Road lateral disconnection and crossing impacts in river landscape of Lancang River Valley in Yunnan Province, China

Roads are conspicuous components in a river landscape;however,their impacts on river landscape patterns and ecological processes have not been systematically studied at the watershed scale.In this paper,the Lancang River Valley in Yunnan Province,China was selected as a case to study road lateral disconnection and crossing impacts and identify river-road network interaction.This study was primarily focused on the road impacts on soil erosion intensity and patch density by using GIS analysis at different scales and explored their distribution with terrain factors.The results showed that river density revealed spatial autocorrelation although both of the roads and rivers were distributed unevenly in the valley.The lateral road(road curvature≥1.1)proportion correlated with soil erosion intensity(p 0.01)at the small sub-basin scale.Soil erosion intensity decreased with increasing lateral road buffer width.Light erosion generally accounted for a large proportion of the erosion in the lateral road buffer zones(1.0–4.0 km),while higher class lateral roads imposed greater impacts on soil erosion than lower class roads,which primarily had a moderate erosion level.In addition,the results of road-river intersection density indicated that road crossing impacts were significantly correlated with patch density at the small sub-basin scale.Topography factor(percent of slope25°in each sub-basin had a close relationship with the ratio of total length of road line with curvature value≥1.1 to the total number of intersections.The correlation(p 0.01)between road impacts and terrain factor revealed that topography affected the road impact distribution in the Lancang River Valley.     

Landscape network approach to assess ecological impacts of road projects on biological conservation

Awareness of the adverse ecological effects of road and other large construction projects has resulted in a rapidly growing demand to quantitatively predict and evaluate the effects on gene flow among plants and animals in natural habitats.In this study,we evaluated the effects of different road construction scenarios on animal species movement by using the methods of ecological landscape connectivity in the typical regions of Yunnan Province,China.The results showed landscape connectivity levels（Probability of Con-nectivity（PC）） decreased after road construction and species with lower dispersal abilities were more affected to the subsequent habitat fragmentation.First level roads affected landscape connectivity most significantly.At a distance of 100 m,the PC index decreased more than 50%.Further analysis suggested that the use of landscape connectivity to assess landscape processes revealed the adverse effects on the species movement more effectively compared with the traditional landscape pattern analysis.In addition,we conducted a graph the-ory and a least-cost modeling discussion,it is obvious that they are powerful tools to represent and analyze landscape networks with respect to related species movement.Network analysis offers a quantitative and simple but effective tool for ecological process assess-ment and biological conservation on large scales.     

基准转换时工艺尺寸换算的一种新方法

采用尺寸公差双向标注和利用尺寸链关系图来求解基准转换时的工艺尺寸换算问题，对工艺尺寸公差的分配提出了一种与传统不同方法，并给出了计算实例。     

2006年7月3日黄淮地区大暴雨过程分析

利用地面和高空常规气象观测资料及全省自动站逐时观测风场资料、MM5中尺度数值模拟资料、多普勒天气雷达观测资料,对2006年7月3日发生在黄淮地区的大暴雨过程进行分析和模拟.结果表明:这次暴雨是由高空低涡前部强盛西南暖湿急流与地面生成的中气旋影响造成的;切变线两侧大气层结的强烈不稳定对形成此次短时暴雨有重要促进作用;此次临沂市短时暴雨是由低空切变线上生成的中β尺度气旋东移影响的;在有利的大尺度环流背景下,可利用数值预报产品预估过程集中影响时段,结合卫星云图资料范围大,雷达回波探测性强,自动站资料实时性、灵活性强等优点,进一步作好短时暴雨的临近预警预报,提高短时暴雨的预报提前量,努力降低短时暴雨造成的经济损失.     

