地下管网空间数据模型的建立与应用

城市综合地下管网系统作为城市地理信息系统的重要组成部分是城市科学规划，管理和辅助决策等工作的重要工具，本文结合昆明市综合地下管网信息系统设计和开发的实际工作，探讨了地下管网空间数据模型的建立和应用。     

祁连山北麓牧区社会-生态系统脆弱性诊断——以甘肃肃南裕固族自治县为例

基于人与自然耦合视角,辨识社会-生态系统脆弱性是区域可持续发展研究的核心议题和前沿领域。依据社会-生态系统和脆弱性经典范式VSD模型(Vulnerability Scoping Diagram),利用显式空间脆弱性指数和致脆因子诊断模型分析了2004—2016年肃南县社会-生态系统脆弱性的变化趋势及其致脆因子。结果表明:该县社会-生态系统的暴露度指数介于0.374～0.725,整体呈先降,再升,后降的趋势。敏感性指数和适应性指数均呈持续波动上涨趋势,脆弱性指数由2006年的0.327持续上升至2014年的1.081后,又下降至0.440。该县社会-生态系统脆弱性的潜在风险和致脆因子主要来源于系统的暴露度,牲畜密度、人均GDP、植被覆盖度是影响系统暴露度涨落的潜在风险因素,退牧还草工程及财政支出支持力度是社会-生态系统脆弱性提升的关键致脆因素。未来肃南县应放缓经济发展增速,提高第三产业GDP比重、加大财政支出力度、推进落实草原生态保护政策及其可持续治理长效机制,以降低社会-生态系统脆弱性的风险。     

太行山区龙华河群的建立与否定

太行山北段早前寒武系龙华河群为六十年代所建,后来发现五台山区的五台群底界已延入龙华河群之中。近年来,许多新资料表明,它实际上包括了龙泉关群、五台群及滹沱群的一部分。因而,应废除龙华河群,并对它进行重新划分。     

A value chain approach to crisis response system: the case of Qingdao

In this paper, we introduce a value chain approach, on the view of the value chain analytic in business management, to be the framework of a crisis response system serving for crisis management strategy in identifying risk sources, responding to unexpected events, and recovering from a shock. This system is not only a computer system but also a system of governmental emergency response mechanism and it is tremendous and complex. The system integrates and coordinates the correlative resources of emergency response units of the city. We consider the efficiency of the system. In addition, the run cost of the system also is taken into account. Based on this framework, the Qingdao’s practical situation is analyzed. As a result, a design proposal of the Qingdao’s crisis response system is put forward.     

IDL在青藏铁路地理信息系统中的应用研究

GIS二次开发中通常使用的GIS组件方法,大多受到开发商限制或组件提供的扩展接口不能满足系统功能需求的限制.在青藏铁路地理信息系统中为满足应用需求,采用了"IDL+C#+ArcS-DE"的开发模式,将IDL集成到青藏铁路地理信息系统的体系结构中,并利用IDL实现了GIS的功能.最后阐述了利用IDL进行时态钻孔数据分析、处理及可视化过程和冻土模型输出结果的可视化过程.     

Effect of pedogenesis on the stable isotopic composition of calcretes and n‐alkanes: Implications for palaeoenvironmental reconstruction

In a fluvial system, depending on sub‐aerial exposure, non‐pedogenic pond calcretes can be modified into pedogenic calcretes. The present study attempts to understand the effect of sub‐aerial exposure and pedogenesis on calcretes using carbon and oxygen isotopic composition. For this purpose, two profiles (profile‐A and profile‐B) from the same stratigraphic level in Rayka from the western part of India were selected. The profiles are separated by a distance of 500 m and showed differences in calcrete characteristics. In profile‐A, the calcretes showed pedogenic features (root traces and void filling spar) whereas calcretes in profile‐B showed non‐pedogenic characteristics (fine laminations). However, some of the calcretes in profile‐A exhibited remnants of fine laminations suggesting that initially the calcretes had a non‐pedogenic origin but were modified due to pedogenesis. In profile‐A, the carbon and oxygen isotope values of pedogenic calcrete (δ¹³C_PC and δ¹⁸O_PC) showed more variation compared with non‐pedogenic pond calcretes (δ¹³C_SPC and δ¹⁸O_SPC) in profile‐B. The δ¹³C_PC and δ¹³C_SPC values exhibited a spread of 3·0‰ and 1·3‰, respectively, and δ¹⁸O_PC and δ¹⁸O_SPC values showed a spread of 2·3‰ and 1·3‰, respectively. The differences in the isotopic composition between the two profiles suggest that pedogenesis controlled the isotopic inheritance in calcretes. In addition, the carbon isotopic composition of organic matter (δ¹³C_OM) and n‐alkanes (δ¹³C_n‐alk) that forms the basis of palaeovegetational reconstruction have also been measured to understand the effect of pedogenesis on organic matter in both of the profiles. The average δ¹³C_OM values in profile‐A and profile‐B are ?23·4‰ and ?21·1‰, respectively. The disparity in δ¹³C_OM values is a result of the difference in the sources and preservation of organic matter. However, the δ¹³C_n‐alk values show a similar trend in profile‐A and profile‐B, indicating that sources of n‐alkanes are the same in both of the profiles and δ¹³C_n‐alk values are unaffected by the pedogenic modifications.     

