Space4SDG6: Clean Water and Sanitation

Published by- Joy Agrawal on 31/05/2021

Potable water is among the few very basic needs of people in order to survive and sustain. Only 1.2% of water on Earth is potable rest is either saline or locked up in ice caps and glaciers. But this 1.2% is huge and enough to sustain but still not everyone has access and millions die. Primary reason being local unavailability. Industrial effluent discharge into local water bodies causes certain chemicals to come up in the food chain causing harm to the population. Stagnating water also invites disease-rich vectors who can affect human health. Space technology can be of high utility to this problem. Satellite imagery can help identify unknown water channels which might be disguised in forest cover or perhaps simply undiscovered due to thick bushy growth or disguised as swamps. The water channels disguised in bush and forests can be detected via lidar system based on satellite or also those on aerial vehicles. Lidar system or SAR systems can penetrate the thick bush because of the millions of light rays they end and receive every second. Special algorithms can then clear the bush and reveal the underlying surface and finally differentiate between land cloud points and water cloud points. This can identify the fresh water channels.

Next important thing that comes is mapping of fresh water sources as shown above, by mapping not only water presence but the purity of water through hyper spectral image analysis. Mapping the extent of pure sources of water along with their extent around the community can give the government or the NGOs access to develop infrastructure.

Countries which are designated as water scarce by international bodies do have substantial ground water resources. Satellite imagery can help identify the ground water reserves and display on Geospatial map. This data can be utilised by the civic bodies to construct wells or other structures for ground water utilisation as potable water.

Mapping of algal blooms which are essentially growth of algae on water bodies which leads to a dead water body and causes water to be unpotable.

Another major reason that has effects to accessibility of clean water is droughts in certain regions. Droughts can be predicted months in advance in some cases years in advance based on satellite monitoring of meteorological conditions and also the rainfall trend of the place. This can allow the government or people to figure out solutions to the issue.

Space Technology can greatly contribute to finding, mapping and checking the purity of water reserves through satellite imagery to allow for potable water for all. It can also help predict droughts for which the public can then prepare through rainwater harvesting or increasing groundwater resources etc.