Population in Advanced Placement Human Geography

Abstract

The Advanced Placement human geography course affords high school students the opportunity to experience an introductory college-level course in geography. Population is one of six major themes in the course. The course outline identifies four key areas of study in the population unit: geographical analysis of population, population distribution and composition, population growth and decline over time and space, and population movement. This article addresses each of these areas of study and identifies examples of concepts, topics, and types of data that could form the basis for instructional activities. A resource list is provided for additional reading.     

Responses of rural households to the impacts of population and land-use changes along the Eastern Escarpment of Wello,Ethiopia

The article analyses the effects of changes in land cover and land use changes together with population changes on the livelihood of rural households, and also farming households' responses to these changes, in typical rural settings of north-eastern Ethiopia. The study shows that the immediate impact of shrubland and forest increase since the late 1970s, coupled with population increase, is an exponential fall of per capita cropland and grazing land, which are the principal physical assets of livelihoods of the rural farming community in the area. Furthermore, the study reveals that the scarcity of cultivated land in the area neither brings about agricultural intensification nor leads to diversification into non-farm activities, and farmers did not respond to the scarcity of cultivated land through large out-migration. In general, the Boserupian assumption of land-use intensification through improved labour and land productivity did not happen in the region. Rather, the Malthusian thesis seems appropriate. The majority of farming households are destitute, unable to satisfy their own food demands, and live in absolute poverty. This situation has been brought about not only due to population pressure but also as a result of the policies that have been applied in all systems since the 1950s.     

浦东新区老龄人口就医现状空间分析

依据上海市第五次人口普查的资料,采用GIS(地理信息系统)空间分析技术,对浦东新区医院的空间分布进行了研究。仅从距离的角度对看病远的区域进行了划分,求出了这些区域内的老龄人口数;而且对现有医院的床位数和其潜在的老年病人数进行了比较,对比较结果进行了图示化的描述。     

Molecular research on the systematically challenging smoothhound shark genus Mustelus: a synthesis of the past 30 years

The species-rich genus Mustelus (smoothhounds) of the shark family Triakidae is one of the most bio-economically important groups of elasmobranchs in the world’s oceans. Despite the commercial value of Mustelus, the systematics of the group remains largely unresolved and there is no global review or synthesis of knowledge about the conservation status and conservation genetics of smoothhounds across all oceanic regions. Here, we analysed published studies as well as grey literature to gain insight into the biogeographic, ecological and behavioural factors that shape genetic diversity in smoothhounds, and we identify critical knowledge gaps. From a series of molecular phylogenetic studies it can be inferred that the genus Mustelus is paraphyletic and that the aplacental species evolved secondarily from the placental species of the genus. The increasing availability of genetic data aids in disentangling systematic issues, such that more meaningful morphological characters can be chosen for use in practical field-identification keys for co-occurring smoothhounds. An integrative taxonomic approach to the genus Mustelus may offer the best chance of recording and protecting the biodiversity of these sharks. Furthermore, it is evident that different smoothhound species exhibit unique gene-flow patterns, suggesting varying rates within species and hence that species-level conservation approaches would be most appropriate. Molecular studies have advanced our understanding of smoothhound biology (including reproductive traits), ecology and evolution. While many knowledge gaps remain, a crucial lesson from this review is that, when doing assessments on a molecular level, it is important to place genetic results in a broader context, by assimilating biological and ecological data, if definitive conclusions are to be drawn.     

利用终端位置时空转移概率预测通讯基站服务用户规模

基站服务用户数的预测对通信基站的空间位置选取、通讯服务带宽的配置优化等有重要作用,并为城市公共安全管理方面中的人群聚集预警与群体事件预防提供辅助决策支持。本文利用海量手机轨迹数据,运用时空转移概率定量化描述城市内不同区域间人群流动的时空特性,结合马尔可夫链和贝叶斯定理,构建手机用户群体在基站间的时空转移概率模型,并以此提出一种城市区域尺度上的基站服务用户数预测方法。利用湖北省某城市长达30 d的手机轨迹数据进行模型训练与预测方法验证,实验结果表明：在时间粒度为60 min时,本文提出的方法对8-22时各时段基站服务用户数预测准确率都大于94.8%;在不同时间粒度下对比本文方法、Castro模型、移动平均法,发现在时间粒度大于20 min时,本文方法预测准确率高于另外两种方法。     

