Geomorphological Environment Research Articles

The role of geomorphology in environmental impact assessment

This paper aims to define the role of Geomorphology in the assessment of the impact of human activities on the environment. Environmental impact assessment (EIA) should be carried out for specific projects, in order to evaluate their suitability for the quality of the environment. In fact, each planned activity may have an impact on various environmental components. Among these, the natural component must be examined in terms of geomorphological hazards, which may endanger a project, and of geomorphological assets (elements forming the educational and cultural heritage of the landscape), which may be damaged to various extents by human activities. The relationships between humans and environment are taken into account, with particular attention to the effects of a project on the geomorphological environment. From a geomorphological point of view, after having assessed the suitability of a certain location, mainly with respect to its morphography and morphometry, the geomorphological hazards of the area which may threaten the project (risk) must be considered; then the geomorphological assets, which may be damaged by the same project (direct impact) have to be individuated. Human activities may produce two other kinds of effect: the first refers to the consequences of the geomorphological hazards induced by a project on the project itself (direct risk) and on the surronding areas (indirect risk); the second takes into account the potential deterioration of a geomorphological asset due to hazards induced by the project (indirect impact). Examples of these different cases are presented.

Geotechnical conditions of the deltaic alluvial plains of Bangladesh and associated problems

A broad assessment of the geotechnical characteristics of the subsoil of the deltaic alluvial plains of Bangladesh is made to provide a useful guide for development planning and construction. The subsoil generally comprises sandy material, although it may vary significantly over short lateral distances as a result of frequent and erratic occurrences of compressible organic silt and peat mixtures. The foundation competency of the upper 6–10 m has been assessed as low to very low. Uniform-textured fine sand with a moderate to high bearing capacity usually dominates the soil profile, particularly below 20 m depth, but in swampy area this is totally absent. Potential construction problems, categorized as geotechnical and environmental are been described. The former include foundation problems in buildings, bridges, hydraulic structures etc., attributed to the weak and erratic nature of the surficial soil. Geotechnical problems are often compounded by the physiographical and geomorphological environment of the country. Flood and river bank erosion are identified as the main environmental problems, posing an enormous threat to life, property and construction. Recommendations to overcome these problems are made.

A preliminary study on the distribution and genesis of underground brine in the littoral plain of Laizhou Bay in the Bohai Sea

Quaternary underground brine in the littoral plain region of the Bohai coast is new type littoral facies evaporation ore deposit in liquid state. This model of “littorally-forming brine” is based on study of the distribution, depositional environment, forming/storing process, and genesis of underground brine in the coast of Laizhou Bay. Essential conditions for genesis of brine are arid and semiarid climate, abundant sources of ancient seawater, and geological and geomorphological environment of wide tidal beach along a coast. The process of underground brine genesis may be: seawater/tidal beach » evaporation and concentration » seeping and accumulation » brine/tidal beach » burial (evolution of the sea-land)» underground brine. Underground brine is characterized by high content of chemical elements, shallow burial depth and easy exploitation. The process of extracting salt from underground brine present in the tidal flat is incomparably superior to that of producing salt from seawater, and has brough great economic benefits to the coastal areas of Laizhou Bay, Shandong Province.

The Location of Relics and Paleogeographical Changes in the Northeastern Part of the Osaka Plain

In this paper, author studied the conditions of location of the Suna Site and deduced the geomorphological environment of those days by restoring the environment with geomorphic and geological methods and by tracing paleogeographical changes. Based on the results, the author concludes that the microforms in this area can be classified into 8 units. A geomorphological map (Fig. 2) was drawn based on the results.The Suna Site is located on the center part of an alluyial fan-like lowland. The surface of the lowland forms an incline of 8.5‰ toward the west. The height of the surface varies from 2 to 14 meters above sea level. This means that not the alluvial deposits of the Yodo and the Neya Rivers but those of the small rivers entrenching terraces and hills to the east formed the lowland. The extensive distribution of the Jori grid-system partition is a characteristic found on this surface. The surface rises to a relative height of 2 meters from the lowland of the Yodo and forms a terrace.According to the observation of archeologically excavated sections, the Suna Site and its vicinity were in a marshy environment with deposits of humus, silt and clay before the late Jomon Period (3, 000∼2, 300y.B.P.). The westerly inclination of layers of early and late Kofun Preriod indicates that deposits were supplied from the Ikoma Mountains, and the alluvial fan-like lowland was expanded to the westward at that time. But the surface of the coarse deposits from the Ikoma Mountains and that of the marshy deposits of silt interfinger each other. This indicates that the Suna Site was located near the end of the alluvial fan-like lowland of those days. The content of sand and gravel within the deposits increased remarkably in the late Kofun Period. This fact shows that the alluvial fan-like lowland expanded again in this period. However, from the Middle Ages onward, there was little accumulation of deposits.By pollen analyses, much pollen of broad-leaved trees such as Cyclobalanosis were detected from the black silt layer of the late Jomon Period. However, not so much pollen of pinus nor that of herbaceous plants were detected from the layer (Fig. 7). It seems that the forest around the Suna Site was not badly damaged at that time. And it seems that this area was situated in the Warm Temperate Zone, because vegetation in this area was dominated by Cyclobalanosis and Quercus. For lack of deposits, the author has not deduced the vegetational history of this area in the Yayoi Period (2, 300∼ 1, 700y.B.P.). Some pollen of Trapa and Typhaceae were detected from the dark gray sandy silt layer of early Kofun Period by pollen analysis. It seems that the ground water table rose. And abundant pollen of Cryptomeria and Chanaecyparis were detected from the dark grey silt layer with pebbles from the late Kofun Period. The author presumes that precipitation increased in this area. In addition, much pollen of Gramineae were detected from the deposits. This suggests the beginning of cultivation in this area.

