首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
2.
3.
Catchments (watersheds) are integrated through water movements. Water moves sediments; and the translocation of materials has geomorphic and pedological responses. Fertiliser and pesticide residues and other toxic substances are also transported by water, in solution and attached to sediment particles, affecting various ecological components of catchments. The insertion of pollutants is directly caused by land‐use practices. In turn, land uses are influenced by the pedo‐geomorphology of the catchments (uplands, valley sides, flood plains and terraces, spurs and hollows, convexities and concavities; position in the upper, middle or lower catchment; and by catenary relationships). Therefore catchment management must deal with interrelationships amongst human activities and various geomorphic elements. Several case study examples from southwestern Australia demonstrate the importance of geomorphology in catchment management. They include: rates of hillslope erosion and translocation of P in micro‐catchments within a drainage basin context; stream salinisation; accumulation of heavy metals in stream sediments; geomorphic elements influencing the spread of weeds and the erosion of access tracks; and some relationships between valley‐side land uses and stream morphology. The incorporation of these and other issues in a management strategy is then illustrated. Complex skills are involved in producing and implementing a management strategy, including but extending well beyond those of the geomorphologist.  相似文献   

4.
The Minister of Geology USSR recommends that geomorphology play a more significant role in prospecting and exploration of mineral deposits. He finds that many Soviet exploration geologists still tend to ignore the potentialities of geomorphology on the ground that it is a geographical discipline with little relevance to the needs of geology. The Minister sees a particularly important area of applied contributions in paleogeomorphology, which deals with the relief forms of past geological eras. In his view, geomorphology also has a major role to perform in engineering designs of major construction and development projects. Failure to select proper project sites often leads to undesirable side-effects, especially in areas affected by mudflows, avalanches and thermokarst caving. If geomorphology is to make a more substantial contribution in areas of application, the training of geomorphologists should be reoriented toward mineral prospecting and engineering applications, and the organizational structure of operating and research agencies must provide for separate geomorphology study units.  相似文献   

5.
6.
Mount Augustus (Burringurrah) at 1105 m AHD, is a prominent elongate inselberg, underlain dominantly by resistant sandstone of Middle Proterozoic age (1.6 billion years old). It is located midway between Meekatharra and Carnarvon in semi-arid Western Australia. The Mount Augustus Sandstone and overlying sediments were folded and tilted about 1 billion years ago, providing the template for the modern Mount Augustus. It is essentially a structural landform. Its shape broadly conforms to the underlying asymmetrical anticline, which has a steep northern limb and a gentler dipping southern limb. The anticline plunges at a shallow angle to the southeast. The mountain is the core of the original fold and it stands some 700 m above the surrounding Gascoyne planation surface. Other rock types present on Mount Augustus include metamorphic and igneous rocks, which preclude it from being termed a monolith. Weathering, fluvial erosion and sedimentation have modified the original bedrock structures. Fluted bedrock provides evidence of rapid runoff from bare bedrock surfaces. A joint system has influenced the orientation of a step-like sequence of numerous scarplets on slopes. The weathered rock is red, but the coloured rock is only a centimetre deep on most surfaces. The surrounding alluvial, gibber and sand plains shallowly bury the eroded bedrock plains of the Gascoyne planation surface. Former alluvial fills have been ferricreted in the lower reaches of some channels and are currently being eroded. Mount Augustus has often been compared with Ayers Rock, and unwarranted claims have been made that it is the biggest rock in the world and the world's biggest monolith.  相似文献   

7.
8.
The author considers the geomorphology of accumulative alluvial-lacustrine plains to have been largely neglected by geomorphologists, with few generalized studies available in the literature compared with the geomorphology of denudation surfaces. He provides a genetic classification of alluvial plains and lists a number of problems in the geomorphic structure and sculpturing of plains worthy of further investigation and generalization.  相似文献   

9.
There is a widespread perception amongst the community of Ingham and surrounding areas that the Herbert River in tropical Queensland has aggraded since the time of European settlement. Yet this perception is not supported by such evidence as historical accounts of the river and river trade, changes at the Ingham gauging station since 1940 and comparison of channel cross-sections surveyed since 1968. No reason has been identified for this divergence, but experience elsewhere teaches us that ignoring local perception is likely to result in an incomplete understanding of environmental issues. Unless the challenge of reconciling popular perception and deductive interpretation of the evidence is met, the potential for conflict will remain. Community proposals for strategies will struggle for support from the ‘rationalists’ and the community will oppose ‘rational’ strategies if they are not seen to be addressing the ‘real’ problems.  相似文献   

