水下地形测量成果质量检验若干问题探讨     

史富贵 《测绘科学》2015,40(7):109-112

由于在GB/T 24356—2009《测绘成果质量检查与验收》中,针对水下地形测量的检验内容过多兼顾相关规范对流速、流向、底质等探测的要求,使得一般的水下地形测量成果检验时参照执行不方便,该文结合实际工作,对水下地形测量成果质量检验方法进行了研究:对水下地形测量成果质量元素及权的划分、样本的确定、特殊水下地形精度检测、粗差率的扣分标准等几个方面作了总结分析,为水下地形测量成果质检提供了操作性较强的方案。  相似文献   

Land cover dynamics monitoring with Landsat data in Kunming,China: a cost-effective sampling and modelling scheme using Google Earth imagery and random forests     

Ning Lu  Alexander J. Hernandez  R. Douglas Ramsey 《国际地球制图》2015,30(2):186-201

Changes in forest composition impact ecological services, and are considered important factors driving global climate change. A hybrid sampling method along with a modelling approach to map current and past land cover in Kunming, China is reported. MODIS land cover (2001–2011) data-sets were used to detect pixels with no apparent change. Around 3000 ‘no change points’ were systematically selected and sampled using Google Earth’s high-resolution imagery. Thirty-five per cent of these points were verified and used for training and validation. We used Random forests to classify multi-temporal Landsat imagery. Results show that forest cover has had a net decrease of 14385?ha (1.3% of forest area), which was primary converted to shrublands (11%), urban and barren land (2.7%) and agriculture (2.5%). Our validation indicates an overall accuracy (Kappa) of 82%. Our methodology can be used to consistently map the dynamics of land cover change in similar areas with minimum costs.  相似文献   

The Truncated Discovery Process Model     

Kenneth?G.?LoganEmail author 《Natural Resources Research》2005,14(3):265-281

The purpose of this paper is to describe a mathematical and computer model that has been developed by TransCanada for TransCanada Pipelines (TCPL) and for the Canadian Gas Potential Committee (CGPC) for future Canadian natural gas resource assessment work. It was developed in the contexts of developing a gas supply model for forecasting future Canadian gas supply for TCPL and of improving the CGPC's assessment methodologies and software. The model developed in this paper integrates two discovery process models used by the CGPC and solves the economic truncation problem for semi-mature to mature plays. It is based on applying techniques developed by G. M. Kaufman and J. D. Fuller and colleagues in new ways which extends the work of these authors. This model has a number of important advantages including: fast computational speed, integration of parametric and nonparametric statistical approaches, integration of the Kaufman and others model and the Arps-Roberts model, overcoming a PETRIMES limitation of a maximum of 1000 samples, providing a finding rate forecast for economic analysis and providing a fresh look at solving the economic truncation problem. The details of the new Modified Arps-Roberts Model (now known as the Truncated Discovery Process Model or TDPM for short) are discussed in this paper.  相似文献   

Electronically conducting brittle-ductile shear zones in the crystalline basement of Rittsteig (Bohemian Massif,Germany): Evidence from self potential and hole-to-surface electrical measurements     

Jürgen?Bigalke  Andreas?Junge  Gernold?ZulaufEmail author 《International Journal of Earth Sciences》2004,93(1):44-51

Crustal-scale shear zones may act as prominent electrical conductors given that sufficient amounts of graphite or fluids are present. There are several graphite-enriched shear zones within the 583-m-deep Rittsteig drilling (Bavaria, Germany), two of which are of major importance. One shear zone cuts through Moldanubian biotite-muscovite schists at 320 m depth. The other shear zone separates Teplá-Barrandian amphibolites from Moldanubian biotite-muscovite schists at 460 m depth. To detect these shear zones adjacent to the drilling, the self-potential method and the non-linear impedance spectroscopy have been applied. From the new data, obtained from hole-to-surface and surface measurements, we conclude that (1) graphite is pervasively distributed within the Rittsteig shear zones resulting in powerful electronic conductors, (2) the graphite-bearing shear zones are dipping moderately towards the S, and (3) the shear zone drilled at 320 m depth extends to the Earths surface where it has been detected ca. 400 m to the N of the drilling. As the graphite-bearing shear zones of both the Rittsteig drilling and the German Continental Deep Drilling (KTB) developed in the brittle-ductile regime of quartzofeldspathic rocks, we argue that the brittle-ductile boundary layer may act as a significant graphite attractor in the continental crust.

