Week 7 Assignment #14

Imagery Africa

By opening the Digital Earth Africa Explorer app, I was able to view the geographical map of Africa but with Sentinel-2 satellite imagery that produces multispectral imagery that allowed me to view several wavelength ranges, even ones that are usually visual to me and the human eye. By combining these different ranges or in other words, bands, we can change the imagery. I was first presented with the normal colors red blue and green which are visible to us before rendering the image with color infrared with DRA in which we could highlight vegetation with the combination of both for the composite image.

I think this is interesting because we are able to apply this digital information, something we are unable to usually see now possible with the technology of the modern age to support and develop our knowledge to use to our advantage. Here with this digital map, we are able to highlight certain features. And in this specific example, we highlight vegetation from the coloring of white and red. We see in the red area vegetation where there is rain and forests whereas in the white area there is an absence of vegetation in the Sahara Desert. Another thing with technology was the satellite images themselves, we were not obstructed by any clouds in the sky as the images were a year-by-year summary and issues like that are removed, we have definitely developed our tools in a way to be more beneficial for us and the most accurate way possible.

After taking a closer look at the vegetation in Abidjan and observing the questions:

At a glance, is the region rich in vegetation? What type of climate is it likely to have? And what about the city of Abidjan; does it seem densely built-up? Does it contain vegetation-covered areas?

I was able to see that although vegetation heavily surrounded it, Abidjan was another color other than red and was blue which probably means something other than vegetation but it seemed layered on the red suggesting there is still lots of vegetation in the area. It is surrounded by abundant vegetation as well as next to sources of water, I assume that its climate is suitable for such an environment similar to that of Hawaii or a coastal area. I can also see certain spots of compact red in some areas which suggest it is more vegetation than in other areas. I can only assume that this is a city as history tells that many people settle by the water where vegetation is abundant.

Despite adding a base layer I was unable to see the map over the imagery. I then rendered the image for agriculture with DRA as well as provided information that tells me that the area in blue I saw earlier which is now purple, are urban areas which correlate to my earlier hypothesis.

Can you gain additional or different insights thanks to the new rendering? For instance, it is easier to distinguish between built-up and sandy areas than it was with color infrared. It is also easier to identify small water bodies within the city.

After I was given more information to which color meant what, my insights made my earlier statements make much more sense as I was unable to really know what the blue color meant without a key of some sort. I do reinforce my earlier insight with this information and the new coloration made it easier to differentiate areas of the map to their respective labels such as sandy areas or smaller water bodies.

This type of information is very useful, especially with all the things going on in the world right now, knowing about our environment and using it to better society would be advantageous. For example, you can use this to find potential spots to start farming and maintaining crops.

After changing the base and rendering it back to natural, we are now taking a closer look at Egypt's moisture by rendering the moisture index in which we see that Egypt is quite low on moisture despite being by the water, the Nile has lots of moisture. Upon closer look at where the moisture gathers we see this pocket or otherwise known as an oasis, the El Fayoum. After rendering different types of bands I was able to see vegetation, see specific canals and waterways, and have a better understanding of the environment around the oasis which again is very useful, especially to those who need to use that to their advantage when living in such an area. I can not imagine how hard it is to live in an area where moisture is quite low, having this information can help.

I then moved to the image of Idaso, Nigeria where we looked at an oil refinery over the years through the images taken over time. At different times we can see how it is developed in different time frames. Which I think is amazing, as we are able to view a time-lapse. Although it is different, I see similarities in an app all of us use today with Google Maps, so it is interesting how information can give us information like this and explore things we may not have been able to see or have access to before.

After Nigeria, I moved to Ghana where I was able to monitor water levels over the course of time as well, similar to the exercise earlier. This time we were able to have a side-by-side comparison in which we see water levels shrink. This gives you better details to explore the geography of the area just by sliding the tab which I thought was interesting to see the development. I did not even know that this type of software existed and for such variable purposes.

After that, I learned how to save an image by using the oasis earlier as an example as well as have it as a layer I can use for later which will be very helpful in the upcoming assignments or should I need any information or pictures.

Overall this assignment was a great exploration of Africa and its different features, as it has been a place I have never been but it was where my grandfather had been born and raised so it was interesting to discover things about Africa without leaving my room. Observing such characteristics gathers useful information just with the click of a button or two. I was able to explore other places within the bookmark such as the Maasi Mau Forest which was full of vegetation but did not see any bodies of water in that specific area as vegetation seemed denser or packed together in the middle and because of this there did not seem to be any dwellings or urban areas. Over time I was able to tell that there used to be more vegetation however there seems to be less as time goes on which we can tell by the fading of the green areas for vegetation.

As mentioned in the activity, the possibilities are endless and one can explore Africa from home once you know how to navigate through the system you can easily find out information in moments which I think is very useful whether you currently need the information or not.