连续台风时期香港区域的水汽变化分析

利用香港卫星定位参考站网GNSS观测数据,提取强热带风暴"塔拉斯"与热带风暴"洛克"影响期间各测站天顶方向对流层延迟,反演香港区域大气可降水量;根据香港区域49个天文台气象站提供的实测降雨量数据,分析大气可降水量与实际降雨量的相关性,以及两次台风对香港区域水汽时空分布的不同影响。结果表明,大气可降水量在台风影响前期均上升,在大量降雨后回落,但在连续台风的间歇期间,仍高于台风来临前的水平;水汽累积是大量降雨的前提条件,当水汽累积量相近时,水汽累积时长与累积降雨量呈正相关;台风期间大气可降水量值超过65 mm的区域面积与台风等级相关,台风路径对局部水汽分布有一定的影响。     

黑河中游夏季昼夜水汽同位素特征及水汽来源分析

基于2012年6~8月的实测水汽同位素数据及相关气象数据，对黑河中游夏季昼夜的同位素基本特征、水汽来源方向及潜在蒸发源地进行了研究。结果表明：空气水汽线斜率白天大于夜晚和水汽过量氘值白天大于夜晚，综合说明白天局地蒸发较夜晚强烈；夏季受西风水汽影响显著。其中，6月主要受西风水汽和北冰洋水汽影响，7、8月主要受西风水汽和东南方向水汽影响，且8月受东南方向水汽影响最为明显；水汽运移路径上下垫面地形和气压带移动会影响水汽后向轨迹高度，西北方向上水汽输送通道较顺畅，风速较大，有利于水汽的输送；水汽蒸发源地主要集中在研究区周围及以东、以北部，其次是西北部。绿洲是主要的水汽蒸发源地，其次是城市和河流，白天较夜晚局地蒸发强烈且面积大。     

THE POSITION AND ROLES OF PORTS AND RAILWAYS IN THE EURASIA LAND BRIDGE TRANSPORTATION IN NORTHEAST CHINA

This paper systematically analyzes and proves the favorable factors of utilizing the ports and the railways in Northeast China for the Asia-Europe land bridge transportation. It will be more beneficial to Dalian Port and HaDa (Harbin-Dalian) and Binzhou (Harbin-Manzhouli) railways in Northeast China to the Siberia railway in Russia than 1) to other ports and the corresponding railways in China, 2) to the Nakhodka Port in Russia and the corresponding railways and 3) to the Chongjin Port in North Korea and the corresponding railways. This paper also puts forward the reform measures to adopt the ports and the railways in the northeast region in China for the land bridge transportation and the problems in transportation policies and management systems.     

STUDY ON DEVELOPMENT STRATEGY OF SHIPPING CENTERS AND TRANSPORTATION NETWORKS IN THE YELLOW SEA RIM IN THE YELLOW SEA RIM

It is very important to establish cooperative mechanism to guarantee all members to develop their e-conomies in the Yellow Sea Rim. In this paper, the development strategies ofshipplng centers and transportation networkare discussed based on economic giobalization tendency. The results argue that a united transportation network should bebuilt in order to promote the economic competition of Northeast Asia in the world. As a key component of the economiccooperation, a hierarchical shipping centers network should be established with Hong Kong, Shanghai, Pusan, Koho,and Tokyo as cores. The authorities of China, Japan, R. O. Korea and D. P. B. Korea should make more efforts tobuild a set of cooperation institutions based on raising the transportation efficiency.     

Tidal effects on temperature front in the Yellow Sea

Temperature front (TF) is one of the important features in the Yellow Sea, which forms in spring, thrives in summer, and fades in autumn as thermocline declines. TF intensity ⋎S _T ⋎ is defined to describe the distribution of TF. Based on the MASNUM wave-tide-circulation coupled model, temperature distribution in the Yellow Sea was simulated with and without tidal effects. Along 36°N, distribution of TF from the simulated results are compared with the observations, and a quantitative analysis is introduced to evaluate the tidal effects on the forming and maintaining processes of the TF. Tidal mixing and the circulation structure adapting to it are the main causes of the TF. Supported by the National Basic Research Program of China (No. G1999043809) and the National Science Foundation of China (No. 49736190).     

The hydrological influence of black locust plantations in the loess area of northwest China

Black locust (Robina pseudoacacia) has become one of the most important shelter species in the loess area of northwest China. This paper summarizes recent research concerning its hydrological influence, including canopy interception, litter absorption capacity, its effect on rainfall kinetic energy, infiltration rates, surface runoff, soil moisture, and evapotranspiration, and its role in soil conservation. Several predictive models are listed. on the basis of existing results, optimum characteristics for an effective plantation are defined, and problems requiring further research are identified.     

