Impacts of land use change on landscape patterns in mountain human settlement: The case study of Hantai District(Shaanxi,China)

Mountain area is an important geographical unit of land,and its ecology is sensitive and fragile.Over the past few decades,human activities have caused dramatic changes in land use in mountainous areas,which caused changes in landscape patterns and impacts on the ecological environment.It is unknown how the mechanism of land use affects the landscape pattern at different scales.The Hantai District,a typical human settlement in the mountain area in Shaanxi,China,was chosen as the study area.Based on the remote sensing images,the mathematical models and landscape indexes were adopted to evaluate the impact of land use change from 1998 to 2017 on the landscape pattern at different scales,and its main driving forces were analyzed.The results showed that the urbanized land expanded largest from 15.39%to 24.30%,and cultivated land experienced the largest decline from 43.54%to 35.35%.Changes in land use have made the patch morphology of most land types developed from a natural random to a sawtooth shape,and its spatial pattern evolved from a ruleset to a fragmented expansion.This reflects the continuous strengthening of human intervention in the process of regional development.Under the jurisdiction of Hantai District,the biggest change in landscape pattern is in Hanzhong City and Qili Town.The improved economy and increasing population and urbanization rate were the main factors that cause these changes.This research could provide necessary information for understanding the evolution mechanism of land resources in mountainous human settlements for mountainous areas with significant geomorphic differentiation.     

房地产宏观政策期待加大执行力

4月27日,中国社会科学院城市发展与环境研究中心和社会科学文献出版社联合主办的2007年中国房地产高峰论坛暨《 房地产蓝皮书》2007年版出版发布会在北京举行.来自中国社会科学院、国土资源部、建设部、国家统计局、中国房地产协会等部门的专家、学者和官员出席了会议.     

边城廿八都

浙西南的江山市廿八都镇,地处浙闽赣三省交界。四面群山拱卫,仙霞古道穿镇而过,自古有“东南锁钥,入闽咽喉”之称。小镇类似文学家沈从文笔下的边城,当时“也有商人落脚的客店,坐镇不动的理发馆。此外,饭店、杂货铺、油行、盐栈、花衣庄,莫不各有一种地位,装点这条小河街。”而唐宋古道驿站遗址和明清古桥民居至今尚存。     

"一户一宅"的思考

《土地管理法》第六十二条规定,农村村民一户只能拥有一处宅基地。这对于节约集约用地,强化农村宅基地管理具有十分重要的指导意义。长期以来,农村旧的宅基地管理模式造成农村村民住房严重超标,一户多宅以及空心村的现象普遍存在,农村宅基地极度浪费。“一户一宅”制从当前全国农村的实际出发,对农村宅基地使用作出了科学合理的界定。但是,在执行“一户一宅”过程中,也出现一些新情况新问题,在市场经济条件下,这些新情况新问题必须在立法和实践中加以解决,并不断完善现有的制度,以达到科学合理地利用农村土地。     

Influence of the roots of mixed-planting species on the shear strength of saline loess soil

In order to improve our knowledge of the mechanical effect of the roots of mixed-plantings on soil reinforcement and slope protection,the influence of roots of a mixed-planting with four herb species(Medicago sativa L.,Elymus nutans Griseb.,Puccinellia distanx(L.),and Poa pratensis L.)and one shrub species(Caragana korshinskii Kom.)were investigated on the shear strength characteristics of saline loess soil.The root distribution characteristics were assessed via a survey when the plants grew for one year.The effects of the root biomass density,the root mass ratio(RMR)of the fine roots to the coarse roots,the moisture content,and the salt content on the shear strength index of the rooted soil were analyzed via a triaxial compression test,and the mechanism of these effects was discussed.The results indicate that the biomass density decreased linearly with increasing depth.The RMR initially decreased with depth and then increased,exhibiting in a quadratic relationship.The cohesion of the rooted soil increased linearly as the biomass density increased.The cohesion of the rooted soil initially increased with increasing RMR and salt content,and then it decreased.The turning point of the cohesion occurred when the RMR was 0.6 and the salt content was 1.18%.The internal friction angle of the rooted soil initially increased with biomass density and then decreased,and the turning point of the internal friction angle occurred when the biomass density was 0.015 g/cm3.The relationships between the internal friction angle of the rooted soil and the RMR and salt content were exponential incremental and linear subtractive relationship,respectively.Both the cohesion and the internal friction angle of the rooted soil linearly decreased with increasing moisture content.     

