土地生态经济适宜性评价模型研究   总被引：4，自引：0，他引：4  

俞艳  何建华  袁艳斌 《武汉大学学报(信息科学版)》2008,33(3):273-276

从土地生态经济系统的角度,将土地适宜性评价看作是物种的最适生态位与评价单元所提供的现实生态位之间的匹配,从区域、评价单元以及单元之间关系3个层次构建评价指标体系,并引入模糊贴近度分析方法构建土地生态经济适宜性评价模型.以武汉市黄陂区为实例验证了模型的合理性.  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   

中国县域尺度生态保护的地域分异及其适宜性     

黄麟  郑瑜晗  肖桐 《地理学报》2017,72(7):1305-1315

鉴于中国对生态保护的投入与奖惩皆以县域为基本单元,需要开展县域尺度生态保护效果的监测评估,以期为县域生态环境质量考核提供科学依据。本文定量分析了近15年县域尺度优良生态系统面积及植被覆盖度变化,及其与生态保护项目数量的关系,进而评估生态保护措施在县域生态变化中的效果,并评价工程措施的地域适宜性。结果表明：① 中国东北地区、南方亚热带区、青藏高原东南部的县域优良生态系统面积占比多高于50%,西北地区、西南喀斯特区、华北平原等县域优良生态系统占比多低于20%。② 近几十年,生态保护重点是生态脆弱区,青海三江源、藏东南、川西、祁连山、新疆南部等西部地区的县域生态保护项目数量多大于5个,东部沿海地区则少于或等于1个。③ 2000-2015年,中国53%县域的优良生态系统面积占比提高,黄土高原、黄淮海平原、京津冀、川黔渝、两广等地区的县域植被覆盖度明显上升,而新疆北部、西藏中部、内蒙古中东部等干旱半干旱区、长三角等区域植被覆盖度下降。④ 生态保护项目数量与优良生态系统、植被覆盖度变化等反映生态状况改善的指标并未呈现正相关关系,生态保护应遵循优良生态系统分布格局,气候变化背景下造林等工程措施应遵循自然规律与地带性差异。  相似文献   

几种蒸散计算方法在怀来地区的适用性研究   总被引：3，自引：0，他引：3  

王晓晨  朱忠礼  季辰  施生锦 《气象》2016,42(11):1395-1401

作物蒸散量即为植株蒸腾与棵间蒸发之和,准确地测定作物实际蒸散量,对研究农作物节水种植技术、加强水资源管理和制定合理的灌溉计划具有十分重要的意义。文章应用2013年生长季(5-10月)自动称重式蒸渗仪实测河北怀来地区夏玉米的蒸散量,从月、日两个时间尺度评价Penman-Monteith(FAO P-M)、Hargreaves、Priestley-Taylor三种基于参考作物蒸散量计算实际蒸散的方法在怀来地区的适用性,结果表明:(1)三种方法计算的夏玉米月、日实际蒸散相对于蒸渗仪实测结果均存在一定偏差,FAO P-M方法与Hargreaves方法表现较好,准确度相差不大,Priestley-Taylor方法准确性最差;(2)影响实际蒸散计算结果的主要气象因子为太阳净辐射和温度,Hargreaves方法计算结果在怀来地区可信度较高;(3)Hargreaves方法所需参数较少,在计算量方面占有很大的优势,在怀来地区适用性最好。  相似文献   

