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胶东地区乡村民居院落尺度与地形分区的相关性研究 被引量:2
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作者 张巍 《烟台大学学报(自然科学与工程版)》 CAS 2014年第1期55-59,共5页
胶东地区乡村民居的单体建筑特征存在较为鲜明的区域差异,其院落的尺度变化与地形分区也有着一定的相关性.为了验证这种假设,通过对前期普查所获得的数据的统计分析,将样本按照地形分区的不同分别进行比对.比较了面积和进深这2个作为院... 胶东地区乡村民居的单体建筑特征存在较为鲜明的区域差异,其院落的尺度变化与地形分区也有着一定的相关性.为了验证这种假设,通过对前期普查所获得的数据的统计分析,将样本按照地形分区的不同分别进行比对.比较了面积和进深这2个作为院落尺度主要指标的变量变化,初步证实胶东地区乡村民居院落尺度与地形分布存在某种相关性. 展开更多
关键词 变量分析 院落尺度 地形分区 相关性
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民居房间尺度与地形分区相关性量化分析 被引量:2
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作者 张巍 《建筑技术》 北大核心 2016年第7期623-625,共3页
基于地理学视角,综合大量实地调研获得的基础数据,使用量化分析方法,对胶东地区民居房间尺度与地形分区做出对比研究。结果表明:胶东地区民居的房间尺度存在较明显的因司分布,与胶东地区的地形分区呈现较高的一致性,反映了胶东地区民居... 基于地理学视角,综合大量实地调研获得的基础数据,使用量化分析方法,对胶东地区民居房间尺度与地形分区做出对比研究。结果表明:胶东地区民居的房间尺度存在较明显的因司分布,与胶东地区的地形分区呈现较高的一致性,反映了胶东地区民居的房间尺度可能与地形差异所带来的用地条件不同存在明显的相关性,为理解和掌握传统民居中的地域特征及在传统民居中蕴含的环境智慧提供了科学基础,可为传统村落保护和新农村建设提供依据。 展开更多
关键词 地理学视角 房间尺度 地形分区
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基于底栖动物的松花江流域不同地形分区水质指标阈值研究 被引量:9
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作者 程佩瑄 孟凡生 +3 位作者 王业耀 张铃松 杨琦 薛浩 《环境科学研究》 EI CAS CSCD 北大核心 2020年第9期2061-2073,共13页
为全面了解松花江流域不同地形分区内底栖动物群落对水质指标的响应规律,识别不同分区水质指标指示物种的差异,于2016-2018年对松花江流域97个采样点的水质指标[EC、ρ(DO)、ρ(CODMn)、ρ(NH3-N)、ρ(TN)、ρ(TP)]和大型底栖动物群落... 为全面了解松花江流域不同地形分区内底栖动物群落对水质指标的响应规律,识别不同分区水质指标指示物种的差异,于2016-2018年对松花江流域97个采样点的水质指标[EC、ρ(DO)、ρ(CODMn)、ρ(NH3-N)、ρ(TN)、ρ(TP)]和大型底栖动物群落进行调查分析,采用临界指示物种分析法(threshold indicator taxa analysis,TITAN)分别探讨松花江流域山区、丘陵区和平原区水质指标的生态阈值,当污染物浓度超过负响应阈值时敏感种密度降低,当超过正响应阈值时耐受种也会受到明显影响,底栖动物群落结构会发生显著变化.将TITAN法所得的负响应阈值作为触发底栖动物群落发生变化的最低值,正响应阈值为底栖动物群落的耐受极限值.结果表明:①松花江流域水质指标在不同地形分区内的阈值不同,除ρ(DO)和ρ(CODMn)外,其他指标负响应阈值均表现为山区<丘陵区<平原区,ρ(DO)则表现相反,ρ(CODMn)在丘陵区出现最高阈值(5.46 mg/L)、山区出现最低阈值(4.01 mg/L).除ρ(DO)以外,其他指标的正响应阈值均呈山区<丘陵区<平原区的趋势,ρ(DO)正响应阈值的变化趋势则与之相反.②松花江流域内超过50%的采样点水质指标值均超过其负响应阈值,超出正响应阈值的采样点比例在6%~40%之间,说明流域受到一定的干扰,但干扰程度不严重.③同一物种在不同地形分区内对水体理化指标的指示方向可能相反.萝卜螺属在丘陵区为ρ(NH3-N)的正响应指示物种,在平原区则转变为负响应指示物种;短沟蜷属在丘陵区为ρ(TN)和ρ(TP)的正响应物种,在平原区则转变为负响应物种.研究显示,大型底栖动物群落结构的分布特征是影响水质指标阈值指示物种识别的主要原因,而不同分区的自然地理状况、栖境状况和水质状况则是造成大型底栖动物群落结构分布差异的主要因素. 展开更多
关键词 松花江流域 地形分区 阈值 临界指示物种分析法(TITAN) 底栖动物
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基于地形分区的射线跟踪法加速方法的研究 被引量:2
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作者 李朋朋 陈亚洲 +1 位作者 石丹 高攸纲 《环境技术》 2014年第S1期176-180,共5页
通过分析影响射线跟踪法计算效率的因素,提出一种基于多线程的用于开放地理环境中的射线跟踪加速方法,以提高射线跟踪法在计算机仿真中的计算效率。该方法应用于特定复杂战场电磁环境,根据电磁波射线传播特性,采用对地形分区的途径减少... 通过分析影响射线跟踪法计算效率的因素,提出一种基于多线程的用于开放地理环境中的射线跟踪加速方法,以提高射线跟踪法在计算机仿真中的计算效率。该方法应用于特定复杂战场电磁环境,根据电磁波射线传播特性,采用对地形分区的途径减少射线与规则三角面地形面的求交次数,同时使用多线程追踪单个辐射源的射线路径。经过对方法进行仿真计算,验证该方法的有效性。 展开更多
关键词 射线跟踪 加速方法 地形分区 多线程技术
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基于地形分区的黄土丘陵区土壤有机质空间预测 被引量:1
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作者 张婧 毕如田 +2 位作者 丁皓希 文伟杰 荆颖蔷 《山西农业科学》 2021年第2期204-210,共7页
