GOCE+EGM08+RTM组合模型计算高程异常

针对EGM08重力场模型构建过程中存在的不足,提出用GOCE重力场模型替换EGM08模型的中低频部分,用剩余地形模型RTM拓展EGM08模型的甚高频信号。模拟分析表明,GOCE模型能大幅提高高程异常计算的精度,而RTM对高程异常的贡献也不可忽视。实测GPS/水准数据表明,GOCE模型对高程异常的贡献达到43%,而RTM也贡献了1cm的精度。     

多期构造变形事件对吉林南部大横路Cu- Co矿床富集成矿的制约

钴矿是重要的战略性金属矿产资源之一,对其成矿作用(如构造与成矿的关系)进行深入的研究能为前期指导找矿提供理论依据。本文对中国东部吉林白山市三道沟镇三岔河村大横路Cu-Co矿开展了相关工作,包括野外构造解析、钻孔-岩芯资料分析、钻孔薄片综合矿物分析系统(TIMA)实验和区域相关岩石年代学等。构造解析显示大横路Cu-Co矿围岩变形包括层片交切、S₁面理和褶劈理等构造要素。钻孔-岩芯资料分析矿区发育大量F₂紧闭褶皱、逆冲断层及断层相关褶皱、倒转褶皱F₂等。钻孔、探槽薄片样品TIMA实验显示含Co流体大量富集于低角度逆冲断裂、倒转褶皱韧性剪切域和断层相关褶皱转折端处。这些工作显示走向为NE的低角度逆冲断裂及断层相关褶皱对大横路Cu-Co矿的富集起到关键的控制作用。相关年代学工作,结合前人研究及大量区域地质资料表明:(1)矿区内逆冲断层及褶皱等控矿构造要素为古元古代构造事件的产物;(2)中生代构造事件对成矿作用的制约(Cu-Co矿的再富集)可能来自于白垩纪大规模的伸展作用。     

Evaluation of the Historical Sampling Error for Global Models

Various ensemble-based schemes are employed in data assimilation because they can use the ensemble to estimate the flow-dependent background error covariance. The most common way to generate the real-time ensemble is to use an ensemble forecast; however, this is very time-consuming. The historical sampling approach is an alternative way to generate the ensemble,by picking some snapshots from historical forecast series.With this approach, many ensemble-based assimilation schemes can be used in a deterministic forecast environment. Furthermore, considering the time that it saves, the method has the potential for operational application.However, the historical sampling approach carries with it a special kind of sampling error because, in a historical forecast, the way to integrate the ensemble members is different from the way to integrate the initial conditions at the analysis time(i.e., forcing and lateral boundary condition differences, and ‘warm start' or ‘cold start' differences). This study analyzes the results of an experiment with the Global Regional Assimilation Prediction System-Global Forecast System(GRAPES-GFS), to evaluate how the different integration configurations influence the historical sampling error for global models. The results show that the sampling error is dominated by diurnal cycle patterns as a result of the radiance forcing difference.Although the RMSEs of the sampling error are small, in view of the correlation coefficients of the perturbed ensemble, the sampling error for some variables on some levels(e.g., low-level temperature and humidity, stratospheric temperature and geopotential height and humidity), is non-negligible. The results suggest some caution must be applied, and advice taken, when using the historical sampling approach.     

Multi-resolution adaptive modeling of groundwater flow and transport problems

Many groundwater flow and transport problems, especially those with sharp fronts, narrow transition zones, layers and fingers, require extensive computational resources. In this paper, we present a novel multi-resolution adaptive Fup approach to solve the above mentioned problems. Our numerical procedure is the Adaptive Fup Collocation Method (AFCM), based on Fup basis functions and designed through a method of lines (MOL). Fup basis functions are localized and infinitely differentiable functions with compact support and are related to more standard choices such as splines or wavelets. This method enables the adaptive multi-resolution approach to solve problems with different spatial and temporal scales with a desired level of accuracy using the entire family of Fup basis functions. In addition, the utilized collocation algorithm enables the mesh free approach with consistent velocity approximation and flux continuity due to properties of the Fup basis functions. The introduced numerical procedure was tested and verified by a few characteristic groundwater flow and transport problems, the Buckley–Leverett multiphase flow problem, the 1-D vertical density driven problem and the standard 2-D seawater intrusion benchmark–Henry problem. The results demonstrate that the method is robust and efficient particularly when describing sharp fronts and narrow transition zones changing in space and time.     

