Abstract
The allocation of water resources between different users is a traditional problem
in many river basins. The objective is to obtain the optimal resource distribution and the
associated circulating flows through the system. Network flow programming is a common
technique for solving this problem. This optimisation procedure has been used many times
for developing applications for concrete water systems, as well as for developing complete
decision support systems. As long as many aspects of a river basin are not purely linear, the
study of non-linearities will also be of great importance in water resources systems optimisation.
This paper presents a generalised model for solving the optimal allocation of water
resources in schemes where the objectives are minimising the demand deficits, complying
with the required flows in the river and storing water in reservoirs. Evaporation from
reservoirs and returns from demands are considered, and an iterative methodology is
followed to solve these two non-network constraints. The model was applied to the Duero
River basin (Spain). Three different network flow algorithms (Out-of-Kilter, RELAX-IVand
NETFLO) were used to solve the allocation problem. Certain convergence issues were
detected during the iterative process. There is a need to relate the data from the studied
systems with the convergence criterion to be able to find the convergence criterion which
yields the best results possible without requiring a long calculation time.