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8. Applications of Groundwater Quality Models
the ith interval, respectively. The management objective is to minimize the
total cost of Z. The constraints include: total water demand must be satisfied,
the drawdowns of groundwater should not exceed a certain level, and the
water extracted from the reservoir must be limited within a certain amount.
In the agricultural economic hydraulic management model considered
by Morel-Seytoux et al. (1980), the irrigation water comes from both the
pumping of groundwater and the diversion of surface water. The goal of the
model is to minimize the cost of the total water consumption, and meanwhile,
guarantee the water demands of various crops and soH conditions. In the
model, if we ass urne that the yields of the crops depend on the irrigation level
and the pumping cost is dependent on the drawdown, then the objective
function becomes a quadratic function with respect to the decision variables,
because the drawdown can be expressed as a linear function of pumping rates
using the influence matrix method mentioned before. Thus, the management
problem becomes a quadratic programming problem.
The water demands of agriculture are stochastic variables because of the
stochastic nature of precipitation. Consequently, various stochastic management models were proposed. Maddock (1974), and Emigdio and Flores
(1976) studied stochastic management models for river-aquifer systems, and
the latter also gave an example of groundwater basin management in
Mexico.
Maddock and Haimes (1975) studied a regional groundwater allocationcharges system by using the influence matrix method associated with agricultural economy. The quota of water supply for the farm is determined by the
model, overuse of water will be punished, and saving on water will be rewarded. The management problem is reduced to a quadratic programming
problem with the goal of maximizing the net income of the farm. The decision
variables are the pumping rates, while the relations between drawdown and
pumping rate are determined by the influence matrix.
Study of groundwater management in combination with surface water has
started in China. Han (1985) proposed a management model for a subsurface
water reservoir in Shimenzhai, with the purpose of supplying as much water
as possible from both the surface and the subsurface reservoirs. The model is
reduced to a linear programming problem and its calculation results provide
an optimal operation scheme for both the subsurface and the surface reservoirs. The General Observation Station of the Geological Bureau of Shaanxi
Province and Shandong University (1990) accomplished a research on
groundwater management for Xi'an City, Shaanxi Province. The research
contained two contradictory goals: maximize the water supply and minimize
the land subsidence.
Groundwater Simulation-Economic Management Models
The management goals of combined groundwater simulation-economic
management models directly reflect economic aspects. Models of this kind
8. Applications of Groundwater Quality Models
the ith interval, respectively. The management objective is to minimize the
total cost of Z. The constraints include: total water demand must be satisfied,
the drawdowns of groundwater should not exceed a certain level, and the
water extracted from the reservoir must be limited within a certain amount.
In the agricultural economic hydraulic management model considered
by Morel-Seytoux et al. (1980), the irrigation water comes from both the
pumping of groundwater and the diversion of surface water. The goal of the
model is to minimize the cost of the total water consumption, and meanwhile,
guarantee the water demands of various crops and soH conditions. In the
model, if we ass urne that the yields of the crops depend on the irrigation level
and the pumping cost is dependent on the drawdown, then the objective
function becomes a quadratic function with respect to the decision variables,
because the drawdown can be expressed as a linear function of pumping rates
using the influence matrix method mentioned before. Thus, the management
problem becomes a quadratic programming problem.
The water demands of agriculture are stochastic variables because of the
stochastic nature of precipitation. Consequently, various stochastic management models were proposed. Maddock (1974), and Emigdio and Flores
(1976) studied stochastic management models for river-aquifer systems, and
the latter also gave an example of groundwater basin management in
Mexico.
Maddock and Haimes (1975) studied a regional groundwater allocationcharges system by using the influence matrix method associated with agricultural economy. The quota of water supply for the farm is determined by the
model, overuse of water will be punished, and saving on water will be rewarded. The management problem is reduced to a quadratic programming
problem with the goal of maximizing the net income of the farm. The decision
variables are the pumping rates, while the relations between drawdown and
pumping rate are determined by the influence matrix.
Study of groundwater management in combination with surface water has
started in China. Han (1985) proposed a management model for a subsurface
water reservoir in Shimenzhai, with the purpose of supplying as much water
as possible from both the surface and the subsurface reservoirs. The model is
reduced to a linear programming problem and its calculation results provide
an optimal operation scheme for both the subsurface and the surface reservoirs. The General Observation Station of the Geological Bureau of Shaanxi
Province and Shandong University (1990) accomplished a research on
groundwater management for Xi'an City, Shaanxi Province. The research
contained two contradictory goals: maximize the water supply and minimize
the land subsidence.
Groundwater Simulation-Economic Management Models
The management goals of combined groundwater simulation-economic
management models directly reflect economic aspects. Models of this kind