GIS based landslide susceptibility mapping using a fuzzy logic approach: A case study from Ghurmi-Dhad Khola area, Eastern Nepal

Landslides cause extensive loss of life and property in the Nepal Himalaya. Since the late 1980s, different mathematical models have been developed and applied for landslide susceptibility mapping and hazard assessment in Nepal. The main goal of this paper is to apply fuzzy logic to landslide susceptibility mapping in the Ghurmi-Dhad Khola area, Eastern Nepal. Seven causative factors are considered: slope angle, slope aspect, distance from drainage, land use, geology, distance from faults and folds, soil and rock type. Likelihood ratios are obtained for each class of causative factors by comparison with past landslide occurrences. The ratios are normalized between zero and one to obtain fuzzy membership values. Further, different fuzzy operators are applied to generate landslide susceptibility maps. Comparison with the landslide inventory map reveals that the fuzzy gamma operator with a γ-value of 0.60 yields the best prediction accuracy. Consequently, this operator is used to produce the final landslide susceptibility zonation map.     

基于流动电位正演模型的非饱和带水流过程监测

为了获取非饱和带水流过程的信息,借助流动电位正演模型,通过数值实验探讨非降雨和降雨两种条件下非饱和带流动电位和水流过程的关系,然后用南京中山植物园试验场地野外观测的流动电位和张力数据加以对比和验证。野外试验表明:流动电位可以有效地反映非饱和带水流过程。在夏季无降雨入渗的条件下,日周期变化的地表地下温度差导致水分的运动,流动电位准确地指示了非饱和带含水量和毛细压力的变化情况,从而指示出了水分运移的方向;在夏季有降雨入渗的条件下,降雨锋面推进之处,含水量和流动电位同时有明显的响应,进而根据不同位置的流动电位对降雨入渗响应的时刻差,直接求出入渗锋面的推进速度。     

Comments on “a statistical prediction technique for deriving contour maps from geophysical data”

Mathematical Geosciences -     

Kinematics of a deep-seated landslide derived from photogrammetric, GPS and geophysical data

The deep-seated landslide located at the intersection of the Gradenbach and Möll valleys near Döllach, Austria, has been the target of many previous investigations [Kronfellner-Kraus, G., 1980. Neue Untersuchungsergebnisse in Wildbächen — Der Talzuschub in Abhängigkeit von Niederschlägen. Int. Symp. Interpraevent Bad Ischl 1: 179–192; Weidner, S., Moser, M., Lang, E., 1998. Influence of hydrology on sagging of mountain slopes (“Talzuschübe”) — New results of time series analysis. 8th International IAEG Congress, Vancouver, Canada, Balkema, Rotterdam, 1259–1266; Weidner, S., 2000. Kinematik und Mechanismus tiefgreifender alpiner Hangdeformationen unter besonderer Berücksichtigung der hydrologischen Verhältnisse. Dissertation, Friedrich–Alexander-Universität Erlangen–Nürnberg, 246.]. In this paper, photogrammetric, GPS and geophysical data have been utilized to derive a constraint on the kinematics of the sagging process. The photogrammetric models have been based on aerial photographs from 1962 and 1996. Displacement vectors of about 50 individual characteristic points have been determined; these clearly show the area of the sagging slope. From 1999 to 2004, eleven GPS campaigns have been carried out, yielding very accurate displacement vectors at four monitoring points. Information about the internal structure of the slope was determined using seismic surveys.

The displacements observed by photogrammetry and GPS have shown a rather uniform movement of the whole sagging slope, with a slight longitudinal compression of 0.6%. In order to extend the kinematic consideration to 3D, a special form of the equation of continuity (conservation of mass) has been applied to the 1962–1996 photogrammetric data, together with the cross-sections derived from the seismic data. The average velocities through cross-sections have been calculated by integrals of the mass-balance above and below these cross-sections. Changes of the total rock mass, due to accumulation and especially to erosion, as well as an overall compaction of 1.5% between 1962 and 1996, have been considered. The calculated average velocities through a cross-section and the surface velocities independently determined by photogrammetry agree within an uncertainty of 15%. The results indicate a block movement with shear concentration at the basal sliding surface.     

