Evaluation and validation of landslide-susceptibility maps obtained by a GIS matrix method: examples from the Betic Cordillera (southern Spain)

This work presents the results of applying the matrix method in a Geographic Information System (GIS) to the drawing of maps of susceptibility to slope movements in different sectors of the Betic Cordillera (southern Spain). In addition, the susceptibility models built by the matrix method were compared with a multivariate statistical method, and the first method gave the best results. The susceptibility maps drawn by the GIS matrix method were validated by calculating the coefficients of association with the degree of fit between recent slope movements registered in 1997 and the different levels of susceptibility of previously drawn maps (1995–1996) in different representative zones of the Betic Cordillera (southern Spain). The first sector studied showed excellent degrees of fit, with an error of less than 10% for all the slope failures and 3% when considering only failures of natural origin. In the second sector, the relative errors were less than 5%. In the third sector, the error hardly exceeded 6%. The results are discussed in the different zones and for each type of slope movement. In any case, these results evidence the predictive capacity of susceptibility maps drawn in GIS by the matrix method, for a great number of slope movements.     

Modelling wind-erosion risk in the Laghouat region (Algeria) using geomatics approach

Wind-erosion risk is a challenge that threatens land development in dry-land regions. Soil analysis, remote sensing, climatic, vegetal cover and topographic data were used in a geographic information system (GIS), using multi-criteria analysis (MCA) to map wind-erosion risk (R_we) in Laghouat, Algeria. The approach was based on modelling the risk and incorporating topographic and climatic effects. The maps were coded according to their sensitivity to wind erosion and to their socio-economic potential, from low to very high. By overlapping the effects of these layers, qualitative maps were drawn to reflect the potential sensitivity to wind erosion per unit area. The results indicated that severe wind erosion affects mainly all the southern parts and some parts in the north of Laghouat, where wind-erosion hazard (H_we) is very high in 43% of the total area, and which was affected mainly by natural parameters such as soil, topography and wind. The results also identified features vulnerable to R_we. The product of the hazard and the stake maps indicated the potential risk areas that need preventive measures; this was more than half of the study area, making it essential to undertake environmental management and land-use planning.     

An objective method to rank the importance of the factors predisposing to landslides with the GIS methodology: application to an area of the Apennines (Valnerina; Perugia, Italy)

The present work aims at contributing to further our knowledge on the predisposing factors to landslides as well as proposing a method that allows us to weigh up, as objectively as possible, the influence that the various factors have on landslides in order to construct a realistic map of potential landslide hazards. In order to assess the differential incidence of very predisposing factor to landslides, maps of the various factors considered were drawn up with the aid of IDRISI software (1997). The factors were as follows: the distance from faults, parallelism between the fractures and the landslide scarps, land use, lithology, distance from the streams, orientation and steepness of slopes, orientation of layers compared to the slope. The global analysis of the different incidence of the factors analyzed on the landslides present in the study area was carried out by comparing the respective maps with that of the scarps; in this way the number of pixels forming the scarps which fell into the various classes of the maps was calculated. The result thus obtained can form the basis of an objective assignation of the different ratings to be attributed to the various factors under consideration. In fact, the analysis carried out in this study has shown that the factors act differently and, for every factor, only some of the classes considered have marked importance.     

Municipal flood hazard mapping: the case of British Columbia,Canada

Historical responses to flood hazards have stimulated development in hazardous areas. Scholars recommend an alternative approach to reducing flood losses that combines flood hazard mapping with land use planning to identify and direct development away from flood-prone areas. Creating flood hazard maps to inform municipal land use planning is an expensive and complex process that can require resources not always available at the municipal government level. Senior levels of government in some countries have addressed deficiencies in municipal capacity by assuming an active role in producing municipal flood hazard maps. In other countries, however, senior governments do not contribute to municipal flood hazard mapping. Despite a large body of research on the importance of municipal land use planning for addressing flood hazards, little is known about the extent of flood hazard information that is available to municipalities that do not receive outside assistance from senior governments for flood hazard mapping. We assess the status of flood hazard maps in British Columbia, where municipalities do not receive outside assistance in creating the maps. Our analysis shows that these maps are generally outdated and/or lacking a variety of features that are critical for supporting effective land use planning. We recommend that senior levels of government play an active role in providing municipalities with (1) detailed and current information regarding flood hazards in their jurisdiction and (2) compelling incentives to utilize this information.     

The first geological maps of the continent of Australia

Two factors limited the compilation of geological maps of the Australian continent during the nineteenth century, the problems of geological mapping over large areas and the fact that Australia was divided into a group of independent colonies. Only four such maps were compiled and published during this period and all others are mere copies of three of these four.

