantified using PHREEQC geochemical code. The different scenarios generated by inverse modeling routine are used as input to the geochemical model and simulation runs are taken as forward models. The obtained results are compared to the target solution chemistry by using the square of the Pearson product moment correlation coefficient. Results reveal that the groundwater is undersaturated with anhydrite, carbon dioxide (gas), fluorite, gypsum, halite, jarosite-K, and siderite. It is oversaturated with aragonite, calcite, dolomite, ferrihydrite, goethite, and hematite. Results further reveal that calcite is precipitating, while dolomite, gypsum, carbon dioxide, and fluorite are dissolving together with ion exchange in the flow path.  相似文献