有机质是土壤的重要属性之一,在保持土壤肥力、提高土壤质量及作物产量等方面发挥着重要作用,所以,精确高效地获取区域土壤有机质的空间特征对监测耕地质量变化和农作物生产至关重要。文章以晋中市太谷区为研究区,通过普通Kriging插值... 有机质是土壤的重要属性之一,在保持土壤肥力、提高土壤质量及作物产量等方面发挥着重要作用,所以,精确高效地获取区域土壤有机质的空间特征对监测耕地质量变化和农作物生产至关重要。文章以晋中市太谷区为研究区,通过普通Kriging插值法和以结合地形起伏度和地貌类型辅助变量的分区Kriging插值法2种方法对研究区的土壤有机质含量进行空间预测,并通过采样点的预测值与实测值对比2种方法的预测精度。结果表明,结合地形起伏度和地貌类型进行的分区Kriging插值法得到的预测值与实测值的相关系数为0.4634,远高于直接进行Kriging插值法得到的预测值与实测值的相关系数0.2615;并且直接进行Kriging插值法的均方根误差为4.1429,高于分区插值法,所以,分区Kriging的预测精度更高。因此,结合地形起伏度和地貌类型分区Kriging插值模式是更适合丘陵区土壤有机质含量的空间预测。 展开更多
关键词 地形分区 土壤有机质 Kriging插值法
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辽宁省地形分类标准及分区方案研究 被引量:10
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作者 王利 任启龙 杨生彪 《辽宁师范大学学报(自然科学版)》 CAS 2015年第3期391-398,共8页
针对省级区域地形特点,提出适合本省的地形分类标准和分区方案,对区域内相关领域研究具有十分重要的现实意义.基于公开的SRTM3数据,并使用1∶25万地形数据补充海域部分,采用VM-MapInfo软件技术体系,建立覆盖辽宁省全域的1km×1km面... 针对省级区域地形特点,提出适合本省的地形分类标准和分区方案,对区域内相关领域研究具有十分重要的现实意义.基于公开的SRTM3数据,并使用1∶25万地形数据补充海域部分,采用VM-MapInfo软件技术体系,建立覆盖辽宁省全域的1km×1km面状矢量公里格网,作为地形分析的基础格网,对辽宁省地形进行高程和高程差分析,得出辽宁省无高山地、高原及大盆地地形;在典型地形剖面线分析基础上,将辽宁省地形类型分为5大类8个亚类,并依据划分的地形类型进行数量统计,辽宁省以丘陵为主,平原面积广阔,分别占全省面积的45.84%、29.30%.为使划定的辽宁省地形分类标准更好地指导全省国土资源开发利用,进一步划分出辽宁省地形分区方案. 展开更多
关键词 地形分类标准 地形分区方案 VM-MapInfo SRTM3 辽宁省
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不同地形环境下道路、河流对人口分布影响的分析——以黄山市为例 被引量:9
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作者 程晓亮 饶芬芳 《资源开发与市场》 CAS CSSCI 2008年第5期417-419,共3页
利用黄山市人口统计数据(2000年)及地形数据,根据地形起伏度进行地形分区,在不同地形环境下分析道路、河流对人口分布的影响。结果表明,道路和河路在平原盆地区、低山丘陵区及中高山区对人口分布的影响范围依次为2km、1.5km、1km和1.8km... 利用黄山市人口统计数据(2000年)及地形数据,根据地形起伏度进行地形分区,在不同地形环境下分析道路、河流对人口分布的影响。结果表明,道路和河路在平原盆地区、低山丘陵区及中高山区对人口分布的影响范围依次为2km、1.5km、1km和1.8km、1.2km、0.8km。通过建立道路、河路影响指数反映其对人口分布的影响程度。结果表明,按影响程度排列的地形环境依次是平原盆地区,低山丘陵区和中高山区。 展开更多
关键词 道路 河流 地形分区 人口分布 影响分析
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秦岭山区脱贫户生计韧性评价及其障碍因子——以陕西省蓝田县为例
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作者 马超群 张硕蒙 +2 位作者 员学锋 张舒媛 王晓峰 《地球科学与环境学报》 CAS 北大核心 2024年第6期790-803,共14页
准确测度山区脱贫户生计韧性及其关键影响因素,可为理解新时期脱贫户生计状况、巩固脱贫攻坚成果与全面乡村振兴有效衔接提供借鉴。以地处秦岭腹地的陕西省蓝田县为例,根据环境禀赋、家庭资本、个人能力的层次结构构建蓝田县脱贫户生计... 准确测度山区脱贫户生计韧性及其关键影响因素,可为理解新时期脱贫户生计状况、巩固脱贫攻坚成果与全面乡村振兴有效衔接提供借鉴。以地处秦岭腹地的陕西省蓝田县为例,根据环境禀赋、家庭资本、个人能力的层次结构构建蓝田县脱贫户生计韧性评价指标体系;基于农户调查数据,采用TOPSIS模型和障碍度模型比较分析了不同地形区、不同脱贫时间、不同生计策略下脱贫户生计韧性的差异及其障碍因素。结果表明:(1)蓝田县脱贫户生计韧性指数均值为0.531,整体处于中等水平,具有较高水平生计韧性的脱贫户仅占14.81%,3个维度层中环境禀赋均值最高,个人能力是脱贫户生计韧性的短板;(2)不同类型脱贫户生计韧性存在分化特征,河谷阶地区脱贫户、早期脱贫户以及自主经营性和务农主导型脱贫户生计韧性较高;(3)影响各类型脱贫户生计韧性的障碍因子呈现趋同态势,劳动参与、技能培训、务工地点、耕地和林地面积、家庭年收入是阻碍蓝田县脱贫户生计韧性提升的主要因素。针对不同区位条件脱贫户生计韧性的障碍因素,从政府和农户2个层面提出了蓝田县脱贫户生计韧性提升的对策。 展开更多
关键词 生计韧性 脱贫户 TOPSIS模型 地形分区 生计策略 障碍因素 提升策略 秦岭山区
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中国农牧交错带30年响应气候变异趋势分析 被引量:5
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作者 马雯思 刘玮玮 +1 位作者 赵宁 马超 《江苏农业科学》 北大核心 2017年第24期279-284,共6页
