Some Storage Characteristics of Reservoir

Water harvesting system for small scale field irrigation (II)

Abstract

Regarding the water harvesting systems for small-scale field irrigation, the reservoir characteristics were elucidated using the water balance simulation method. Replenishing of the reservoir with other sources of water leads to a reduction in the size of the reservoir capacity. That is also reduces the construction and land costs. The size reduction effect from such a supply is greatly influenced both by the catchment area, when it continues; and by the time during which it lasts when it is conditional. When a reservoir (designed for an irrigated area of 1 ha and a catchment area of 6 ha) has a capacity of 5, 000m³, the average pondage factor of the inflow is about 50%, and the ratio of water use is 40% or so. The water pondage system scheduled for several years is more advantageous than that for a year because of the reduction in the reservoir capacity. As reservoirs decrease in size, sensitiveness to the unit of water balance becomes striking. It is desirable to operate small-scale reservoirs on a daily basis, not every 5 or 10 days or on a monthly basis.