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.     

A Simulating Experiment in the Process of Soil Erosion on Bare Land in Mt. Tanakami

In order to understand the process of surface erosion and acquire basic data of conditions on hillslope without vege tation, a sprinkling experiment is conducted on a bare slope in Mt. Tanakami in the central part of Japan. Based on the mea surements of runoff, mean soil erosion depth, and sediment yield, etc. , the results suggest the following characteristics in the process of surface erosion in the experimental area. (1) The occurrence of sediment discharge is interrupted; (2) Surface runoff is a saturated overland flow; (3) The mean soil erosion depth is thick compared with other areas in Mt. Tanakami;(4) Sediment discharge process is detachment- limited.     

Sonar acoustic facies and sediment distribution on an area of the deep ocean floor

Long-range sidescan sonar can be used to map sediment distributions over wide expanses of deep ocean floor. Seven acoustic facies that arise from differing sediment or rock types have been mapped over the low-relief Saharan continental rise and Madeira abyssal plain. These have been calibrated with sampling, profiling and camera studies and the facies can be traced confidently on a regional scale using the sidescan data. The mapping of the sediment distribution shows that a complex interplay of turbidity current and debris flow processes can occur at a continental rise/abysaal plain transition over 1000 km from the nearest continental slope.     

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。     

Heavy metals in sediments of the Tecate River, Mexico

Ten sites along the Tecate River, Mexico were sampled to evaluate the cadmium, lead, nickel and chromium concentrations in sediments. The result shows contamination for cadmium in most of the sites, where two sites were class 4 (polluted to strongly polluted) according to geoaccumulation index proposed by Muller. Two sites were found polluted for all the heavy metals analyzed (Cr, Cd, Pb and Ni), indicating the effect of anthropogenic activities. A correlation between Ni and Cd concentration had been found indicating a common source. These metals are usually used in electroplating industry. The results of this study can be used for decision makers to prioritize measures to control the pollution for these metals.     

Evaluation of geochemical impact of tsunami on Pichavaram mangrove ecosystem,southeast coast of India

The 26 December 2004-tsunami has deposited sediments in the Pichavaram mangrove ecosystem, east coast of India. Ten surface and three core sediment samples were collected within 30 days of the event and analyzed for nutrients. Water samples were also analyzed to see the impact of tsunami on the geochemical behavior of nutrients. An increase in the concentration of various nutrients namely nitrate and phosphate was observed. The geochemistry of the mangrove forest was observed to be influenced by a number of factors like rapid increase of aquaculture farms, agricultural practices and the anthropogenic discharge from the nearby-inhabited areas. Further the sediment column was disturbed due to energetic tsunami waves, which has caused a sheer increase in the dissolved oxygen in water. As a result, the change in the redox potential has resulted in change in the nutrients absorbed/associated with the sediments. In addition, role of retreating water after tsunami on the nutrient geochemistry was also evaluated.     

Temporal variability of Pb fluxes and bioturbation in shelf sediments beneath the high primary production area off Concepción, central-southern Chile (36°S)

We estimated monthly fluxes of ²¹⁰Pb in shelf sediments beneath a high productivity area off central-southern Chile (36°S) during 1 year (September 2002-August 2003). Sediment cores were obtained using a multiple corer and were analyzed mainly for ²¹⁰Pb, total pigments, and macrofauna abundance. The ²¹⁰Pb inventories and fluxes were estimated for surface sediments (0-5 cm) and bioturbation coefficients were inferred using chlorophyll-a (reactive) profiles. In general, ²¹⁰Pb content was inversely correlated with phytodetritus fluxes. High photosynthetic pigment contents in surface sediments were consistently associated with lower ²¹⁰Pb contents. Macrofaunal activity responded to oxygen and organic matter supplies at the sediment surface, generally concentrated in the first centimeters, but particularly so during months of high organic matter fluxes and deficient bottom water oxygen conditions. At this study site, several processes involved in the ²¹⁰Pb surface distribution make it difficult to accurately estimate ages at the surface. We postulate that the organic fluxes promote changes in the faunal activity, which, in combination with sediment resuspension and water circulation over the shelf, produce seasonal variations in the ²¹⁰Pb inventories.     

How tides and river flows determine estuarine bathymetries

For strongly tidal, funnel-shaped estuaries, we examine how tides and river flows determine size and shape. We also consider how long it takes for bathymetric adjustment, both to determine whether present-day bathymetry reflects prevailing forcing and how rapidly changes might occur under future forcing scenarios.Starting with the assumption of a 'synchronous' estuary (i.e., where the sea surface slope resulting from the axial gradient in phase of tidal elevation significantly exceeds the gradient in tidal amplitude ), an expression is derived for the slope of the sea bed. Thence, by integration we derive expressions for the axial depth profile and estuarine length, L, as a function of and D, the prescribed depth at the mouth. Calculated values of L are broadly consistent with observations. The synchronous estuary approach enables a number of dynamical parameters to be directly calculated and conveniently illustrated as functions of and D, namely: current amplitude Û, ratio of friction to inertia terms, estuarine length, stratification, saline intrusion length, flushing time, mean suspended sediment concentration and sediment in-fill times.Four separate derivations for the length of saline intrusion, L_I, all indicate a dependency on (U_o is the residual river flow velocity and f is the bed friction coefficient). Likely bathymetries for `mixed' estuaries can be delineated by mapping, against and D, the conditions L<sub>I</sub>/L<1,E<sub>X</sub>/L<1 (E<sub>X</sub> is the tidal excursion) alongside the Simpson-Hunter criteria D/U<sup>3</sup><50 m<sup>−2</sup> s<sup>3</sup>. This zone encompasses 24 out of 25 `randomly' selected UK estuaries.However, the length of saline intrusion in a funnel-shaped estuary is also sensitive to axial location. Observations suggest that this location corresponds to a minimum in landward intrusion of salt. By combining the derived expressions for L and L_I with this latter criterion, an expression is derived relating D_i, the depth at the centre of the intrusion, to the corresponding value of U_o. This expression indicates U_o is always close to 1 cm s⁻¹, as commonly observed. Converting from U_o to river flow, Q, provides a morphological expression linking estuarine depth to Q (with a small dependence on side slope gradients).These dynamical solutions are coupled with further generalised theory related to depth and time-mean, suspended sediment concentrations (as functions of and D). Then, by assuming the transport of fine marine sediments approximates that of a dissolved tracer, the rate of estuarine supply can be determined by combining these derived mean concentrations with estimates of flushing time, F_T, based on L_I. By further assuming that all such sediments are deposited, minimum times for these deposition rates to in-fill estuaries are determined. These times range from a decade for the shortest, shallowest estuaries to upwards of millennia in longer, deeper estuaries with smaller tidal ranges.