农牧交错带是典型的生态脆弱区和环境变化敏感区,有气象-环境放大镜作用,及时准确地了解农牧交错带的气候时空变异状况,对环境响应全球气候变化具有重要的生态学意义。利用中国大陆752个站点1982—2012年的逐年降水、气温数据资料,运用... 农牧交错带是典型的生态脆弱区和环境变化敏感区,有气象-环境放大镜作用,及时准确地了解农牧交错带的气候时空变异状况,对环境响应全球气候变化具有重要的生态学意义。利用中国大陆752个站点1982—2012年的逐年降水、气温数据资料,运用反距离空间加权法、掩膜提取、变异系数运算等对中国北方和川滇农牧交错带降水、气温进行分区对比分析。结果表明:(1)除北方农牧交错带丘陵草原区(Ⅳ区)降水量增加外,其他4区均呈减少趋势,气候变化对北方农牧交错带草甸草原区(Ⅰ区)影响最大(降水量变异系数VCp=18%),川滇农牧交错带山地草原区(Ⅴ区)受其波动性最小(VCp=7%)。(2)1982—2012年间,研究区总体增温速率为0.45℃/10年,总体变异系数达29%;30年平均变异系数空间上存在差异性,表现为草甸草原区(Ⅰ区)(温度变异系数VCt=14%)>丘陵草原区(Ⅳ区)(VCt=12%)>荒漠草原区(Ⅲ区)(VCt=9%)>灌丛草原区(Ⅱ区)(VCt=7%)>山地草原区(Ⅴ区)(VCt=6%)。(3)30年来400 mm等雨量线有向东、向北发展趋势,空间动态变化范围(102°~111°E、35°~40°N)与北方农牧交错带区域(105°45'~124°42'E、36°01'~49°36'N)重合度达89%,且重合度有升高之势。 展开更多
关键词 农牧交错带 变异系数 地形分区 400mm等雨量线 降水量 气温 增温速率 空间动态变化 重合度
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作者 《山西农业科学》编辑部 《山西农业科学》 2021年第4期439-439,共1页
2021年第49卷第2期第一作者为张婧的《基于地形分区的黄土丘陵区土壤有机质空间预测》文章中,收稿日期应为“2020-12-03”。
关键词 黄土丘陵区 空间预测 土壤有机质 地形分区
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山东半岛蓝色经济区水系连通模式研究 被引量:2
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作者 张泽玉 王金山 +2 位作者 高月奎 郭小雅 顾伟 《中国水利》 2015年第8期43-45,共3页
对山东半岛蓝色经济区水系连通现状进行分析,阐述了目前水系连通存在的主要问题及其根源。根据水资源、地理及地貌特点,将山东半岛分为胶东低山丘陵区、鲁中南低山丘陵区、黄河冲积平原区三个分区,针对不同的连通目标,初步研究采用不同... 对山东半岛蓝色经济区水系连通现状进行分析,阐述了目前水系连通存在的主要问题及其根源。根据水资源、地理及地貌特点,将山东半岛分为胶东低山丘陵区、鲁中南低山丘陵区、黄河冲积平原区三个分区,针对不同的连通目标,初步研究采用不同的连通工程组合,确定各区域的水系连通模式,为做好山东半岛水系连通总体和局部布局奠定了基础。 展开更多
关键词 山东半岛 蓝色经济区 水系连通 模式 水系及地形特征分区
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Multi-fractal Behaviors of Relative Humidity over China 被引量:2
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作者 GAO Li-Hao FU Zun-Tao 《Atmospheric and Oceanic Science Letters》 CSCD 2013年第2期74-78,共5页
The multi-fractal ity over China are studied behaviors of relative humid using the multi-fractal de trended fluctuation analysis (DFA) method. Three multi fractal parameters (the spectrum width Aa, the asymmetry Aa... The multi-fractal ity over China are studied behaviors of relative humid using the multi-fractal de trended fluctuation analysis (DFA) method. Three multi fractal parameters (the spectrum width Aa, the asymmetry Aaas, and the long-range correlation exponent a0) of the singularity spectrum are introduced to quantify the multi-fractal behaviors. The results show that multi-frac tality exists in daily humidity records over most stations in China and is mainly due to the broad distribution of the probability density of the sequence values. Strong multi fractal behaviors over some stations in the Yunnan, Guangdong, and Inner Mongolia provinces are obvious. These behaviors are mainly caused by different long range correlations between large and small fluctuations. The asymmetry of the singularity of relative humidity records is weak, except for a small number of stations in the far east and west of China, where the singularity spec trum is left-skewed. Finally, the long-range correlations in North China are stronger than those in South China, which indicates better predictability in North China. By studying the parameters of the multi-fractal spectrum, various data of long-range power law correlations of the relative humidity records are obtained, which may pro vide theoretical support for climate prediction. 展开更多
