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311.
312.
当前地图自动综合的理论与算法研究已经取得一定的进展,空间拓扑关系对制图综合起到重要的制约作用。土地利用图主要包含图斑、线状地物、零星地类3类图形要素,数据综合的工作量较大。本文结合土地利用现状图综合过程实践,基于点集拓扑交模型的理论与方法,讨论并分析如何根据图斑之间可能的拓扑关系(相离、点相接、外相邻、内相邻),结合语义等约束条件,选择合适的操作算子(如聚合、融合、退化等),抽象出土地利用图中图斑、线状地物综合前后存在的一些拓扑关系约束性规则。研究成果可作为土地利用制图综合前后的拓扑关系检查的一项依据,为综合算法的设计与实现提供一定的参考价值。后续的工作是:进一步完善该规则与算法,进行实验与应用。建议规则库与算法相分离,以保持各自的灵活性和独立性。 相似文献
313.
AbstractMultidisciplinary models are useful for integrating different disciplines when addressing water planning and management problems. We combine water resources management, water quality and habitat analysis tools that were developed with the decision support system AQUATOOL at the basin scale. The water management model solves the allocation problem through network flow optimization and considers the environmental flows in some river stretches. Once volumes and flows are estimated, the water quality model is applied. Furthermore, the flows are evaluated from an ecological perspective using time series of aquatic species habitat indicators. This approach was applied in the Tormes River Water System, where agricultural demands jeopardize the environmental needs of the river ecosystem. Additionally, water quality problems in the lower part of the river result from wastewater loading and agricultural pollution. Our methodological framework can be used to define water management rules that maintain water supply, aquatic ecosystem and legal standards of water quality. The integration of ecological and water management criteria in a software platform with objective criteria and heuristic optimization procedures allows realistic assessment and application of environmental flows to be made. Here, we improve the general methodological framework by assessing the hydrological alteration of selected environmental flow regime scenarios.
Editor D. Koutsoyiannis; Guest editor M. AcremanCitation Paredes-Arquiola, J., Solera, A., Martinez-Capel, F., Momblanch, A., and Andreu, J., 2014. Integrating water management, habitat modelling and water quality at the basin scale and environmental flow assessment: case study of the Tormes River, Spain. Hydrological Sciences Journal, 59 (3–4), 878–889. 相似文献
314.
针对传统空间数据关联规则挖掘缺乏不确定性处理及度量的局限性,将空间数据的不确定性和空间数据挖掘的不确定性有机结合,初步建立了空间数据关联规则挖掘的不确定性处理模型及度量指标,包括空间数据不确定性的Monte Carlo模拟、基于不确定性空间数据的空间自相关度量和关联规则不确定性度量等,并以我国某地区环境调查数据为例进行验证。 相似文献
315.
从学习防震减灾法律法规的必要性,重要性和紧迫性;《四川省防震减灾条例》的产生过程及其意义;《四川省防震减灾条例》修改后的新内容和新特点;对依法行政,做好执法和执法监督工作等方面,阐述了认真学习《四川省防震灾条例》,努力提高依法治震水平的问题。 相似文献
316.
热带气旋在移动过程中,环境气压场和其自身内力等都在发生变化。假设这些影响热带气旋的力之和随时间的变化在某一时段内是张性的,从而导出热带气旋的路径曲线方程。分析方程,得逞以热带气旋移动的三个基本规律。通过实例计算,可以看到方程曲线与实际路径几乎一致的个例验证结果,并有意义地证实一些人们以前的研究成果。 相似文献
317.
以突水样例的一个子集为例,采用可变精度的Rough集模型,经过对原始决策信息表的数据预处理、属性约简、值约简和规则生成等主要步骤,最终获得了与该样例子集相适应的若干突水规则,这些规则较好地覆盖了该样例子集所包含的突水信息,具有同等的分类决策效果。 相似文献
318.
通过对贵州务川大竹园铝土矿床的研究,发现矿床中伴生镓的含量普遍超过了工业综合利用的最低指标。Ga在含铝岩系中均有不同程度的分布,Ga与TiO2、Cr、Zr、Sn呈中等正相关关系,说明Ga可能赋存于含TiO2、Cr、Zr、Sn的矿物中; Ga与Al2O3呈弱正相关关系,说明Ga可能以类质同象的形式存在于Al的化合物中。Sr/Ba=1.09~19.69>1,表明铝土矿形成于海相沉积环境; Th/U=1.72~12.31,表明铝土矿可能风化作用不彻底; Ga/Al=0.45~1.84,表明成矿介质酸碱度的变化幅度较小。从含矿岩系矿物组合中含黄铁矿、高岭石等矿物可以推断介质为酸性的可能性较大; 稀土元素(rare earth element, REE)球粒陨石标准化分布曲线向右倾斜,轻稀土元素(LREE)富集,重稀土元素(HREE)亏损,δCe显示为弱正异常,Ce/Ce*=1.17~10.17>1,表明铝土矿形成于富氧的沉积环境,δEu显示为负异常,进一步表明成矿是以氧化环境为主。综合分析认为大竹园铝土矿床形成于以海相沉积作用为主的富氧的沉积环境。 相似文献
319.
The modal combination rules commonly used in response spectrum analyses implicitly assume that the peak factor associated with the response quantity of interest is equal to the peak factors of the contributing modal responses. In this paper, we examine the validity of this assumption and demonstrate that it causes the modal combination rules to over‐represent the contribution of the higher modes of vibration to the total response and under‐represent the contribution of the lower modes. Consequently, a response‐spectrum‐based analysis can yield a biased estimate for the peak value of a response quantity when two or more well‐separated modal frequencies make significant contributions to the total response. To correct this potential bias in response‐spectrum‐based estimates, we develop a procedure for estimating the peak factors that is suitable to the response spectrum analysis calculations commonly used in the current design practice. Examples are presented to demonstrate the proper use and potential impact of the proposed procedure. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
320.
Marion Glaser Wasistini Baitoningsih Sebastian C.A. Ferse Muhammad Neil Rio Deswandi 《Marine Policy》2010
A review of a major community-based marine protected area programme (CB-MPA) in an Indonesian island archipelago is the point of departure for this article. Despite a well-designed institutional structure to facilitate local participation, local knowledge about the CB-MPA is found to be low and resource access and influence on decision-making in the programme is negligible for the majority of islanders. At the same time, most of those who know about the programme consider it as pertaining to the public authority only. These findings stand in contrast to evidence on non-formal ways of protecting and managing marine areas in the same geographical area but outside the formal MPA institutional framework. In particular, the article identifies a number of emergent rules-in-use in marine management, which operate parallel to legally established MPAs. It is argued that emergent forms of marine area protection such as non-formal self-organising island exclusion zones (IEZ) offer as yet mostly unused potentials for formal MPA development, particularly in those coastal and marine areas without traditional forms of marine and coastal management. 相似文献