ISSS608 2016-17 T3 Assign ZHANG YANRONG Answer

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Page.jpg VAST Challenge 2017 MC3

Background

Data Preparation

Visualization

Answer

Reference

Feedback

 



Question1

Area of Boonsong Lake

The left image is the RGB image of Boonsong Lake. As we can see in the graph, the vertical length of Boonsong Lake is 3,000 feet. After using NDWI as the measure to identify the feature of Water Region, we focus on the coordinates involving Boonsong Lake only, which is shown on the right.

The range of Y coordinate in the filtered graph is from 474 to 504. So the length of 30 pixels (504 minus 474) are 3,000 feet in the real world. Then the length of each pixel is 100 feet (3000 divided by 30) and the area of each pixel in the real world is 10,000 sqaure feet(100 ft × 100 ft). Besides, there are 287 pixels so the area of Boonsong Lake is 2,870,000 sqf which is around 27 hectares.

Question2

Feature Identification

By using derived measurement, we can identify features such as Plant, Lake, Cloud, Path, Farmland and Construction.

Overview

Feature.png

Plant Region

Plant.png

Water Region

Water.png

Soil and Path

Soil.png

Cloud Region

Cloud.png

Farmland

Construction

Construction.png

Question3

Additional Insights

This dash board shows the analysis with each measure by choosing the target measure in the drop-down list on the top-right. Graph on the left is the choropleth map of the satellite image. Line chart on the left shows the two factors deriving the measure and their change by month. Chart on the bottom is the histogram for certain measure.

For example, we choose NDVI as our measure. The higher NDVI value is, the healthier or denser the plant is. And the factor1 is B4 Factor2 is B3 according to the formula of NDVI. From the line chart, there is obvious difference between two factors from June to September.The result would be significant if we use month among them.

  • From the multiple dropdown list, we compare the performance of NDVI on September from 2014 to 2015. There is obvious shift towards left from 2014 to 2015, which means the plant became less denser and the preserve is less healthier for some certain reasons. And it might be the possible cause of the decreasing of the Pipit Birds. It deserves a deeper researach for that.

Because the habitat for Pipit might be grassland rather than tall trees.Certain areas with relatively low NDVI could be the key factors. Although the overall NDVI can be improved, further research is required to focus more on the target areas that can be the habitat of Pipit.