Abstract:
The problem of water shortage in arid and semi-arid regions is one
due to low rainfall and uneven distribution throughout the season, which
makes rain fed agriculture a risky enterprise. Rain water harvesting for
dry-land agriculture is a traditional water management technology to ease
future water scarcity in many arid and semi-arid regions of world.
Rainwater harvesting (RWH) is a method of inducing, collecting, storing
and conserving local surface runoff for agricultural production. This
study presents a brief treatise, of rainwater harvesting, and its historical
perspectives. Optimum reservoir capacity is reported to be estimated by
the tedious graphical method. In this study an alternative procedure is
presented for determining the optimum reservoir size for supplemental
irrigation of multiple crops using a water balance algorithm. It includes
the short-term real-time reservoir operation model is developed for
irrigation. Integration of reservoir operation with on-farm utilization of
water by crops is achieved through the use of two methods: An operating
policy model, which optimizes reservoir releases across time periods, and
an allocation procedure which optimizes irrigation allocations across
crops within a time period of the storage .The volume of water stored
depends on the available runoff during the time interval considered along
the rainy season, (user defined) and the water demand, which also varies
depending crop type and its stage of growth (model predicted). Rate of
sedimentation and useful life time of a reservoir were estimated using the
trap efficiency (Te) approach.