Spatio-temporal analysis of different levels of road expansion on soil erosion distribution: a case study of Fengqing county, Southwest China

The construction of roads has direct and indirect impacts on soil erosion, with spatio-temporal variations existing among different levels of road zones. Aiming to quantitatively analyze the soil loss, this paper explored the relationship between the erosion of soil and its distance from the road in Fengqing county, Southwest China in 1987 and 2004, respectively. The average soil erosion was calculated and expressed with grid map using universal soil loss equation (USLE) model based on GIS and RS. Along the different levels of roads classified as trunk, county, town, village and unpaved road, the buffer zones were subdivided into five stripes, each of which was 200 meters wide. The average soil erosion modulus of each buffer zone was also counted. Results show that the soil loss decreases with increasing distance to the road except rare trunk roads in the region. In addition, the declined intensity varies with the different levels of roads. Soil erosion was more serious along the lower level road than the higher ones. And soil erosion was more severe for all levels of roads in 1987 than those in 2004 because much more rainfalls affected the situation of soil erosion in 1987.     

Numerical Simulation of the Lagging Water Inrush Process from Insidious Fault in Coal Seam Floor

Because of insidious fault’s concealing performance and lagging nature, water inrush from insidious faults in coal seam floor can cause great threads to the mine safety. Based on analyzing the engineering geology conceptual model, this paper simulated the insidious fault lagging water inrush process and showed the lift height of the confined water in the insidious fault fractured zone (LHCWIFFZ) and the formation of water inrush channel. Then the concept of the potential water inrush channel with time effect was put forward. In order to further illustrate the time effect of the lagging water inrush from insidious fault, theoretical analysis was made from two aspects of the time effect of the plastic zone development height in the insidious fault fractured zone (PZDHIFFZ) based on the differential flow deformation theory and the time effect of water inrush channel in the upper part of the insidious fault (WICUPIF) based on the subcritical crack propagation theory. Simulation results showed that the results are basically consistent with mining practice.     

地震次生地质灾害风险评估集对态势分析

5．12四川汶川8级强震引发了大量次生地质灾害,加剧了灾情并严重影响抗震救灾。地震次生地质灾害受多重因素制约,其孕育与致灾过程具有不确定性。利用集对分析原理与方法,对地震次生地质灾害进行同异反态势分析,拟定了风险评估的集对分析同一度、差异度、对立度等指标体系的构建原则与赋值标准,对承灾体系统的不确定性及其作用作了刻画与分析,建立了不同风险分区代表性的集对分析联系度表达式,为地震灾害研究提供了可资借鉴的新思路和技术方法。     

基于逐月标准化降水蒸散指数的多尺度方法分析气候变化对澜沧江流域归一化植被指数的影响

基于澜沧江流域10个气象站点1951~2012年的日降水资料的逐月标准化降水蒸散指数(SPEI)值、各站1998~2012年流域的归一化植被指数(NDVI)值,利用SPEI以及趋势分析法,多尺度分析了澜沧江流域干旱发生的时间和强度演变特征以及上中下游NDVI时间变化特征,探讨了气候变化对植被变化的影响,并对NDVI与SPEI的变化进行了相关性分析。结果表明,不同站点和不同时间尺度的SPEI值均呈现出干旱化逐年加强的线性趋势,上游相对于中下游干旱态势较轻,且时间尺度越大,干旱波动趋势越明显;在季节尺度上,夏、秋、冬的SPEI值均呈下降趋势,其中冬季干旱最为严重;15年来澜沧江流域各区域年平均NDVI总体表现为先降低后增加,总体植被状况得到改善,其中下游较明显。从年际变化看,对于流域的不同区域,NDVI与不同尺度的SPEI的相关性和滞后性有较大差异,年代际之间的响应规律也不同,中下游的SPEI对同年NDVI的响应比较敏感,而上游则表现出明显的滞后性。说明NDVI对SPEI的响应比较敏感,干旱程度的变化在一定程度上影响着流域的植被状况,SPEI是影响NDVI的因素之一。     

磨削温度遥测法的研究

利用半人工热电偶在M131W万能外圆磨床上通过对磨削进给量等工艺参数与磨削温度之间关系曲线的多次实验,结果表明:在无冷却液的情况下用遥测法测得的磨削温度曲线与用传统的集流环法测得的磨削温度曲线基本一致,且能在有冷却液条件下进行测量。与集流环法相比本方法测量稳定,精度高。     

层次分析法及其地面沉降研究应用

层次分析法是系统工程中的一种决策分析方法。本文应用其基本原理与方法对上海地面沉降进行了分析。