Category Archives: #Throwback Thursday

Way back when before the Saylorville Dam – #Throwback Thursday

By #Throwback Thursday, Education, Environmental Change, Imagery, Landsat Golden Jubilee, Observation, Outreach, , , , , , , , , , ,

It’s another Throwback Thursday. Saylorville Lake and Dam are located in Central Iowa northwest of Des Moines, Iowa. The Saylorville complex was built to help with flood control and as a drinking water source for surrounding communities. At normal levels, the Saylorville reservoir stores 21.1 billion gallons of water with capacity at flood levels to hold 204.1 billion gallons of water.

Landsat 1 – 1976
Landsat 3 – 1980

Below are several resources if you are interested to learn more about this important structure north of Des Moines:

This year we are celebrating 50 years of the Landsat earth observing satellite mission. Landsat data helps us observe changes in our communities and environment over time.

Traveling Way Back – Landsat Images From Aprils Gone By

By #Throwback Thursday, Education, Environmental Change, Imagery, Landsat, Landsat Golden Jubilee, Observation, Phenology, Remote Sensing, Resource, , , , , , , , , , , , , ,

Welcome to another Throwback Thursday. Today we are going back into the archives to compare imagery from the first five Landsat satellites (all images are featured in natural color). Click on each image for a closer view.

  • Try to notice the differences in resolution and image quality between the different years.
  • Another thing to note is the wide seasonal variation between the images. All the images were from the same three week period in April. Some images are have snow while other years are very green.
  • Observe that the Des Moines River is swollen in the Landsat 4 -1983 image.
Landsat 1 – April 5, 1976
Landsat 2 – April 3, 1975

Landsat 3 – April 21, 1980
Landsat 4 – April 15, 1983
Landsat 5 – April 12, 1985

You can explore the raw images using this web app: https://arcg.is/0XrG4f. Happy exploring.

This year we are celebrating 50 years of the Landsat earth observing satellite mission. Landsat data helps us observe changes in our communities and environment over time.

Thanks for stopping by and keep observing the world around you!

#Landsat Throwback Thursday – 50 years of Growth in Dubai

By #Throwback Thursday, Education, Imagery, Landsat, Landsat Golden Jubilee, Remote Sensing, , , , , , , ,
1973 – Landsat 1
2002 – Landsat 5
2013 – Landsat 8
2022 – Landsat 9

Over the last 50 years, the city of Dubai, in the United Arab Emirates, has transformed from a small fishing and pearl diving village into a luxurious, modern metropolis. The population has grown from just over 100,000 residents in 1972 to an estimated 2.9 million residents in 2022. While the beauty and distinction of this city is undeniable, some question the sustainability of this fast-growing city located in a land of desert and salt water. The images are shown in false color infrared.  Areas appearing red show healthy vegetation. Notice the dramatic change from first image in 1973 (very little vegetation and urbanization) to 2022 with many areas of red far from the water. 

To create these images, individual bands were downloaded from the United States Geological Survey’s Earth Explorer Website (https://earthexplorer.usgs.gov/) in April 2022. The composite false color infrared images were created in ArcGIS Pro using the composite imagery processing tool.

This year we are celebrating 50 years of the Landsat earth observing satellite mission. Landsat data helps us observe changes in our communities and environment over time.