With fast depleting water sources and a growing population, our planet is threatened by serious water crisis in the near future. Adoption of new-age tools and technologies help reduce the current water stress and tap alternative sources
About 70% of the Earth’s surface is covered by water, but only 2.5% of it is fresh or potable. Alterations in the hydrologic regime due to global climatic, demographic and economic changes have put considerable pressure on this resource.
According to the World Health Organization (WHO), water scarcity affects one-third of the people on the planet and almost one-fifth of the world’s population live in areas where water is physically scarce. Even areas which have abundant supply of rain and fresh water may face shortages in future due to poor water management. Also, by 2030, the WHO predicts 6 in 10 people to live in cities, up from about 50% in 2010. The ongoing urbanisation and a growing middle class is further exhausting the already limited resource of water. Developments in geospatial technologies — including mapping, remote sensing, satellite imagery, GPS, and unmanned aerial vehicles — can and do provide important tools to water resource managers across the globe. New developments can affect how easily communities and governments use geospatial technology to monitor and control water use. For example, the so-called Internet of Things, in which devices of all kinds are connected online, could mean water metres and valve controls with wireless remote sensing capabilities, adding to the amount of information that a system can consider in decision making.
Improvements in visual analysis and image processing mean getting more useful information out of a collection of photos to supplement mapping and other data. Social networks can let managers collect anecdotal data married to a geographic location as alerts to potential problems or to treat like a giant focus group, identifying topics and questions that they might be well off to explore. Even combinations of technology like social networks and business models like crowdsourcing can augment the available data and the way in which officials can undertake their duties.
Here are some real-world examples of how new uses of geospatial technologies are making a difference in water management, whether through identifying potential hazards to water sources, improving water use in citrus crops, or taking measures of snow masses that are vital sources for regional water consumption.
Water management begins with knowing where water is and where it will come from. Rainfall, ground water supplies and surface water such as rivers and lakes all contribute to the supply side of the water equation. Another important source of freshwater is snow accumulation, as mountains act like cold-weather reservoirs.
LiDAR is rapidly becoming an important geospatial tool for water management because of its ability to effectively eliminate vegetative or artificial cover to achieve more accurate bare earth measurements and improved digital elevation models. NASA has used the technology to better measure major mountain watersheds in Colorado and California. Snowmelt provides three-quarters of the freshwater supply. Having more accurate earth measurements means a more complete grasp of the amount of snowpack volume and, therefore, the potential amount of water available.
NASA’s Twin Otter plane equipped with an imaging spectrometer integrated with a scanning LiDAR system from Optech flies at 22,000 feet above sea level to measure snowpack volume and the amount that will melt and run off. Such information has been largely unavailable anywhere in the world, which means runoff models are challenged. Approximately 1.5 billion people globally relying on snowmelt for water, which is a dangerous amount of uncertainty.
Poland has also used LiDAR in water management, creating a floodplain map as part of a prediction system for extreme weather. An area of more than 22,000 sq km was surveyed to create a digital terrain and surface model using airborne laser scanning technology. The system acts as an integrated information and warning system for government authorities and the public for extraordinary risks, i.e. the effects of extreme weather events. Supply prediction means taking into account all sources at specific locations and then modelling how they combine as a total water source at any given place. As water becomes an ever more critical resource, accurate measurements are a vital tool in management.
Using GIS to protect water supplies
In the Middle East, water is a particularly challenging problem as increased desertification in countries like Syria, Jordan, Iraq, and Iran reduces arable land. According to The Water Project, the heavy use of irrigation, which consumes an estimated 85% of the area’s water, makes water management even more unstable. Jordan, for example, has about the same area as Portugal but its per-capita annual freshwater withdrawal (the amount used for any purpose) is less than 17% as much. Environmental hazards that spill over into water supplies can be devastating.
