Grandville’s tree canopy is estimated at 25% (Table 11), which is on the lower end of the reference Michigan communities. Impervious surfaces (buildings and roads) make up 41% of the land cover. Grass and low-lying vegetation comprises 29% of the community. The city's border, particularly to the north by the river, have the greatest canopy cover, while the areas along the major neighborhoods, industrial areas, and shopping centers have the greatest amount of impervious surfaces (Figure 7).
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The planting priority levels map (Figure 9) can be used to focus in on the locations in which plantings may deliver the highest impacts in terms of ecosystem benefits and overall benefits to the community. Grandville can use this as a guideline for deciding where future trees can be planted to have the greatest impact on benefits and stormwater runoff. Of the 1,359 plantable acres, 40% of those acres (557 acres) are listed as a planting priority of moderate or above. If only these areas are planted, Grandville’s canopy would increase from 1,232 acres to 1,789 acres, increasing the total canopy cover to 36%.
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By analyzing the spectral characteristics of the tree canopy layer, the Normalized Difference Vegetation Index (NDVI) was used as an indicator to assess vegetation health by analyzing the visible and near infra-red bands. Using remote sensing method, locations of poor vegetation health was quantified and further assessed to determine possible dead or dying trees. Grandville’s 1,232 acres of tree canopy were analyzed for health assessment.
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