The objective of this article is to explain the hydraulic function of subsurface pipe drainage system on agricultural experimental field in Mashtul Pilot Area (Nile Delta) in non-steady state drainage flow conditions. Subsurface drainage structures were designed for the conditions of steady state drainage flow. However, in reality non-steady state drainage situations prevail. A model to solve the problem is presented. Boussinesq's equation was used to study the non-steady state drainage flow. The final expression of lowering of water table in time was approximated by Glover-Dumm.

This project will address the important external drivers that influence water resources of the coastal zone and to assess the anticipated changes in flooding, drainage congestions, salinity intrusion, water availability, sedimentation and risk of inundation of cyclone induced storm surge as a consequence of these drivers. The water resources in the coastal zone of the Ganges basin are vital for crop production, ecosystem sustenance and livelihoods.

After a hiatus in dam investment, through the 1990s and the early part of this century, construction of large dams is increasing again. Modern decision support systems can usefully input to this process by guiding the analysis of complicated hydrological, environmental, social and economic factors associated with water allocation and assessing the impact of different, often conflicting, management options both in planning and operation of dams. This publication highlights the constructive role that decision support systems can play in planning and operation of dams.