In large fields, recent studies have shown that the within-field variability of drip irrigation can induce significant differences in vine vigor. This problem questions the use of multispectral images. Indeed, the origin of the variability observed by remote sensing remains uncertain as it can be linked either to stable parameters of the environment or to heterogeneous irrigation. In order to study the within field variability of the drip irrigation in the specific case of southern France, an experiment was carried out on two representative vine fields. Observations of flow rates were performed. Estimations of theoretical flow rates were performed through a model. The results show that the distributions of theoretical and observed flow rates are very similar. Both present a rather low magnitude of variation (CV~0.1). The spatial model shows a significant effect of the slope in the flow rate distribution. However, the model explains a small proportion of the observed spatial variability.