CHAPTER THREE: IRRIGATION METHODS AND DESIGNS. 3.1 IRRIGATION METHODS a) Surface Irrigation: Just flooding water. About 90% of the irrigated areas in the world are by this method.
Soil Type Maximum slopes*
Sandy loam 0.40
Fine sandy loam 0.50
Loam 6.25 Source: Withers & Vipond (1974)
Depth of Water, D (mm)
D = KTn
Time, T (mins)
Fig 3.5: Cumulative Infiltration Curve
I = c Tn
h = 87 kPa or 8.9 m ( or use Chart to obtain h). This is the
Average operating head, Ha.