Delivering pro-poor water and sanitation services: The technical and political challenges in Malawi and Zambia

Meeting Millennium Development Goals on water and sanitation services in developing countries are fraught with difficulties, as can be seen most clearly from the experiences of Malawi and Zambia, two of the world’s poorest countries that have committed to meeting these goals. The challenges are not only technical, requiring programmatic or engineering solutions, but are also and most importantly political, because solutions will most often cause a rearrangement of the peculiar forms of power relations that have emerged within institutional and political environments of the two countries. The challenges include weak state support for water and sanitation provision, unreliable and contested indicators of coverage, poor sectoral co-ordination, and fragmented donor efforts. This field note examines these challenges in greater detail to cast new light as well as draw attention to possible solutions that can be implemented.     

变异函数在异常空间插值中的应用

针对数据空间架构中异常点对地质数据解译过程的干扰，以协方差数学理论为基础，提出界定空间数据分布方法-变异函数。着重阐述变异函数的求取过程，对新疆贝克滩水系沉积物化探数据处理，预测误差均值为0．1032、平均预测标准差为21．12、标准均方根预测误差为0．9841。预测值与样品实测值误差较小，界定的空间数据分布与实际矿床（点）分布吻合较好。     

2006年新疆地质矿产勘查进展及2007年工作要点

2006年是新疆地质矿产勘查“十一五”规划实施的第一年,地质勘查投入进一步加大,钠硝石找矿取得了重大突破,铁、铅锌、铜镍及煤的找矿也取得了重要进展,基础地质工作程度进一步提高,高新技术方法的应用得到加强,“环准噶尔”和“环塔里木”控制铜、铜镍、铅锌、铁等矿床重要成矿类型的规律逐渐显现.2007年将突出“环准噶尔”和“环塔里木”两个新领域的找矿工作,加快构建基础科研、高新技术应用研究、矿产勘查等相配套的科学的地质勘查体系.     

Road Surface Modeling and Representation from Point Cloud Based on Fuzzy Clustering

A scheme for an automatic road surface modeling from a noisy point cloud is presented. The normal vectors of the point cloud are estimated by distance-weighted fitting of local plane. Then, an automati...     

基于距离变换的提取和识别点状符号的方法

提出了一种基于距离变换提取和识别点状符号的新方法。首先对分版图的提取结果进行优化处理，然后根据弯曲密度和线划密度等特征，进一步过滤掉不满足点状符号特征的线划。为了更准确地度量图像间的相似性，提出了加权距离函数，并用该函数值为度量标准进行模板匹配以识别符号。该算法较好地解决了字线粘连、背景复杂等情况下的点状符号提取和识别问题，识别准确率较高。     

RTK在航测像控点测量中的应用

重点介绍了RTK技术在航测像控点测量中的应用，同时对GPSRTK技术的原理，软、硬件配置以及操作流程等方面也进行了简要阐述。通过应用并分析得出，GPSRTK技术完全可以满足航测像控点测量的精度要求，并且与常规方法相比具有很大的优越性，具有广泛的应用前景。     

Analysis of the impact of conservation measures on stream flow regime in catchments of the Loess Plateau,China

Catchments in the Loess Plateau have been under the influence of human activities for centuries. In the last four decades, soil conservation measures have accelerated and intensified. These measures were designed to reduce soil erosion, improve agricultural productivity, and enhance environmental quality. It is important to evaluate the effects of these measures on hydrology in order to develop sustainable catchment management plans in the region. This study evaluated changes in stream flow data for four selected catchments in the Loess Plateau following large‐scale soil conservation measures. The non‐parametric Mann–Kendall test was used to identify trends in annual stream flow and the results showed significant downward trends in three of the four catchments. The Pettitt test indicated that a change point occurred in 1978 in these three catchments. Annual precipitation in all the catchments showed no significant trend during the period of record. Comparison of daily flow duration curves for two 20‐year periods (1957–1978) and (1979–2003) showed significant changes in stream flow regime. Reduction in most percentile flows varied between 20 and 45%, and the reduction in low flows was greatest. Overall, the reductions in daily flow were increasing with time, with significant changes occurring in the 1990s. However, it is not clear whether these catchments have seen the full effects of the soil conservation measures, so the results of this study might underestimate the final impact of soil conservation on stream flow regime. Copyright © 2007 John Wiley & Sons, Ltd.     

逐次滤波方法在GPS单点定位中的应用研究

采用平差计算中得到的观测值的残差来估计指数函数经验模型中的参数，从而使随机模型更真实地反映观测值中的随机误差和偏差。由实际GPS观测数据厦广播里历，按以上的函数模型和随机模型采用逐次滤波方法进行解算。结果表明，此方法在未剔除和修复周跳的情况下，可以使单点静态定位的平面外符合精度达1．46m，高程方向的外符合精度为1．72m。     

基于PPP技术的GPS浮标海啸预警模拟研究

提出了利用精密单点定位（precise point positioning,PPP）技术进行海啸预警的方法,并利用TriP软件对实测浮标数据进行了处理,将得出的海面高数据和海啸波模型叠加进行了模拟分析。仿真结果表明,利用精密单点定位技术进行海啸预警,能够监测判断海啸的发生,并获得海啸波到达海岸的波高和时间,提供一定的预警信息。     

边长勘丈法在村庄地籍测量中的应用

探计了村庄地籍测量的三种方法,重点发析了边长勘丈法在溧水县村庄地籍测量的可行性,通过实践对比,分析了该方法对测量成果的精度影响.