Mapping road network communities for guiding disease surveillance and control strategies

Human mobility is increasing in its volume, speed and reach, leading to the movement and introduction of pathogens through infected travelers. An understanding of how areas are connected, the strength of these connections and how this translates into disease spread is valuable for planning surveillance and designing control and elimination strategies. While analyses have been undertaken to identify and map connectivity in global air, shipping and migration networks, such analyses have yet to be undertaken on the road networks that carry the vast majority of travellers in low and middle income settings. Here we present methods for identifying road connectivity communities, as well as mapping bridge areas between communities and key linkage routes. We apply these to Africa, and show how many highly-connected communities straddle national borders and when integrating malaria prevalence and population data as an example, the communities change, highlighting regions most strongly connected to areas of high burden. The approaches and results presented provide a flexible tool for supporting the design of disease surveillance and control strategies through mapping areas of high connectivity that form coherent units of intervention and key link routes between communities for targeting surveillance.Comment: 11 pages, 5 figures, research pape

A Supervised Approach to Delineate Built-Up Areas for Monitoring and Analysis of Settlements

Monitoring urban growth and measuring urban sprawl is essential for improving urban planning and development. In this paper, we introduce a supervised approach for the delineation of urban areas using commonly available topographic data and commercial GIS software. The method uses a supervised parameter optimization approach along with buffer-based quality measuring method. The approach was developed, tested and evaluated in terms of possible usage in monitoring built-up areas in spatial science at a very fine-grained level. Results show that built-up area boundaries can be delineated automatically with higher quality compared to the settlement boundaries actually used. The approach has been applied to 166 settlement bodies in Germany. The study shows a very efficient way of extracting settlement boundaries from topographic data and maps and contributes to the quantification and monitoring of urban sprawl. Moreover, the findings from this study can potentially guide policy makers and urban planners from other countries

A multi-method approach to delineate and validate migratory corridors

Context: Managers are faced with numerous methods for delineating wildlife movement corridors, and often must make decisions with limited data. Delineated corridors should be robust to different data and models. Objectives: We present a multi-method approach for delineating and validating wildlife corridors using multiple data sources, which can be used conserve landscape connectivity. We used this approach to delineate and validate migration corridors for wildebeest (Connochaetes taurinus) in the Tarangire Ecosystem of northern Tanzania. Methods: We used two types of locational data (distance sampling detections and GPS collar locations), and three modeling methods (negative binomial regression, logistic regression, and Maxent), to generate resource selection functions (RSFs) and define resistance surfaces. We compared two corridor detection algorithms (cost-distance and circuit theory), to delineate corridors. We validated corridors by comparing random and wildebeest locations that fell within corridors, and cross-validated by data type. Results: Both data types produced similar RSFs. Wildebeest consistently selected migration habitat in flatter terrain farther from human settlements. Validation indicated three of the combinations of data type, modeling, and corridor detection algorithms (detection data with Maxent modeling, GPS collar data with logistic regression modeling, and GPS collar data with Maxent modeling, all using cost-distance) far outperformed the other seven. We merged the predictive corridors from these three data-method combinations to reveal habitat with highest probability of use. Conclusions: The use of multiple methods ensures that planning is able to prioritize conservation of migration corridors based on all available information

An Analysis of Landuse/Landcover Change Distribution in Kuje Area Council Federal Capital Territory, Abuja, Nigeria

The aim of this paper is to assess landuse/landcover change distribution in Kuje area council Federal Capital Teritory Abuja Nigeria. To achieve this, the landuse/area coverage of the study area over a period of 35 years was identified. Also determined were the rate, nature and direction of urban growth in the study area. The landuse change and its effects during the time period were also determined. To obtain the necessary data for the study, seven hundred and eighty - three (783) respondents constituting about 0.2% of the total population of Kuje Area Council as projected from the census figures of National Population Commission of 2006 to 2010, questionnaire was also administered to 140 professional Urban Planners, Land Administrators and Ward heads. The secondary data were sourced from Institutions and Governmental Organizations relevant to the study. Onscreen digitization of the study area maps was employed in delineating the built-up area, hill, stream, roads, forest land, fadama land and the arable land from the various data sets for the years. Map overlay operation was performed in order to identify and detect landuse classes over the years. The mean change per year (arithmetic mean) in Km2/year and % / year for the periods was calculated. The rate of development (increase or decrease) was ascertained. The study revealed that between 1975 and 1980, the built-up area expanded from 2.6% (47 Km2) to 4.2% (75 Km2) of the total area. The major road networks expanded from 7.3% (131 Km) to 8.8% (159Km). ‘Fadama’ landcover which is the Hausa word for irrigable land, flood plains and low lying areas decreased from 17.7% (319 Km2) to 16.4% (310 Km2). The research therefore concluded that the present innovations in GIS and Remote Sensing technologies make available potent instruments for detecting and mapping of transformations in landuse/land cover.Keywords: Fadama Land, Landuse/Landcover, Arable Land, Degradation, Environment,Vegetation

Towards a common standard: comparing European and American cities

This paper assesses to what extent it is possible to construct standardised geographical definitions of cities that will allow American and European cities to be compared in a consistent manner. It reproduces, in citable form and, for scholarly purposes, the report of the same name produced by the author for the Greater London Authority.Keywords: City; global city; Functional Urban Region; Larger Urban Zone; Territorial Indicators; Metropolitan Region; pluralism

EXPLORING THE WALKABILITY CONCEPT IN A POST-SOCIALIST CITY THROUGH GIS ANALYSIS. THE CASE STUDY OF IAȘI, ROMANIA

The walkability concept is widely researched and applied in western societies, being a major benchmark for creating a friendly urban environment by the local authorities. While in these countries the concept has a strong tradition, in Eastern Europe it has not received enough attention yet (neither from researchers nor local stakeholders). The present study aims to explore the possibilities of adapting this concept to the post-socialist city by analyzing the walkability potential in a medium-size city (Iași, Romania). The three main objectives envisaged by this research - delineating Walkability Areas, exploring their internal structure and highlighting patterns in regard to the urban structure of a post-socialist city – are accomplished by using the specific GIS tools and statistical methods. The results reveal a heterogeneous construction of the six walkability areas resulted, shaped by the socialist legacy and market economy transition. A walkability score, computed in order to quantitatively assess these differences among them, represents an effective tool for decision makers as it spots the major dysfunctionalities each of the walkability areas. The emergence of the concept in the post-socialist city favors the construction of a more livable urban environment