快速城市化下的城市土地利用结构信息熵变化及其动因分析——以陕西省商州区为例     

杜学  杨海娟 《地下水》2011,(4):150-152

应用熵值函数模型,对处于快速城市化状态下的商州区的土地利用结构的变化进行了定量分析。结果表明,1999～2005年期间商州区土地利用结构熵呈稳定下降趋势,从1999年的1.216调整为2005年的1.207,均衡度由1999年的0.585减少到2005年的0.581,优势度则在2005年增加到0.419。最后,对这一变...  相似文献   

熵增理论对海洋空间资源"一张图"综合监管平台系统建设的启示          下载免费PDF全文

陈冲  蒋婵娟  徐兵峰  朱永  徐开达  胡申威 《海洋开发与管理》2020,37(9):35-39

近年来，随着海洋管理理念转变和水平提升，海洋空间资源监管业务方向持续优化调整，对全流程精准数据的要求越来越高，各类多源异构数据不断增加，自下而上新的业务需求层出不穷，系统顶层设计有限性和应用需要无限性之间的矛盾日益凸显。为破解此难题，文章首次应用熵增理论，分析系统平台日益臃肿、难以维护的原因，并提出应用开放系统、远离平衡态、涨落、非线性关系等耗散系统的关键点来解决系统平台存在的问题，从理念层面为系统平台优化设计提供参考。  相似文献   

熵权法储层非均质定量评价方法研究——以鄂尔多斯盆地下寺湾长8储层为例          下载免费PDF全文

杨争光  汤军  张云鹏 《江苏地质》2012,36(4):373-378

在相控约束条件下,利用熵权方法,考虑了砂层厚度、有效厚度、砂岩系数、有效厚度系数、分层系数、夹层频数、夹层分布密度、孔隙度、渗透率、渗透率变异系数、突进系数、级差、含油饱和度共13种反映储层非均质性的参数,定量计算储层非均质综合指数。该方法包括确定对象集合、指标因素集合、指标矩阵、归一化指标值、指标权重和计算综合指数等。熵权非均质综合指数算法可将数值有差异的属性参数对非均质指数的贡献进行弱化和强化,即去同存异;熵权非均质综合指数的大小能定量表征储层的非均质性。利用该方法在下寺湾油田柳洛峪区长8储层进行了应用,定量地刻画了储层的平面非均质性,取得了满意的效果。  相似文献   

Analysing urban sprawl and land consumption patterns in major capital cities in the Himalayan region using geoinformatics     

《Applied geography (Sevenoaks, England)》2017

In the present study, spatio-temporal urban sprawl and land consumption patterns were analysed in seven capital cities located in the Himalayan region during 1972, 1991 and 2015 using multi-temporal satellite images. The study exhibits that capital Himalayan cities experienced rapid growth (830.92%) with high population increase (333.45%) during the observation period (1972–2015). The significant urban growth was observed in the cities of western and middle Himalayan region viz., Srinagar (9.36 km²–142.19 km²), Kathmandu (11.38 km²–92.58 km²) and Dehradun (4.1 km²–50.09 km²) in the higher altitudes due to remarkable increase in the population (0.5–1 million persons) during 1972–2015. On the contrary, Itanagar (7.19 km²), Gangtok (7.09 km²), Shimla (3.04 km²) and Thimphu (2.93 km²) observed less urban growth with moderate to low population growth (i.e., 0.05 to 0.15 million persons). The Shannon entropy based study exhibits that the cities viz., Kathmandu, Gangtok and Itanagar observed comparatively more dispersed urban growth during later period (1991–2015) as compared to the previous period (1972–1991) whereas, the remaining cities observed comparatively less dispersed urban growth during later period. The temporal land consumption pattern exhibits low density urban growth in Srinagar, Dehradun and Kathmandu, as observed with decrease in population density and increasing land consumption during 1972–2015 as compared to other cities, wherein urban densification was evident with increase in population density and decrease in land consumption. The cities in central and western Himalayan region observed high urban growth as compared to cities in eastern Himalayan region. The result shows that the capital cities contributes insignificant proportion (0.5%; 314 km²) of urban area in Himalayan region and accommodating large (ca. 4 million) population during 2015. The study indicates unplanned and haphazard growth in all capital Himalayan cities, leading towards urban densification as well as dispersion in the periphery with varied pattern and intensity. The specific trends and patterns of urban and population growth are governed by geographical as well as socio-economic-political factors at local to regional scale. The high population pressure induced higher risk to the urban residents as well as constrained urban growth over higher vulnerable zones. The study necessitates implementation of suitable urban planning methods considering socio-economic and physico-cultural characteristics of the region.  相似文献   

