Debris flow occurrence is a common feature in hydrological events, correlated with intense damage and destruction. Morphometric parameters in catchment scale are quite useful to understand debris flow nucleation, development and deposition, improving the susceptibility and hazard maps. The parameters used are the Watershed Length (WL) < 2.7 Km and Melton ratio (R) > 0.6. In Serra da Prata range, Southern Brazil, 11 catchments were studied, hit by debris flows related to the hydrological event of march/2011. Most of the catchments have values below (or above) to thresholds and only 3 of them fulfill the conditions stated for debris flow occurrence. The result could indicate catchment R values as representative of debris flow occurrence, but it may also represent imprecision of the obtained bases, the influence of more than one phenomenon in the same catchment, and/or the influence of factors as geomorphology and material availability.