广西冬季最低气温的小网格分析

研究各重现期广西冬季最低气温的小网格气候分析方法。采用网格距为 0 .1× 0 .1经纬度的小网格 ,从地理信息系统 GIS中读取海拔高度资料 ,用回归分析方法求气候方程 ,利用 Gr ADS绘图系统提供的 oacres内部插值函数求取格点余差插值 ,利用改进的 Gr ADS绘图系统绘制小网格气候分析图     

构造柱一圈梁体系外多孔砖内混凝土小型空心砌块六层足尺房屋抗震性能试验研究

本文简述了六层构造柱 -圈梁体系外墙用多孔砖、内墙用混凝土小型空心砌块足尺房屋抗震试验的设计 ,介绍了模型楼的试验结果 ,并对试验结果进行了分析 ,评价了此类房屋的抗震能力。最后 ,本文对此类房屋的工程实践提出一些建议     

黄土塬区坡面及小集水区泥沙输移比变化特征

文章首先推荐了计算泥沙输移比SDR时，所需侵蚀量、输移量的量测方法：侵蚀量用坡长为20m（水平距）、宽5m直线坡，在不同降雨及土地利用下，通过小区出口断面的泥沙量；输移量为坡长大于20m的径流小区小集水区出口处的拦蓄量。然后通过黄土塬区坡面坡度为9%的30m、40m、60m径流小区9年野外实验所得45组有效数据的分析，发现单宽最小径流率qmin和最大含沙量ρmax可判别坡面泥沙侵蚀与输移的对比关系，即输移比SDR，并依据这些参数值，可将侵蚀输移状态划分为“侵蚀——输移区”，“侵蚀——堆积——输移区”和“侵蚀——输移挠动区”3个侵蚀输移状态类型区，同时通过研究给出了各区之间过度转换临界值的计算公式，即ρmax=11.96 0.117qmin和qmin=0.187ρmax-85.676。并能过对21条塬面不同面积（0.5hm^2-41.3hm^2）、坡长（30m-965m)小集水区淤积（输移量）的测量，将测量值与标准小区侵蚀量作对比，计算出各自的输移比SDR，并分别建立了SDR与坡长L、SDR与集水面积A的关系式，即SDR=2.85L^-0.306和SDR=0.735A^-0.151，为快速估算塬面小集水区泥沙输移比SDR值提供了方便。最后，分析了植被覆盖、土壤含水状况、人为活动等其它基因素对泥沙输移比SDR的影响。     

滦河源区东沟小流域土壤风蚀特征分析

土壤风蚀是世界许多地区面临的一个严峻环境问题，土壤风蚀特征是建立土壤风蚀预报模型，制定土壤风蚀防治措施的基础信息，综合考察了湾河源区东沟小流域地理环境特征，分析了不同风蚀强度下暗粟钙土的诊断特性，其结果表明，自然环境提供了土壤风蚀的物质条件，区域日益强化的农牧业及砍薪材活动则是土壤风蚀的触发驱动力；失去植被保护的干旱松散表土，在大风驱动下，其中的细砂和极细砂（0．01－0．10mm)首先以跃移，悬浮方式流失，而粗砂（2－0．25mm)则相对是非可风蚀颗粒；建立了定量刻划土壤风蚀相对强度指数，即SWEI＝粗砂含量／风蚀粒子含量，东沟小流域自然暗粟钙土表土SWEI≤2．0，轻度风蚀区表土SWEI≥3．0，重度风蚀区表土SWEI≥9．0，而在风积区表土SWEI≤1．5，该指标较好地反映了区域土壤风蚀强度的差异性。     

小流域岩土侵蚀规律研究——以子洲县周家圪崂乡桥沟小流域为例

桥沟小流域位于子洲县周家圪崂乡东部,系黄河四级支流,面积19km^2。桥沟主沟长5．75km,坡降12．8％,沟谷切深100m左右。流域内地貌为黄土梁峁及沟壑,出露地层主要有侏罗系砂泥岩、新近系（原为第三系）红土和第四系黄土。黄土层中下部含地下水,在黄土与基岩接触带,多有下降泉溢出。从地层岩性上看,第四系黄土分布广,厚度大,结构松散,遇水易解体。岩土侵蚀环境地质类型有三：一是降雨对谷坡面的面状冲刷一坡面侵蚀;二是地表径流对谷底的侧蚀一沟谷侵蚀,三是滑塌对谷坡坡体的破坏一重力侵蚀。三种侵重力蚀的防治措施各有侧重点,对于坡面侵蚀的防治措施主要是退耕还林种草,改造微地貌;对于沟谷及重力侵蚀的防治措施主要是沟道坝系建设,即在重力侵蚀及沟谷侵蚀发育区下游,修建淤地坝,从而抬高侵蚀基准,减少重力侵蚀的发生。     