On the first map, compiled by J. B. Jukes and published in London in 1850 at a scale of 225 miles to an inch, the geological colours are.confined to the coastal areas and a small portion of the interior which had been examined by explorers. The second, compiled by R. B. Smyth and published by the Victorian Department of Mines in 1875 at a scale of 110 miles to an inch, was drawn up from a large number of published and unpublished geological maps including those of Victoria and Queensland. Large areas were filled in from information in explorers’ journals and from their maps. A revised reprint was issued in 1876. The third map, compiled by Arthur Everett who was closely associated with the production of the 1875 map, was again published by the Victorian Mines Department in 1887 at a scale of 50 miles to an inch. Geological maps of the colonies of Victoria, Queensland, New South Wales, Tasmania, and South Australia were used, together with large scale maps and data previously gathered for the 1875 map of Western Australia and the Northern Territory. The fourth map, compiled by H. Berghaus and published in Gotha in 1888 at a scale of 1:30 000 000, was drawn up from sources similar to those used by Everett.

The compilation of the 1875 and 1887 maps is analysed in detail and annotated lists of the actual source maps used are given in Appendix 1. Mention is made of the numerous copies of these two maps issued in the nineteenth century. A complete list of all known geological maps of the Australian continent, published to date, is given in Appendix 2.     

Soil loss tolerance limits: an environmental management tool

Soil loss tolerance is defined as the maximum acceptable level of soil loss from an area which will allow a high level of productivity to be maintained. Furthermore the criteria which determines soil loss tolerance limits are discussed, and two methods currently in use in Southern Africa, i.e. those proposed by the Department of Agricultural Technical Services (DATS) and Skidmore are discussed. It is concluded that for various reasons the latter approach is more acceptable, and that it is imperative that a different T-value be determined for each soil series.Application of the principle of soil loss tolerance in the Tugela River Basin reveals that various areas are subjected to severe stress. Maps indicating areas with soil loss of more than 10 t/ha/yr; areas with a soil loss higher than its allocated soil loss tolerance limits; and soil loss as a percentage of its T-values are included. These maps reveal startling facts, and emphasize the need for swift action in order to combat the problem of soil erosion in the area.The conclusion is drawn that the technique by which soil loss tolerance limits are determied could be applied to large areas, and its representation on large scale maps could be very useful in environmental planning and management.     

Short communication: collection of isoseismal maps for South Africa

An atlas of isoseismal maps for South Africa, dating from as far back as 1932–2005, is provided. This work involved searching through historical reports to find records of macroseismic effects. In many instances, when there was a large tremor, questionnaires were distributed to local towns to assess the severity of the tremor and the damage it caused. Based on the results of these questionnaires and site investigations, isoseismal maps were drawn. These isoseismal maps were revisited and digitised for this study. Five additional isoseismal maps were prepared by the authors based on the results of questionnaires alone. Most isoseismal maps in the historical record use the Modified Mercalli scale. All maps are hence provided according to this scale. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Planning versus youth: Stamping out spatial unruliness in Harare

The paper examines the illegal occupation and use of urban spaces by Harare’s youth and the ensuing tussles with the repressive machinery of the local authority and the nation-state. It analyses efforts by planning to contain rampant spatial unruliness. The paper maps the patterns of official hostile responses to the illegal activities of the youth whose daily routines inevitably entail the disregard of the spatial planning framework as reflected in existing legal and regulatory controls. The analysis reveals the reliance by the urban planning and management system on the use of force and violence, a feat made possible by the mobilisation of the repressive state apparatus. The discussion argues that what comes out in the relationship between the order-imposing planning system and the regulation-flouting youth is a situation that can largely be comprehended by turning to the non-progressive side of planning.     

Large-scale assessment of avalanche and debris flow hazards in the Sakhalin region,Russian Federation

We explore the challenges of avalanche and debris flow hazard assessment for urban areas exposed in the Sakhalin region. Avalanches are a threat to more than 60 settlements in the region and debris flows to more than 30. Data are provided for avalanche and debris flow events that occurred in the Sakhalin region between 1928 and 2015. In this paper, the method for the design of hazard maps for snow avalanches and debris flows is described, providing the starting point for any planning constraints in general settlement planning schemes. These maps further allow conducting an assessment of avalanche and debris flow risk within a short time period for a larger territory and at minimum cost.