Spatial concentration patterns of South Asian low-skilled immigrants in Oman: A spatial analysis of residential geographies     

《Applied geography (Sevenoaks, England)》2017

Oman is a major recipient of South Asian labor immigrants, and correspondingly, the demographic statistics reveal that the non-Omani populations primarily are constituted of the Asians. This research examines whether the largest immigrant groups (Indian, Bangladesh, Pakistani and Sri Lankan) in Oman form residential clusters according to their work skills (higher and lower skills). The residential geographies of South Asian workers at the subnational administrative boundaries have been investigated in the current study. Empirically, the study employs the use of Location Quotients (LQ) and Entropy Index within the GIS environment to spatially analyze the immigrant residential distributions based on their work skills. Interestingly, the findings of this research confirm the primary influence of geography on the residential patterns of the low-skilled immigrants. Initially, Al-Batnah governorates constituted the main destinations of low-skilled Bangladeshis. Further, the research also highlights significant clusters of Indian and Pakistani high-skilled immigrants in urban residential communities within the Muscat governorate. In addition, the South Asian are found to be a relatively constant stream of immigrants to inhabit the Omani urban areas, with employments in various public and private economic sectors (e.g. educational, health, manufacturing, finance, business etc.). This concentration pattern of low skilled immigrants is attributable to the need to labor shortages of native populations in certain jobs. The research results also indicate that the rural and suburban communities of Al-Batnah coastal plain not only have a greater number of low skilled immigrants but also display equitable distributions of the four South Asian groups in the residential settlements. For policy makers, it is imperative to understand the spatial patterns of low and high-skilled immigrants in Oman, which exert several geographic, economic, social and demographic implications. The significant role of immigration in development necessitates the identification of the predominant destinations for immigrants. It has been observed that the immigrants are crucial to several sectors of Omani urban economy, and urban areas with a large number of immigrants are more likely to grow and expand faster. In addition, the immigrants’ laborers offer potential economic benefits to the host country, which include fostering entrepreneurial activities, small businesses and reducing wages, especially in unskilled jobs. Despite the negative impacts of immigration (e.g. losing national cultural and creating socio-spatial segregation), the diverse and distinctive locational patterns of immigrant groups in Oman contribute crucially to the socioeconomic development and immigration policy. Yet understanding of the spatial dynamics of immigration in structuring the Omani regions and its influences remains very limited. Thus, further research accounting for the different spatial and attribute ancillary data is necessitated.  相似文献   

Entropy of sea wave height field and its annual variation in Northwest Pacific Ocean     

Sun Fu  Guo Peifang 《海洋学报(英文版)》1997,16(3):327-337

ＥｎｔｒｏｐｙｏｆｓｅａｗａｖｅｈｅｉｇｈｔｆｉｅｌｄａｎｄｉｔｓａｎｎｕａｌｖａｒｉａｔｉｏｎｉｎＮｏｒｔｈｗｅｓｔＰａｃｉｆｉｃＯｃｅａｎＳｕｎＦｕａｎｄＧｕｏＰｅｉｆａｎｇ（ＲｅｃｅｉｖｅｄＯｃｔｏｂｅｒ６，１９９５；ａｃｃｅｐｔｅｄＯｃｔｏｂ...  相似文献   

