A remote-sensing technique for the identification of aeolian fetch distance

This paper describes a new method for assessing aeolian fetch distances in beach/dune systems. The remote‐sensing technique has advantages over currently used proxy measures of fetch distance, such as those based on tide gauges and beach profiles. The method uses a digital camera, global positioning system surveying, and a geographical information system software package to produce a rectified image of the beach surface. From this, direct measurements of the wet–dry beach boundary can be combined with wind direction measurements to determine fetch distance. The method offers an improvement on current approaches to sediment transport estimates: a 28‐day study on Magilligan Strand, Northern Ireland, showed that the commonly used high water mark approach overestimated fetch distance by 30% compared with the technique reported here.     

Spatial heterogeneity of local flood vulnerability indicators within flood-prone areas in Taiwan

Global environmental change is bringing extreme precipitation, and the combination of natural and artificial impacts are resulting in serious floods on the west coast of Taiwan. Disparity in social, economic and infrastructure resources contributes to spatial variation in the vulnerability to flood disaster. Owing to the high frequency of torrential rain and serious land subsidence in the study area, this paper attempts to categorize vulnerability indicators under varied assumptions of spatial homogeneity and spatial heterogeneity. The results show that the spatial heterogeneity indeed affects the distribution of flood vulnerability indicators. The core value of this article is that it measures the improvement from using geographically weighted statistics rather than traditional statistics. For the flood vulnerability discussion, this paper demonstrates the importance of considering spatial heterogeneity when allocating resources against floods.     

Newspapers as a validation proxy for GIS modeling in Fujairah,United Arab Emirates: identifying flood-prone areas

Prediction and control of blast-induced ground vibration is a matter of concern in mining industry since long. Several approaches ranging from scaled distance regression, different numerical methods to wave superimposition theories have been tried by many researchers for better prediction and control of blast-induced ground vibration. Signature hole analysis is one of the popular simulation methods to predict the ground vibration generated due to production blast. It superimposes the recorded signature hole waveform using a computer program to predict the production blast-induced vibration. The technique inputs the designated time of detonation of each hole and superimposes the waves generated by each hole to predict the nearest value of peak particle velocity and frequency of blast-induced ground vibration. Although a very useful approach, it requires a computer program to simulate the linear superimposition of waveforms. The simulation is not possible for every blast as it takes time and also is difficult for field engineers to simulate every time, whereas it is always easy for blasting engineers to adapt and use an empirical equation/approach for prediction and control of blast-induced ground vibration than simulation. In this paper, an attempt has been made to develop an innovative and simplified analytical approach of signature hole analysis. The simplified sinusoidal wave equation is obtained from recorded signature hole ground vibration waveform properties and is superimposed mathematically according to the multi-hole blast design to predict the production blast-induced ground vibrations. The validation of the developed approach was done in three different sites, and up to 15% more accuracy in prediction of the blast, vibrations are achieved in comparison with signature hole analysis prediction.

     

Multi-criteria analysis for the identification of waste disposal areas

The municipality of Cachoeiro de Itapemirim (ES) is currently the largest domestic producer and exporter of marble and granite in Brazil. The processing of the rock, especially the sawing results in a large volume of waste, including the abrasives used during sawing and the off-cut pieces. Presently these waste products are disposed of without proper environmental protection and cause pollution to surface water and groundwater resources, including silting, an increase in hardness and increased aluminium values in the groundwater. In order to minimize the harmful effects of these practices on the environment, a research project was undertaken to identify potential disposal sites for the generated waste. A multi-criteria approach was followed during which a database was compiled of all the companies generating waste products and also including a baseline environmental study of the region, integrated analysis (multi-criteria analysis) of the restriction factors and the preliminary identification of possible disposal sites. This revised version was published online in July 2006 with corrections to the Cover Date.     

