平原地区水文地质结构条件模拟及其应用:以华北平原为例   总被引：4，自引：2，他引：2  

李长青  邵景力  靳萍  崔亚莉 《现代地质》2009,23(1):137-143

为了分析储水介质非均质性问题,采用了基于马尔柯夫地层序列分析的分布条件模拟方法,用转移概率矩阵的谱分析函数替代传统地质统计学中的变差函数,利用协同指示克里格方法和条件模拟建立结构模型。以华北平原为例,论述了模拟结构建立过程及其在水流模型中的应用。通过对模拟结果与实测数据的分析比较,认为模拟结果能够客观反映整个研究区的沉积规律,以岩性赋水文地质参数的方法更加客观准确地解决储水介质非均质性问题。分析了该方法的优、缺点,并提出了该方法深入研究的方向与思路。  相似文献   

霍林河流域下游地区土地利用变化动态及趋势预测   总被引：6，自引：0，他引：6  

崔健  林年丰  汤洁  姜玲玲  蔡宇 《吉林大学学报(地球科学版)》2006,36(2):259-264

霍林河流域下游地区为半农半牧区,土地利用的变化对该地区的生态环境会产生重大的影响。采用空间分析测算模型,揭示了1989～2001年期间该地区土地利用的空间变化特征以及土地利用类型三减（草地、水体、湿地）两增（耕地和未利用土地）的变化规律;并通过马尔可夫模型预测出未来24年内该区土地利用类型的演变趋势,得出水田、旱田、林地、城乡用地的继续增加是以草地、水域、湿地的减少为代价的结论,对生态环境的保护和土地资源的合理利用具有参考价值。  相似文献   

Interplay of orbital forcing and tectonic pulses in the Cambrian Iberian platform, NE Spain     

J. J. Álvaro  E. Vennin  A. Muñoz  B. Sánchez-Valverde  J. L. Ojeda 《International Journal of Earth Sciences》2000,89(2):366-376

The stratigraphy of carbonate/shale couplets, cycles and cycle-stacking patterns in a Cambrian shallow water platform (Iberian Chains, NE Spain) are related to sea-level changes driven by orbital forcing and by tectonic pulses. The interplay of both effects can be discriminated in the Iberian fault-controlled platform, in which the tectonic activity can be analysed by accurate and detailed biostratigraphic correlations based on trilobite zonation. The stratigraphic hierarchy of rhythmically interbedded limestones and shales, in two coeval but structurally separated geodynamic settings, yields cycle ratios of 1.44 :1. This ratio is supported by time thickness and spectral analysis, which is based on a graphic method of analysis: the Map of Grey Lines. The cycle ratio seems to be evidence for orbital forcing by obliquity and precession cycles predicted for early Paleozoic time. Carbonate/shale couplets, the smallest rhythmic units recognisable in the field, represent short-term, periodic fluctuations in supply of terrigenous sediments and carbonate productivity of uncertain origin, which could be associated with one of several harmonics of the former orbital cycles. The pulsating tectonic activity was approximated by using a quantitative analysis of tectonically induced subsidence (Shaw method). Recurrence frequencies of tectonic pulses were estimated and dated by biostratigraphy. As a result, tectonic disturbances in the Cambrian Iberian platform show an episodic periodicity comparable to that of orbital eccentricity cycles, which could mask their recognition. Received: 15 November 1999 / Accepted: 9 February 2000  相似文献   

龙羊峡水库年入库径流的Markov预测模型   总被引：12，自引：6，他引：6  

蓝永超  康尔泗  徐中民 《中国沙漠》2000,20(1):95-97

Markov预测技术是应用Markov链的相关预测的基本原理与方法来研究分析时间序列的变化规律,并预测其未来变化趋势的一种预报方法,适用于随机波动较大的预报问题。根据Markov链原理,提出了一个用于龙羊峡水库年平均入库径流预报的离散随机过程模型。实测资料的验证结果表明,这种模型计算精度较高,具有良好应用价值。  相似文献   

Mining transition rules of cellular automata for simulating urban expansion by using the deep learning techniques   总被引：3，自引：0，他引：3  

Jialv He  Yao Yao  Ye Hong  Zhang Jinbao 《International journal of geographical information science》2018,32(10):2076-2097

Along with the gradually accelerated urbanization process, simulating and predicting the future pattern of the city is of great importance to the prediction and prevention of some environmental, economic and urban issues. Previous studies have generally integrated traditional machine learning with cellular automaton (CA) models to simulate urban development. Nevertheless, difficulties still exist in the process of obtaining more accurate results with CA models; such difficulties are mainly due to the insufficient consideration of neighborhood effects during urban transition rule mining. In this paper, we used an effective deep learning method, named convolution neural network for united mining (UMCNN), to solve the problem. UMCNN has substantial potential to get neighborhood information from its receptive field. Thus, a novel CA model coupled with UMCNN and Markov chain was designed to improve the performance of simulating urban expansion processes. Choosing the Pearl River Delta of China as the study area, we excavate the driving factors and the transformational relations revealed by the urban land-use patterns in 2000, 2005 and 2010 and further simulate the urban expansion status in 2020 and 2030. Additionally, three traditional machine-learning-based CA models (LR, ANN and RFA) are built to attest the practicality of the proposed model. In the comparison, the proposed method reaches the highest simulation accuracy and landscape index similarity. The predicted urban expansion results reveal that the economy will continue to be the primary factor in the study area from 2010 to 2030. The proposed model can serve as guidance in urban planning and government decision-making.  相似文献   

