ISSN:1085-3278    

DOI:10.1002/ldr.3400010102

出版商:John Wiley&Sons, Ltd.    

年代:1989

数据来源: WILEY

摘要:

AbstractThe accelerating rate of change in urban areas calls for more rapid and cost‐effective surveys of derelict land. A review of the use of remote sensing1for this task reveals that, although aerial photography has been used for urban analysis since the 1940s, it has not been widely adopted for surveys of derelict land, despite demonstrations of its utility. Other forms of remote sensing are similarly shown to have been little‐used and to have had patchy success. The hitherto restricted utility of remote sensing is found to be due to a combination of limitations of the forms of imagery available and the methods of analysis employed. Recent changes in available remote sensing imagery, notably the higher resolution now provided by the SPOT satellite, coupled with advances in digital image‐processing techniques point to improved opportunities for using remote sensing to monitor derelict land. As a demonstration of these developments, a texture image based on scene variance is derived from a SPOT image of part of north Staffordshire. All derelict and neglected land parcels larger than 1.25 ha are delimited on this image. Remote sensing techniques are not yet ready to supplant detailed ground surveys but they have a growing role to play in monitoring various aspects of land dereli

ISSN:1085-3278    

DOI:10.1002/ldr.3400010103

出版商:John Wiley&Sons, Ltd.    

年代:1989

数据来源: WILEY

摘要:

AbstractThe paper examines why land management practices are not carried out, and what can be done about this. It focuses on the need to obtain an accurate explanation of why degradation has occurred, and highlights the need to examine: whether degradation really is taking place; the identification of those for whom land degradation is, or will be, a problem; the identification of why land degradation is taking place; the need to find solutions and means to reach them (i.e. policy formulation).

ISSN:1085-3278    

DOI:10.1002/ldr.3400010104

出版商:John Wiley&Sons, Ltd.    

年代:1989

数据来源: WILEY

摘要:

AbstractThe nuclear accident at Chernobyl in April 1986 resulted in a significant increase in the inventory of radiocaesium retained in the soil in many regions of the United Kingdom. The deposition of134Cs provides a convenient tool for the examination of erosional processes in upland systems. Detailed soil sampling has been undertaken within the Plynlimon experimental catchments to establish the pattern of deposition of Chernobyl‐derived radionuclides. The preliminary results of a combined radiometric and mineral magnetic approach to the study of the transport of Chernobyl‐labelled sediments and their source areas on these upland catchments in mid‐Wales are desc

ISSN:1085-3278    

DOI:10.1002/ldr.3400010105

出版商:John Wiley&Sons, Ltd.    

年代:1989

数据来源: WILEY

摘要:

AbstractThis paper examines soil and land degradation. It describes basic processes and factors responsible for degradation, illustrates the cause‐effect relationships and differentiates between natural and man‐induced regressive effects. The ‘critical limit’ concept is described in terms of properties beyond which the soil will not support an economically‐viable agriculture. This paper is not an exhaustive literature review but emphasizes the scientific principles involved and highlights natural against man‐induced processes. Important natural processes are: laterization, hard‐setting, fragipan and clay pan formation, and geologic erosion. In comparison, man‐induced processes consist of: soil compaction, accelerated erosion, desertification, salt accumulation and leaching and acidification. One of the principal constraints is the problem of data reliability. A reliable database and precise criteria are definitely lacking and hinder the assessment of the extent, type and degree of soil degradation and establishing the cause‐effect scenario. Improving our database is, therefore, of a high priority if we are to adopt land use policy for sustainable soil management and long‐range resource management. Also outlined, are vital research and development strategies. Judicious resource management policy should emphasize managing prime agricultural land to produce to its maximum potential so that there is no need to cultivate marginal and easily‐degraded fragile ecosystems. A strict code of conduct is needed for utilizing marginal/fragile lands. Methods of restoring the productivity of degraded lands must be researched so as to minimize the need to clear

ISSN:1085-3278    

DOI:10.1002/ldr.3400010106

出版商:John Wiley&Sons, Ltd.    

年代:1989

数据来源: WILEY

ISSN:1085-3278    

DOI:10.1002/ldr.3400010107

出版商:John Wiley&Sons, Ltd.    

年代:1989

数据来源: WILEY

ISSN:1085-3278    

DOI:10.1002/ldr.3400010108

出版商:John Wiley&Sons, Ltd.    

年代:1989

数据来源: WILEY

ISSN:1085-3278    

DOI:10.1002/ldr.3400010109

出版商:John Wiley&Sons, Ltd.    

年代:1989

数据来源: WILEY

ISSN:1085-3278    

DOI:10.1002/ldr.3400010110

出版商:John Wiley&Sons, Ltd.    

年代:1989

数据来源: WILEY

ISSN:1085-3278    

DOI:10.1002/ldr.3400010101

出版商:John Wiley&Sons, Ltd.    

年代:1989

数据来源: WILEY