A petroleum discovery-rate forecast revisited—The problem of field growth     

Lawrence J. Drew  John H. Schuenemeyer 《Natural Resources Research》1992,1(1):51-60

A forecast of the future rates of discovery of crude oil and natural gas for the 123,027-km² Miocene/Pliocene trend in the Gulf of Mexico was made in 1980. This forecast was evaluated in 1988 by comparing two sets of data: (1) the actual versus the forecasted number of fields discovered, and (2) the actual versus the forecasted volumes of crude oil and natural gas discovered with the drilling of 1,820 wildcat wells along the trend between January 1, 1977, and December 31, 1985. The forecast specified that this level of drilling would result in the discovery of 217 fields containing 1.78 billion barrels of oil equivalent; however, 238 fields containing 3.57 billion barrels of oil equivalent were actually discovered. This underestimation is attributed to biases introduced by field growth and, to a lesser degree, the artificially low, pre-1970's price of natural gas that prevented many smaller gas fields from being brought into production at the time of their discovery; most of these fields contained less than 50 billion cubic feet of producible natural gas.  相似文献   

Evaluation of intermediate TanDEM-X digital elevation data products over Tasmania using other digital elevation models and accurate heights from the Australian National Gravity Database     

M. Rexer  C. Hirt 《Australian Journal of Earth Sciences》2016,63(5):599-609

The successful operation of the TanDEM-X satellite mission is the start of a new era of globally consistent and accurate digital elevation data for planet Earth. In this work available 12 m-resolution intermediate TanDEM-X products (DEM: digital elevation model; HEM: height error map; COV: coverage map; WAM: water indication mask) are evaluated over Tasmania. Elevations from the TanDEM-X intermediate digital elevation model (IDEM) are compared with (a) other global DEMs (30 m-resolution SRTM1 USGS v3 and 30 m-resolution Advanced Spaceborne Thermal Emission Reflectometer (ASTER GDEM2), (b) the local 25 m-resolution DEM made available by Tasmanian environmental authority (DPIPWE), and (c) over 15 000 accurate ground-control-points (GCPs) from the Australian National Gravity Database (ANGD). The comparison with ASTER and SRTM over the area of Tasmania involves over 500 million valid TanDEM-X IDEM elevations. The root-mean-square (RMS) of 8.8 m indicates a reasonable to good agreement of TanDEM-X IDEM and SRTM, while ASTER shows almost twice the disagreement in terms of RMS (～16.5 m). Both, ASTER and SRTM show a (mean) offset of –1.9 m and –2.3 m w.r.t. TanDEM-X IDEM, respectively. By comparisons with GCPs, we find that SRTM and ASTER overestimate the terrain height. The comparison with the AGND GCPs also allows an estimate of the absolute accuracy of the IDEM, which is found to be superior to that of SRTM or ASTER. The RMS error of 6.6 m shows that the IDEM is close to the officially denoted 4 m absolute vertical accuracy considering that the GCPs are not error free. The height error map information layer is found to a suitable first indicator of the (local) accuracy of the IDEM in a relative sense. However, we find that the HEM tends to underestimate observed differences to the GCPs. Terrain-type analyses reveal that the TanDEM-X IDEM is a very consistent elevation database over Tasmania. In conclusion, our study demonstrates that the new TanDEM-X elevation data sets provide improved high-resolution terrain information over Tasmania and beyond.  相似文献   

WindSat近海岸风场与美国沿岸浮标对比分析   总被引：1，自引：1，他引：0  

张雷  石汉青  俞宏  易欣 《海洋学报(英文版)》2016,35(7):50-58

利用美国近海岸2004-2014年的固定浮标数据,本文对比分析了WindSat的近海岸风速产品。匹配时空窗口分别为30分钟和25公里。对比分析结果表明：WindSat反演的美国近海岸风速产品的均方根误差优于1.44 m/s,并且东海岸风速反演结果优于西海岸。WindSat下降轨道的风速反演结果优于上升轨道的结果。通过浮标相互间的对比分析发现,WindSat近海岸的风速反演结果与近岸海水深度、经度及距岸距离等因素并无明显的相关性。此外,利用2007-2008年的固定浮标数据,本文还对比分析了WindSat和QuikSCAT的近海岸风速反演结果,结果表明：相对于浮标数据,WindSat的风速反演值偏低,而QuikSCAT的风速反演值偏高;总体上来看,WindSat的近岸风速反演结果略优于QuikSCAT的近海岸风速反演结果。以上风速反演的精度均达到了传感器设定的指标,其为进一步的科学研究提供了良好的数据支撑。  相似文献   

亚热带山地丘陵区气象要素空间化方法分析     

陈晓玲  曾永年  柳文杰 《测绘与空间地理信息》2017,(12):51-56

空间连续的气象要素是区域环境、生态系统模拟的重要参数,空间插值是实现气象观测站点数据空间化的主要方法。由于不同区域气候要素时空分布的复杂性,研究适用于特定区域的空间化方法具有重要意义。本文以湖南省为研究区,分析长江中游亚热带丘陵区气象要素的空间化方法。基于湖南省及其毗邻地区的46个气象站点14年(2000—2013年)的气象观测数据(月降水量、月均温)和DEM数据,对普通克里金法(OK)、反距离加权法(IDW)、样条法(SPLINE)和基于DEM的多元线性回归插值法(MLR)进行比较分析研究。研究结果表明:1)月降水量和月均温的MRE和RMISE值排序分别为:SPLINEIDWMLROK和SPLINOKIDWMLR;年平均降水量和年均温插值的MRE和RMISE值排序分别为:SPLINEIDWOKMLR和SPLINOKIDWMLR;2)MLR法不仅插值误差小,而且能从细节上反映出气象变化的空间变异性;3)对多变量进行数据探索分析表明,MLR插值法中,经度、坡度与年降水量空间分布存在空间的一致性;纬度、高程和坡度对年均温的空间分布具有很强的解释力。  相似文献   

