The Need for Complementing Data to Check Deduced Gradients and Flow Directions

4 The Need for Complementing Data to Check Deduced Gradients and Flow Directions 

Determination of the flow gradient between two wells (Fig. 4.11) is based on the assumption that the two wells are hydraulically interconnected, as shown in Fig. 4.13a. Flowever, wells may be separated by an impermeable rock bed with no hydraulic interconnection (Fig. 4.13b). Thus the gradient measurement between the two wells in the second case is meaningless. The 

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Geological information of the rock sequence and tectonic settings may be instructive but not definitive, as it is hard to translate field data into hydraulic conductivity values a shale bed may be fractured and let water flow through in one case, and a clay bed may be weathered and act as an aquiclude in another. In addition, a variety of processes lower the local water conductance, occasionally preventing lateral flow. An example of such a process is chemical clogging (Goldenberg et al., 1983). 

Other parameters are needed to check for hydraulic interconnections between studied wells. Chemical constituents of the water may indicate 

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