Project

Download data for Cachuma Reservoir

It includes:

  • a DEM from summer of 2018 (as tiles)
  • Sentinel-2 image from July, 2018
  • Sentinel-2 image from February, 2024

Task

Find the following:

  • The approximate surface area of the lake in summer, 2018
  • The approximate elevation of the lake surface in summer, 2018
  • The approximate surface area of the lake in February, 2024
  • The approximate elevation of the lake surface in February, 2024
  • The approximate change in volume of water stored in the reservoir between 2018 and 2024. (See this painfully slow video or this webpage for tips.)
  • The change in NDVI between 2018 and 2024 in the four plots (vectors/plots.geojson)

Deliverables

1) Description of methods
Write a short document describing the methods you used to solve the problem. Here is an example faux-document It should contain:

  • Methods: Write a clear explanation of what you did, and why. Document the steps you took, use figures where needed.
  • A table of important layers created in your workflow. (These layers should be cross referenced in your methods.)
  • Results: Tell me your estimate for the volume of water, how confident you are in your answer, and what the major sources of error are.

2) GIS Poject Files
A zip file of your project directory.

3) A pdf map of the project area
Should include scale, legend, and North arrow.

How the Project will be graded

Recall from the syllabus that the Project is worth 20% of the grade. The final exam, which is about the project, is worth another 20%.

The project grade will be based on:

  • Explanation of the methods, methods are applicable to the problem (25%)
  • Reasonable estimates of the values (25%)
  • The project opens and contains all of the layers you describe in you methods (25%)
  • Your map has all of the required elements, and looks ok (25%)

The final exam grade will be based on:

  • You can explain your methods, and answer questions about them.

Hints

  • You will need to mosaic the raster tiles or build a vrt
  • For a sanity check on your volume estimation, the total capacity of the reservoir is currently estimated as 232,000,000 \(m^{3}\) New hints as of 2026-05-18
  • There are several ways to figure out the elevation of the surface after finding it. None of them (that I can think of) involve zonal statistics.
  • The lake surface area in 2018 can be found from the Sentinel 2 imagery, or from the DEM.