Gernold ZulaufEmail: Phone: +49-9131-8522617Fax: +49-9131-8529295

  相似文献   

The use of adaptive cluster sampling for hydroacoustic surveys   总被引：5，自引：0，他引：5  

Conners  M. Elizabeth; Schwager  Steven J. 《ICES Journal of Marine Science》2002,59(6):1314-1325

  相似文献   

Spatial dynamics of a nearshore, micronekton sound-scattering layer     

Benoit-Bird  Kelly J; Au  Whitlow W.L 《ICES Journal of Marine Science》2003,60(4):899-913

  相似文献   

On estimating the age composition of the commercial catch of Northeast Arctic cod from a sample of clusters   总被引：1，自引：0，他引：1  

Sondre  Aanes; Pennington  Michael 《ICES Journal of Marine Science》2003,60(2):297-303

  相似文献   

Spatio-temporal variation in the structure of a deep water Posidonia oceanica meadow assessed using non-destructive techniques     

Joseph Anthony Borg  Mark Alan Micallef  & Patrick Joseph Schembri 《Marine Ecology》2006,27(4):320-327

The Malta‐Comino Channel (Maltese islands, central Mediterranean), supports extensive meadows of the seagrass Posidonia oceanica that in some places extend to a depth of around 43 m, which is rare for this seagrass. To assess spatial and temporal variation in the state of the deeper parts of the P. oceanica meadow with time, data on the structural characteristics of the seagrass meadow at its lower bathymetric limit were collected during the summers of 2001, 2003 and 2004 from four stations (two stations within each of two sites) located at a similar depth, over a spatial extent of 500 m. Shoot density was estimated in situ, while data on plant architecture (number of leaves, mean leaf length, and epiphyte load) were successfully obtained using an underwater photographic technique that was specifically designed to avoid destructive sampling of the seagrass. Results indicated that P. oceanica shoot density was lower than that recorded from the same meadow during a study undertaken in 1995; the observed decrease was attributed to the activities of an offshore aquaculture farm that operated during the period 1995–2000 in the vicinity of the meadow. ANOVA indicated significant spatial and temporal variations in meadow structural attributes at both sites during the 3‐year study; for example, shoot density values increased overall with time at site A; a indication of potential recovery of the meadow following cessation of the aquaculture operations. Lower shoot density values recorded from site B (compared with site A) were attributed to higher epiphyte loads on the seagrass, relative to those at site A. The findings, which include new data on the structural characteristics of P. oceanica occurring at depths >40 m, are discussed with reference to the use of the non‐destructive photographic technique to monitor the state of health of deep water seagrass meadows.  相似文献   

Long-term change in the structure of a Posidonia oceanica landscape and its reference for a monitoring plan     

Giandomenico Ardizzone  rea Belluscio  & Luigi Maiorano 《Marine Ecology》2006,27(4):299-309

Abstract On the basis of a detailed cartographic survey carried out by Side Scan Sonar and a towed underwater video camera during 2005, and from a series of historical maps (1959, 1980, 1990), an extensive regression of Posidonia oceanica (L.) Delile beds was evidenced for a vast area of the central Tyrrhenian Sea (Latium coast, Italy). The total loss of P. oceanica surface was assessed through GIS estimate. In 1959, the Posidonia beds extended over 7290 ha, while in the 2005 survey they had regressed to 2899 ha, a loss of about 60% of their coverage. Also the seagrass lower limit showed a general depth decrease in time. Total seagrass coverage loss and lower limit regression were not uniform along the whole investigated areas and three main sub-areas have been identified with different degrees of regression somehow related with coastal potential human-mediated impacts. From different coverage estimates of the present survey and of the previous maps, minimum sampling areas were calculated through bootstrapping simulation routines from small sampling areas (Landscape Units) to reach the nearest estimate of the observed condition in the different periods.  相似文献   

Comparative ecology of over-wintering Calanus finmarchicus in the northern North Atlantic, and implications for life-cycle patterns     

Heath  Michael R; Boyle  Peter R; Gislason  Astthor; Gurney  William S.C; Hay  Stephen J; Head  Erica J.H; Holmes  Steven; Ingvarsdottir  Anna; Jonasdottir  Sigrun H; Lindeque  Pennie; Pollard  Raymond T; Rasmussen  Jens; Richards  Kelvin; Richardson  Katherine; Smerdon  Gary; Speirs  Douglas 《ICES Journal of Marine Science》2004,61(4):698-708

  相似文献