Effect of spatial and temporal scales on habitat suitability modeling: A case study of Ommastrephes bartramii in the northwest pacific ocean     

Caixia Gong  Xinjun Chen  Feng Gao  Siquan Tian 《中国海洋大学学报(英文版)》2014,13(6):1043-1053

Temporal and spatial scales play important roles in fishery ecology, and an inappropriate spatio-temporal scale may result in large errors in modeling fish distribution. The objective of this study is to evaluate the roles of spatio-temporal scales in habitat suitability modeling, with the western stock of winter-spring cohort of neon flying squid(Ommastrephes bartramii) in the northwest Pacific Ocean as an example. In this study, the fishery-dependent data from the Chinese Mainland Squid Jigging Technical Group and sea surface temperature(SST) from remote sensing during August to October of 2003–2008 were used. We evaluated the differences in a habitat suitability index model resulting from aggregating data with 36 different spatial scales with a combination of three latitude scales(0.5°, 1° and 2°), four longitude scales(0.5°, 1°, 2° and 4°), and three temporal scales(week, fortnight, and month). The coefficients of variation(CV) of the weekly, biweekly and monthly suitability index(SI) were compared to determine which temporal and spatial scales of SI model are more precise. This study shows that the optimal temporal and spatial scales with the lowest CV are month, and 0.5° latitude and 0.5° longitude for O. bartramii in the northwest Pacific Ocean. This suitability index model developed with an optimal scale can be cost-effective in improving forecasting fishing ground and requires no excessive sampling efforts. We suggest that the uncertainty associated with spatial and temporal scales used in data aggregations needs to be considered in habitat suitability modeling.  相似文献   

Social participation and social capital with equity and efficiency: An approach from central-place theory     

《Applied geography (Sevenoaks, England)》2014

A great deal of attention has been paid to the efficiency of the analysis of sustainable urban and regional growth. This includes social participation and social capital, which require a consideration of equity. In this paper, an approach from central-place theory for sustainable urban and regional growth is examined, taking into consideration relevant variables such as ageing, social interaction and accessibility. A lack of consideration of equity could cause several social exclusion problems, and these problems could develop into spatial consumer exclusion. Solutions for these problems would not only improve equity but also efficiency, and the outcome would addresses the necessity of an alternative spatial formation based on a wider-regional rural central-place system according to given economic, social and spatial configurations.  相似文献   

The measure and characteristics of spatial-temporal evolution of China’s science and technology resource allocation efficiency     

FAN Fei  DU Debin  WANG Xinzhu 《地理学报》2014,24(3):492-508

According to the connotation and structure of science and technology resources and some relevant data of more than 286 cities at prefecture level and above during 2001-2010, using modified method—Data Envelopment Analysis (DEA), science and technology (S&T) resource allocation efficiency of different cities in different periods has been figured out, which, uncovers the distributional difference and change law of S&T resource allocation efficiency from the time-space dimension. Based on that, this paper has analyzed and discussed the spatial distribution pattern and evolution trend of S&T resource allocation efficiency in different cities by virtue of the Exploratory Spatial Data Analysis (ESDA). It turned out that: (1) the average of S&T resource allocation efficiency in cities at prefecture level and above has always stayed at low levels, moreover, with repeated fluctuations between high and low, which shows a decreasing trend year by year. Besides, the gap between the East and the West is widening. (2) The asymmetrical distribution of S&T resource allocation efficiency presents a spatial pattern of successively decreasing from Eastern China, Central China to Western China. The cities whose S&T resource allocation efficiency are at higher level and high level take on a cluster distribution, which fits well with the 23 forming urban agglomerations in China. (3) The coupling degree between S&T resource allocation efficiency and economic environment assumes a certain positive correlation, but not completely the same. The differentiation of S&T resource allocation efficiency is common in regional development, whose existence and evolution are directly or indirectly influenced by and regarded as the reflection of many elements, such as geographical location, the natural endowment and environment of S&T resources and so on. (4) In the perspective of the evolution of spatial structure, S&T resource allocation efficiency of the cities at prefecture level and above shows a notable spatial autocorrelation, which in every period presents a positive correlation. The spatial distribution of S&T resource allocation efficiency in neighboring cities seems to be similar in group, which tends to escalate stepwise. Meanwhile, the whole differentiation of geographical space has a diminishing tendency. (5) Viewed from LISA agglomeration map of S&T resource allocation efficiency in different periods, four agglomeration types have changed differently in spatial location and the range of spatial agglomeration. And the continuity of S&T resource allocation efficiency in geographical space is gradually increasing.  相似文献   

