基于GIS、RS的西藏墨脱高等级公路工程地质勘察

以ETM 图像为信息源，以基于地学知识的地学遥感解译及图像识别技术为主要方法，结合数字图像处理技术和地理信息技术，在图像波谱分析的基础上，选择TM4(R)、3(G)、2(B)波段组合与TM8融合图像为基础底图，在ENVI及ARC／INFO平台下，对墨脱公路方案线廊带的工程地质信息进行图像识别、机助解译及专题制图，取得了较好的应用效果。     

天山乌鲁木齐河源区大西沟表土花粉散布特征

在天山乌鲁木齐河源区大西沟垂直植被带表土孢粉分析及植被调查的基础上，对大西沟垂直带的植被与表土孢粉的关系进行了探讨。从表土孢粉百分比含量可划分出4个孢粉带，其对应的植被带分别为高山垫状植被、高山草甸、亚高山草甸和云杉(Picea)林带。孢粉百分含量基本上反映了大西沟地区垂直植被带分布的特征。云杉、麻黄(Ephedra)、藜科(Chenopodiaceae)和蒿属(Artemisia)等植物花粉明显表现为超代表性。山谷上升气流在天山山地垂直植被带的表土孢粉散布中起着重要的作用。     

GEOGRAPHERS AND THE TENNESSEE VALLEY AUTHORITY*

ABSTRACT. The Tennessee Valley Authority (TVA) was the largest, most comprehensive, and most controversial regional development and planning project in U.S. history. Geographers were involved from its inception and made impressive contributions. Aside from the unit area method of data gathering and mapping, little is known about their contributions, some of which were truly ahead of their time. Although their work and recommendations were often discarded and unheeded because of political turbulence, the geographers rarely complained or entered into the political arena. Their work in the TVA has generally gone unheralded and even unappreciated within the geography profession. The primary purpose of this article is to document their contributions.     

Depositional features and transportation mechanism of valley-filling Iwasegawa and Kaida debris avalanches, Japan

 The depositional features of two valley-filling debris avalanche deposits were studied to reveal their transportation and depositional mechanisms. The valley-filling Iwasegawa debris avalanche deposit (ca. 0.1 km³) is distributed along the valleys at the southeastern foot of Tashirodake Volcano, northern Honshu, Japan. Debris-avalanche blocks range in size from <35 m proximally to <10 m in the distal zone and consist dominantly of fragile materials. Debris-avalanche matrix percentages increase from 35–60% in the proximal zone to 95% in the distal zone. The debris-avalanche matrix is greater in volume (80–90%) at the bottom and margins of the deposit. Normal grading of large clasts and reverse grading of wood logs and branches occur within the debris-avalanche matrix. Preferred orientation of 311 wood logs and branches within the deposit coincide with the interpreted local flow direction. The basal part of the deposit is characterized by (1) erosional features and incorporated clasts of underlying material; (2) a higher proportion (30–50%) of incorporated clasts than the upper part; and (3) reverse grading of clasts. The valley-filling Kaida debris avalanche deposit (50 000 y B.P., >0.3 km³) is distributed along the valleys at the eastern-southeastern foot of Ontake Volcano, central Japan. Debris-avalanche blocks range in size from <25 m proximally to <7 m in the medial zone. Debris-avalanche matrix percentages increase from 50–70% in the proximal zone to 80% in the distal zone. The debris-avalanche matrix is more abundant (80–90%) at the bottom part of the deposit. Deformation structures observed in the debris-avalanche blocks include elongation, folding, conjugate reverse faults, and numerous minor faults in unconsolidated materials. Lithic components within the debris-avalanche matrix tend to have a higher percentage of plucked clasts from the adjacent underlying formations. A Bingham "plug flow" model is consistent with the transportation and depositional mechanisms of the valley-filling debris avalanches. In the plug of the debris avalanche, fragile blocks were transported without major rupturing due to relatively small shear stresses in regions of small strain rate. The debris-avalanche matrix was mainly produced by shearing at the bottom and margins of the avalanche. Valley-filling debris avalanches tend to have smaller debris-avalanche blocks and larger amounts of debris-avalanche matrix than do unconfined debris avalanches. These differences may be due to disaggregation of debris-avalanche blocks by shearing against valley walls and interaction between debris-avalanche blocks and valley walls. Oriented wood logs and branches, reverse grading of clasts at the base, and a higher proportion of incorporated clasts at the base are interpreted to result from shearing along the bottom and valley walls. Received: 25 March 1998 / Accepted: 10 October 1998     

Valley asymmetry: Evidence for periglacial activity in the central North Sea

Present-day open valleys with distinct asymmetric profiles have been studied from the central North Sea. The bulk of the valleys exhibit steep north-facing and shallow south-facing slopes. This asymmetry is ascribed to preferential slumping of the south-facing slope under periglacial climatic conditions. Exceptions to the regional asymmetric trend are probably the result of more localized factors such as fluvial and microclimatic processes and the effects of local geology. The recognition of this type of within-valley asymmetry associated with slumping in buried valleys within the Quaternary sequence may be indicative of former periglacial activity.     

