4Munafo M, Ceochi G, Baioeeo F,et al. River pollution from non-point sources: a new simplified method of assessment [ J ]. Journal of Environmental Management,2005,77:93-98.
5Cecchi G, Munafo M, Baiocco F, et al. Estimating fiver pollution from diffuse sources in the Viterbo province using the potential non-point pollution index [ J]. Ann Ist Super Sanita, 2007, 43 ( 3 ) :295-301.
6David K T. Groundwater Hydrology[ M ]. Canada: John Wiley & Sons, Inc. , 1976.68-72.