美国空气质量尺度管理与国土空间规划策略分析     

李乐  关小克 《国土资源情报》2014,(10):18-24

空气质量作为人类基本生存权利,一直受到美国各级政府的重视,围绕空气质量管理方面的标准、立法与规划,不同尺度的政府管理层面均着力于系统完善或规划设计.作为分权制国家,美国联邦政府、州政府和县市政府在空气质量控制涉及的标准、法律、政策等方面存在明显的权限差异和分工.本文通过梳理美国联邦政府、加州利福尼亚政府在空气质量管理方面的管理机构和管制策略,并结合洛杉矶县国土空间规划体系的设计,探索美国解决空气质量问题的有效管理尺度和职能分工,以期为我国空气质量改善提供实践和理论方面的参考.  相似文献   

基于工作流的基础地形数据建库及动态更新关键技术研究与实现     

汪洋  唐华  徐佳 《国土资源信息化》2014,(6):24-28

基于南京市国土资源＂一张图＂总体架构,提出了Oralce Spatial 11g＋FME Server的一体化地形数据库建库策略,实现了B/S模式下基于工作流的对任意范围地形的快速更新与智能检查,形成了要素级元数据的管理模式,并在生产中得到实际应用。  相似文献   

An adaptive approach for the segmentation and extraction of planar and linear/cylindrical features from laser scanning data     

《ISPRS Journal of Photogrammetry and Remote Sensing》2014

Laser scanning systems have been established as leading tools for the collection of high density three-dimensional data over physical surfaces. The collected point cloud does not provide semantic information about the characteristics of the scanned surfaces. Therefore, different processing techniques have been developed for the extraction of useful information from this data which could be applied for diverse civil, industrial, and military applications. Planar and linear/cylindrical features are among the most important primitive information to be extracted from laser scanning data, especially those collected in urban areas. This paper introduces a new approach for the identification, parameterization, and segmentation of these features from laser scanning data while considering the internal characteristics of the utilized point cloud – i.e., local point density variation and noise level in the dataset. In the first step of this approach, a Principal Component Analysis of the local neighborhood of individual points is implemented to identify the points that belong to planar and linear/cylindrical features and select their appropriate representation model. For the detected planar features, the segmentation attributes are then computed through an adaptive cylinder neighborhood definition. Two clustering approaches are then introduced to segment and extract individual planar features in the reconstructed parameter domain. For the linear/cylindrical features, their directional and positional parameters are utilized as the segmentation attributes. A sequential clustering technique is proposed to isolate the points which belong to individual linear/cylindrical features through directional and positional attribute subspaces. Experimental results from simulated and real datasets demonstrate the feasibility of the proposed approach for the extraction of planar and linear/cylindrical features from laser scanning data.  相似文献   

An improved geopositioning model of QuickBird high resolution satellite imagery by compensating spatial correlated errors     

《ISPRS Journal of Photogrammetry and Remote Sensing》2014

A lot of studies have been done for correcting the systematic biases of high resolution satellite images (HRSI), which is a fundamental work in the geometric orientation and the geopositioning of HRSI. All the existing bias-corrected models eliminate the biases in the images by expressing the biases as a function of some deterministic parameters (i.e. shift, drift, or affine transformation models), which is indeed effective for most of the commercial high resolution satellite imagery (i.e. IKONOS, GeoEye-1, WorldView-1/2) except for QuickBird. Studies found that QuickBird is the only one that needs more than a simple shift model to absorb the strong residual systematic errors. To further improve the image geopositioning of QuickBird image, in this paper, we introduce space correlated errors (SCEs) and model them as signals in the bias-corrected rational function model (RFM) and estimate the SCEs at the ground control points (GCPs) together with the bias-corrected parameters using least squares collocation. With these estimated SCEs at GCPs, we then predict the SCEs at the unknown points according to their stochastic correlation with SCEs at the GCPs. Finally, we carry out geopositioning for these unknown points after compensating both the biases and the SCEs. The performance of our improved geopositioning model is demonstrated with a stereo pair of QuickBird cross-track images in the Shanghai urban area. The results show that the SCEs exist in HRSI and the presented geopositioning model exhibits a significant improvement, larger than 20% in both latitude and height directions and about 2.8% in longitude direction, in geopositioning accuracy compared to the common used affine transformation model (ATM), which is not taking SCEs into account. The statistical results also show that our improved geopositioning model is superior to the ATM and the second polynomial model (SPM) in both accuracy and reliability for the geopositioning of HRSI.  相似文献   

