They are some areas of the city that already had been taken by these great plantations. Of ownership of these information, is noticed that the ground is predominantly arenaceous, characterizing itself for the high friabilidade and, consequentemente, a well developed erosive susceptibilidade. RECITAL TERICA-METODOLGICA the research presented here searched in the inductive method of inquiry, which part of the acceptance as starting point of a particular case and for, later, formulating a statement general: the empirismo has for origin the search of overcoming of the theoretical speculation. In the place of it, it is placed empirical comment, the experimental test, the quantitative mensurao as criteria of what it would be or not scientific (DEMON, 1985, P. 102).
Author according to cited, the basic method of the empirismo is described as of the induction, that he means to accept the generalization after to only have evidenced the concrete cases. The empirical or inductive studies allow to quantify the loss of ground in determined place; they are about experimental studies that aim at to monitor the phenomenon, quantifying it. The Technique of the Bolts of Erosion is one old technique and still very used, was proposal for Of Ploey and Gabriels (1980), cited for War (2005, P. 34), that it consists of: to choose a hillside (of preference without vegetal covering) and to cravar in the ground the numbered bolts (that they can be of vergalho or pregos). Everything must be located in a diagram, to know its space distribution accurately. The monitoramento of the erosion bolts consists of coming back to the study area (of preference after each significant rainy event) and measuring how much the bolt is being displayed in relation to the ground (the measures can be made in millimeters). These bolts must be embedded in the ground the 10 centimeters or more, of preference in hillsides where it does not have ticket of animals and people, or then, the area must be surrounded so that it does not have no type of disturbance.