Hydrology is the science that studies the waters that are on the earth, both above and below the surface: their formation, movement and distribution in time and space, their biological properties, physical and chemical properties and their interactions with the environment, including those with living beings.
In a nutshell it study the water flows that form the so-called water cycle.
The water flows from the atmosphere to the land surface are called precipitation; the rainfall flows into the surface or infiltrates into the soil and flows in the terrain. Finally there is the evaporation from the soil, from surface water such as lakes and other basins, and transpiration by plants and animals that release water back to the atmosphere.
Knowledge of the hydrological cycle allows to effectively manage the water resources, to forecast the floods, to limit soil erosion and landslides, but also to optimize the water resources usage for electricity production.
Among the activities taking place at the IST in this division has to be mentioned an hydrological model that, in warning and pre-warning weather alerts periods, provides a water levels prediction of the Lake Maggiore and its main tributaries for Civil Defense purposes.
The IST also provides consulting on hydrological aspects to the cantonal offices involved in the management of water resources.
It has to be noted:
1. Verification of the design flow of rivers and creeks for remediation projects;
2. Determination and monitoring of minimal residual flow in order to ensure the ecosystems protection and the application of the Federal Law on Waters Protection: the minimum amount of water along the rivers downstream of hydropower or other collection points must be ensured.
3. Pubblication, since the 1979, of the Hydrological Yearbook of the Canton Ticino;