北京西郊玉泉山地区岩溶水强径流路径地球物理分析

为研究北京西郊玉泉山地区岩溶水径流路径,需查明区内地层结构和断裂构造发育情况,故在玉泉山周边地区开展了综合地球物理勘查工作。完成1∶25000面积性重力测量3670点,在重力数据解释推断成果基础上,有针对性地布设可控源音频大地电磁测深(CSAMT)剖面测量5.1 km及微动测深点4个。综合研究了基岩起伏形态和构造展布特征,新解释推断了10条可能存在的断裂构造。结合区域水文地质资料,对主要断裂的水文地质意义进行了分析,形成了玉泉山地区岩溶水强径流路径新的认识,部分成果与最新的同位素水化学研究成果一致。本研究为玉泉山泉恢复确定合理的回灌方案提供了地球物理依据。     

The typology of Irish hard-rock aquifers based on an integrated hydrogeological and geophysical approach

Groundwater flow in hard-rock aquifers is strongly controlled by the characteristics and distribution of structural heterogeneity. A methodology for catchment-scale characterisation is presented, based on the integration of complementary, multi-scale hydrogeological, geophysical and geological approaches. This was applied to three contrasting catchments underlain by metamorphic rocks in the northern parts of Ireland (Republic of Ireland and Northern Ireland, UK). Cross-validated surface and borehole geophysical investigations confirm the discontinuous overburden, lithological compartmentalisation of the bedrock and important spatial variations of the weathered bedrock profiles at macro-scale. Fracture analysis suggests that the recent (Alpine) tectonic fabric exerts strong control on the internal aquifer structure at meso-scale, which is likely to impact on the anisotropy of aquifer properties. The combination of the interpretation of depth-specific hydraulic-test data with the structural information provided by geophysical tests allows characterisation of the hydrodynamic properties of the identified aquifer units. Regionally, the distribution of hydraulic conductivities can be described by inverse power laws specific to the aquifer litho-type. Observed groundwater flow directions reflect this multi-scale structure. The proposed integrated approach applies widely available investigative tools to identify key dominant structures controlling groundwater flow, characterising the aquifer type for each catchment and resolving the spatial distribution of relevant aquifer units and associated hydrodynamic parameters.     

盾构法隧道施工变形智能模糊控制方法研究

在对盾构施工变形规律认识的基础上,引入了智能控制学科的思想与方法,采用模糊逻辑控制技术建立了变形的智能模糊逻辑控制系统模型,并进一步在地铁盾构法区间隧道工程中进行了初步实证研究。控制分析结果表明,采用本文提出的理论控制模型能够实现定量化盾构诸施工参数的主动与实时控制。     

Prospectivity of Western Australian iron ore from geophysical data using a reject option classifier

There has recently been a rapid growth in the amount and quality of digital geological and geophysical data for the majority of the Australian continent. Coupled with an increase in computational power and the rising importance of computational methods, there are new possibilities for a large scale, low expenditure digital exploration of mineral deposits. Here we use a multivariate analysis of geophysical datasets to develop a methodology that utilises machine learning algorithms to build and train two-class classifiers for provincial-scale, greenfield mineral exploration. We use iron ore in Western Australia as a case study, and our selected classifier, a mixture of a Gaussian classifier with reject option, successfully identifies 88% of iron ore locations, and 92% of non-iron ore locations. Parameter optimisation allows the user to choose the suite of variables or parameters, such as classifier and degree of dimensionality reduction, that provide the best classification result. We use randomised hold-out to ensure the generalisation of our classifier, and test it against known ground-truth information to demonstrate its ability to detect iron ore and non-iron ore locations. Our classification strategy is based on the heterogeneous nature of the data, where a well-defined target “iron-ore” class is to be separated from a poorly defined non-target class. We apply a classifier with reject option to known data to create a discriminant function that best separates sampled data, while simultaneously “protecting” against new unseen data by “closing” the domain in feature space occupied by the target class. This shows a substantial 4% improvement in classification performance. Our predictive confidence maps successfully identify known areas of iron ore deposits through the Yilgarn Craton, an area that is not heavily sampled in training, as well as suggesting areas for further exploration throughout the Yilgarn Craton. These areas tend to be more concentrated in the north and west of the Yilgarn Craton, such as around the Twin Peaks mine (~ 27°S, 116°E) and a series of lineaments running east–west at ~ 25°S. Within the Pilbara Craton, potential areas for further expansion occur throughout the Marble Bar vicinity between the existing Spinifex Ridge and Abydos mines (21°S, 119–121°E), as well as small, isolated areas north of the Hamersley Group at ~ 21.5°S, ~ 118°E. We also test the usefulness of radiometric data for province-scale iron ore exploration, while our selected classifier makes no use of the radiometric data, we demonstrate that there is no performance penalty from including redundant data and features, suggesting that where possible all potentially pertinent data should be included within a data-driven analysis. This methodology lends itself to large scale, reconnaissance mineral explorations, and, through varying the datasets used and the commodity being targeted, predictive confidence maps for a wide range of minerals can be produced.     

