Drainage different soil types

Variations can occur due to different topography, farming procedures, soil type, drainage and the underlying geology. 

Flood-control technology deals with the myriad techniques that can be employed to deal with water that overflows stream banks, thereby leading to deaths and injuries, property and crop damage, and severe erosion. The magnitude of the flood damage varies considerably, as it depends on the duration of the storm and the amount of precipitation. Each watershed has different physical features, such as size, slope, basin relief, impoundments, flood history, soil types, and drainage characteristics. 

Fig. 6. Mean concentrations of total dissolved solids in different types of waters, in relation with soil drainage intensity.

The effective shear strength can be tested in the laboratory by means of different test procedures such as a the direct shear test, simple shear test and the triaxial test. Normally testing is performed on saturated material. For every test setup, a clear distinction must be made between testing the material under drained or undrained conditions. From this point of view triaxial tests, type CU (Consolidated Undrained) or CD (Consohdated Drained) allow for a better control of the drainage conditions and porewater pressures than for instance shear box tests. For further elaboration on these types of tests, reference is made to textbooks on Soil Mechanics and laboratory testing (Head, 2006). 

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