Geologic and infrastructure factors for delineating areas for clean coal: examples in Texas, USA

Texas has a wide variety of areas that can be targeted for new clean-coal facilities. These areas are delineated by mapping spatial linkages between coal- and lignite-bearing formations, groundwater and surface-water resources, and CO₂ sinks in brine formations for long-term CO₂ storage or in mature oil fields with potential for enhanced oil recovery (EOR). However, a variety of infrastructure factors make it feasible to also target numerous areas outside coal and lignite basins in Texas. These infrastructure factors include pipelines for delivery of CO₂ to subsurface sinks and delivery of coal-produced hydrogen to refineries, ease of connection to existing transmission lines, distribution of nonattainment areas where new clean-coal facilities could be constructed and be compliant with strict air-quality standards, and railroads that can transport coal and other feedstock to new clean-coal facilities. Primary regions in Texas where favorably co-located CO₂ source-sink factors related to coal and lignite trends include the Gulf Coast, the Eastern Shelf of the Permian Basin, and the Fort Worth Basin. However, areas outside coal and lignite basins, particularly the Permian Basin where a new clean-coal facility is being planned, also have clean-coal potential because of existing CO₂ pipelines and proximity to EOR fields that can economically sustain new clean-coal facilities.     

Satellite remote sensing applications for surface soil moisture monitoring: A review

Surface soil moisture is one of the crucial variables in hydrological processes, which influences the exchange of water and energy fluxes at the land surface/atmosphere interface. Accurate estimate of the spatial and temporal variations of soil moisture is critical for numerous environmental studies. Recent technological advances in satellite remote sensing have shown that soil moisture can be measured by a variety of remote sensing techniques, each with its own strengths and weaknesses. This paper presents a comprehensive review of the progress in remote sensing of soil moisture, with focus on technique approaches for soil moisture estimation from optical, thermal, passive microwave, and active microwave measurements. The physical principles and the status of current retrieval methods are summarized. Limitations existing in current soil moisture estimation algorithms and key issues that have to be addressed in the near future are also discussed.     

干旱半干旱区土壤含水量反演与验证

基于MODIS遥感影像和表观热惯量法,以新疆为研究区,建立了适用于干旱半干旱区1 m土体的土壤含水量反演模型。模型根据高表观热惯量,高土壤含水量,低表观热惯量,低土壤含水量这一理论,通过日地表温差和宽波段反照率确定土壤含水量的时空变化。假设通过1 m土体的土壤水通量正比于上下底层土壤含水量的差值,利用水平衡方程建立土壤表面和底层土壤含水量关系方程,并利用中国土壤类型特点确定优化模型。通过验证结果表明,壤土和壤质粘土这两类土壤含水量接近真实值,砂土在区域验证中,模拟与实测差值为2.16%,整个模型模拟精度较好,能够准确地从时空上反演干旱半干旱地区1 m土体的土壤水分情况。     

遥感降水资料后处理研究综述

获取高精度高分辨率的降水数据对于流域水文分析、水资源管理及洪涝干旱监测等均具有重要意义。遥感技术虽然能有效再现降水的时空分布,但原始遥感降水资料无法满足水文领域对高精度高分辨率数据的需求,需要开展遥感降水资料的后处理研究。介绍获取降水资料的主要方法,包括雨量站观测、地面天气雷达估测以及气象卫星反演,讨论各方法的主要优势和当前存在的问题,在此基础上综述遥感降水资料的后处理方法研究进展,包括空间降尺度、偏差校正以及产品融合,并归纳后处理降水产品的评价指标,最后指出今后的研究重点:发展和改进降水估计技术;构建更为合理的多源降水数据融合框架;加强降尺度法对比研究,进一步改进和完善降尺度法;开展降水相关的不确定性分析。     

沙漠包气带水分运移机理研究

针对沙漠包气带的特点,运用中子仪—负压计—地温计联合观测法,对试验场典型地段水位埋深分别为lm,2m,3m的包气带含水量、水分势能和温度场进行了长期野外实地观测,并总结出相应的日变化、季节变化规律,分析了降水、蒸发等气象因素对包气带水分的影响过程,从而得出沙漠包气带水分运移机理及运移规律。为红砂岗矿区水源地水资源评价提供了科学依据。     

