APPLICATION OF DSS -IN IRRIGATION MANAGEMENT -- A CASE STUDY OF MEGHNA - DHONAGODA IRRIGATION PROJECT. BANGLADESH

Abstract

Meghna-Dhonagoda. Irrigation Project (MDIP) is one of the most aspirant projects ever commissioned in Bangladesh. The project could not achieve its irrigation objectives because of poor irrigation management practice and deterioration of the canal system due to breach of flood embankment. Bangladesh Water Development Board carried out a study in 1997 to overcome the problems associated with the project. The study recommended. rehabilitation of the system network and use of a Decision Support System (DSS) in irrigation management. The rehabilitation work has already been completed in the year 2000. DSS developed in 2000 has not yet been applied in MDIP. This study aimed at the application of MDIP-DSS in U2 Canal System to prepare irrigation schedule for BORO rice crop and to prepare pump and gates operation schedules. Various methods have been used to calculate the crop water requirement (CWR). CWR calculated using Pan-Evaporation method is close to the actual field requirement observed in MDIP. Accordingly, using Pan-Evaporation method crop growth decade wise irrigation schedule has been prepared. Four likely pump and gate operation schedules have been prepared to follow the irrigation schedule. The pump operation schedules are prepared on the basis of different likely scenarios of the project such as availability of power supply, efficiency of system monitoring, farmers working hours, etc. The gate operation schedule has been prepared on the basis field experience. It is found from the analysis that Option-2 is the most suitable option for U2 canal system. It gives 82 percent dependable irrigation index and 92 percent average irrigation index. Thus the pump and gate operation schedule, used in Option-2, are recommended to meet the irrigation schedule for Boro rice in U2 catchment of MDIP. Many problems have been faced during the application of MDIP-DSS. The main problem is that it is a very loosely coupled system having multiple entry and exit points. The interfaces used to integrate modes are not user-friendly. Lastly, it is very difficult for an irrigation manager to use it unless he possesses a sound knowledge of computer systems and irrigation management.