Applying fuzzy logic to open data for sustainable development decision-making: a case study of the planned city Amaravati

Surf zone injuries (SZIs) are common worldwide, yet limited data are available for many geographical regions, including Europe. This study provides the first preliminary overview of SZIs along approximately 230 km of hazardous surf beaches in SW France during the summer season. A total of 2523 SZIs over 186 sample days during the summers of 2007, 2009 and 2015 were analysed. Documented injury data included date and time; beach location; flag colour; outside/inside of the bathing zone; age, gender, country and home postal code of the victim; activity; cause of injury; injury type and severity. Injuries sustained ranged from mild contusion to fatal drowning, including severe spinal injuries, wounds and luxation. While the most severe injuries (drowning) were related to rip currents, a large number of SZIs occurred as a result of shore-break waves (44.6%; n = 1125) and surfing activity (31.0%; n = 783) primarily inside and outside of lifeguard-patrolled bathing zones, respectively. Victims were primarily French living more than 40 km from the beach (75.9% of the reported addresses; n = 1729), although a substantial number of victims originated from Europe (14.7% of the addresses reported; n = 335), including the Netherlands (44.2%; n = 148), Germany (26.3%; n = 88) and Belgium (12.5%; n = 49). The predominant age group involved in the incidents was between 10 and 25 years (54.5%; n = 1376) followed by between 35 and 50 years (22.6%; n = 570), with the majority of SZIs involving males (69.6%, n = 1617). Despite the large predominance (74.1%; n = 33) of males involved in the most severe drowning incidents, all of which occurred outside the bathing zone, a surprisingly large proportion of females (48.0%; n = 133) experienced milder drowning incidents involving only minor to moderate respiratory impairment, peaking at 58.2% (n = 85) within the age group 10–25. The spine/cervical injury population is very young, with 58.5% (n = 313) within the age group 10–20. Specific injuries tended to occur in clusters (e.g. rip-current drowning or shore-break injury) with particular days prone to rip-current drowning or hazardous shore-break waves, suggesting the potential to predict the level of risk to beachgoers based on basic weather and marine conditions. This study calls for increased social-based beach safety research in France and the development of more effective public awareness campaigns to highlight the surf zone hazards, even within a supervised bathing zone. These campaigns should be targeted towards young males and females, in order to reduce the number of injuries and drownings occurring on beaches in SW France.     

基于模糊识别的水资源承载能力综合评价

应用模糊识别模型解决水资源承载能力综合评价问题,根据水资源承载能力相关因子自身的数据结构特性,通过模糊识别模型得到样本的级别特征值,从而达到对待评价区域的识别、归类,同时可以得到各相关因子在评价过程中的贡献率,实例部分将模型应用于全国30个省市、自治区的水资源承载能力评价,结果表明该方法的实用性和客观性。     

Sedimentogenesis in the Amundsen Basin from geophysical data and drilling results on the Lomonosov Ridge

Studies in the Amundsen Basin have revealed six seismostratigraphic complexes (SSCs) in this region. The horizons bounding these complexes were dated by identifying the linear magnetic anomalies. The recognized SSCs are correlated with the seismostratigraphic and lithostratigraphic units of the Lomonosov Ridge. Based on these correlations, the lithological composition of SSCs in the Amundsen Basin is suggested. The formation of SSC2 is supposed to be due to the diagenetic processes associated with the transition of opal-A to opal-CT. It is found that, generally, the rate of sedimentation in the Amundsen Basin has consistently decreased since the beginning of its formation. However, in the Chattian time, the global regression resulted in a sharp increase in the rate of sedimentation in the basin. Arguments in favor of the duration of the Middle Cenozoic sedimentary hiatus on the Lomonosov Ridge reduced to 16.3 Ma are presented. It is supposed that the decrease in the intensity of oceanic crustal accretion in the Eurasian Basin, which is identified by the slowdown in the rate of its opening in the interval from 46 to 20–23 Ma might have resulted in a gradual sea level falling in the Arctic Ocean isolated from the World Ocean. This fact probably accounts for the Lomonosov Ridge having remained in subaerial conditions over the period from 36.7 to 20.4 Ma.     