城市修建主题公园适宜性评价指标体系研究   总被引：3，自引：1，他引：2  

闫闪闪  梁留科  余汝艺  王伟 《地理科学》2016,36(2):213-221

以国内外城市修建主题公园适宜性研究的已有成果和产业实践为基础,预选出城市修建主题公园适宜性的55个影响因素,运用德尔菲法、自相关分析法、变差系数法对55个因素进行3轮筛选,构建了包含16个因素的评价指标体系,运用AHP和熵权法对指标确权,并对全国33个主要大中城市建设主题公园的适宜性开展实证研究。结果表明：① 本研究所构建的指标体系仅用28%的指标反映了96%的原始信息,指标体系更简明科学、便于操作;② 二级指标中的人口因素影响作用显著,三级指标中的城市常住人口、GDP、旅游总人数、地价水平以及周边城市常住人口是影响主题公园在城市选址的关键因素。③ 四大直辖市叠加四大一线城市修建主题公园适宜性最高,海口、银川、西宁等16个城市修建主题公园适宜性指数最低,城市修建主题公园适宜性指数与已有研究成果中的国内城市群发育指数基本一致;④ 实证研究结论与中国主题公园的实际分布情况相吻合,表明指标体系的科学性及可行性,可用以指导主题公园的在全国城市的选址。  相似文献   

Spatial inequality of foreign direct investment in China: Institutional change,agglomeration economies,and market access     

《Applied geography (Sevenoaks, England)》2016

The spatial inequality of foreign direct investment (FDI) can intensify uneven economic development. As globalization and economic transition proceeds, foreign investors are changing their behaviors in FDI location, based on institutional change and agglomeration effects. In order to reduce the inequality, this research employs spatial statistics and analyses to examine the change in the spatial inequality of FDI among regions and among prefectural cities, and uses regression models and spatial regime analyses to investigate factors influencing the inequality from 1990 to 2010. The spatial diffusion of FDI clusters from the eastern/coastal region to the interior shows the trend of FDI convergence among regions. However, increasing numbers of FDI clusters and hot spots show the increasing divergence among cities within three regions. Agglomeration effects have replaced institutional factors to become one of the most significant factors influencing the FDI inequality among cities. Additionally, special economic zones, coastal open cities, provincial capital cities, and development zones lost their advantages in FDI as more reforms set in. The spatial regime analyses further indicate the significance of market size in FDI in prefecture-level cities and the significance of agglomeration economies in FDI in capitals and municipalities.  相似文献   

The effect of sub-alpine landslides on headwater stream gradient and beaver habitat     

Kelsey A. Krueger 《自然地理学》2016,37(5):344-360

During previous work in the San Juan Mountains of Colorado, we observed that headwater (first-order) streams draining landslides were often characterized by the presence of beaver (Castor canadensis) dams whereas other headwater tributaries typically lacked evidence of beaver. Here, we hypothesize that hummocky landslide topography attracts beaver. To test the hypothesis, we examined 10 landslides and 11 adjacent headwater streams in the area, noting location, vegetation, elevation, and evidence of beaver activity, and then compared the landslide and non-landslide headwater streams using the G-test to determine whether or not variables were independent of one another. We reject the null hypothesis that beaver dam presence is unrelated to landslide deposits (p = 0.003). We further hypothesize that this relationship results from differences in stream gradient and concavity between landslide streams and other streams. We found streams on landslides to have a greater portion of their gradients below what geologic and ecologic literature suggests is a reasonable upper threshold (12%) for beaver dam maintenance. Additionally, streams on landslides are more concave. We conclude that the relationship between beaver presence and landslides results from a higher proportion of reaches below the 12% threshold and increased concavity of headwater streams on landslides.  相似文献   

Long‐term presence and habitat use of Cuvier's beaked whale (Ziphius cavirostris) in the Central Tyrrhenian Sea          下载免费PDF全文

Antonella Arcangeli  Ilaria Campana  Luca Marini  Colin D. MacLeod 《Marine Ecology》2016,37(2):269-282