FUZZY COMPREHENSIVE EVALUATION OF CONTAINER TRANSPORTATION MODES ALONG THE CHANGJIANG RIVER MAIN LINE AND ITS DELTA AREA

The Changjiang River (Yangtze) is one of the fastest growth areas of container transportation in Chi-na. Rail, road and water transportation have competed against each other for container transportation in the Chang-jiang River main line and its delta area. It is of significance to assess these different transportation modes scientifi-cally in order to organize container transportation efficiently in this area and make decision for integral plan and construction of transportation system in this area. This paper outlines application of fuzzy comprehensive evaluation to appraise different modes of typical direction of containers. Twelve assessment indexes were decided. Membership functions were formulated. Evaluation results indicated that road transportation was optimal mode in the Changjiang River delta area, however water transportation was the primary way in the Changjiang River main line.     

不整合运移通道类型及输导油气特征

在对不整合空间结构特征研究的基础上,提出了油气沿不整合运移的通道类型:宏观上,存在由不整合面之上底砾岩和不整合面之下半风化岩石两种高效运载层组合成的双运移通道型和单运移通道型两种通道类型;微观上,底砾岩连通孔隙、半风化岩石构造卸荷风化裂缝系统及溶蚀孔洞系统可作为油气运移的主要通道。通过对不整合面上、下岩石物性分析,认为半风化岩石“孔洞缝”系统较底砾岩连通孔隙有更高的输导油气的能力。研究结果表明,不同的运移通道类型具有不同的输导油气特征。在地史时期,构造裂缝系统和溶蚀孔洞系统一直是不整合输导油气的主要通道;对于软地层构成的不整合来说,开始应是卸荷、风化裂缝系统和底砾岩连通孔隙共同构成不整合输导油气的主要通道,当上覆沉积载荷达到一定程度后,主要是底砾岩连通孔隙起输导油气通道作用;对于脆硬地层构成的不整合来说,卸荷、风化裂缝系统和底砾岩连通孔隙一直是不整合输导油气的主要通道。     

Application of MODFLOW and geographic information system to groundwater flow simulation in North China Plain, China

MODFLOW is a groundwater modeling program. It can be compiled and remedied according to the practical applications. Because of its structure and fixed data format, MODFLOW can be integrated with Geographic Information Systems (GIS) technology for water resource management. The North China Plain (NCP), which is the politic, economic and cultural center of China, is facing with water resources shortage and water pollution. Groundwater is the main water resource for industrial, agricultural and domestic usage. It is necessary to evaluate the groundwater resources of the NCP as an entire aquifer system. With the development of computer and internet information technology it is also necessary to integrate the groundwater model with the GIS technology. Because the geological and hydrogeological data in the NCP was mainly in MAPGIS format, the powerful function of GIS of disposing of and analyzing spatial data and computer languages such as Visual C and Visual Basic were used to define the relationship between the original data and model data. After analyzing the geological and hydrogeological conditions of the NCP, the groundwater flow numerical simulation modeling was constructed with MODFLOW. On the basis of GIS, a dynamic evaluation system for groundwater resources under the internet circumstance was completed. During the process of constructing the groundwater model, a water budget was analyzed, which showed a negative budget in the NCP. The simulation period was from 1 January 2002 to 31 December 2003. During this period, the total recharge of the groundwater system was 49,374 × 10⁶ m³ and the total discharge was 56,530 × 10⁶ m³ the budget deficit was −7,156 × 10⁶ m³. In this integrated system, the original data including graphs and attribution data could be stored in the database. When the process of evaluating and predicting groundwater flow was started, these data were transformed into files that the core program of MODFLOW could read. The calculated water level and drawdown could be displayed and reviewed online.     

Impacts of at-site wastewater disposal systems on the groundwater aquifer in arid regions: case of Sfax City, Southern Tunisia

Groundwater in Sfax City (Tunisia) has been known since the beginning of the century for its deterioration in quality, as a result of wastewater recharge into the aquifer. An average value of 12 × 10⁶ m³ of untreated wastewater reaches the groundwater aquifer each year. This would result not only in a chemical and biological contamination of the groundwater, but also in an increase of the aquifer piezometric level. Quantitative impacts were evaluated by examining the groundwater piezometric level at 57 surface wells and piezometers. The survey showed that, during the last two decades, the groundwater level was ever increasing in the urban area with values reaching 7 m in part; and decreasing in Sidi Abid (agricultural area) with values exceeding −3 m. Groundwater samples for chemical and microbial analysis were collected from 41 wells spread throughout the study area. Results showed significantly elevated levels of sodium, chlorides, nitrates and coliform bacteria all over the urban area. High levels (NO₃: 56–254 mg/l; Na >1,500 mg/l; Coliforms >30/100 ml) can be related to more densely populated areas with a higher density of pit latrine and recharge wells. Alternatively results showed a very variable chemical composition of groundwater, e.g. electrical conductivity ranges from 4,040 to19,620 μs/cm and the dry residual varies between 1.4 and 14 g/l with concentrations increasing downstream. Furthermore a softening of groundwater in Set Ezzit (highly populated sector) was observed.