基于GIS的地质项目管理系统研究与实现——以战略性矿产远景调查专项项目管理系统为例

GIS在空间信息表达和管理方面有很强的优势,目前已广泛应用于社会各领域。地质项目管理是国家地质专项开展实施的重要工作,本文以战略性矿产远景调查专项项目管理系统建设为例,分析了战略性矿产远景调查专项项目管理的特点,提出了将地理信息技术应用于战略性矿产远景调查专项管理的方案,以综合管理地质项目的属性信息和空间信息。在此基础上,笔者对研发的战略性矿产专项项目管理系统进行了介绍。     

莱芜市茶业口镇船厂地区泥(渣)石流灾害区治理

详细介绍了莱芜市茶业口镇船厂地区的矿山地质环境,提出了治理方案,对矿区存留矿体开发的可行性进行了论证,对开采与治理同步的技术路线进行了合理性分析。通过开发利用存留资源,可为地质灾害治理提供了资金保障,实现了资源利用与地质灾害治理的双赢局面,为类似地质灾害防治提供借鉴。     

东北地区历史时期森林空间格局网格化重建方法研究(英文)

The spatially explicit reconstruction of historical land-cover datasets plays an important role in studying the climatic and ecological effects of land-use and land-cover change(LUCC). Using potential natural vegetation(PNV) and satellite-based land use data, we determined the possible maximum distribution extent of forest cover in the absence of human disturbance. Subsequently, topography and climate factors were selected to assess the suitability of land for cultivation. Finally, a historical forest area allocation model was devised on the basis of the suitability of land for cultivation. As a case study, we used the historical forest area allocation model to reconstruct forest cover for 1780 and 1940 in Northeast China with a 10-km resolution. To validate the model, we compared satellite-based forest cover data with our reconstruction for 2000. A one-sample t-test of absolute bias showed that the two-tailed significance was 0.12, larger than the significant level 0.05, suggesting that the model has strong ability to capture the spatial distribution of forests. In addition, we calculated the relative difference of our reconstruction at the county scale for 1780 in Northeast China. The number of counties whose relative difference ranged from-30% to 30% is 99, accounting for 74.44% of all counties. These findings demonstrated that the provincial forest area could be transformed into forest cover maps well using the model.     

Improving the simulation of fine-resolution landscape changes by coupling top-down and bottom-up land use and cover changes rules

Modelling land use and cover changes (LUCC) at local and landscape scales simultaneously, in terms of composition and configuration, remains today highly challenging. Agricultural landscapes offer an illustrative context for this purpose. This article presents a modelling platform (DYPAL) able to simulate LUCC at both local (agricultural parcel, farm) and landscape levels by combining LUCC processes with an optimization algorithm. The efficiency of this approach is assessed by comparing it with an approach applying the same LUCC processes without optimization. Simulations have been developed for two representative case studies of temperate intensive agricultural mosaics: (1) neutral landscapes with simple and theoretical rules and (2) observed landscapes with realistic crop successions rules. Results show that this modelling platform improves the simulation of LUCC achieved at fine resolution, although not systematically. Improvements are observed when compared to theoretical farming practices. But, when compared with an observed landscape, it is true for one type of (arable) farms only. Several hypotheses are discussed, such as the fact that farmers possibly do not follow optimized rules. Finally, this study illustrates that the use of several indices is crucial to assess whether a simulated landscape is realistic or not, because it does not rely to the assessment of the predictive power of the model.     

The precautionary approach to non-native fisheries—The case of striped bass in Texas

Fisheries managers have long relied on non-native fish to improve, sustain, or create recreational fishing opportunities, often without adequate consideration of potentially negative ecological consequences. There is growing advocacy for using the precautionary approach to avoid potentially serious or irreversible harm to the environment in the face of scientific uncertainty. This paper uses striped bass (Morone saxitilis) in Texas to examine possible effects that might have resulted had the precautionary approach been applied before stocking began in the 1960s when the species was considered non-native to Texas. The current range of reproducing striped bass populations extends from the North Atlantic Ocean to the U.S.–Mexico border. However, the western extent of the species current range beyond Louisiana is probably the result of stocking begun in 1965 that continues today. The historic range is yet unresolved. The best available information suggests that striped bass are not native to Texas, fish stocking has resulted in beneficial economic impacts, and any negative effects (i.e., harm) are currently unknown. It seems unlikely that application of the precautionary approach would have led to different outcomes in Texas than currently exist. However, the complete striped bass story has yet to be written.