OPTIMAL GROUNDWATER QUANTITY MANAGEMENT FOR LAND SUBSIDENCE CONTROL

摘要

Groundwater overpumping could cause serious landrnsubsidence. Although groundwater management modelsrnhave been widely applied to obtain optimal pumpingrnstrategies for land subsidence control, most of them havernnot explicitly incorporated the land subsidence intornmodel’s constraints. This study presented a groundwaterrnmanagement model explicitly considering land subsidence.rnTo quantify the relation between land subsidence andrndrawdown, the one-dimensional consolidation equationrnwas adopted which simultaneously accounts for the elasticrnand inelastic compaction due to pumping. Based on thernresponse matrix technique along with one-dimensionalrnconsolidation equation, a groundwater quantityrnmanagement model was developed which enables therndetermination of maximum total pumpage subject that thernland subsidence do not exceed the allowable value. Therndeveloped management model was non-smoothrnoptimization problem. To improve the solution efficiency,rnthe non-smooth optimization was transferred into mixedrninteger linear programming (MILP) by introducing thernbinary variables. A hypothetical example was utilized torndemonstrate the applicability of developed model. Thernresults indicated that the land subsidence should bernexplicitly incorporated into model’s constraints; otherwisernthe optimal total pumpage might be overestimated.rnMoreover, the simultaneous consideration of elastic andrninelastic compaction in groundwater management wasrnimportant, especially when the difference between initialrnhead and preconsolidation head was significant.