Browsing by Subject "Geographic information systems"

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    Open Access
    Geographic Information Systems for electrification: scoping study
    (1998) Trollip, Hilton
    Because this is a short scoping study with only 15 days allocated to its production the initial discussions with the most important stakeholders and the round 1 of interviews were used to provide a tight focus for the project. The main area that has been chosen as the focus is institutional issues relevant to GIS for electrification as follows: 1. Access to data for GIS 2. Data maintenance 3. Financial and intellectual property aspects related to the above three issues. 4. In addition to these institutional issues the project will attempt to give an indication of the extent of agreement on data content in two ways. Firstly, a list of the most basic data required over the first phase of use of GIS for electrification policy and implementation. Secondly, a list of data required in the subsequent phase which may require more detailed data.
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    Open Access
    Optimising regionalisation techniques: identifying centres of endemism in the extraordinarily endemic-rich Cape Floristic Region
    (Public Library of Science, 2015) Bradshaw, Peter L; Colville, Jonathan F; Linder, H Peter
    We used a very large dataset (>40% of all species) from the endemic-rich Cape Floristic Region (CFR) to explore the impact of different weighting techniques, coefficients to calculate similarity among the cells, and clustering approaches on biogeographical regionalisation. The results were used to revise the biogeographical subdivision of the CFR. We show that weighted data (down-weighting widespread species), similarity calculated using Kulczinsky's second measure, and clustering using UPGMA resulted in the optimal classification. This maximized the number of endemic species, the number of centres recognized, and operational geographic units assigned to centres of endemism (CoEs). We developed a dendrogram branch order cut-off (BOC) method to locate the optimal cut-off points on the dendrogram to define candidate clusters. Kulczinsky's second measure dendrograms were combined using consensus, identifying areas of conflict which could be due to biotic element overlap or transitional areas. Post-clustering GIS manipulation substantially enhanced the endemic composition and geographic size of candidate CoEs. Although there was broad spatial congruence with previous phytogeographic studies, our techniques allowed for the recovery of additional phytogeographic detail not previously described for the CFR.