Freshwater is integral to our survival on earth; whether itâ€™s for drinking, growing food, sanitation or energy production. However, water is also a finite natural resource controlled by the complex and evolving water cycle. Many people know that 97% of the worldâ€™s water is salt water, but of the remaining freshwater 70% is locked in ice caps and of what remains only 1% is readily accessible.
The bodies of UN Water and Water.org estimate that 85% of the worldâ€™s population live in the driest half of the planet; taking a five-minute shower uses more water than the average person in a developing country uses for an entire day and more people in the world have access to a mobile phone than a toilet. Global demand for water is forecast to increase by 55% in the next 40 years, added to which climate evolution is going to change the distribution and availability of freshwater across the world. Last winterâ€™s weather in the UK demonstrated how important itâ€™s going to be to for us to adapt to new water patterns.
Satellite remote sensing has an important role to play in helping the world monitor and manage this natural resource. From the identification and mapping of water bodies by optical remote sensing, through the monitoring of hydrologic variables (like rainfall, soil moisture and water quality) to real time flood monitoring and disaster relief. Remote sensing applications are offering real value to the world and with launch of Sentinel-1 the European Copernicus data stream has started to come online; this week Iâ€™m at the Sentinel-2 for Science Workshop. Sentinel-2 is a high resolution optical mission due to launch in early 2015.
Over the last year Iâ€™ve developed a systemÂ to determine water heights in estuaries, rivers and lakes using satellite optical and altimetry data. Radar altimeters emit short bursts of microwave energy towards the earthâ€™s surface, and the time delay of the return of those pulses gives a height. It becomes complicated over inland water bodies, especially those that are relatively small (not large inland seas) and varying river banks and general land topography; however there are improved approaches and new data coming on-stream.
Testing my altimetry based height determination has given positive results, when compared to in situ data taken for the Congo; the first study site. By using this approach I was able to provide the customer with water heights without them needing to get data from a water gauge. The other major advantage was the generation of a historical time series for several sites of interest where water gauges had never been installed.
Wednesday next week, 28th May, I will be giving a presentation on my work at the 2014 Geo-Business Conference in London and Iâ€™ll give you more details in a future blog. If youâ€™re at Geo-Business, come up and say hello, otherwise come back to the blog for more details.