Cuvier's beaked whale (Ziphius cavirostris, G. Cuvier 1823) is a poorly known species and many international agreements have asked for a better understanding of its biology for conservation purposes. In the present study, systematic cetacean surveys were carried out from ferries along a trans‐regional fixed transect in the Central Tyrrhenian Sea (Civitavecchia, Latium – Golfo Aranci, Sardinia), just outside the southeastern border of the Pelagos Sanctuary. This research provided long‐term, consistent data on Cuvier's beaked whale during two research periods (1990–1992 and 2007–2011). The objective of the research was to compare the presence, distribution and habitat use of Cuvier's beaked whale between the two investigated periods. Summer data (June–September) from the two periods were compared in terms of frequency of sightings, group size and spatial distribution related to the main ecogeographical features. A presence‐absence model (generalized additive modelling) was performed to predict habitat suitability in the two study periods. The results highlight long‐term site fidelity of Cuvier's beaked whale in the Central Tyrrhenian Sea with encounter rates comparable to the ones reported for other key areas. Separate suitability models based on 1990s and 2000s data appeared to work for each individual time period but differences were evident between the two periods, indicating changes in habitat selection over time. Our findings of the study appear to expand the definition of suitable beaked whale habitat and underline how the temporal scale of the analysis can affect the results in habitat studies. Moreover, this research highlights the importance of the Central Tyrrhenian Sea marine region for Cuvier's beaked whale and the ability of continuous monitoring to identify changes in cetacean frequency and distribution, necessary for adaptive conservation management approaches.  相似文献   

基于表层及温跃层环境变量的南太平洋长鳍金枪鱼栖息地适应性指数模型比较   总被引：2，自引：0，他引：2  

郭刚刚  张胜茂  樊伟  张衡  杨胜龙 《海洋学报》2016,38(10):44-51

为了量化比较海表层环境及温跃层环境对南太平洋长鳍金枪鱼渔场分布的影响程度;本研究采用2010-2012年南太平洋长鳍金枪鱼延绳钓渔船实际生产统计数据;结合卫星遥感所获取的海表面温度（sea surface temperature;SST）和海表面高度（sea surface height;SSH）数据以及Argo浮标所获取的温跃层上、下界水温和深度数据;运用外包络法分别构建了基于海表层环境变量、温跃层上界环境变量以及温跃层下界环境变量的3种栖息地适应性指数（habitat suitability index;HSI）模型。模型验证结果显示;基于海表层环境变量的HSI模型;HSI>0.6时所占产量比重为70.04%;投钩数量比重为70.86%;HSI>0.8时所占产量比重为24.92%;投钩数量比重为25.79%;基于温跃层上界环境变量的HSI模型;HSI>0.6时所占产量比重为82.17%;投钩数量比重为80.95%;HSI>0.8时所占产量比重为33.24%;投钩数量比重为32.69%;基于温跃层下界环境变量的HSI模型;HSI>0.6时所占产量比重为81.01%;投钩数量比重为81.54%;HSI>0.8时所占产量比重为43.51%;投钩数量比重为43.73%。研究发现;基于温跃层上界和下界环境变量的两个HSI模型预报精度明显高于基于表层环境变量的HSI模型;且基于温跃层下界环境变量的HSI模型预报精度高于基于温跃层上界环境变量的HSI模型。研究结果表明;相较于海表层环境;温跃层环境;尤其是温跃层下界环境特征对南太平洋长鳍金枪鱼资源分布的影响更为显著。  相似文献   

基于GIS的石漠化区域光伏项目建设适宜容量估算 —以镇宁县、紫云县及关岭县为例          下载免费PDF全文

段莹  廖留峰  杨娟  詹沛刚 《中低纬山地气象》2021,45(6):26-30

该文利用卫星遥感技术,采用30米DEM及16米GF1号卫星遥感数据,选取安顺市镇宁县、紫云县及关岭县区域内坡度、坡向及石漠化情况进行卫星遥感反演。结合气象站点日照资料,运用ArcGIS软件对三个县石漠化区域光伏利用潜力分布进行空间分析,计算光伏项目建设适宜容量,得到光伏电站建设的空间适宜性分布。通过研究表明,关岭县适宜建设面积为149.6km2,占总面积42.3%,镇宁为85km2,占24%,紫云占33.7%,适宜建设面积为119.1km2;三个县总适宜装机容量达3315.9万千瓦,其中关岭为1402.5万千瓦,镇宁为796.9万千瓦,紫云为1116.6万千瓦。精细化提取石漠化区光伏建设适宜区域并定量估算装机容量,能够为该区域进行太阳能资源开发提供科学依据  相似文献