关键词 long-range correlation scaling exponent MULTI-FRACTAL multi-fractal detrended fluctuation analysisCitation: Gao L.-H. and Z.-T. Fu 2013: Multi-fractalbehaviors of relative humidity over China Atmos. Oce-anic Sci. Lett. 6 74-78.
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Study on the Relationship Between Recent Crustal Deformation and the Temporal-Spatial Distribution of Strong Earthquakes (M_s≥6.0) in the Sichuan-Yunnan Region
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作者 LiTieming DengZhihui LüYipei 《Earthquake Research in China》 2003年第4期324-341,共18页
Analysis of deformation data measured across the faults, regional vertical deformation data and GPS measurements in the Sichuan-Yunnan region made since the 1980s permitted us to conclude that the crustal deformation ... Analysis of deformation data measured across the faults, regional vertical deformation data and GPS measurements in the Sichuan-Yunnan region made since the 1980s permitted us to conclude that the crustal deformation in the region during this period of time was relatively weak and caused the occurrence of earthquakes (M S≥6.0), which were not distributed along the major boundary active faults in the region after the 1981 Dawu M S 6.9 earthquake and that the seismic activity is characterized by quasi-clockwise migration. Thus, it follows that earthquake prediction research should be focused on the central part of the Sichuan-Yunnan region in the coming years. Finally, a concept of temporal division of the region into active blocks is suggested and the preliminary result of the division is given in the paper. 展开更多
关键词 Crustal deformation GPS measurement EARTHQUAKE BLOCK DIVISION Sichuan-Yunnan region
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Simulation of Morphological Development of Soil Cracks in Yuanmou Dry-hot Valley Region, Southwest China 被引量:9
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作者 XIONG Donghong YAN Dongchun +4 位作者 LONG Yi LU Xiaoning HAN Jianning HAN Xueqin SHI Liangtao 《Chinese Geographical Science》 SCIE CSCD 2010年第2期112-122,共11页