黄河南徙期间淮河流域水灾研究与制图*

本文以历史洪涝潮灾史料为依据,分析了在黄河南徙入淮期间淮河流域的洪涝潮灾情况,着重阐述了明清时期人类治河及漕运活动对淮河流域水灾的多方面作用。对历史自然灾害研究提出了自己的认识,并根据史料描述和统计结果做出多种类型的历史水灾地图。     

On The Small-Scale Dynamics Of Flow Splitting In The Rhine Valley During A Shallow Foehn Event

Flow splitting in the Rhine valley has been observed with a transportable wind lidar (TWL) during a shallow-foehn event in the framework of the Mesoscale Alpine Programme (MAP). The Doppler lidar recorded in detail flow splitting, foehn wind gusts, and flow reversal. Such structures have not previously been observed with comparable detail by conventional in-situinstruments. In addition to the TWL, boundary-layer processes have been documented by means of rawinsondes and surface stations. This paper presents an analysis of the processes giving birth to flow splitting between the Seez and Rhine valleys during Intensive Observation Period (IOP) 5 (1–3 October 1999) by combining the collected data with hydraulic theory. The study shows thatthe splitting of the channelled flow is associated with (1) the existence of a stagnation point at the intersection of the Seez and Rhine valleys, and (2) the deflection of the flow by the lateral sidewalls of the valleys.     

Is Eilat-Aqaba a bi-national city? Can economic opportunities overcome the barriers of politics and psychology?

Unlike other bi-national cities, Eilat and Aqaba constitute a special case in which the interaction between the two cities is dependent upon external factors, mainly of a political nature. Eilat in Israel and Aqaba in Jordan straddle each side of the Gulf of Aqaba. Both are similar from a functional aspect: they are port and tourism towns and both constitute a gateway to east Africa and the Far East. They are both situated in a desert region near a sea. The Oslo Accords and subsequently the peace agreement between Jordan and Israel, have opened up many possibilities for cooperation and joint development activity. A number of projects have been put forward, including a joint airport aimed at serving both cities, as well as the shared use of the seaports. Tour packages from Europe to both cities are another feature that holds a substantial economic potential, as do connecting roads and joint plans for the preservation of the unique landscape in this region. A border-crossing point between the two countries has been opened up and tens of thousands of tourists have flocked (mostly from Israel) to visit nearby Petra and Wadi Ram. Laborers from Jordan have begun to be seen in Eilat, working mostly in construction. The long history of the Arab-Israeli conflict is still casting a heavy shadow on the great possibilities for cooperation. The signing of a peace treaty is a necessary but not a sufficient condition for the bringing about of cooperation in the field. The enmity and the military activity between Israel and the Palestinians, especially during recent months since the outbreak the intifada for the second time, have resulted in a drastic decline in cooperation that started initially at a slow and hesitant pace following the signing of the peace treaty with Jordan (1994). The fact that about 60% of the Jordanian population is of Palestinian origin, causes the Jordanian government to maintain a cautious stance in promoting cooperation with Israel. Thus, the development of Eilat and Aqaba as a bi-national city is, to a great extent, dependent on the advancement of the peace process between Israel and all its Arab neighbors, and especially on the outcome of the Israeli-Palestinian conflict. This revised version was published online in July 2006 with corrections to the Cover Date.     

Probabilistic models for ore body recognition

Four statistical models have been developed to aid in exploration drilling for ore deposits. The Austinville (Virginia) deposit, which is a Mississippi Valley-type deposit with 31 million metric tons of ore in 17 ore bodies, provides the data base. Because most ore bodies are not solid ore, holes drilled through them will intersect sub-ore mineralization as well as ore. The statistical models were designed to show whether drilling is through an ore body or not, depending on the mineralization intersected by holes. The models are based on a threefold classification of mineralization penetrated by surface drill holes and were developed for cases of fixed budgets with specified number of drill holes and floating budgets with variable number of drill holes. Two classifications were used: (1) binomial ore/non-ore classification and (2) trinomial ore/mineralized/barren. For the fixed budget model with the ore/non-ore classification, at least five holes need to be drilled to decide whether or not an ore body has been penetrated. For the fixed budget model with the ore/mineralized/barren classification, and for both floating budget models, at least three holes need to be drilled. All decisions are based on a 90% confidence level.