Effects of green space spatial pattern on land surface temperature: Implications for sustainable urban planning and climate change adaptation

The urban heat island (UHI) refers to the phenomenon of higher atmospheric and surface temperatures occurring in urban areas than in the surrounding rural areas. Mitigation of the UHI effects via the configuration of green spaces and sustainable design of urban environments has become an issue of increasing concern under changing climate. In this paper, the effects of the composition and configuration of green space on land surface temperatures (LST) were explored using landscape metrics including percentage of landscape (PLAND), edge density (ED) and patch density (PD). An oasis city of Aksu in Northwestern China was used as a case study. The metrics were calculated by moving window method based on a green space map derived from Landsat Thematic Mapper (TM) imagery, and LST data were retrieved from Landsat TM thermal band. A normalized mutual information measure was employed to investigate the relationship between LST and the spatial pattern of green space. The results showed that while the PLAND is the most important variable that elicits LST dynamics, spatial configuration of green space also has significant effect on LST. Though, the highest normalized mutual information measure was with the PLAND (0.71), it was found that the ED and PD combination is the most deterministic factors of LST than the unique effects of a single variable or the joint effects of PLAND and PD or PLAND and ED. Normalized mutual information measure estimations between LST and PLAND and ED, PLAND and PD and ED and PD were 0.7679, 0.7650 and 0.7832, respectively. A combination of the three factors PLAND, PD and ED explained much of the variance of LST with a normalized mutual information measure of 0.8694. Results from this study can expand our understanding of the relationship between LST and street trees and vegetation, and provide insights for sustainable urban planning and management under changing climate.     

攀枝花市三区地质灾害分布特征及防治

简要论述了攀枝花市三区自然地理、地形地貌、地层岩性、地质构造、地震及新构造运动、岩土体工程地质特征及分布的基础上,统计了攀枝花市三区地质灾害情况,分析了三区地质灾害类型及分布特征,提出了相应的防治原则与对策措施。     

兰州市地质灾害特征与防治对策研究

从地质环境条件、地质灾害特征和城市发展建设方面,分析兰州市地质灾害的成因。从科学技术和社会管理方面,结合国内外的经验和兰州的实际,提出兰州市地质灾害防治的对策和建议。该研究的突破在于把地质灾害防治的科技支撑与社会管理相结合。     

Reliability analysis of piles in spatially varying soils considering multiple failure modes

In most limit state design codes, the serviceability limit checks for drilled shafts still use deterministic approaches. Moreover, different limit states are usually considered separately. This paper develops a probabilistic framework to assess the serviceability performance with the consideration of soil spatial variability in reliability analysis. Specifically, the performance of a drilled shaft is defined in terms of the vertical settlement, lateral deflection, and angular distortion at the top of the shaft, corresponding to three limit states in the reliability analysis. Failure is defined as the event that the displacements exceed the corresponding tolerable displacements. The spatial variability of soil properties is considered using random field modeling. To illustrate the proposed framework, this study assesses the reliability of each limit state and the system reliability of a numerical example of a drilled shaft. The results show the system reliability should be considered for the serviceability performance. The importance measures of the random variables indicate that the external loads, the performance criteria, the model errors of load transfer curves and soil strength parameter are the most important factors in reliability analysis. Moreover, it is shown that the correlation length and coefficient of variation of soil strength can exert significant impacts on the calculated failure probability.     

未确知测度BP神经网络模型在黑河流域水质预测中的应用

水质预测是水环境规划、评价和管理的重要依据,对促进水资源可持续利用及生态发展具有重要意义。针对水质预测中各项因子的不确定性,基于未确知测度理论(unascertained measure,UM),采用改变网络初值的方法,对BP神经网络加以改进,并利用黑河流域莺落峡水文站1998~2011年的水质监测资料进行分析和预测。以挥发酚为参考序列,用灰色关联方法分析参考序列与其他因子的关联度,并最终确定BP网络的输入节点为CODmn、DO、SO42-、Cr6+以及挥发酚,输出节点为挥发酚,从而建立UMBP模型。分析结果表明,UM-BP预测模型比标准的BP神经网络模型具有更高的预测精度。因此,该模型应用于黑河流域水质预测是可行的。     

兰考县地理国情监测应用研究

随着信息化的发展以及测绘高新技术和先进测绘设备的广泛应用,在第一次全国地理国情普查工作正在有序开展且部分完成的情况下,地理国情监测的条件日益成熟。本文主要选择政府和有关部门关注的相关方面,结合地理国情的要素,从6个方面进行监测研究。     

建设工程基础验线与竣工规划测量的研究

基础验线与竣工规划测量是城市规划管理的重要环节,其成果是规划过程监督管理与竣工验收审核的重要依据。无锡市自2012年1月1日起正式实施建设工程基础验线与竣工规划测量工作。本文介绍了无锡市建设工程基础验线与竣工规划测量的作业依据与资料准备、工作内容及提交的成果,并结合工程实例对成果进行分析,为今后工作提供参考。     

油企业抗震防灾规划信息管理系统的设计

基于石油企业抗震防灾工作对网络与数据库的信息管理系统的需求，对数据库产品进行了简要分析，并根据石油企业抗震防灾规划的需求和信息管理的一般模式，提出了石油企业抗震防灾规划信息计算机管理系统的设想。认为，以 Ｍｉｃｒｏｓｏｆｔ Ａｃｃｅｓｓ 数据库软件为基础，利用 Ｖ Ｂ或 Ｖ Ｃ等可视化前端应用开发工具，是目前比较好的方案，它将使石油企业抗震防灾规划工作在办公自动化方面迈向新的台阶     

坡麓地带工程勘察应注意的问题

在坡麓地带进行工程勘察时，应注意论证工程建设对工程地质环境的改变，评价其对设计、施工的适宜性和可行性，采取相应的工程技术措施。     

单基准线向量解算法在GPS变形监测中的应用

GPS测量目前在三峡库区变形监测应用较为广泛,但常规数据处理中,网平差这一步骤导致了因某点测量误差偏大而导致的整个监测网中其他监测点测量误差偏大,为解决这一问题,介绍了单基线向量解算法,并利用该方法对长屋滑坡2005年3月-2007年3月的监测点数据进行解算,提出了该方法能减少测量误差和内业工作量,并能运用于实际工程。