In groundwater management,the exchanges between groundwater and other water such as surface water and spring water need to be considered.Some exchange is dependent on the ground-water level,which is called covariate.The pumping rate,groundwater level,and covariate interact and the relation of mutual-feed joint-variation is used to describe their interaction.This article presents a new approach of dealing with the relation in groundwater management model.The mathematical for-mulation of the relation,as an additional equality constraint in the optimization model,is developed using response matrix method.Thereby the groundwater management model with covariate is set up.The code for the simulation and management of groundwater system with covariate is programmed with Fortran 90,and the optimal pumping rate,groundwater level,and covariate are obtained.The approach is verified with a hypothetical case.Finally,the approach is applied to the groundwater management of Qianguo(前郭) area in western Jilin(吉林) Province.The results indicate that the ap-proach is feasible.It provides a universal solution for various covariates and reduces the computational complexity compared to iteration method.The approach is proven to be very efficient to solve ground-water management problem with covariate.