2016—2018 年夏季渤海浮游生物和大型底栖 动物多样性与优势种的时空变化研究     

沙婧婧  刘欣禹  鲍萌萌  齐衍萍  杜小媛  刘霜  张继民 《海洋通报》2022,(3)

浮游生物和大型底栖动物参与水体营养物循环, 影响着污染物的迁移转化与沉积物的稳定性, 对海洋生态系统的能 流和物流起着至关重要的作用。为系统了解渤海海域浮游生物和大型底栖动物多样性与优势种的时空变化状况, 本研究以生 态监测调查结果为依据, 站位重点布设在渤海海域重要的河口、海湾、海岛周边海域以及渤海中部海域, 同时结合相关历史 资料, 对渤海海域的浮游生物和大型底栖动物的种类组成 、密度 、生物多样性指数 、优势种等的变化趋势进行了分析。从 2016—2018 年浮游植物的细胞密度空间分布可以看出, 细胞密度均值在滦河口-北戴河海域相对较高, 而在锦州湾 、莱州湾 和庙岛群岛海域相对偏低。渤海浮游植物多样性在各调查海域之间相差不大, 但渤海湾海域的浮游植物多样性呈现明显的逐 年下降趋势。浮游动物细胞密度在滦河口-北戴河海域相对偏高, 其余各海域差别不大。2016—2018 年, 浮游动物多样性在 双台子河口 、渤海湾 、黄河口海域明显增加, 大型底栖动物群落物种数在渤海湾 、黄河口 、莱州湾和庙岛群岛均呈减少趋 势, 大型底栖动物多样性在锦州湾 、滦河口-北戴河的水平偏低, 在渤海湾有所下降, 耐污能力较强的多毛类成为目前渤海 近岸海域大型底栖动物最主要的优势类群。通过与历史数据对比可知, 2014—2018 年, 渤海浮游植物及浮游动物的群落种 类数、密度 、多样性指数总体变化不大, 主要优势种基本一致, 但大型底栖动物种类数 、生物量和密度总体上呈减少趋势, 主要优势种类由软体动物转变为环节动物多毛类。本研究丰富了渤海海域浮游生物和大型底栖动物群落的研究, 并为渤海生 态系统的健康评价与生物多样性保护提供了数据支持, 对合理开发海洋生物资源具有一定的指导意义。  相似文献   

Towards a National Atlas of the Netherlands as part of the National Spatial Data Infrastructure     

《The Cartographic journal》2013,50(3):225-231

Abstract

This paper is about different worlds, and how we try to unite them. One of these worlds is the world of National Atlases: collections of complex, high-quality maps presenting a nation to the geographically interested. The second is the world of National Spatial Infrastructures: highly organized, standardized and institutionalized large collections of spatial data and services. In the paper, we describe the two worlds and their fundamental differences and we present the theoretical framework in which these worlds could be united. We introduce a test bed we are using to try out the theoretical framework in a real-life use case. In the architecture of that test bed, we introduce a National Atlas Services layer and describe how we have created an Atlas Map Viewer component, using the Open Web Platform. We conclude by commenting on the results thus far and taking a look into future developments.  相似文献   

Global and local indicators of spatial association between points and polygons: A study of land use change     

《International Journal of Applied Earth Observation and Geoinformation》2013

The existing indicators related to spatial association, especially the K function, can measure only the same dimension of vector data, such as points, lines and polygons, respectively. We develop four new indicators that can analyze and model spatial association for the mixture of different dimensions of vector data, such as lines and points, points and polygons, lines and polygons. The four indicators can measure the spatial association between points and polygons from both global and local perspectives. We also apply the presented methods to investigate the association of temples and villages on land-use change at multiple distance scales in the Guoluo Tibetan Autonomous Prefecture in Qinghai Province, PR China. Global indicators show that temples are positively associated with land-use change at large spatial distances (e.g., >6000 m), while the association between villages and land-use change is insignificant at all distance scales. Thus temples, as religious and cultural centers, have a stronger association with land-use change than the places where people live. However, local indicators show that these associations vary significantly in different sub-areas of the study region. Furthermore, the association of temples with land-use change is also dependent on the specific type of land-use change. The case study demonstrates that the presented indicators are powerful tools for analyzing the spatial association between points and polygons.  相似文献