AN~2 APPLICATION IN THE METRODS OF POPULATION GEOGRAPHY     

Zhang Shulin 《地理学报(英文版)》1995,(1)

1.PoPulation~aphyisthestudy0fthespatialdistributionmdarrangnatsofhumanpoPulation.ItisthesdenceofhowspatialvariarionsinthecomPosihon,growth,whgraion,anddistribLItionofpoPulatonsaiere1ataltospatialvariationsinthenatureofplaces.ThemethodsplayanimPohanroleinr…  相似文献   

中国塔吉克族人口发展初探     

吐尔.  马 《干旱区地理》1995,18(3):72-78

本文根据全国历来四次人口普查资料，对我国塔吉克族人口形热进行了简要的论述。文中阐述了塔吉克族人口规模的发展、变化以及人口再生产类型，并简述了相关的社会、经济、文化等方面的问题。  相似文献   

四川绵阳官司河流域防护林的演替预测     

阳小成  李旭光  叶志义 《山地学报》1995,(4)

选取６个样地，以“空间代替时间”法研究了官司河流域的松柏栎混交防护林的优势种群动态。结果显示：各种群在群落次生演替过程中普遍更新欠佳，林木大小级结构呈不稳定或衰退状态，据非线性演替理论，并结合防护林现状，预测防护林的可能演替趋势为：今后人为干扰若能保持较长期相对稳定，则针阔叶混交的群落类型亦将保持基本稳定；但随土壤类型的不同，而渐分化成松栋混交林和柏栎混交林．  相似文献   

双等距离投影及其应用   总被引：1，自引：0，他引：1  

李宏利 《测绘学报》1993,22(1):65-73

双等距离投影是指自图上两定点出发至图上任意点间的距离都与实地等长的投影。本文先从球面极坐标出发，讨论了双等距离投影公式的建立，继而给出了在地理坐标下的正轴和斜轴投影计算方法。本文证明了该投影的性质属任意投影，其计算方法是可行的，有实用价值。双等距离投影在测量上可用于圆圆系统定位，在军事上可用于敌情监测等。  相似文献   

川西地区劳动就业研究   总被引：3，自引：0，他引：3  

陈国阶 《地理研究》1993,12(3):89-99

以川西作为研究区域,对农村劳动力转移或非农就业从自然—人文相结合的观点进行了探讨。  相似文献   

辽东山区人口地域分布研究     

高明辛 《山地学报》1993,(3)

本文在分析了辽东山区土地资源特征和人口特征的基础上,从三个角度讨论了辽东山区的人口垂直分布特征,同时还详细分析了人口布局不合理对山区生态环境和经济的影响。并指出,适度移民、并村并点、整合山村及建设农村小集镇是调整山区人口布局,促进山区经济发展和生态环境恢复的有效途径。  相似文献   

Structural Spatial Interaction*     

James Pooler 《The Professional geographer》1993,45(3):297-305

This paper identifies a concept of structural spatial interaction. Although it is defined differently from its counterpart of structural unemployment in economics, it attempts to define a similar idea. In economics, the focus is on equilibrium in the supply and demand of labor. In this paper structural interaction is that which minimizes aggregate distance travelled, subject to constraints on origins and destinations. The structural interaction model produces an equilibrium, therefore, in the supply and demand of movers, while identifying a spatially efficient trip distribution. It is portrayed as a type of relaxed interaction model and is illustrated using an example of structural migration with Canadian interprovincial migration data.  相似文献   

POPULATION DYNAMICS AND PRODUCTION OF NEANTHES JAPONIC A (IZUKA)IN A SHRIMP POND   总被引：1，自引：0，他引：1  

丘建文  吴宝铃 《中国海洋湖沼学报》1993,11(4):360-367

During late February to mid-March, 1991, when mature N. japonica swarmed in the sea surface off Jimo County, Qingdao, seawater containing numerous early embryos was pumped into a nearby 2.7 ha. muddy-sand shrimp pond, where the embryos continued to develop. 800000 Penaeus chinensis seedlings were introduced into the pond on May 30, 1991. Monthly benthic samplings were carried out to determine the population dynamics and production of N. japonica in this atypical environ -ment.The density of N. japonica varied from 0 to 20400 ind./m2. The predation of P. chinensis was considered to be responsible for the mass mortality of N. japonica in June through July, when the worms were 2.2-3.3cm in length and lived in the top 2-4cm sediment. From August to September of 1991, the hottest period in the site, there was no substantial mortality of N. japonica as reported in earlier literature. This was explained by the deeper burrowing of the' worms that protected them from predation by shrimps.Monthly biomass ranged f  相似文献   

冬季北半球10hPa爆发性增温过程的诊断分析   总被引：3，自引：1，他引：3  

王玉佩  李维京 《高原气象》1991,10(2):202-208

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城市人口的遥感估算方法     

邹尚辉 《遥感学报》1991,(3)

常规人口估算方法耗时、费力、财物消耗大且周期长,况且,仅靠少数年份的人口统计资料也是难以准确揭示人口状况的。尽管应用遥感方法估算人口的历史并不长,精度也还不高,但已显示了其优越性。遥感估算人口的主要原理如下。 (1)美国国防卫星及NOAA卫星的热红外通道图像说明,人口分布及其数量与城市耗能量(人工热源)相关,而耗能量又与图像灰度相关;(2)城市人口的膨胀与城市面积的扩展相关;(3)像片上进行住宅计数,用人口普查资料或抽样调查方法确定每户平均人数则可进行人口估算;4)人口密度大小也反映在人工结构物及自然物体的波谱反射率差异上,据此可建立人口数量与反射率的回归方程。  相似文献