臨海都市と地形環境 : 「臨海都市と地形環境 : つくる・いきる・かえる」 : 1991年度秋季学術大会シンポジウム

臨海都市と地形環境 : 「臨海都市と地形環境 : つくる・いきる・かえる」 : 1991年度秋季学術大会シンポジウム

古代の「難波京」と大阪 : 「臨海都市と地形環境 : つくる・いきる・かえる」 : 1991年度秋季学術大会シンポジウム

古代の「難波京」と大阪 : 「臨海都市と地形環境 : つくる・いきる・かえる」 : 1991年度秋季学術大会シンポジウム

臨海都市の発展・政策・未来 : 「臨海都市と地形環境 : つくる・いきる・かえる」 : 1991年度秋季学術大会シンポジウム

臨海都市の発展・政策・未来 : 「臨海都市と地形環境 : つくる・いきる・かえる」 : 1991年度秋季学術大会シンポジウム

シンポジウム「臨海都市と地形環境 : つくる・いきる・かえる」 : 1991年度秋季学術大会シンポジウム

シンポジウム「臨海都市と地形環境 : つくる・いきる・かえる」 : 1991年度秋季学術大会シンポジウム

The UNESCO Libyan Valleys Survey XXI: Geomorphological Studies of the Romano-Libyan Farm, its Floodwater Control Structures and Weathered Building Stone at Site Lm4, at the Confluence of Wadi el Amud and Wadi Umm el Bagul in the Libyan Pre-desert

AbstractThe Romano-Libyan farm Lm4 includes a ‘barrage’, water control walls and farm buildings. These were built as part of an agro-hydrological farm system at the confluence of the Wadi el Amud and the Wadi Umm el Bagul in the Libyan pre-desert. The farm appears to have functioned in a geomorphological environment not dissimilar to that which prevails today — with occasional rain storms producing overland flow and floods interrupting a dominance of aeolian processes. Field mapping revealed that substantial scatters of midden made up of abraded pottery, bone, and animal dung occur around the buildings. Animals appear to have been kept near to these buildings, which lead to coprolites becoming a very important component of these anthropogenic sediments. Such activity gave rise to significant bioturbation of the sediments, and a notable former vegetation cover. The petrology of the building stones used in the farm buildings is described using petrographic thin section studies. Cavernous weathering and case-hardening are shown to have developed after the stone was incorporated within the building. The size and distribution of these features are shown to relate to the nature of the bedrock used — especially the form and distribution of joints and sedimentary parting planes — as well as the distribution and thickness of the surficial soils and sediments, and the shape and form of the building.

Geomorphological control of gold distribution and gold particle evolution in glacial and fluvioglacial placers of the Ancocala-Ananea basin - Southeastern Andes of Peru

Gold placers are formed as a result of surficial processes but glacial and fluvioglacial systems are generally considered to be unfavourable for placer genesis. Nevertheless, some important glacial and fluvioglacial placers have been discovered and are currently being exploited in the Andes of Peru and Bolivia. In the Plio-Pleistocene Ananea-Ancocala basin (4300–4900 m above sea-level), the gold content of the various formations indicates that only glacial and fluvioglacial sediments related to the Ancocala and Chaquiminas Glaciations (middle and upper Pleistocene) contain gold in any notable quantity. Local concentrations of economic interest occur only where a glacier has cut through a primary mineralized zone. Glacial erosion of dispersed primary mineralizations does not produce high-content placers of the kind found in fluviatile environments. Gold distribution in tills is more irregular than in fluviatile sediments and no marked enrichment at bedrock occurs. The transition from a glacial to a fluvioglacial environment is characterized by an increase in gold content due to a relative concentration of the biggest gold flakes and by the appearance of a gold distribution pattern similar to that found in a fluviatile environment. During their transport by glacial and fluvioglacial processes, gold particles acquire specific features; the size and morphology of a gold flake population are determined by the sedimentological and geomorphological environment in which the flakes are carried.

