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71.
Deeply weathered soils cover most of the Piedmont physiographic province of the south-eastern United States of America (USA). These soils have traditionally been inferred to derive from weathered bedrock, but recent work (e.g. Ferguson et al., 2019) suggests that deposited sediments are more prevalent than recognized. Distinguishing sediment from weathered bedrock is integral to understanding critical-zone processes and overall Quaternary landscape evolution, yet the well-developed, red, clay-dominated Ultisols of this temperate and humid region mask differences between transported from non-transported material. Our goal is to determine if optically stimulated luminescence (OSL) methods can distinguish quartz sand from allochthonous (e.g. transported sediment) versus autochthonous (e.g. in situ weathered bedrock) material in soil-profile and core samples from the Redlair Observatory in southwestern North Carolina, USA. Here, we turn to OSL sensitivity and linear-modulated OSL (LM-OSL) to observe the intensity or lack thereof of the fast-decay luminescence component (most light-sensitive signal) in quartz grains from soil horizons and crystalline bedrock-derived saprolite. We find that quartz grains sampled from in situ weathered bedrock as well as from saprolotized clasts of rock have weak luminescence properties and are not dominated by a fast-decay luminescence component. In contrast, quartz grains from transported sediment (e.g. mobile regolith; colluvium; alluvium) contain sensitive grains with more dominant fast components. These results suggest that quartz luminescence sensitivity can be a tool to differentiate between in situ weathered bedrock and similar looking mobile regolith and colluvium over-printed by soil development. 相似文献
72.
In the eastern part of the Indian shield,late PaleozoiceMesozoic sedimentary rocks of the Talchir Basin lie precisely along a contact of Neoproterozoic age between granulites of the Eastern Ghats Mobile Belt(EGMB)and amphibolite facies rocks of the Rengali Province.At present,the northern part of the basin experiences periodic seismicity by reactivation of faults located both within the basin,and in the Rengali Province to the north.Detailed gravity data collected across the basin show that Bouguer anomalies decrease from the EGMB(wt15 mGal),through the basin(w 10 mGal),into the Rengali Province(w 15 mGal).The data are consistent with the reportedly uncompensated nature of the EGMB,and indicate that the crust below the Rengali Province has a cratonic gravity signature.The contact between the two domains with distinct sub-surface structure,inferred from gravity data,coincides with the North Orissa Boundary Fault(NOBF)that defnes the northern boundary of the Talchir Basin.Post-Gondwana faults are also localized along the northern margin of the basin,and present-day seismic tremors also have epicenters close to the NOBF.This indicates that the NOBF was formed by reactivation of a Neoproterozoic terrane boundary,and continues to be susceptible to seismic activity even at the present-day. 相似文献
73.
Baleseng Tlholohelo Mokoena 《地球空间信息科学学报》2013,16(4):322-330
ABSTRACTRelocating people in informal settlements and upgrading the lives of those people require consistent commitment, good strategies, and supporting systems. In South Africa, in order to allocate subsidized housing to beneficiaries of an informal settlement, beneficiary administration needs to determine the number of people who qualify for subsidized houses. Without geo-spatial data-based technical verification, conventional methods of occupancy audits are often cumbersome, are unreliable, and do not promote smart and evidence-based decision making. Accordingly, the aim of this study is to propose and develop an Oracle-based mobile GIS tool to conduct an occupancy audit for Ulana, an informal settlement in Ekurhuleni Municipality in South Africa. Android-based tablets were used to collect the geographic and socio-economic attributes of the informal dwelling units (DU). Spatial analysis (in ArcGIS software and geo-spatial modeling environment) and statistical analysis were conducted to produce the occupancy audit. The results indicated that the use of mobile GIS provides up-to-date, accurate, comprehensive, and real-time data so as to facilitate the development of smart and integrated human settlements. The results of this audit also indicated that only 57% of the households residing in Ulana could potentially benefit from receiving a subsidized house. Accordingly, the occupancy audit enables planners to plan appropriate upgrading and housing development strategies for informal settlement. This study demonstrates that successful planning of housing delivery for post independent integrated neighborhoods is not a mere political rhetoric but is viable when it is based on reasonable geo-spatial techniques and information. The use of mobile GIS therefore needs to be extended to other informal settlement upgrading projects in South Africa as well as other cities in the global south. However, proper professional training is required to ensure the successful usage of smart mobile GIS tools. 相似文献
74.