Interpretation of seismic and potential field data from western New York State and Lake Ontario

Lithoprobe and industry seismic profiles have furnished evidence of major zones of easterly dipping Grenville deformed crust extending southwest from exposed Grenville rocks north of Lake Ontario. Additional constraints on subsurface structure limited to the postulated Clarendon–Linden fault system south of Lake Ontario are provided by five east–west reflection lines recorded in 1976. Spatial correlations between seismic structure and magnetic anomalies are described from both Lake Ontario and the newly reprocessed New York lines.In the Paleozoic to Precambrian upper crust, the New York seismic sections show: (1) An easterly thickening wedge of subhorizontal Paleozoic strata unconformably overlying a Precambrian basement whose surface has an apparent regional easterly dip of 1–2°. Minor apparent normal offsets, possibly on the order of tens of meters, occur within the Paleozoic section. The generally poorly reflective unconformity may be locally characterized by topographic relief on the order of 100 m; (2) Apparent local displacement on the order of 90 m at the level of the Black River Group diminishes upward to little or no apparent offset of Queenston Shale; (3) Within the limited seismic sections, there appears to be no evidence that the complete upper crustal section is vertically or subvertically offset; (4) Dipping structure in the Paleozoic strata (15° to 35°) resembles some underlying Precambrian basement elements; (5) The surface continuity of inferred faults constituting the Clarendon–Linden system is not strongly supported by the seismic data.Beneath the Paleozoic strata, the seismic sections show both linear and arcuate reflector geometry with easterly apparent dips of 15° to 35° similar to the deep structures imaged on seismic lines from nearby Lake Ontario and on Lithoprobe lines to the north. The similarity supports an extension of easterly dipping Central Metasedimentary Belt structures of the Grenville orogen from southern Ontario to beneath western New York State.From a comparison of the magnetic and gravity fields with the New York seismic sections, we suggest: (1) The largely nonmagnetic Paleozoic strata appear to contribute negligibly to magnetic anomalies. Seismically imaged fractures in the New York Paleozoic strata appear to lie mainly west of a positive gravity anomaly. The relationship between magnetic and gravity anomalies and the changes in the geometry of interpreted Precambrian structures remains enigmatic; (2) North to northeast trending curvilinear magnetic and gravity anomalies parallel, but are not restricted to the principal trend of the postulated Clarendon–Linden fault system. Paleozoic fractures of the Clarendon–Linden system may partly overlie a southward extension of the Composite Arc Belt boundary zone.     

Modelling infiltration enhancement in a tropical urban catchment for improved stormwater management

To mitigate the impacts of impervious surfaces in urban areas, structures such as bioretention systems and permeable pavements have been installed to enhance infiltration in many countries. However, relatively little knowledge is available regarding the performance of such infiltration‐based structures in humid tropical and highly urbanized areas. This study investigates the feasibility of enhancing the infiltration of stormwater in tropical urbanized areas using Singapore as a case study. It first shows that the rainfall depth and intensity are both high, but the time interval between consecutive rainfall event is long in Singapore. It then numerically simulates single‐event local infiltration and finds that the fraction of infiltrated rainfall is actually high. It finally performs catchment‐scale simulations and finds that bioretention systems can enhance infiltration and groundwater recharge particularly during wet periods. However, local mounding of groundwater can be significant and can hinder the performance of those structures. Furthermore, with 5% of catchment area being converted to such structures, the infiltration of the entire catchment is enhanced but still not yet up to the natural level. To increase the overall effectiveness, future studies can look into bioretention systems with underdrain systems. Copyright © 2016 John Wiley & Sons, Ltd.     