Temporal shoreline change and infrastructure influences along the southern Red Sea coast of Saudi Arabia

Jizan is one of the Saudi Arabian coastal cities endowed with diverse natural settings, which includes Ash Shuqayq in the north, Turfah in the centre and Jizan in the South. This work analysed specific environmental characteristics, such as spits, sabkhas and wadis. Assessments used Landsat imagery to examine coastal change between 1973 and 2011. The cumulative temporal change identified regression trends given by coefficients of determination that explained a significant percentage of data variation for Jizan (R ² = 69%) and Turfah (R ² = 72%), while Ash Shuqayq was insignificant (R ² = 14%). Inter-survey results predicted future change, although trends were not significant, i.e. Jizan (R ² = 22%), Turfah (R ² = 14%) and Ash Shuqayq (R ² = 3 and 61% with outlying value removed). Aerial photos showed regional coastal changes, which included a maximum accretion of 36.4 m and maximum erosion of 12.9 m. These are scientifically effective techniques to monitor regional coastal change, i.e. erosion and accretion and identified rates of 0.59, 1.80 and 3.53 myr^?1 for Ash Shuqayq, Turfah and Jizan. Changes were linked to infrastructure developments, e.g. tourism, port development and natural causes, e.g. spit formations and wadi outfalls.     

Heat-induced moisture transport in the vicinity of a spherical heat source

The present paper develops an analytical approach to the problem of heat-induced moisture movement in the vicinity of a spherical heat source embedded in an undeformable, moist porous solid of infinite extent. A transient-state distribution of temperature within the infinite medium is assumed to induce the moisture transport process. The numerical results, presented in the paper, illustrate the influence of the moisture transport characteristics on the time-dependent distribution of moisture within the porous medium. © 1998 John Wiley & Sons, Ltd.     

Variations in technical infrastructure and private economic activity in the rural areas of Southern Poland

Restructuring the Polish countryside is a complex and urgent task. Adapting agriculture for EU entry will mean a considerable reduction in employment and rural diversification is needed because other sectors of the national economy will not be able to absorb all the displaced people if they arrive in the towns. However, providing non-agricultural employment in rural areas depends to a large extent on the technical infrastructure available: running water, sewerage systems, gas supply and telecommunications. The paper deals with voivodeships in southern and southwestern Poland (formerly Galicia) and shows that while much progress has been made since the end of the communist period, the inherited inequalities are being perpetuated and in some cases increased. However, even where the infrastructure is satisfactory, private business does not develop at a uniform rate and action is needed to stimulate communities in remoter rural areas, particularly in the eastern part of the study region. This revised version was published online in July 2006 with corrections to the Cover Date.     

区域构造遥感图像地质成因模型

模型方法是一种科学研究方法。遥感图像是地壳表层的图像模型 ,是建立地质成因模型的理想原型。郯庐断裂带中段沭河断裂带与五莲—青岛构造带在山东东部斜接 ,二者在遥感图像上组成一个倒“入”字图形。“入”字图形的结构、笔画顺序和倒置形态 ,表征了两大构造带的时空特征 ,揭示了该区构造组成和演化规律 ,是这一地区区域地质构造遥感图像地质成因模型。     

Estimation of improved resolution soil moisture in vegetated areas using passive AMSR-E data

Microwave remote sensing provides a unique capability for soil parameter retrievals. Therefore, various soil parameters estimation models have been developed using brightness temperature (BT) measured by passive microwave sensors. Due to the low resolution of satellite microwave radiometer data, the main goal of this study is to develop a downscaling approach to improve the spatial resolution of soil moisture estimates with the use of higher resolution visible/infrared sensor data. Accordingly, after the soil parameters have been obtained using Simultaneous Land Parameters Retrieval Model algorithm, the downscaling method has been applied to the soil moisture estimations that have been validated against in situ soil moisture data. Advance Microwave Scanning Radiometer-EOS BT data in Soil Moisture Experiment 2003 region in the south and north of Oklahoma have been used to this end. Results illustrated that the soil moisture variability is effectively captured at 5 km spatial scales without a significant degradation of the accuracy.     

