Water Resources

Water resources are among the most important natural resources on Earth and proper monitoring is important all over the world. Many parameters in the water balance can be estimated using remote sensing and GIS data. This is especially an advantage in places where in situ data are scarce. In these cases, the temporal archives of remote sensing data can be used to extract information on agriculture, snow cover, reservoirs and even estimates of precipitation and evaporation/evapotranspiration.

Temporal changes
Remote sensing data are excellent for identifying temporal changes in the water balance. Satellite image archives date several decades back in time and in this way it is possible to analyse temporal trends. Seasonal differences can also be analysed very efficiently based on satellite data.



Water resource parameters
Remote sensing data can be used to extract information that can be used for hydrological models. Land cover type and maps of agricultural crops and irrigated areas indicate the surface roughness and water retention capabilities of the area. This information can easily be extracted from remote sensing data. Similarly, volume changes in lakes and reservoirs and changes in the water storage of ice and snow can be estimated using satellite data.

Precipitation can be estimated directly using historical microwave satellite data. Back to the beginning of the 1980s changes in precipitation can also be assessed from analyses of vegetation greenness as these two parameters are highly correlated. Evaporation from free water surfaces and evapotranspiration from crops and natural vegetation can also be estimated.

Water resource analyses are highly relevant for natural resource management and conservation projects. However, it is also very important for reservoir and hydropower projects, irrigation etc.