海浪波面的信息熵与海浪的谱宽度参量   总被引：6，自引：0，他引：6  

吴克俭  孙孚 《海洋与湖沼》1996,27(3):251-257

将信息熵（ＩｎｆｏｒｍａｔｉｏｎＥｎｔｒｏｐｙ）引入到浪波面的研究，通过谱的参量化，建立了谱宽度参量Ｐ，Ｒ，ε＾２，ｖ＾２与它们对应的信息熵之间的关系，这些谱宽度参量，皆可引人到波面与波高的分布函数之中，并指出谱宽度参量具有熵的含义，给出了海浪波面熵的一种合理表示。  相似文献   

Low-temperature heat capacities,entropies and high-pressure phase relations of MgSiO<Subscript>3</Subscript> ilmenite and perovskite     

M. Akaogi  H. Kojitani  T. Morita  H. Kawaji  T. Atake 《Physics and Chemistry of Minerals》2008,35(5):287-297

Low-temperature isobaric heat capacities (C _p ) of MgSiO₃ ilmenite and perovskite were measured in the temperature range of 1.9–302.4 K with a thermal relaxation method using the Physical Properties Measurement System. The measured C _p of perovskite was higher than that of ilmenite in the whole temperature range studied. From the measured C _p , standard entropies at 298.15 K of MgSiO₃ ilmenite and perovskite were determined to be 53.7 ± 0.4 and 57.9 ± 0.3 J/mol K, respectively. The positive entropy change (4.2 ± 0.5 J/mol K) of the ilmenite–perovskite transition in MgSiO₃ is compatible with structural change across the transition in which coordination of Mg atoms is changed from sixfold to eightfold. Calculation of the ilmenite–perovskite transition boundary using the measured entropies and published enthalpy data gives an equilibrium transition boundary at about 20–23 GPa at 1,000–2,000 K with a Clapeyron slope of −2.4 ± 0.4 MPa/K at 1,600 K. The calculated boundary is almost consistent within the errors with those determined by high-pressure high-temperature in situ X-ray diffraction experiments.  相似文献   

Application of entropy analysis of in situ droplet-size spectra in evaluation of oil chemical dispersion efficacy     

Li Z  Lee K  King T  Niu H  Boufadel MC  Venosa AD 《Marine pollution bulletin》2011,62(10):2129-2136

In situ droplet-size distributions were measured using a laser in situ scattering and transmissiometry (LISST-100X) particle size analyzer during the evaluation of natural and chemical dispersion efficiency of crude oils under different wave and current conditions. An entropy grouping of the in situ dispersed oil droplet-size spectra has classified the multi-modal droplet-size distributions into different groups based on similar droplet-size spectra characteristics within groups and distinction between groups. A generalized linear logistic regression model was fitted to analyze the effects of a number of factors and their interactions on the grouping of oil droplet-size spectra. The grouped results corresponded to the oil dispersion efficiency at different levels. This new method for droplet-size distribution data analysis can have significant implication in field evaluation of natural and chemical dispersion efficiency of oil.  相似文献   

一种适于震后快速评估的群体易损性分析方法   总被引：1，自引：0，他引：1  

陈健云  毕可为  温瑞智 《震灾防御技术》2009,4(2):174-181

本文提出了一种适用于震后快速评估的群体易损性分析方法,将模糊数学中的熵权法确定权重和相似理论引入到群体易损性分析中,可快速准确地评估出群体建筑物的震害情况。本方法不需要详细调查城市所有房屋的结构力学参数,所采用的影响结构抗震能力的主要因素从房屋普查资料中即可获得,可作为将来震后快速评估系统的重要组成部分。同时,本方法还可以得到群体易损性曲线,可应用于预测城市震害、估计城市的综合抗震能力。本文以城镇中量大、面广的砌体结构为例,详细介绍了该方法的研究过程。最后,用算例证明了本方法的准确性和实用性。  相似文献