Dams play an important role in controlling floods

To build a dam, various studies on the construction of the dam are performed by experts in various fields such as meteorology and hydrology, social and economic, agriculture and drinking, environment and water quality, geology and soil and foundations, structures and hydraulics.
Dams play an important role in controlling floods, so that together with watershed management in tributaries, they create a suitable combination for the conservation and proper use of water and soil resources.
In dam construction, there is a great need for watershed management projects in the upstream tributaries, and watershed management and aquifer projects in alluvial fans are not at all in conflict with dam construction and are complementary.
In one division, dams are divided into two general parts, earth and concrete.
The useful life of a dam is usually between 30 and 50 years. After this time, up to 80% of the dam reservoirs are filled with sediments, and in such cases, due to the difficulty and very high costs of the sedimentation process, study for construction Another dam is built upstream or upstream of the existing dam.

General review and evaluation of the site (selection of the location of the dam)

For a particular dam, the site and the construction site meet the specific technical and practical needs, and the presence of fit in the site can strike a balance between its natural physical characteristics and the main objectives of the dam. There are factors that affect this balance, the most important of which are:

A: Topography of the area and capacity of the reservoir

The first factor to determine the location of the dam axis is the existence of a suitable valley that can be constructed with a limited length dam and inside it. In order to be economical and reduce costs, it is necessary for a certain height, the length of the canopy to be as short as possible and in front of the reservoir capacity as much as possible, so in terms of topography, it will be a suitable area that is completely closed and upstream. It will return completely. If two rivers join at a point and form a single river, it is preferable that the axis of the dam be located downstream of the junction.

B: Foundation, tectonic and geotechnical conditions

In concrete dams, the floor and sides of the river should have strong rock and also the depth of the floor rock (alluvial thickness) should be acceptable. Prepared and according to the morphology and structure of the earth. Important faults and other existing fractures such as joint system and cracking layering and the direction of the layer is determined. Suitability and bearing capacity of the foundation against forces and its load-bearing capacity, deformability and impermeability are factors that can determine the location and even the type of dam.

C: Hydrology and sedimentation rate

One of the important factors in choosing the location of the dam is the hydrological characteristics of the area, which should be used during the useful life of the project. In general, it is economically possible to use it during the useful life of the project. In general, the lower the fluctuations of hydrological characteristics such as floods and runoff in different years, the better the conditions for permanent use. Among other factors that are of considerable importance in this field, the rate of evaporation from the free surface water of the topographic reservoir and the capacity of the reservoir should be considered as the potential for water evaporation potential. The amount of granulation sediment is one of the factors that directly affect the dead volume and therefore the total volume of the tank and therefore in the calculations should be estimated as accurately as possible.