What can be learned from sequential multi-well pumping tests in fracture-karst media? A case study in Zhangji, ChinaQue peut-on apprendre d’essais de pompage successifs multi-puits dans un aquifère de type fissure-karstique ? Cas d’étude à Zhangji, ChineQue se puede aprender de los ensayos de bombeo secuenciales en múltiples pozos en un medio fracturado kárstico? Un caso de estudio en Zhangji, China群井序列抽水试验对裂隙岩溶介质中的应用——中国张集实例O que é se pode aprender a partir de testes de bombagem multi-captação em meios cársico-fracturados ? Uma caso de estudo em Zhangji, China

A fracture-karst aquifer is a karst aquifer with a fractured rock matrix, and its parameters are difficult to determine. Two sequential pumping tests in a fracture-karst aquifer system at the Zhangji well field of China are considered, one carried out before (in 2000) and one after (in 2005) the operation of a pumping station in the well field (2003–2005). The sequential tests serve multiple purposes. First, they provide a cross check of the parameters obtained. Second, they can be used to assess the effect of long-term groundwater exploitation of the aquifer. A three-dimensional finite-element transient flow model has been developed to simulate groundwater flow at the site. Generally good agreement has been found between the simulated and observed hydraulic heads for both tests. The hydraulic parameters obtained from the 2005 test are generally consistent with their counterparts from the 2000 test. However, a small but steady increase of hydraulic conductivities from 2000 to 2005 at the site has been observed. A 10-year prediction of groundwater resources has been made and indicates that the well field can accommodate the proposed 8.0 × 104 m3/day exploitation rate under relative drought conditions without causing a steady decline of groundwater levels.