Soil cracking is an important process influencing water and solutes transport in the Yuanmou Dry-hot Valley region of Southwest China. Studying the morphological development of soil cracks helps to further reveal the ... Soil cracking is an important process influencing water and solutes transport in the Yuanmou Dry-hot Valley region of Southwest China. Studying the morphological development of soil cracks helps to further reveal the close relationship between the soil cracking process and water movement in such semi-arid regions. Here we report regular changes on surface morphology of soil cracks with decreasing water in four different soils (Typ-Ustic Ferrisols,Ver-Ustic Ferrisols,Tru-Ustic Vertisols and Typ-Ustic Vertisols) through simulation experiments. Our results indicate the following: 1) Different soils ultimately have different development degrees of soil cracks,according to their various values of crack area density. Soil cracks in Typ-Ustic Ferrisols can only develop to the feeble degree,while those in the other three soils are capable of developing into the intensive degree,and even into the extremely intensive degree. 2) Soil crack complexity,as expressed by the value of the area-weighted mean of crack fractal dimension (AWMFRAC),is found to continuously decrease as a whole through the whole cracking process in all the studied soils. 3) Soil crack connectivity shows a uniform trend in the studied soils,that is to say,connectivity gradually increases with soil crack development. 展开更多
关键词 soil cracks morphological development simulation experiment Yuanmou Dry-hot Valley region Southwest China
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Description of desertification evolution in Fuxin district of Liaoning province based on fractal theory
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作者 ZHANG Shu-guang 《Journal of Environmental Science and Engineering》 2008年第5期55-58,共4页
Desertification is the most serious environmental problem in the world today. Fractal feature of granularity composition was studied by using the fractal theory in view of desertification soil in Fuxin district, there... Desertification is the most serious environmental problem in the world today. Fractal feature of granularity composition was studied by using the fractal theory in view of desertification soil in Fuxin district, thereby evolution patterns of desertification was promulgated. The result shows that the self-formation degree of the developing desertification areas is higher than the relatively steady desertification areas. Evolution of desertification is beginning of forming sandy soil of framework composition, and then the sandy soil be came complex by the effect of environment, climate and anthropo-activity. 展开更多
关键词 land desertification fractal feature evolution patterns
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The Relationship Between Strong Earthquake Activity of M_S≥7.0 on the Chinese Mainland and the West Kunlun-A'nyêmaqên Secondary Arcuate Tectonic Zone
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作者 ZhangXiaodon WangHuimin LuMeimei YuSurong 《Earthquake Research in China》 2004年第2期171-177,共7页