10.
Since 1996, a broad range of publications has been produced by Canadian geomorphologists and hydrolo‐gists. These publications have been distributed in journals with national and international circulations. Although there remains a major focus on the study of observable processes in fluvial, aeolian, coastal and slope environments there is also a strong, historical component to explanations oflandforms, landform assemblages and sedimentary sequences. Some of these histories have incorporated the effects of high‐magnitude (catastrophic) events, some of which may have no modern analogues. Perspectives on the interactions among microclimatic variables, including changes induced by human actions, continue to evolve. Forest clearance and its effects on evaporation rates, water‐table levels and timing ofsnowmelt, the human use of wetlands and release of methane and carbon dioxide, will continue to demand the attention of scholars interested in explaining future climatic scenarios. Depuis 1996, un large éventail de publications a été produit par les géomorphologues et hydrologues du Canada. Ces travaux ont été diffusés dans des revues nationales et internationales. Bien qu'il y ait encore une attention privilégiée portée à l'étude des processus observables dans des environnements fluviaux, éoliens, côtiers et de pente, il existe aussi une importante composante historique dans l'explication des formes du paysage et de leurs assemblages ainsi que des séquences sédimentaires. Certaines de ces reconstitutions historiques ont incorporé les effets d'événements de haute magnitude (catastrophique), dont certains n'ont peut‐être pas d'analogues modernes. Les points de vue sur les interactions entre les variables microclimatiques, et notamment les changements d'origine anthropique, continuent d'évoluer. Le recul des forêts et ses effets sur les taux d'évaporation, le niveau des nappes phreatiques et le calendrier de la fonte des neiges, l'utilisation humaine des zones humides et l'émission de méthane et de gaz carbonique, continueront d'exiger l'attention des spécialistes qui se penchent sur l'explication des scénarios climatiques futurs.  相似文献   

11.
Abstract

Simulation is becoming increasingly popular in teaching in higher education. Dissatisfaction with traditional teaching techniques such as the lecture, the need to understand processes and to teach problem‐solving skills are some of the reasons for this. The roots of simulation are in war‐gaming, in management and business studies, and in psychologists’ approaches to ‘experiential learning’. Simulation in geography developed in the late 1960s. The example of the Caribbean Fishing Game is used to demonstrate flexibility of gaming. Three styles of simulation are outlined: role‐play, operational games and individual exercises. To be most effective, simulations need to be carefully prepared and properly integrated into the course. Simulation's open‐endedness makes evaluation difficult.  相似文献   

12.
Simultaneous-equation statistical models are an attractive method for directly analyzing interactions among components of geomorphic systems. This study demonstrates that the utility of simultaneous-equation analysis is limited for fluvial systems by inherent multicollinearity among hydrologic and morphologic variables. Although multicollinearity for observed data may not be severe, estimation procedures for simultaneous-equation models often enhance this multicollinearity to problematic levels. Diagnostic tests are applied to three models of fluvial systems to illustrate the severity of the problem. It is recommended that investigators who develop simultaneous-equation models perform appropriate diagnostic evaluations to determine the impact of multicollinearity on specific parameter estimates.  相似文献   

13.
The countryside around towns is under increasing pressure for development as a result of the centrifugal forces which have characterised the capitalist urbanisation process in the post‐war era. Conflict between pro‐growth and anti‐growth interests is now endemic in many peri‐urban areas. This paper identifies the principal agents involved in the production of the built environment in the urban fringe and presents a detailed analysis of how divergent interests interact to determine the nature of the fringe environment. The research informs academic debate on rural land conversion and provides guidance for decision‐makers charged with management of the urban fringe.  相似文献   

14.
The author discusses three specific areas in which he made personal observations: Lake Bonneville, Yellowstone National Park, and ancient soil formations near Washington, D. C., and reports the latest American findings on the paleogeography of these areas. He finds the teaching and applications of geomorphology in the United States to be at a lower stage than would appear from American Geography: Inventory and Prospect.  相似文献   

15.
Statistical analyses of pre-test and post-test results, as well as qualitative insight obtained by essays, compared introductory physical geography college students who learned desert geomorphology only virtually, in the field and both ways. With the exception of establishing geographic context, the virtual field trip was statistically indistinguishable from real field trips in establishing basic knowledge about desert geomorphology. However, qualitative results reveal the deepest personal ownership of knowledge among field trip participants. These findings should not be construed as having validity beyond an introductory course.  相似文献   

16.
17.
昆仑文化作为一个学术体系,是一个令人肃然起敬,一个令人心驰神往,一个令人回肠荡气的文化,她给中华民族带来了无法估量的深远影响。近年来,国内外专家学者有关昆仑文化学  相似文献   

18.
19.
20.
Recent philosophical discussions on the nature of geomorphology ( Bassett 1994 ; Richards 1994 ; Rhoads 1994 ) have concluded that the way forward in geomorphological explanation is through either an empiricist or a realist approach. This paper draws lessons from quantum mechanics and the related concepts of decoherence and entanglement to explore the theoretical limitations of both of these existing approaches to geomorphology. It is suggested that empiricist and realist approaches are misguided in their attempts to view the researcher as being in some way 'detached' from the reality of the environmental system under investigation. Instead, this reality is viewed here as being consciousness-dependent. The paper also challenges the claims to represent 'truth', and the deterministic view of causation, which are inherent within empiricist and realist approaches. It concludes by suggesting that an idealist approach to geomorphology – one that recognizes the primacy of consciousness – can better appreciate the unpredictable and probabilistic nature of the world.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号