Design of Surface Irrigation Systems

Surface methods are the following types: (i) Border (ii) Basin (iii) Furrow or corrugation (iv) Contour ditch (v) Contour levee irrigation.

Phases of Surface Irrigation

(a) Advance phase: That portion of the total irrigation time during which water advances in overland flow from the upper field boundary toward the lower field boundary.

Fig. 1. Water movement vertically downward.

(b) Storage (continuing) phase: That portion of the total irrigation time between the end of advance and inflow shutoff. If shutoff occurs first, this phase is of zero duration.

(c) Depletion phase : That portion of the total irrigation time between inflow shutoff and the beginning of recession of the upper field boundary. This is also known as the recession lag time.

Fig. 2. Water movement in the soil (a) Water moving on soil surface (b) water

moving in soil profiles

(d) Recession phase: That portion of the total irrigation time between the beginning of recession at the upper field boundary and the disappearance of the last water from the field surface.