南极帝企鹅种群栖息地动态变化遥感分析

帝企鹅是南极生态的指示器,其种群栖息地分布变化对研究南极气候具有重要意义,但传统的人工实地调查难以获取全面、准确的种群栖息地信息。本文依据帝企鹅种群排泄物在卫星影像上的蓝、红波段和近红外与短波红外波段的反射率差异,提出2种可以有效判别种群排泄物的光谱指数（NDII、EI）,据此精确识别帝企鹅种群排泄物并确定其种群栖息地位置。根据2009年195景时相合适、质量较好的Landsat 7 ETM+卫星影像,获取了南极共计38个帝企鹅种群栖息地,其中新发现7处（Bowman Island , Dibble Glacier , Auster, Point Geologie , Cape Crozier , Brownson Islands和Rupert Coast）,消失2处（Amundsen Bay 和Ledda Bay）,另外25处（除Thuston Glacier, Luitpold, Sanae, Gould, Ragnhild和Beaufort Island外）位置未发生明显变化,实现了全南极帝企鹅种群栖息地的识别与定位。种群栖息地提取的正确率为94%,提取结果受限于影像质量和种群规模,且随着种群规模的提高,该方法的提取效果也越好。帝企鹅种群栖息地的分布与气候要素息息相关,种群栖息地往往倾向于气温较低和海冰密集度较高的区域,气候变化对每个种群栖息地的影响不同,因此气候与种群栖息地变化的具体关系需要长时间、区域性的观测进行研究。随着气温持续上升和海冰密集度的变化,南纬70°以北的种群栖息地面临较大的威胁,帝企鹅种群呈现向极点逐渐收缩的趋势。     

云南地区地震受灾人口与经济损失评估

地震灾害损失评估标准实施以来,云南地区共发生过46次破坏性地震。以46次破坏性地震的灾害损失评估资料为基础,分析了受灾人口与地震灾害经济损失的相关性,结果为两者呈非线性关系。提出利用受灾人口数据进行地震灾害损失快速预估的简便方法,并应用所提的方法对2001年云南地区7组地震的灾害损失进行了分析研究。     

湖北省随州城市化进程中人口变动及其对土地利用的影响

采用GIS技术及多种统计分析方法,对湖北省随州市城市化进程中人口变动状况及其对土地利用方式的影响进行了整体分析,初步揭示了城市化的综合发展状态及其所包含的人口及土地两个方面的变化特征,并明确了人口变化的主导作用。分析表明,随州城市化处于中期发展阶段并呈现与工业化同步的发展状态,在此前提下城镇人口迅速增长,空间分布向中心市区集中,但农业就业比重偏高,同时土地利用方式发生相应的变化。     

Preliminary studies onIndomysis annandalei (Mysidacea,crustacea) from Karachi waters with a brief account of its larval development

Population, seasonal abundance of the mysidIndomysis annandalei Tattersal (1914) from Karachi waters (northern Arabian Sea) are studied. Occurrence of breeding females is noted and developmental stages are described.     

COMMENT ON “WHO WILL FEED CHINA”

I.MR.BROWN'SMAINOPINIONMr.LesterBrown,'presidentoftheWorldWatchinstituteintheU.S.A,publishedalongicicletitledas"WhowillfeedChina"in1994(Brown,1995),whicharousedgreatresponSeSfromhomeandabroadandattractedmuchattentionfromallsides.Theadnideasofthearticleincludethefollowingthreepoints:(1)ItisestimatedthatthepopulationofChinawillincrare490whitionfrom1990tO2030,uptol,600whition;thecultivatedlandofChinaisaffectedbythemedeAnzationoftheeconomy,andisevendisap~ng;inaddition,thepotentiality…