基于多目标遗传算法和FLUS模型的西北农牧交错带土地利用优化配置   总被引：1，自引：0，他引：1  

杨露  颉耀文  宗乐丽  邱天  焦继宗 《地球信息科学学报》2020,22(3):568-579

西北农牧交错带生态环境脆弱,区位特殊性和生态重要性使其在我国社会经济发展和生态环境保护方面具有重要战略意义。通过对该区域进行土地利用优化配置,使有限的土地资源支撑起生态环境保护和经济发展的重任是本文的出发点。多目标遗传算法和FLUS模型的应用可以从多方面（数量结构、空间布局、综合效益）完善土地利用优化配置,为土地利用优化配置提供更多的选择方案。本文选用多目标遗传算法和FLUS模型对该区域进行2025年的土地利用变化模拟,通过设置自然发展、生态保护优先、经济发展优先、生态-经济均衡4种情景,探讨了如何在兼顾生态环境保护与社会经济发展的情况下进行土地利用的优化配置。结果表明,基于生态-经济均衡情景下的优化方案,土地利用类型的数量结构和空间布局更为合理,其综合效益优于另外3种情景。该情景在合理限制经济发展速度的前提下,使生态建设获得稳定发展,其经济效益较生态保护优先情景下增长了8.96%,生态效益较经济发展优先情景下增长了0.77%,在生态保护与经济发展2种目标之间达到平衡,为西北农牧交错带的土地利用规划提供了决策辅助。  相似文献   

Data Configurations and the Cokriging System: Simplification by Screen Effects   总被引：1，自引：0，他引：1  

A. Subramanyam  H. S. Pandalai 《Mathematical Geosciences》2008,40(4):425-443

Large cokriging systems arise in many situations and are difficult to handle in practice. Simplifications such as simple kriging, strictly collocated and multicollocated cokriging are often used and models under which such simplifications are, in fact, equivalent to cokriging have recently received attention. In this paper, a two-dimensional second-order stationary random process with known mean is considered and the redundancy of certain components of the data at certain locations vis-à-vis the solution to the simple cokriging system is examined. Conditions for the simple cokriging weights of these components at these locations are set to zero. The conditions generalise the notion of the autokrigeability coefficient and can, in principle, be applied to any data configuration. In specific sampling situations such as the isotopic and certain heterotropic configurations, models under which simple kriging, strictly collocated, multicollocated and dislocated cokriging are equivalent to simple cokriging are readily identified and results already available in the literature are obtained. These are readily identified and the results are already available in the literature. The advantage of the approach presented here is that it can be applied to any data configuration for analysis of permissible simplifications in simple cokriging.  相似文献   

Multi-Scale and Multi-Resolution Stochastic Modeling of Subsurface Heterogeneity by Tree-Indexed Markov Chains     

Michel Dekking  Amro Elfeki  Cor Kraaikamp  Johannes Bruining 《Computational Geosciences》2001,5(1):47-60

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Markov chain Monte Carlo methods for conditioning a permeability field to pressure data   总被引：3，自引：0，他引：3  

Dean S. Oliver  Luciane B. Cunha  Albert C. Reynolds 《Mathematical Geology》1997,29(1):61-91

Generating one realization of a random permeability field that is consistent with observed pressure data and a known variogram model is not a difficult problem. If, however, one wants to investigate the uncertainty of reservior behavior, one must generate a large number of realizations and ensure that the distribution of realizations properly reflects the uncertainty in reservoir properties. The most widely used method for conditioning permeability fields to production data has been the method of simulated annealing, in which practitioners attempt to minimize the difference between the ’ ’true and simulated production data, and “true” and simulated variograms. Unfortunately, the meaning of the resulting realization is not clear and the method can be extremely slow. In this paper, we present an alternative approach to generating realizations that are conditional to pressure data, focusing on the distribution of realizations and on the efficiency of the method. Under certain conditions that can be verified easily, the Markov chain Monte Carlo method is known to produce states whose frequencies of appearance correspond to a given probability distribution, so we use this method to generate the realizations. To make the method more efficient, we perturb the states in such a way that the variogram is satisfied automatically and the pressure data are approximately matched at every step. These perturbations make use of sensitivity coefficients calculated from the reservoir simulator.  相似文献   

The GF algorithm for reservoir storage, yield and spillage distributions for non-seasonal and seasonal independent inflow processes     

E. H. Lloyd  D. Warren 《Stochastic Hydrology and Hydraulics》1992,6(2):135-149

a well-known generating function formula for the equilibrium storage distribution in a finite Moran reservoir having IID inflows and unit release is extended to apply to a class of nondecreasing staircase-like release policies withm unit increments,m>1, and to seasonal inflows. The analysis is conducted in terms of an alternative to the Moran inflow-outflow sequencing scheme, with the release during a working interval controlled by the water level at the beginning of that interval.In addition to the storage, the equilibrium distributions of yield and spillage are obtained. Illustrative examples are provided.  相似文献