Calculation methods and characteristic analyses of deep well loss values in the eastern plain of northern China

This paper discusses the applicability and disadvantage of methods for calculation of the well loss values,such as the direct method,s-lg r method,repeated steady flow pumping test method and mlti-drawdown-pumping test method.In the eastern plain of northern China,the area depression cone is huge and the change in groundwater level is obvious,making it difficult to calculate the well loss values by conventional methods.This paper presents a method,namely the C-G method,to address the issue.Compared with the modified repeated steady flow pumping test-double steady flow pumping,the result of the C-G method is more reliable.A method to correct the influence of the atmospheric pressure by a DIVER in the well and regional groundwater level variation on well loss values is introduced in this paper.The change in the well loss value with time and with groundwater level drawdown is also discussed.