An NGO called Friends of the Earth Middle East that operates in Israel, Jordan, and the Palestinian territories worked with Israeli IT consultant Taldor to build a GIS system, as part of its Protecting Groundwater project, to track environmental hazards. Rather than creating a replicated set of applications requiring duplicate funding, the system runs off a cloud-based delivery model. Taldor created a tool called Map Expert for Municipal & Water, which provides “management, planning, operation and maintenance tools” for local water authorities. Another Israeli firm, Ecology Engineering, added a groundwater vulnerability layer to the mapping. Ultimately, information about potential environmental hazards will be available to the public via a Web interface.
Remote sensing via UAVs
To monitor water, it is vital to be able to see resources and uses above ground. Researchers at Utah State University have done extensive work in using unmanned aerial vehicles (UAVs) in water management. The state of Utah is similar in many ways to the Middle East, as it incorporates extensive desert areas and must direct 85% of its water resources to agriculture.
Satellite imagery and aerial photography of course have their place in providing visual information that is important to help water managers avoid shortages and more accurately target where to apply resources. Utah State created the AggieAir Flying Circus, a service that uses Styrofoam UAVs that can be launched from almost anywhere and provide multispectral imagery at higher resolution and lower cost than satellite or manned aircraft.
UAVs can be put into service almost anywhere. Researchers see a number of potential uses, including wetland mapping, hydraulic modelling of rivers, and monitoring soil moisture in agriculture to better pinpoint where irrigation is most needed. UAV use in agriculture is already underway in Florida orange groves, where farmers employ regulated deficit irrigation (RDI), in which they restrict water at particular times to better regulate the growth of oranges and promote characteristics that bring a higher price in the market. Normally, RDI is difficult and expensive to implement because it requires extensive physical monitoring of trees. Researchers have found they can use UAVs equipped with thermal imaging technology to examine heat levels throughout an orchard. Software stitches the images together, providing a visual map that shows precisely what levels of stress trees are receiving to better target exactly where more water needs to be delivered. As the technique makes more efficient use of water, it effectively releases water resources, which might not be needed, for other uses.
Remaking water topologies
Sometimes regions and countries move beyond measurement and monitoring and reach for true massive change of geography, literally reforming water topologies through such projects as river linking, which connects multiple rivers through canals and brings surface water to land without river access, and dams.
India’s National River-Linking Project (NRLP)is a large-scale, long-term attempt to mitigate water resource fluctuations resulting from over dependence on seasonal monsoons. Irrigation has been a key factor in greatly increasing food production, but irrigation only goes so far. So the country is linking major rivers to extend water access to vast regions, better control seasonal flooding that would otherwise take place in regions with significant surface water presence, and to reduce the loss of water that would flow to the sea without diversion. The NRLP is also an attempt to remediate pollution and overuse of rivers in north India with water from the south.
GIS and remote sensing provide important information for the research, modeling, simulation, and engineering of such a major project. Given the scale of the work, officials must have a relative certainty of the effects river-linking would make to avoid the potential irony of making a problem worse through attempts to solve it. India is not the only region looking to reforming its water topology. Libya created its Great Man-Made River, using pipes to channel 6.5 million cubic meters of water daily from the Nubian Sandstone Aquifer System to coastal cities. Any such large-scale construction project requires GIS technology to help manage the construction and maintenance.
China depends on dam projects, like the massive Three Gorges Dam, to reshape how it manages water. The National Committee on Large Dams has made extensive use of database technology and Java-based Web GIS systems to manage information about 4,681 dams over 30 metres in height. The geospatial data uses references of 25°N and 47°N latitude, with a central meridian of 105°E. Data includes territorial boundaries, coastline, associated governments, and type of water body. The database aids research, engineering management, operation, and strategic planning.
Water availability and quality continues to be a growing issue for our crowded planet. Geospatial technologies offer a broad variety of tools to help communities and countries make wiser decisions. We have put in place some systems and sensors, but much more needs to be done to integrate these findings for a more holistic understanding and to assess the current status and trends. Incentives offered by governments for the use of geospatial technologies and applications, the development of water apps, and open data platforms to share groundwater data are some other areas that need to be examined . Finally, people must learn to become effective stewards of water resources.