75.
A velocity formula is proposed for flow over a mobile sediment bed induced by velocity-skewed waves and current. The formula is obtained by a separation of waves and current velocities and requires seven free variables related to free stream velocity and sediment characteristics. The formula includes two parts:(1) a wave part consisting of the free stream velocity and defect function, which considers phase lead, wave boundary layer thickness, and mobile bed level, and(2) a current part, which ch... 相似文献
76.
基于商用运输平台的流动大气和环境监测系统 总被引:2,自引:2,他引:0
高时空精度大气观测资料的缺乏,仍是制约提高数值天气预报水平和深入开展大气科学研究的一个主要因素。为了克服这一问题,除了研制自动化程度高、测量精度高和性能价格比高的仪器设备来装备现有的定点大气观测网外,还应建设一些流动的大气监测系统,以获得常规大气观测台站空档间(如大洋、山区和荒漠等无人区)的天气现象和大气环境变化的信息。然而,在现有台站网之外,再重新建立并运行一个流动专业观测网,既不经济也是不现实的。随着交通和通信技术的快速发展,利用民用的交通运输工具(主要是商船、民航飞机、火车甚至长途汽车),加装大气环境监测传感器,逐步建立海陆空三位一体的流动大气环境监测系统已成为可能。 相似文献
77.
基于Pocket PC 的海洋渔业调查数据采集 总被引:1,自引:0,他引:1
针对传统的主要依赖于纸质日志记录海洋渔业资源调查数据所存在的数据质量差、难以保存、作业效率低等弊端,结合Pocket PC移动终端的优越性,提出利用Pocket PC平台记录海洋渔业资源调查数据,并分别就近海调查和远洋调查数据采集提出了相应的基于 Pocket PC 平台的信息化数据采集解决方案。然后以大洋性鱿鱼资源调查为例,设计并开发了一个基于Pocket PC的海洋渔业调查数据采集系统。通过实践检验,该系统可较好地完成大洋性鱿鱼资源调查的数据采集任务,同时也表明了基于 Pocket PC的海洋渔业调查数据采集的可行性和优越性。讨论的数据采集解决方案和相关技术可为海洋渔业和海洋环境相关的调查数据采集提供信息化支持。 相似文献
78.
We extend the particle-tracking method to simulate general multi-rate mass transfer (MRMT) equations. Previous methods for single-rate equations used two-state Markov chains and found that the time a particle spends in the mobile state between waiting time epochs is random and exponentially distributed. Using Bochner’s subordination technique for Markov processes, we find that the random mobile times are still exponential for the stochastic process that corresponds to the MRMT equations. The random times in the immobile phase have a distribution that is directly related to the memory function of the MRMT equation. This connection allows us to interpret the MRMT memory function as the rate at which particles of a certain age, measured by residence time in the immobile zone, exit to become mobile once again. Because the exact distributions of mobile and immobile times are known from the MRMT equations, they can be simulated very simply and efficiently using random walks. 相似文献
79.
80.
Vessels found contaminated with biofouling non-indigenous marine species are predominantly removed from the water and treated in vessel maintenance facilities (i.e., slipways, travel lifts and dry-docks). Using pre-fouled settlement plates to simulate a vessel’s removal from the water for treatment, we demonstrate that a range of mobile organisms (including non-indigenous marine species) may be lost to the marine environment as a consequence of this process. We also determined that different levels of biofouling (primary, secondary and tertiary) and emersion durations (0.5, 5 and 15 min) affected the abundance and composition of mobile taxa lost to the marine environment. Primary biofouling plates lost 3.2% of total animals, secondary plates lost 19.8% and tertiary plates lost 8.2%, while hanging duration had only minor effects. The results suggest that removing vessels contaminated with biofouling non-indigenous marine species from the water for treatment may not be as biosecure as is currently recognised. 相似文献