Combined Bearing Capacity of Spudcans on a Double Layer Deposit of Strong-Over-Weak Clays

An extreme sea storm process can lead to a jack-up rig under the combined loading condition of vertical load(V), horizontal load(H), and moment(M) to have stability problems. This paper presents the analysis of combined bearing capacities of a circular spudcan on layered clays with a strong layer overlying a comparatively weaker layer. Numerical models combined with displacement-based load tests, swipe tests, and constant ratio displacement probe tests are adopted to calculate the uniaxial bearing capacities, failure envelopes in combined V-H, V-M planes, and failure envelopes in a combined V-H-M load space, respectively. A parametric study on the effects of vertical load level V, the layer strength ratio s_u,t/s_u,b, and the hard layer thickness t_1 on the bearing capacities is then performed. Results show that the vertical load level is a key factor that influences the values of H and M and the size of the H-M failure envelope. The existence of the underlying weak clay decreases the bearing capacities in all directions, and the vertical capacity Vult is affected more than the horizontal(H_ult) and moment(M_ult) capacities based on a single uniform deposit. The influence of the underlying weak clay on H-M failure envelope is mainly shown where H and M are coupled in the same direction. In contrast, little difference is observed when H and M are coupled in opposite directions.     

一件值得称颂的大喜事——热烈祝贺全省53个县(市)告别"秦砖汉瓦"时代

这是一个令人振奋的喜讯. 据河南省国土资源厅于2007年9月5日召开的新闻发布会透露,截至8月底,全省已有4个省辖市、53个县(市、区),在经历了一年多的艰苦、细致工作后,终于关闭了辖区内的所有砖瓦窑厂,与"秦砖汉瓦"彻底告别.让我们记住吧,记住这4个省辖市的名字.它们分别是:漯河市、安阳市、鹤壁市、焦作市.让我们记住吧,记住这53个县(市、区)的名字.它们中有:舞阳县、临颍县、召陵区、文峰区、淇滨区、修武县、孟州市、伊川县等.     

庭院小经济推进节约集约用地

一边是蒜苗、菠菜、生菜等各种时令蔬菜,一边的猪圈内有五头将要出栏的肥猪.猪圈旁边是沼气池,沼气池为水泥结构,圆锥形,上边留一个直径有半米的圆孔以便向内填充植物垃圾和秸秆,其余的地方用土填好以后还可以种上菜,墙根没有硬化的地方,还零落地留着苦瓜、南瓜的枯藤.这是日前笔者在修武县城关镇河北辛庄村民范庆河家中看到的景象.     

Characteristics and dynamics of the Ganqiuchi rock avalanche triggered by a paleo-earthquake in the Northern Qinling Mountains

Analyzing large prehistoric rock avalanches provides significant data for evaluating the disaster posed by these relatively infrequent but destructive geological events. This paper attempts to study the characteristics and dynamics of the Ganqiuchi granitic rock avalanche, in the middle of the northern margin of Qinling Mountains, 30 km to the south of Xi’an, Shaanxi Province, China. In plane view, this rock avalanche is characterized by source area, accumulation area and dammed lake area. Based on previous studies, historical records and regional geological data, the major trigger of the Ganqiuchi rock avalanche is considered to be a strong paleo-earthquake with tremendous energy. The in situ deposit block size distributions of the intact rock mass and the debris deposits are presented and analyzed by using a simple model for estimating the number of fragmentation cycles that the blocks underwent. The results show that the primary controlling factor of the fragmentation process is the pre-existing fractures, and there is a relationship between the potential energy and the fragmentation energy: the latter is approximately 20% of the former. Based on the dynamic discrete element technique, the study proposes a four-stage model for the dynamic course of the Ganqiuchi rock avalanche:(1) failing;(2) highspeed sliding;(3) collision with obstacles;(4) decelerated sliding, which has implication for hazard assessment of the potential rock avalanches in China and other countries with similar geological setting.     

湘西自治州贯彻执行《土地管理法》调查报告

为推进湘西自治州贯彻执行《中华人民共和国土地管理法》(以下简称《土地管理法》)工作的健康发展,州政协委员视察组一行13人,对《土地管理法》颁布实施以来全州8     

中国人口空间分布不均匀性分析及其可视化

中国人口空间分布的不均匀性是一种客观存在的现象,自从1935年胡焕庸先生提出"爱辉-腾冲线"以来,中国人口东西部的不均匀现象并没有发生显著的变化。这种不均匀不仅仅存在于"胡焕庸线"两侧,而是广泛存在的。本文引用经济学家研究收入分配平均程度常用的LORENZ曲线方法,结合相关图、表,对中国人口空间分布的不均匀性进行研究。通过对曲线特征点的分析,结合地图可视化可以形象地反映人口空间分布的特点,同时对人口空间分布进行定量化描述。     

GPS监测水汽与水汽辐射计数据的对比研究

针对水汽辐射计观测数据和并址的GPS观测数据,用GAMIT软件求解了台站的天顶总延迟和湿项延迟。运用湿项延迟与水汽含量之间的转换关系,对GPS监测的大气可降水量与水汽辐射计观测的水汽含量进行了对比研究,得出结果：由GAMIT解算出的水汽含量与WVR观测值的差值平均值为0．02mm,均方差为0．02mm,由气象文件求出的水汽含量与WVR观测值的差值平均值为0．03mm,均方差为0．02mm。表明用地面GPS监测大气水汽含量是完全可行的。     

Blasius问题临界值β~＊的一个新上界

为了研究流体力学边界层理论中的Blasius问题临界值上界的性质,给出了Blasius问题的等价奇异积分方程,通过研究等价的奇异积分方程的正解来研究Blasius问题临界值β＊的上界.通过选用新的比较函数c（t）和g（β）来研究奇异积分方程在C[β,1]中解的存在性,证明所获得的正解是等价奇异积分方程的解,得到Blasius问题临界值的新上界β＊≤-0.1971,改进了最近的首次估计β＊〈-0.18773.     