Contrast of evolution models for agricultural contaminants in ground waters by means of fuzzy logic and data mining

This work aims at contrasting, by means of a set of fuzzy logic- and data mining-based algorithms, the functioning model of a detritic aquifer undergoing overexploitation and nitrate excess input coming from strawberry and citrus intensive crops in its recharge zone. To provide researchers unskilled in data mining techniques with an easy and intuitive interpretation, the authors have developed a computer tool based on fuzzy logic that allows immediate qualitative analysis of the data contained in a data mass from the water chemical analyses, and serves as a contrast to functioning models previously proposed with classical statistics. M.L. de la Torre and J.A. Grande belongs to Water Resources and Quality Research Group. J.M. Andujar and J. Aroba belongs to Control and Robotics Research Group     

基于数据字典的MapGIS属性数据逻辑检查——以全国矿产资源潜力评价基础成果数据检查为例

在"全国矿产资源潜力评价"项目的基础成果数据验收汇总工作中,保证属性数据的填写质量是非常重要的一个环节,在专业领域内属性数据之中存在着一定的逻辑关系,可以通过计算机程序实现的方式检查数据是否存在着逻辑上的错误。在MapGIS 67二次开发环境下利用VC编程语言实现了属性数据逻辑检查程序,该程序基于数据字典技术,通过调用用户已设定的逻辑关系表达式对潜力评价基础数据进行属性逻辑检查,并将检查结果以报表的形式导出,大大提高了图件的检查验收工作的效率,并保证了数据的准确性与可靠性。该项技术已经成功应用于全国矿产资源潜力评价项目中稀土矿和钨矿的汇总工作。     

基于Bayes融合理论的某坝段帷幕体防渗效果评价

坝基帷幕体的防渗性能及其时效可由传感器采集到的地下水宏观动态反映出来,而在异类多个传感器数据融合的过程中,常常出现各个评价指标不一致的现象。为消除这种现象,采用Bayes融合方法,首先验证各个传感器的可靠程度,确立正确的关系矩阵,然后将各传感器的可靠程度模糊化,进而给出各传感器的综合支持程度指标,最后给出融合结果。将其应用于某坝13坝段帷幕体防渗效果分析,结果较为符合规律。经分析知,2003－2008年间帷幕体防渗效果呈现了阶段性衰减,其中2005年和2008年为该坝段帷幕体防渗性能的相对明显衰减时期。建议加强监测,为必要时采取工程措施提供依据。     

Mapping land limitations for agricultural land use planning using fuzzy logic approach: a case study for Marinduque Island,Philippines

This study demonstrated the use of fuzzy logic approach in mapping land limitations for agricultural land use planning using publicly available data for the province of Marinduque, Philippines. The paper focused only on the two major crops in the province, coconut, and banana. Based on the results, slope is the major factor limiting the production of these two crops. Slope is identified as a limitation in approximately 80% and 18% of the agricultural land of the province for coconut and banana production, respectively. Other land limitations for coconut production in the province include rainfall, soil, and combination of these factors with slope. In the case of banana, soil and combination of this factor with slope were identified as land limitations.

     

Understanding the dynamics of high and low spring flow: a key to managing the water resources in a small urbanized hillslope of Lesser Himalaya, India

Water scarcity is becoming a major problem in High Mountain Basins of Indian Himalaya. Access to fresh water becomes a core concern for every dweller in the summer season all across the Indian Himalayan Region. This paper presents an assessment of two low yielding perennial springs in one of the urban center located in the very steep mountain slopes of Lesser Himalaya. Spring hydrographs were analyzed to investigate the variability and availability of spring flow in three seasons. Dynamic spring flow volume in storage and time at which the flow may cease were also assessed, as they play a crucial role for planning short-term measures. The linear model using the exponential decay equation is found to be sufficiently accurate to model the recession characteristics of spring outflow from the hardrock aquifers for winter season, as the main contribution comes from baseflow with delayed interflow, which is slow diffuse flow in nature. The present study examines the findings from 1 year of spring outflow and rainfall when deficient monsoonal rainfall (moderate drought) is recorded in major parts of the country. The data can play a significant role in estimating dependable minimum water availability from the spring outflow and planning for appropriate capacity of low to medium storage structure for conserving the excess water which goes unutilized even during the high scarcity period. The analysis of duration curve suggests, more focus should be given for conserving the surplus water available during the monsoon through appropriate storage structures, which can be used during the leanest month.