The active and quiet phenomenon of moderate strong earthquakes one year before the earthquakes with M S≥7.0, the spatial distribution characteristics of the solid tide modulating and triggering earthquakes and the st... The active and quiet phenomenon of moderate strong earthquakes one year before the earthquakes with M S≥7.0, the spatial distribution characteristics of the solid tide modulating and triggering earthquakes and the strong earthquake mechanisms on the Chinese continent have been studied. The secondary arcuate tectonic zone composed of the west Kunlun-Anyêmaqên faults is believed to be a very important boundary to characterize strong earthquake activity of M S≥7.0 on the Chinese continent, that is, a boundary between the seismically active region and the quiet region of moderately strong earthquakes one year before earthquakes with M S≥7.0, and a boundary of the spatial distributions between the solid tide modulating strong earthquakes (M S≥7.0) and the non-modulating ones. It might be related with the characteristics of spatial distribution of focal mechanism solutions of strong earthquakes on the Chinese Continent. 展开更多
关键词 Arcuate tectonic zone Boundary zone Strong earthquake Seismicity characteristics
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Recent Data on Birds of Kinshasa in Democratic Republic of Congo
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作者 Julien Kumanenge Punga Seraphin Ndey Bibuya Ifuta 《Journal of Agricultural Science and Technology(A)》 2015年第3期218-233,共16页
The study aimed at understanding the current avifauna characteristics, like composition, species diversity and evolution, in the city of Kinshasa. The study was conducted from 2006 to 2014, using observation, photogra... The study aimed at understanding the current avifauna characteristics, like composition, species diversity and evolution, in the city of Kinshasa. The study was conducted from 2006 to 2014, using observation, photography and Japanese nets. Results of the study indicate that there are 131 species of birds, which represents 40 families and 16 orders. Avifauna of Kinshasa represents 11% of species of the all country. Among those species, 12 are new. Passerines are the most, representing 86 species and 21 families, and are the most diversified. Few species have extended their geographical distribution and some are migratory. Overtime, avian fauna of Kinshasa region has undergone a lot of changes in its composition and diversity. Horizontal extension of the city associated with the consecutive various changes of the habitats seems to be the principal factors which modulate those characteristics. However, the study found that the majority of these species were under precarious statute of conservation. 展开更多
关键词 BIRDS specific diversity KINSHASA Democratic Republic of Congo.