基于osgEarth的虚拟校园场景建模研究

osgEarth是一个基于OSG开发的实时地形模型加载和渲染工具.本文对数字地球及其应用进行了介绍,同时探讨了建设虚拟校园场景的关键技术.接着使用osgEarth获取了Google Earth的数据并且建立了数字地球底图,然后使用本地地形数据和3维模型建立了西南交通大学虚拟场景.最后发布了虚拟校园场景,从而使用户能够通...     

基于GIS的煤炭资源遥感动态分析——以山西省乡宁县为例

本文以多时相TM与ETM影像为数据源,对乡宁县的煤炭资源进行了动态监测。直接采用原数据进行煤矿信息提取精度很低,为此需要进行图像预处理。依据多元数理统计分析,确定了探测煤炭资源的最优波段组合为4,5,3。由于其他地物信息的干扰,此时影像仍不能很好地反映煤矿信息,因此需要对图像进一步做增强处理。通过对图像的主成分变换,有效地消除了山体阴影的影响。在此基础上,对图像进行计算机监督分类,制作了乡宁县煤炭资源分布图。采用这种方法极大地提高了遥感图像的解译精度。利用GIS的叠加和统计分析,获得了矿点的数量。通过实验,证明了基于GIS的煤炭资源遥感动态监测是可行的,而且对于环境保护和规范煤矿开采也具有很好的应用价值。     

浅谈电影片名翻译技巧

电影不仅是作为一种艺术品，同时也是作为一种商品存在，而电影片名就好比是电影的一件外衣，因此，确切地翻译电影片名非常重要。电影片名的翻译技巧有很多，同时影响电影片名的翻译的因素也有很多。因此．在翻译电影片名时要从各方面因素考虑，从而选择恰当的翻译技巧．使得译名不仅能够从意义上忠实于源名。涵盖电影的内容，同时在形式上做到简练并具有吸引力。     

一种基于BDS-3四频数据的周跳探测与修复方法

为充分发挥BDS-3四频观测信息的优势,提出一种周跳探测与修复方法。首先对无几何相位组合和无几何无电离层组合系数进行优选,联合3个无几何相位组合和1个无几何无电离层组合对不同周跳进行探测,然后使用最小二乘法估计周跳浮点解,最后采用LAMBDA方法进一步得到周跳整数解。经过BDS-3四频观测数据验证可知,本文方法可有效、快速地识别各类周跳,并对其进行修复。     

土地利用数据在不同空间尺度下的精度研究

目前大部分土地利用图都是由不同的比例尺所组成,在对两个不同年度的土地利用数据进行变化研究时,如果手中拿到的两个不同年度的土地利用数据是在不同空间尺度下获得的,这时要想对它们进行土地利用变化研究就会有一定的困难,就需要把它们转化到相同的比例尺下。具体在同一时间尺度下不同空间尺度的土地利用数据中各种土地利用类型的精度损失情况是怎么样的呢?本文对广州市海珠区在1:2000、1:5000、1:10000几种比例尺下的土地利用数据进行了分析研究,最后得出每种地类的精度损失情况。     

海洋自然资源国民经济评价体系的探讨

海洋开发主体在开发利用海洋自然资源时 ,往往会产生负的外部性 ,所以在对项目中费用和效益识别的基础上应加强海洋开发项目的国民经济评价 ,其中采用的主要经济指标有经济净现值、经济净现值率、经济内部收益率、经济外汇净现值和经济换汇成本     

无人机遥感数据处理与滑坡信息提取

高分辨率的DEM和DOM数据是对地形地貌信息的准确描述,也是滑坡信息提取的重要数据源。首先,针对滑坡信息提取的要求,本文采用无人搭载微型单反相机的影像获取平台,结合野外测量的GPS数据,弥补了无人机POS信息精度低的劣势;针对无人机影像的特点,运用摄影测量基本原理与计算机视觉算法,获取高精度、高分辨率的DEM与DOM影像,保留了丰富的光谱与纹理信息。其次,借助ESP辅助工具获取了DOM影像的最佳分割尺度,并结合研究区地物特征构建了基于模糊分类与SVM算法相结合的决策树,运用面向对象的分类方法实现了对研究区内植被、道路、疑似滑坡区域的信息提取。最后,依照研究区地物分布的空间特征确定了高风险等级区域,并对该区域进行滑坡的形态与纹理分析以及精度评价,其中提取的疑似滑坡区域用户精度为91.44%、生产者精度为84.65%,结果表明无人机遥感在滑坡信息提取领域具有较高的应用价值。