Abstract: Tarim River is the longest continental river in China,and is essential to the oases in the watershed and of the ”Green Corridor” in its lower reaches.The research of groundwater transportation is more and more important to the ecological restoration.Based on the groundwater movement in different stages of filtration of water from the river,an one-dimensional unsteady groundwater flow model in the intermittent water infusing process is established and a new method of converting boundary conditions of the first kind and second kind eachother is introduced to solve the model.And finally applying the method to the analyses of groundwater movement in the riverside in the water infusing process at the lower parts of Tarim River.The results show the feasibility and reliability of this method.Basing on the conventional erfc(λ） and ierfc(λ） formula,a new method is introduced in this paper to determine groundwater transport parameters,which do not require integral and tableconsultation in the cause of calculation.By referring to them,a mixed model for non-stable groundwater flow was established.The author additionally developed the Decision Support System of water resources in Tarim River watershed by making use of the languages of Visual Basic and GIS.The accuracy and validity of the formula were tested through DSS at the end of this paper,suggesting certain practical value.

Key words: approximation formula of erfc(λ）and ierfc(λ）, non-stable flow, mixed model, leakage, groundwater, DSS