Google Earth Engine Project: Data Arrangement and Sample Map Preparation

Entering the month of June, that is, the second month into the SoEE program, I decided to work full-time with the organization (WRI) I had applied for. I moved to Bangalore on 6^th June 2019. Before moving there, I discussed with my mentor Raj as to where I should look for a residing place. I decided to move to a PG at BTM Layout, 2^nd phase. I did have issues in adjusting myself there, but that was manageable.

I joined WRI on 6^th June itself. I met my mentor, Raj who introduced me to the other people in his team. The first day I met Samrat and Sahana. Samrat is Director, Urban Water and Sahana is Manager, Sustainable Cities. In the next few days, I got a chance to meet Jaya who is Strategy head, Urban Development. I also got a chance to interact with Akash, who is being hired as a GIS/Remote Sensing Consultant in the team.

Initially, I was assigned to arrange the ground truth data. The data was confidential as it was collected from Namami Gange project. Since it was in excel format, I had to turn it into the earth engine asset. I first filtered the available data based on the Sentinel-2 satellite passing time in the excel sheet itself. Then, I converted that into a shapefile using the ArcGIS platform. The shapefile was later imported as the earth engine asset in the GEE platform.

The data had a temporal resolution from January 2017 to September 2018. I bifurcated the data in two temporal stretches, that is, 2017 and 2018. This was done just to simplify the amount of data to be handled on earth engine initially. Later it is proposed to be combined.

I also generated some sample maps using the C2RCC processor in the SNAP toolbox, just to validate the expected outputs. The maps were for two water quality parameters – Total Suspended Matter (TSM) and Chlorophyll-a (Chl-a). I ran the generation for three study areas (1. Upper Lake, MP; 2. Bellandur Lake, Karnataka; 3. Hussain Sagar Lake, AP) out of which I got visually good results for Hussain Sagar Lake, Hyderabad. For the other two areas, the processor was not able to give out proper results. The visual representation was prepared in the ArcGIS platform and for map representation, I had used Google Earth images as background. I have added a few images here showing the samples.