     

地层综合柱状图自动绘制的技术研究

介绍的软件及绘制技术成功地处理了地层综合柱状图中的化石、火成岩及相变等的绘制技术问题；其自动化程度高，具有很大的灵活性，以适应不同格式图件的要求。通过自编的接口软件由原始数据最终形成ＡｕｔｏＣＡＤ环境下的二进制图形交换文件。     

Tourist behaviour,local values,and interpretation at Ulu<Emphasis Type="Underline">r</Emphasis>u: ‘The sacred deed at Australia’s mighty heart’

This paper explores issues relating to multiple and changing values and uses of desert landscapes in the context of tourism at Uluru-Kata Tjuta National Park (UKTNP), co-managed by Aboriginal people and the Australian Government agency Parks Australia. More than 400,000 people visit the park each year, drawn mostly by the massive red monolith. To the local Aboriginal people, Anangu, this rock is Uluru, a complex of places with great spiritual importance. Since co-management, UKTNP has become a symbol of the reconciliation process between Aboriginal and settler Australians. Climbing the rock is a popular activity. Aboriginal co-managers ask visitors not to climb Uluru but rather to learn about their culture and home through their eyes. Park management aims to discourage climbing. This research investigated how visitors respond to the Anangu request not to climb, and why some climb while others do not. We argue that spatial and experiential aspects of the park support climbing at the expense of participation in other activities more attuned to Aboriginal understandings of landscape at Uluru.     

Hydrographic surveys and sedimentation in Deep Bay,Hong Kong

Three hydrographic surveys were carried out in Deep Bay, which is located in the eastern part of Pearl estuary between Shenzhen, the most successful special economic zone of PRC, and Hong Kong. Data on current, size distributions of bottom sediment, suspended solids, and some water quality parameters were obtained. This information is of value for mathematical modeling of tidal circulation and sediment transport in the bay, and also useful in the planning of further development in this area. The sedimentation rate in Deep Bay was estimated by two different approaches, viz. comparison of historical navigation maps and²¹⁰Pb dating. Information obtained from the maps indicated that average sedimentation rate between 1898 and 1949 was about 8 mm/yr, while a 15 mm/yr figure was obtained from the²¹⁰Pb dating for recent years.     

A comparative evaluation of heuristic and bivariate statistical modelling for landslide susceptibility mappings in Ghurmi–Dhad Khola, east Nepal

Landslides are one of the major natural disasters that occur in the Himalayan range with recurring frequency, causing enormous loss of life and property every year. Preparation of landslide inventory maps and landslide susceptibility zonation maps are the important tasks to be taken into account initially for safe mitigation measures. The present paper focuses on landslide susceptibility maps of the Ghurmi–Dhad Khola area, east Nepal, using Geographic Information System. For this purpose, the landslide susceptibility maps are prepared by using the heuristic and bivariate statistical methods. The parameters considered for the study are slope angle, slope aspect, elevation, distance from drainage, geology, land cover, rock and soil type, and distance from faults and folds. The landslide susceptibility zonation map produced from the heuristic method shows that 42.59 % of the observed landslide falls under the very high susceptible zone and 33.00 % under the high susceptible zone. Likewise, the landslide susceptibility zonation map produced from the bivariate method depicts that 44.19 % of the observed landslide falls under the very high susceptible zone and 31.59 % under the high susceptible zone. Both the landslide susceptibility zonation maps are identical, and success rates of both the maps are above 80 %. While comparing the landslide susceptibility maps obtained from two different methods, about 78 % of the study area falls in the identical susceptible zones. Special attention should be taken into consideration for the construction works in the areas which have been spatially agreed as very high and high susceptible zones from both techniques. Moreover, these maps can be used for slope management, land use planning, disaster management planning, etc., by the concerned authorities.     

Differential productions of rural gentrification: illustrations from North and South Norfolk

This paper focuses attention on the making of space for rural gentrification, both discursively and materially. The paper emphasises the differential constructions of gentrification within urban and rural studies. Connections are drawn between production-side theories of gentrification, notions of the ‘post-productivist countryside’ and studies that have related rural demographic change and gentrification with planning and property relations. Drawing on these three sets of ideas, the paper explores gentrification in rural Norfolk. It is argued that the contemporary geography of rural gentrification may in part reflect historic structures of landownership as well as settlement classifications associated with the land-use planning system. Country and District level analysis is followed up by detailed study of gentrification of two villages in Norfolk, which highlights how gentrified rural spaces may be produced in rather different way and through different agencies, and as a result takes different forms.     

Resource suitability analysis in regional planning—with special reference to Wisconsin,USA

The demands and needs of our presently increasing population require that the social decisions for land use must be based on the best and most reliable information that the decision-makers can obtain. Growing mass of natural resource information should be presented in a concise and practical form which the planners and public administrators can readily use without a need to learn about natural resources in detail. One of the means to present this information is a resource evaluation system which consists of four levels of maps: basic resource maps, single-factor maps, limiting-factor maps and final land suitability maps. The basic process used in the system is developing a series of individual maps showing specific kinds of information and superimposing them to identify a degree of suitability for a specific land use. The authors provide an overview of the use of land suitability maps in land use planning in the United States; show what natural resource data planners can require and put to use; outline the way in which earth scientists can evaluate and present the data needed; and finally demonstrate the land suitability analysis by case studies. Also briefly discussed is the need for information other than earth-science data. Land use planning and decision-making process is an intricate mixture of scientific, engineering, ecological, sociological, economic, cultural and political factors and forces. Obvious as it may seem this fact is nevertheless often ignored in practice resulting in misunderstandings and mutual disbelief of parties involved.     

