Final ProjectIdentifying Priority ConservationAreas in Centre County |
| This lesson used input data layers including a study site polygons, habitat potential polygons, road line themes, and an external database containing species richness data to determine which areas had environmental characteristics suitable for possible reserve sites. You will note that I intersected the study sites with the high potential habitat theme before unioning with buffer road areas. I did this because I felt that if high densities of road area were within low potential habitat areas, this should not eliminate the portions within high potential habitat areas. |
After joining an external data table to the study sites theme, a new field is added to it to contain the result of a calculation adding the number of mammal and bird species. This field is queried and the sites containing greater than 75 species become a new theme. The next step is to intersect these species rich sites with areas deemed to have high potential habitats.
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The species rich sites, high potential habitats are not considered to be viable reserve sites if more than 10% of there area is occupied by roads buffered by type. To reduce the time required to calculate buffers, the first step is to select only those roads which cross the sites. A buffer width is assigned based on the road type, and a buffer theme is created. Before unioning the buffers with the sites, the area of the sites needs to be calculated and stored in a new field.
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The image to the right is a close-up of a sites after the union with the road buffers. The yellow area represents non-road areas of the sites. The new area of these sites is calculated and stored in the AreaSMNR column below. Using these areas and the original areas calculated above, the PercentRD field is calculated. A query is performed to create a new theme of areas with less than 10% buffered road area. These are the final candidate reserve sites.
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This map shows the candidate reserve sites overlaid onto a theme showing public and private land ownership.
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This map shows the candidate reserve sites classified into three categories of species richness overlaid onto an elevation grid of the county. The good news for Centre County is that two of the dark green "Very High" species richness candidate reserve sites are mostly within areas that are publicly owned.
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