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Lithospheric Structure Model of Central Indian Ocean Basin Using Ocean Bottom Seismometer Data
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作者 Pasupuleti Prasada Rao Sanjeev Rajput +5 位作者 Bhaskarbhatla Ashalatha Uma Shankar Kalachand Sain Maradani Simhadri Naidu Vuyyuru Triveni Naresh Kumar Thakur 《Journal of Earth Science and Engineering》 2012年第6期344-359,共16页
The intense deformation zone in the central Indian Ocean, south of Indian continent is one of the most complex regions in terms of its structure and geodynamics. The deformation zone has been studied and debated in 19... The intense deformation zone in the central Indian Ocean, south of Indian continent is one of the most complex regions in terms of its structure and geodynamics. The deformation zone has been studied and debated in 1990s for its genesis. It was argued that deformation is mainly confined to sedimentary and oceanic crustal layers, while the large wave length geoidal anomalies, on which the deformation region lies, called for deeper sources. The inter connection between deeper and the shallower sources is found missing. The current study focuses on the complexities of this region by analyzing OBS (ocean bottom seismometer) data. The data acquired by five OBS systems along a 300 km long south-north profile in the CIOB (central Indian Ocean basin) have been modeled and the crustal and sub-crustal structure has been determined using 2-D tomographic inversion. Four subsurface layers are identified representing the sediment column, upper crustal layer, lower crustal layer and a sub-crustal layer (upper mantle layer). A considerable variation in thickness as well as velocity at all interfaces from sedimentary column to upper mantle is observed which indicates that the tectonic forces have affected the entire crust and sub-crustal configuration. The sediments are characterized by higher velocities (2.1 kin/s) due to the increased confining pressure. Modeling results indicated that the velocity in upper crust is in the range of 5.7-6.2 km/s and the velocity of the lower crust varies from 7.0-7.6 km/s. The velocity of the sub-crustal layer is in the range of 7.8-8.4 km/s. This high-velocity layer is interpreted as magmatic under-plating with strong lateral variations. The base of the 7.0 km/s layer at 12-15 km depth is interpreted as the Moho. 展开更多
关键词 OBS (ocean bottom seismometer) CIOB (central Indian Ocean basin) tomographic inversion.
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Potential Impacts of Various Land Use Forms on Land Degradation in Arid Regions (Case Study: Kuwait)
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作者 Raafat Misak Adeeba Al-Hurban 《Journal of Agricultural Science and Technology(A)》 2013年第5期368-379,共12页
During the last 20 years, land use in Kuwait was remarkably changed in various forms. Such changes resulted in positively constructive, as well as, adversely destructive impacts on the local environment and ecology. I... During the last 20 years, land use in Kuwait was remarkably changed in various forms. Such changes resulted in positively constructive, as well as, adversely destructive impacts on the local environment and ecology. In 1993-1994, a buffer zone of 15 km wide and more than 200 km long was established between Iraq and Kuwait. This allowed the restoration of biodiversity, enhancement of ecological conditions and stabilization of fragile soils. In 1991, long bund walls were constructed along the Saudi-Kuwaiti borders by Saudi Arabia and in 1993-1994, a ground trench was dug along the Iraqi-Kuwaiti borders by Kuwait. Bund walls are piles of excavated soils, 2-3 m high, 3-5 m wide and several tens of kilometers length. Constructing 1 km length of a bund wall required 2,500-3,000 m3 (1,000 m length x 5 m average width x 0.5 m depth) amount of soil, which disturbed a groundcover strip of an average area of 10,000 m2 (1,000 m length x 10 m average width). Border trenches are ground hollows 2-3 m deep, 3-5 m wide and 220 km long. The amount of excavated soil from digging 1 km long trench ranged from 6,000-8,000 m3. Field work indicated that 1 km long of trench had disturbed a groundcover of an average area of 12,000 m2 (1,000 m length ~ 12 m average width). Such man-induced land features are closely related to land degradation processes, as they were of adverse environmental impacts on soil, surface hydrologic conditions and natural vegetation. The main objective of this study is to assess the immediate and long term impacts of the introduced land use forms in selected areas in Kuwait, such as Wadi AI Batin (Western part of Kuwait). To achieve such an objective, intensive field program was designed and implemented and the collected data and available information were analyzed and interpreted. 展开更多
关键词 Bund walls TRENCHES man-induced land features surface hydrologic conditions.
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