岩溶顶板模拟试验研究

利用自制的桩基物理模型，对溶洞顶板进行了一组模拟试验，通过受力分析认为顶板尺寸在跨高比与宽度比不是很大时，可以把顶板简化为简支梁进行计算，但是需乘以一个适当的系数，同时对顶板进行了变形分析，给出了顶板的三维沉降等高图以及试件表面形变图。     

Accidents in mountain recreation —The experiences of international and domestic visitors in New Zealand

An important component of recreation in mountain areas is the experience of risk. Visitors to such places may be seeking the challenge provided by risk, but they may also experience the negative side of risk — accident and injury. International and domestic visitors to mountain lands may have differing experiences of risk. Indeed, it has been suggested frequently in New Zealand that international visitors face considerably more danger than do New Zealanders in mountain recreation. This view is pursued in an examination of one of the negative outcomes of risk — fatal accidents.Coroners' reports form the basis of a comparative study of such negative outcomes for the two groups. Patterns and trends are elaborated in an exploration of the number, location and cause of fatalities, and the activity of the deceased. Differences between two groups are discussed, as are some reasons why the impression that international visitors face more danger exists.     

Influence of seismic acceleration on landslide susceptibility maps: a case study from NE Turkey (the Kelkit Valley)

Particularly in the last decade, landslide susceptibility and hazard maps have been used for urban planning and site selection of infrastructures. Most of the procedures for preparing of landslide susceptibility maps need high-quality landslide inventory map. Although the rainfall and seismic activities are accepted as triggering factor for landslides, designation of the triggering factor for each landslide in the inventory is almost impossible when well-documented records are unavailable. Therefore, during preparation of landslide susceptibility map, whole landslide records in the inventory map are used together without classifying based on the triggering factors. Although seismic activity is accepted as a triggering factor, possible effect of the use of seismic activity on production of landslide susceptibility map was investigated in this study, and the subject is open to discussion. For this purpose, a series of stability analyses based on circular failure and infinite slope model were performed considering different pseudostatic conditions. The results of analyses show that gentle slopes have higher susceptibility to failure than steeper ones, even if their stability conditions (susceptibilities) are similar for static condition. The seismic forces acting on failure surfaces may not be sufficiently taken into consideration in the conventionally prepared landslide susceptibility maps. Employing the general decreasing trend in stability condition based on slope face angle and the seismic acceleration, a new procedure was introduced for preparing of the landslide susceptibility map for a scenario earthquake. The prediction performance of occurring landslides increased after the procedure was applied to the conventionally prepared landslide susceptibility map. According to the threshold independent spatial performance analyses of the proposed methodology and the produced landslide susceptibility maps, the area under ROC curve values were calculated as 0.801, 0.933, and 0.947 for the maps prepared by considering conventional method and scenario earthquakes having M _w values of 5.5 and 7.5, respectively.     

山地旅游规划工程地质方法及其应用前景分析

我国作为多山国家,山地旅游资源极为丰富。但由于山地地质灾害多发,许多山地旅游景区都或多或少地存在着地质灾害隐患。山地旅游的成功开发,需要一个完善的山地旅游规划作为保证,而是否充分考虑到山地灾害及其防治,对山地旅游的成功开发和安全运营起到至关重要的作用。然而,现阶段旅游规划专业涉及山地灾害及其防治方法的内容相当少,不足以解决问题。鉴于此,作者提出了山地旅游规划工程地质方法的概念,旨在通过与旅游规划学科交叉,使山地旅游的安全得到进一步保障,并推动山地旅游的可持续发展。另外,上述学科交叉也为工程地质学提供了一个新的研究方向。     

支撑服务广州市规划建设与绿色发展资源环境图集数据集

在对最新的水工环地质调查资料和成果进行梳理和总结的基础上,以粤港澳大湾区三极之一的广州市为重点,编制了地学专业综合图集——《支撑服务广州市规划建设与绿色发展资源环境图集》。《图集》收集和整理了国土资源大调查以来粤港澳湾区开展的环境地质调查、监测数据资料和研究成果等,经二次开发研究,以通俗易读或图或表的形式表示出来。《图集》整体分为序图、国土空间开发利用的地质适宜性评价、城市规划建设应关注的重大地质安全问题、产业发展可以充分利用的优势地质资源、生态环境保护需要重视的资源环境状况和基础地质条件类图件6大类,共53张图,并提出了助力大湾区绿色生态农业发展、清洁能源产业发展、用水安全、旅游产业发展和提升防灾减灾能力等五方面的地质建议,有效服务了广州国土空间规划与海绵城市建设。