Esther Githae is a final-year Geospatial Engineering student at the University of Nairobi, with a passion for applying mapping science to real-world challenges. Growing up in Ongata Rongai, she witnessed first-hand how fast the area transformed from open spaces to dense urban development. That experience, coupled with her love for geography and math, inspired her to study urban expansion using Earth Observation tools. Using Digital Earth Africa’s Sandbox, she tracked the growth of built-up areas in Kajiado North from 2014 to 2024, turning personal curiosity into mapped evidence. In this spotlight, she reflects on the process, the tools she used, and how EO can shape sustainable development in Kenya.
Tell us a bit about yourself. What’s your academic background, and what sparked your interest in Earth Observation or the field you’re currently in?
My name is Esther Githae, a passionate final-year student in the applications of geographic information to study and address real-world challenges. What sparked an interest in my current field was my high school studies, where my favourite subjects were geography and mathematics, which are the major constituents of mapping sciences. This instilled the urge to pursue something that would enhance a deeper understanding of the role of these two subjects simultaneously in real-world situations. Beyond my career endeavours, I am also passionate about graphic design and using its creativity to tell visual stories. I also find solace in capturing moments as a way to document my life.
What are you currently studying or researching, and at which institution?
I am currently studying Geospatial Engineering at the University of Nairobi.
What inspired the project you’ve been working on using Digital Earth Africa tools? How did the idea come about?
My project was inspired by the rapid growth of a major satellite town in Kajiado North called Ongata Rongai. As a resident of the area over the past years, I have seen places that used to be covered by bush transform into built-up areas. Another great inspiration was my father. Having resided there for over 20 years, he still wonders how vast parcels of land where they’d play football or cut across have now been occupied by residential buildings. From that, I felt the need to pursue this project to visualize these changes from Earth observation data using a platform I was familiar with and confident in.
What was the main goal of your project, and what were you hoping to investigate, understand, or solve?
My main goal was to assess urban expansion in Kajiado North Constituency from 2014 - 2024. The focus was to determine the extent of the built-up environment in comparison with other land uses, monitor its growth over the years, and account for these changes.
Which specific DE Africa datasets or Notebooks did you use in your analysis?
I used Landsat8 Surface Reflectance data and the Urban Change Detection notebook for reference.
Were there particular tools or data features that helped you gain insights or reach your goals?
Digital Earth Africa acted as an all-in-one platform for me, a major advantage that I really enjoyed. The access to pre-processed satellite data, analysis capabilities, and visualization, all made possible by the Python-based sandbox environment, was what helped me achieve my objectives. The built-in tools, such as the Enhanced Normalized Difference Impervious Surface Index, allowed for the extraction of the built-up extent, which was a major highlight of my project.
Were you able to achieve the outcomes you had hoped for?
Yes. I was able to map the LULC and extract the built-up extent over the epochs 2014, 2019, and 2024 for the constituency. The results depicted a growth of the urban extent properly visualized by the comparison bar graphs generated.
What impact do you hope your research will have, either academically or in real-world applications?
I hope that my research contributes to the decision-making by urban planners and policymakers of Kajiado North Constituency regarding future infrastructure and development projects, as well as environmental sustainability in the constituency.
What was one challenge you faced while using EO data, and how did you work through it?
A challenge I faced while using EO data was the availability of high-resolution satellite data for the years 2014 - 2016. As I planned on pursuing this project, I intended to use Sentinel 2 data due to its high resolution. However, due to its unavailability for the said years, I opted for Landsat 8 imagery to achieve consistent results over all the epochs.
What are your future plans? How do you see Earth Observation or DE Africa playing a role in your career or research journey?
I plan to continue working towards my geospatial engineering career and pursue further studies, particularly in earth observation data analysis. As a Digital Earth Africa user, I hope to contribute to the success of Digital Earth Africa by applying its tools for sustainable development, impactful research, and collaboration.