基于GPS卫星测量的远距离滑坡监测应用研究

利用GPS进行远距监控滑坡区并做适用性的评估研究,整合系统中含供电系统(室内及室外电源设置)、无线传输(利用GSM传输)、GPS资料后处理软件及监控软件等。所组合的系统将应用在某滑坡区,进行长时间持续监测。试验方式包含现场模拟试验、滑坡模拟测试,同时以远近两不同距离的主控站来评估此监测系统因基线长短不同所造成的精度影响,以期能通过此研究提出GPS监测系统设置的经验。根据研究成果指出,GPS监测系统应用在滑坡监测上可行,利用无线传输(GSM)可成功将现场的资料传给远程的操作者。试验结果显示,利用近基站观测可提高观测的精度及解算的成功率,但不论在远基线或近基线的试验,GPS监测系统的精度均可达到公分等级。     

局部地区小范围大比例尺地形图实测技术探讨

在工程测量的应用方面,经常会遇到很多特殊任务。例如各种观测站选址测绘,往往选在边远山区,虽然面积很小,但难度很大。本文以农安三岗观测站站址1∶500比例尺地形图的施测为例,探讨了局部地区小范围大比例尺地形图实测的技术问题。     

The contribution of gully erosion to total sediment production in a small watershed in Southwest China

Determining the contribution of gully erosion to the total sediment yield is important for enhancing decision-making regarding sediment abatement and soil conservation measures. The dry-hot valley region of the Jinsha River is one of the most intensive areas of gully erosion in China. However, the contribution of gully erosion to total sediment production in this region is unclear. Instead of using the source tracing technique commonly employed in other studies, this study provides a method of rapidly reconstructing historical sediment yields based on the properties of sediment that accumulated in an undrained pond at a small gully watershed outlet. We produced a three-dimensional model in geographical information system software to calculate the volume of each layer of accumulated pond deposits from 2006 to 2011. Moreover, we estimated sheet erosion amounts using the Universal Soil Loss Equation. The results showed that sheet erosion accounted for between 14.28 and 23.39% of the total sediment yield in the watershed in the case that the sediment delivery ratio was 100%. Therefore, gully erosion is the major source of total soil loss in this area, and effective soil measures of gully erosion mitigation are crucial for managing the sediment yield.     

Africa’s middle class: building houses and constructing identities in the small town of Buea,Cameroon

Across Africa households are commissioning new domestic buildings for their own use or to rent out rather than waiting for governments to supply urban shelter. We conceptualize this as two interwoven processes: building houses for a new middle class and the building of a new middle class identity. We draw particular attention to the impact of international migration on these processes. The paper uses quantitative data from building permits and qualitative data from 29 interviews and walk-round tours with homeowners and government officials in Buea, Cameroon. Despite some significant caveats (related to housing the urban poor, regulating building standards, and lost local government revenue), we argue that these individually initiated building projects do a reasonable job of meeting local demand for shelter. However, from the perspective of identity-building these buildings are less successful. Whilst homeowners take considerable pride in their building projects, the statements that these structures make about their identities are not always “read” by their neighbours in the way owners hope. New housing is the lens through which Buea’s residents interpret growing levels of inequality and its associated social tensions.     

怒江小流域土地利用变化及人文驱动力分析--以茶山小流域为例

通过实地调查和两期土地利用现状数据对比以及对农户的访谈,分析研究怒江茶山小流域土地利用现状及时空变化特征,从人文地理视角研究人地关系地域系统,分析导致土地利用变化的驱动力,为确立可持续发展背景下土地利用优化模式及产业结构的优化提供重要前提和科学依据。