Mouvements de terrain et érosion hydrique dans les Baronnies méridionales : méthodes d'étude et premiers résultats

Situated in the middle part of the Baronnies (Southern Prealps) the study area consents to a detailed mapping (1/10.000) of the effects of mass movements and water erosion. The following research of the factors of instability is turned chiefly to the vegetative cover and the geomor-phological environment (several generation of glacis and rectilinear slopes). It involves also the setting of some équipements (a climatic station, several lines of stakes and of painted stones) in order to specify the nature and the degree of activity of the processes at work, as a preliminary to the drawing of the zonation map of such hazards ; the first results of the experimentation of erosion and transport processes by overland flow on slopes of marly limestones are stated.

A Few and Miscellaneous Pi-Chi Jottings on Early Indonesia

Those interested in studies know that inscriptions and a diverse range of archaeological materials have now taken precedence over Chinese documents as research tools. The pilgrim I-ching's writings, the chapters on foreign countries in the Chinese dynastic histories, and Chao Ju-kua's Chu-fan chih were translated as long ago as the second half of the nineteenth and early years of the twentieth centuries, and since then nothing of comparable importance has come to light in Chinese sources. The participants in the SPAFA-sponsored Project have properly recommended that what has already been translated needs to be catalogued, verified, and reconsidered alongside other sources of information, especially archaeological evidence now being unearthed in southeastern Sumatra and peninsular Thailand. 2 Current field research is gradually shifting the discussion from the shopworn topic of the location of Sriwijaya's capital to the substance of Sriwijayan history, which is the geomorphological environment and political systems of early Malay culture.

A note on the geomorphological environment of Çatal Hüyük, Turkey

Abstract It had previously been proposed ( Cohen, 1970 ) that after large-scale Early Holocene alluviation, no post-occupational sediment accumulated around the neolithic site of Catal Huyuk in south-central Anatolia. Data presented here, however, indicate that several metres of archaeological deposit at both east and west mounds are overlain by alluvium. This implies that the modern distribution of soil and water resources cannot be used directly to assess past agricultural potential in the vicinity of the site.

Modern Analogues and the Evaluation of a Pleistocene Sedimentary Sequence

Recent sands from the Saunton Sands-Braunton Burrows beach-dune complex bordering Bideford Bay provide modern analogues for interpreting the depositional history of Pleistocene raised littoral sediments on Saunton Down and Baggy Point. Use of size-frequency statistics determined by moments and the analysis of size-curve components illustrate the similarity between the Recent dune sands from Braunton Burrows and the Pleistocene deposits on Saunton Down. A linear discriminant function derived for the classification of modern eolian and wavelaid sands is used as a predictive model to identify the environments of deposition of the Pleistocene sands. Of the twenty-three sand samples from Saunton Down, twenty-one are clearly classified as eolian using size-frequency statistics. Three sand samples from the basal section on Baggy Point are classified as wave-laid while a sample from higher in the section is eolian. Graphical dissection of the size-frequency curves supports the inference of the sizefrequency statistics. The Saunton Down sands can be analysed into two phi-normal components in the majority of cases and three components at most. This is similar to the Recent backshore and dune sands where a fine suspension population, a dominant saltation population and only occasionally a coarse rolling population are evident. In contrast, the lower layers at Pencil Rock on Baggy Point illustrate the existence of a double saltation population (associated with swash-backwash currents) and a coarse bed rolling or sliding component. The upper layers are typically eolian in form. Electron-microscopic analysis of the surface textures of quartz reveal similar patterns in both Recent and Pleistocene sands. Particularly common on wave-laid sands from both Saunton Sands and the lower layers on Baggy Point are V-shaped impact fractures generally less than 0-75 ,um in size. They are not found on either the Recent or Pleistocene dune sands of Saunton Down. Instead, conchoidal fractures arranged in concentric series together with smooth blocky structures characterize the wind-blown material. The tentative conclusion to be drawn is that the Saunton Down sands are most probably eolian in origin throughout and form part of a Pleistocene backshore-dune sequence backing a foreshore, with a strand-line running close to the Pencil Rock sands on Baggy Point and sea level higher than at present. A MAJOR field in geomorphological research is the chronological analysis of the evolution of the landscape and the study of the associated changes in the spatial pattern of geomorphological environments. Often evidence of such changes is scarce or absent but, frequently, past environments are represented by the presence of superficial sedimentary deposits. This has led to the use of techniques of sedimentological analysis in investigating previous depositional environments. Complete understanding of past geomorphological environments does, however, necessitate the use of modern systems as analogues for ancient ones and the adoption of the principle of uniformitarianism1. This paper examines certain techniques of sedimentological analysis which have proved to be of value in differentiating Recent sediments and compares the results with those obtained from a study of a Pleistocene sedimentary sequence. An attempt is made to provide methods which are useful in analysing coastal sands, and the paper presents the initial results of a larger study of the sedimentology of the Pleistocene littoral sands in several sites in south-west England. I45 This content downloaded from 157.55.39.144 on Wed, 11 May 2016 05:16:45 UTC All use subject to http://about.jstor.org/terms

The Kamiyachi Site of Early Paleolithic Era and Its Geomorphological Environment

The Kamiyachi Site of Early Paleolithic Era and Its Geomorphological Environment