Water – Conservation, Planning and Management

We never know the worth of water till the well is dry.
                                                                                    – Thomas Fuller

Fresh water

It is naturally occurring water except seawater and brackish water. Fresh water includes water in ice sheets, ice caps, glaciers, icebergs, bogs, ponds, lakes, rivers, streams, and even underground water called groundwater. Availability of freshwater has determined the growth of civilization in the past. As the world’s population continues to increase, it is predicted that the availability of fresh water for human needs is a serious limiting factor in the future.

Some facts 

1. Nearly 11 Percent of the total global population have no access to clean water
2. Countries will be affected by water shortage by the year 2025
3. Producing 1 kg of rice needs more than 3000 L of water
4. For producing 1 Kg of cotton, 20,000 L or more water is needed
5. Closing taps on time can save 80% of water

   

Why we should care ?

Human insensitivity towards water may lead to war for water in upcoming future. This is the right time to take serious actions for water management. Water conservation means using our water wisely and caring for it properly. Since each of us depends on water for life, it is our responsibility to learn more about water conservation and how we can help keep our water pure and safe for generations to come. Our water supply is finite, which means that we do not have an endless supply. We only have the water that we have now.

 
Potential of GIS

A significant problem of water scarcity and groundwater depletion is that it is difficult to formulate effective policies. The application of GIS in water resources is constantly on the rise. GIS help to use aerial photography and satellite imagery to assess water resources. GIS further helps in terrain modeling, flow modeling and debris flow probability that are parts of watershed management. For ground water management GIS is used for modeling surface flow, well and spring models. GIS is also used for water quality monitoring system.

• For watershed management

GIS technology have played a critical role in all aspects of watershed management. Watershed studies conducted using a GIS platform have demonstrated that the spatial analysis capabilities of GIS hold the key to improved watershed modeling techniques. Automated GIS tools also enable engineers to spend more time on the analysis and refinement of computer models and less on the laborious task of watershed parameterization for model setups.

• Digital Elevation Model (DEM)

GIS-based watershed modeling process begins with a digital representation of the ground surface topography, or a Digital Elevation Model (DEM). Using GIS to analyze DEMs, an engineer can produce draft watershed delineation and drainage patterns with limited manipulation. DEM can be used to represent the physical parameters of the watershed in terms of the flow direction, drainage network, and drainage slopes.

• Assessing Ground Water Potential

GIS and multi-criteria decision analysis techniques are used for identifying the groundwater potential zones and favourable artificial recharge sites. GIS-based multi-criteria analysis is also useful in mapping groundwater recharge zones.

Remote sensing solutions

Satellite remote sensing is increasingly being used as a complementary source of information and in many cases is the only feasible source. Satellite based sensors are now capable of making direct and indirect measurements of nearly all components of the hydrological cycle. These include precipitation, evaporation, lake and river levels, surface water, soil moisture, snow, and total water storage 

Following are some applications of remote sensing for water resources:

 

• Rainfall estimation and monitoring
• Snow mechanics, Mapping and Monitoring
• Rainfall-runoff studies
• Watershed planning and management
• Reservoir sediment monitoring and control
• Flood forecasting and control

For water resources engineer, locating a real extent of water bodies like lakes, rivers, ponds, etc. from remotely sensed data is an important task.

Land cover

The increment in urbanization has a major impact on groundwater. As there is increase in usage of groundwater  a major concern is also the decrease in rate of recharge of groundwater. The rate of recharge is decreasing with time. Multispectral classification of land cover types was one of the first well established remote sensing applications for water resources. Numerous investigators have used classifications of land cover from various remote sensing sources as input to various water resources studies.

Snow cover extent

The measurement of the area of a basin covered by snow is similar to land cover measurement. Various types of snow cover can be classified. Snow cover plays an important role in the Earth’s climate system, it is necessary to map snow-cover extent and snow mass in both high temporal and high spatial resolutions. This task can only be achieved by the use of remotely sensed data.

Surface water extent

Recent advances in satellite?based optical remote sensors have promoted the field of sensing surface water to a new era. Remote sensing technology offers effective ways to observe surface water dynamics. Compared to traditional in situ measurements, remote sensing is much more efficient, because of its ability to continuously monitor Earth's surface at multiple scales.

Summary

As the world’s population continues to increase, it is predicted that the availability of fresh water for human needs is a serious limiting factor in the future. Since each of us depends on water for life, it is our responsibility to learn more about water conservation. GIS is a potential tool for watershed management and planning. Remote sensing data is widely used for Rainfall estimation, Snow mechanics, Reservoir sediment monitoring, Surface water extent, and many more.