Investigating the potential for efficient water management in spate irrigation schemes using the Spate Management Model

摘要

The Spate Management Model (SMM) has been developed for the purpose of simulating spate irrigation practices in the flood wadis of Yemen, with emphasis on Wadi Tuban and Wadi Zabid. The model can be used as an aid to decision making in ihe improved operation and management procedures planned for the wadis. It could also be used to explore the scope for changes to water allocation procedures in order to achieve better water management. The SMM can simulate the passage and distribution of floodwater inwadi plains starting from the head of the wadi down to the command areas. Flow distribution at the diversion structures and canal offtakes is based on user-defined water rights, canal/offtake capacities, and the crop water requirements of the command areas or spate irrigation practices. Bed losses from the wadi and canal network and the field application losses are taken into consideration. The output from the SMM includes the volumes of water diverted to each command area, the quantities of water still due to each crop in each command area, the quantity of water that has been used to meet crop water requirements and that that has been lost, the volume of spate water that has not been diverted to the command areas, and the volume of excess flow that may either go to the wadi drainage area (e.g. to the sea) or replenish the groundwater. The direct output from the SMM is in tabular and report formats. In addition, the model can export selected output data to G1S for graphical presentation.