构件模型库的客家古村落三维建模方法——以白鹭古村为例

针对客家历史的重要载体--客家古村落正在面临着被破坏甚至消亡的风险问题,该文对其开展了三维建模方法研究,以进行数字化保护。通过分析客家古村落的建筑特点,首先对客家古村落中的建筑群整体布局展开研究,合理划分出单体古建筑;其次,将单体古建筑拆分成不同类型的子构件并研究各自建模规则,创建了面向客家古村落的建模体系与框架;最后采用CityEngine的规则建模技术为主,结合3DS Max三维建模软件,对子构件进行三维精细建模,构建了基于模型库的客家古村落三维建模方法。并以白鹭古村为例,利用此方法完成了白鹭古村古建筑群的三维精细模型的展示,并开发出了白鹭古村三维仿真系统。实验表明:该方法能够大大提高三维建模效率,快速完成对客家古村落的三维建模。     

Amoeboid olivine aggregates and related objects in carbonaceous chondrites: records of nebular and asteroid processes

Amoeboid olivine aggregates (AOAs) are the most common type of refractory inclusions in CM, CR, CH, CV, CO, and ungrouped carbonaceous chondrites Acfer 094 and Adelaide; only one AOA was found in the CB_b chondrite Hammadah al Hamra 237 and none were observed in the CB_a chondrites Bencubbin, Gujba, and Weatherford. In primitive (unaltered and unmetamorphosed) carbonaceous chondrites, AOAs consist of forsterite (Fa_<2), Fe, Ni-metal (5-12 wt% Ni), and Ca, Al-rich inclusions (CAIs) composed of Al-diopside, spinel, anorthite, and very rare melilite. Melilite is typically replaced by a fine-grained mixture of spinel, Al-diopside, and ±anorthite; spinel is replaced by anorthite. About 10% of AOAs contain low-Ca pyroxene replacing forsterite. Forsterite and spinel are always ¹⁶O-rich (δ^17,18O∼−40‰ to −50‰), whereas melilite, anorthite, and diopside could be either similarly ¹⁶O-rich or ¹⁶O-depleted to varying degrees; the latter is common in AOAs from altered and metamorphosed carbonaceous chondrites such as some CVs and COs. Low-Ca pyroxene is either ¹⁶O-rich (δ^17,18O∼−40‰) or ¹⁶O-poor (δ^17,18O∼0‰). Most AOAs in CV chondrites have unfractionated (∼2-10×CI) rare-earth element patterns. AOAs have similar textures, mineralogy and oxygen isotopic compositions to those of forsterite-rich accretionary rims surrounding different types of CAIs (compact and fluffy Type A, Type B, and fine-grained, spinel-rich) in CV and CR chondrites. AOAs in primitive carbonaceous chondrites show no evidence for alteration and thermal metamorphism. Secondary minerals in AOAs from CR, CM, and CO, and CV chondrites are similar to those in chondrules, CAIs, and matrices of their host meteorites and include phyllosilicates, magnetite, carbonates, nepheline, sodalite, grossular, wollastonite, hedenbergite, andradite, and ferrous olivine.Our observations and a thermodynamic analysis suggest that AOAs and forsterite-rich accretionary rims formed in ¹⁶O-rich gaseous reservoirs, probably in the CAI-forming region(s), as aggregates of solar nebular condensates originally composed of forsterite, Fe, Ni-metal, and CAIs. Some of the CAIs were melted prior to aggregation into AOAs and experienced formation of Wark-Lovering rims. Before and possibly after the aggregation, melilite and spinel in CAIs reacted with SiO and Mg of the solar nebula gas enriched in ¹⁶O to form Al-diopside and anorthite. Forsterite in some AOAs reacted with ¹⁶O-enriched SiO gas to form low-Ca pyroxene. Some other AOAs were either reheated in ¹⁶O-poor gaseous reservoirs or coated by ¹⁶O-depleted pyroxene-rich dust and melted to varying degrees, possibly during chondrule formation. The most extensively melted AOAs experienced oxygen isotope exchange with ¹⁶O-poor nebular gas and may have been transformed into magnesian (Type I) chondrules. Secondary mineralization and at least some of the oxygen isotope exchange in AOAs from altered and metamorphosed chondrites must have resulted from alteration in the presence of aqueous solutions after aggregation and lithification of the chondrite parent asteroids.