典型岩溶峰丛洼地坡面土壤水分空间变异性

采用网格法测量典型坡面上旱季（12月）和雨季（5月）的表层(0~5 cm)土壤含水量,以地统计学方法分析其空间变异性,结果表明:（1）与单一土地利用坡面相比,人为扰动强、土地利用多样的岩溶峰丛坡地表层土壤含水量表现为坡上未被扰动的自然植被区明显高于坡下人为改造的区域;旱季时坡地林地表层土壤平均含水量（32.8%）明显高于位于坡下的梯田空闲地（24.2%）、梯田橘园（20.0%）、梯田菜园（22.0%）、坡地裸地（23.5%）;雨季时,坡地裸地（30.2%）和梯田橘园（32.1%）有明显增大,梯田空闲地（17.8%）剧烈减小,坡地林地（32.2%）土壤含水量依然最高;（2）旱、雨季整个坡面上空间结构比分别为21.0%、8.7%,表现为雨季的空间相关性更好;旱、雨季表层土壤含水量变异系数分别为20.1%和31.7%,属中等程度变异;雨季表层土壤含水量的变程（77.5 m）显著高于旱季（8.0 m）,雨季的土壤含水量具有较好的空间变异结构;（3）裸岩周围空间的土壤含水量随与裸岩的距离增大而减小,梯田石坎周围空间的土壤含水量随与梯田石坎的距离增大而递减。      

路基土体“锅盖效应”的数值模拟分析

基于对道面下路基土体中"锅盖效应"形成机制的定性认识,依据非饱和土中气液传输及热传导多场耦合理论并考虑水的气液相转换,建议了对此问题进行分析的数学模型。采用有限元方法对道面下路基一维土柱进行模拟分析,揭示了土中水和水蒸气在变温作用下的运移及相变规律,分析了"锅盖效应"形成条件和影响因素。数值结果显示,土质和温度分布对路基土发生"锅盖效应"有较大影响。粉土路基较黏土或砂土路基更易形成水分聚集;路基顶部温度较路基深处温度低时,在温度作用下易引起路基土的"锅盖效应"。这些结果可为进一步研究道路工程中的"锅盖效应"提供参考。     

岩溶地区土洞地基灌浆处理过程研究

[摘 要] 灌浆是岩溶土洞地基处理的一种常用方法,灌浆压力对灌浆施工的有效性有着至关重要 的作用。针对岩溶地区土洞地基所处地质环境的复杂性,为了科学合理地确定其灌浆施工过程中的灌 浆压力,本文通过传统理论力学分析方法以及数值模拟方法对灌浆过程中灌浆压力变化及其引起的整 个地基应力应变场的变化进行了分析与研究,同时与施工现场监测结果进行了对比研究。研究结果表 明:在灌浆施工过程中,合理适当的灌浆压力既能确保浆液充分填充土洞,又不会破坏原土体结构;通过 对原土体抬升位移的监测,能准确预测与控制施工时的灌浆压力;理论分析与数值模拟结果和现场情况 吻合较好,为灌浆工艺施工提供了可靠的理论依据与指导。     

基于遥感检测的输油管道泥石流灾害危险性评价

兰成渝成品油管道是我国能源战略的重要组成部分,礼县—广元段基岩山区线路上崩塌、滑坡、泥石流等地质灾害均较为发育,对管道安全运行存在着潜在的威胁。基于多源遥感检测信息,以该段线路泥石流为例,建立了泥石流灾害的遥感解译标志,采用模糊综合评判法分析了降雨作用下泥石流灾害发生概率,并对管道泥石流灾害危险性进行了评价,从而实现了管道泥石流灾害的快速预警。