Validation of landslide hazard models using a semantic engine on online news     

《Applied geography (Sevenoaks, England)》2017

The objective of this work is twofold: (i) automatically setting up a landslide inventory using a state-of-the art semantic engine based on data mining on online news and (ii) evaluating if the automatically generated inventory can be used to validate a regional scale landslide warning system based on rainfall-thresholds.The semantic engine scanned internet news in real time in a 50 months test period. At the end of the process, an inventory of approximately 900 landslides was automatically set up for the Tuscany region (23,000 km², Italy). Using a completely automated procedure, the inventory was compared with the outputs of the regional landslide early warning system and a good correspondence was found, e.g. 84% of the events reported in the news is correctly identified by the warning system.On the basis of the obtained results, we conclude that automatic validation of landslide models using geolocalized landslide events feedback is possible. The source of data for validation can be obtained directly from the Internet channel using an appropriate semantic engine dedicated to perform a monitoring of the Google News aggregator.Moreover, validation statistics can be used to evaluate the effectiveness of the predictive model and, if deemed necessary, an update of the rainfall thresholds could be performed to obtain an improvement of the forecasting effectiveness of the warning system.In the near future, the proposed procedure could operate in continuous time and could allow for a periodic update of landslide hazard models and landslide early warning systems with minimum or none human intervention.  相似文献   

卫星激光测高严密几何模型构建及精度初步验证   总被引：4，自引：0，他引：4  

唐新明  李国元  高小明  陈继溢 《测绘学报》2016,45(10):1182-1191

采用星载激光测高仪辅助提高卫星立体影像几何定位精度特别是高程精度,已经得到了航天摄影测量界的重视,计划于2018年发射的高分七号卫星上将同时搭载光学立体相机和激光测高仪。虽然,已有相关文献针对美国的ICESat(Ice,Cloud,and land Elevation Satellite)卫星上搭载的地球科学激光测高系统(Geo-science Laser Altimeter System,GLAS)的几何模型和产品精度作了相关介绍,但对其严密的几何定位模型和精度验证目前还没有系统性的阐述。本文较全面地对激光测高卫星的严密几何模型进行了构建与精度分析,并选择ICESat/GLAS的0级辅助文件,采用严密几何模型重现了2级产品的生产过程。将本文计算的结果与ICESat/GLAS的结果进行了对比分析,其中基于几何模型的高程误差约11 cm,平面误差在3 cm以内,表明所提出的严密几何模型的正确性,同时采用新发射的资源三号02星的激光测高数据进行了初步处理和验证。相关结论可为国产高分后续卫星的激光测高数据处理提供参考。  相似文献   

Assessment of three-dimensional physical-biological ECOHAM1 simulations by quantified validation for the North Sea with ICES and ERSEM data     

Moll  Andreas 《ICES Journal of Marine Science》2000,57(4):1060-1068

  相似文献   

Evidence of underestimation of European hake growth in the Bay of Biscay, and its relationship with bias in the agreed method of age estimation   总被引：2，自引：1，他引：2  

de Pontual  Helene; Groison  Anne Laure; Pineiro  Carmen; Bertignac  Michel 《ICES Journal of Marine Science》2006,63(9):1674-1681

  相似文献   

Reconstruction of incomplete oceanographic data sets using empirical orthogonal functions: application to the Adriatic Sea surface temperature   总被引：8，自引：1，他引：8  

A. Alvera-Azcrate  A. Barth  M. Rixen  J.M. Beckers 《Ocean Modelling》2005,9(4):325-346

A method for the reconstruction of missing data based on an EOF decomposition has been applied to a large data set, a test case of Sea Surface Temperature satellite images of the Adriatic Sea. The EOF decomposition is realised with a Lanczos method, which allows optimising computational time for large matrices. The results show that the reconstruction method leads to accurate reconstructions as well as a low cpu time when dealing with realistic cases. The method has been tested with different amounts of missing data, artificially adding clouds ranging from 40% to 80% of data loss, and then compared to the same data set with no missing data. A comparison with in situ data has also been made. These validation studies show that results are robust, even when the amount of missing data is very high. The reconstruction of the data from the Adriatic Sea shows realistic features and a reliable temperature distribution. In addition, the method is compared to an Optimal Interpolation reconstruction. The results obtained with both methods are very similar. The main difference is the computational time, which is reduced nearly 30 times with the method presented here. Once the reconstruction has been performed, the EOF decomposition is analysed to show the method’s reliability, and a cold event on the Albanian coast is studied. The reconstructed data reflect the effect of wind on the Albanian coast, that led to a cold-water episode in this zone for a 6-day period.  相似文献   

The Harvest Experiment: Monitoring Jason-1 and TOPEX/POSEIDON from a California Offshore Platform     

Bruce J. Haines  Danan Dong  George H. Born  Stephen K. Gill 《Marine Geodesy》2003,26(3):239-259

We present calibration results from Jason-1 (2001-) and TOPEX/POSEIDON (1992-) overflights of a California offshore oil platform (Harvest). Data from Harvest indicate that current Jason-1 sea-surface height (SSH) measurements are high by 138 ± 18 mm. Excepting the bias, the high accuracy of the Jason-1 measurements is in evidence from the overflights. In orbit for over 10 years, the T/P measurement system is well calibrated, and the SSH bias is statistically indistinguishable from zero. Also reviewed are over 10 years of geodetic results from the Harvest experiment.  相似文献