IWRA World Water Congress 2008 Montpellier France
1. Water availability, use and management
Research Fellows at INRA,
Integrated water management, River basin, Optimization, Scenarios
MoGIRE is a model for integrated water management at the river basin level,
allowing to optimise water use under several possible scenarios (agronomic, climatic or economic).
is currently under development by an interdisciplinary team within the APPEAU project (2007-2010) funded by the
French National Research Agency within the “Agriculture and Sustainable Development” program. An application of
the model is proposed for the Neste system located in South-West of France.
objective of the MoGIRE is to develop an interdisciplinary integrated framework based on mathematical
programming in order to evaluate scenarios for a better planning of agricultural and non-agricultural water use at the
river basin level.
Architecture of MoGIRE
MoGIRE may be viewed as a multi-use water allocation
model with an explicit representation of the water network at the river basin level.
(domestic and industrial) and environmental water uses are represented in the model. Agricultural production
functions are derived from a biophysical models of crop growth, STICS (Brisson et al., 1998). The crop growth
model allows to characterize the relationships between agricultural water use and crop yields. Those relationships are
used as inputs in a regional agricultural production model that determines the optimal allocation of land among
possible crops and the resulting agricultural net profit. The urban water value is derived from econometric
estimations of water demands, see for instance Garcia and Reynaud (2004) for such a derivation in France.
MoGIRE then operates the network facilities and allocates water so as to maximise the river basin agricultural and
urban economic value from water use, under water delivery constraints resulting from the characteristics of the water
network and the minimum flow requirements. We make the distinction between two minimum flow levels: the Crisis
Minimum Flow (CMF) and the Target Minimum Flow (TMF). The CMF (in French, débit de crise) defines the
minimum flow under which biological life is not possible. When the water flow is lower than CMF, no irrigation is
allowed. The TMF (in French, débit objectif d’étiage) defines the water flow level above which biological life is not
constrained. When the water flow is greater than TMF, irrigation is not limited.
This pursuit of economic
objectives (aggregated social surplus resulting from water consumption in agricultural and non-agricultural regions) is
then limited only by water availability, water network characteristics, and minimum flow constraints.
Application of MoGIRE to the Neste sytem (France)
Within the APPEAU project, MoGIRE is
currently applied on the Neste system located in South-West of France. The Neste system is a system of rivers
artificially recharged by upstream reservoirs located in the Pyrenees mountain. This system has been chosen first
because it is managed by a single operator, the Compagnie d’Aménagement des Coteaux de Gascogne (CACG).
Second there are significant water scarcity issues in that area that make the development of an integrated water
management model relevant. For instance, the relationship between the CACG and farmers is defined by a contract.
This contract specifies first, a discharge rate and second, a quota associated to each unit of discharge rate (l/s)
subscribed by a farmer. Given the current price for the discharge rate, the demand of discharge rates by farmers
exceeds the flow capacity of the system. The CACG must then manage a waiting list for quota allocation
then plan to use MoGIRE in order to optimize and simulate various agronomic, climatic or economic scenarios on
the Neste system. For instance, a set of scenarios concerning various spatial distributions of cropping systems within
the Neste system chosen to reach a compromise between minimising the irrigation demand and maximising the farm
and the regional income is currently under development.
Brisson, N., Mary, B.,
Ripoche, D., Jeuffroy, M. H., Ruget, F. e. al., 1998. "STICS : a generic model for the simulation of crops and their
water and nitrogen balances. Theory and parameterization applied to wheat and corn". Agronomie, 18: 311-
Garcia, S. and A. Reynaud, 2004. "Estimating the benefits of efficient water pricing in France" , Resource
and Energy Economics, (26), 1-25.