Zoneamento ambiental da sub-bacia hidrografica do Arroio Cadena, Santa Maria (RS) - (Estudo de caso)

The county of Santa Maria presents a series of environmental conflicts, being caused mainly by the inadequate use of the soil and by the bad use of the territorial physical space, generating environmental deterioration. The Environmental Zoning of Arroio Cadena s inaprocess of watershed management allowed evaluate the environmental deterioration in the referred sub - basin, where were it analyzed six environmental parameters: slope, drainage density, ruggdeness number, vegetation, human occupation and soil s use. The sub-basin was divided in four classes: Area of Recovery (AR), Area of Human Use (AUA), Area of Permanent Preservation (APP) and Area of Permanent Conservation (ACP), where was observed 2.986,13 ha (50,35%) for the class AR, occupying the largest area of the sub-basin, followed by 2.741,61 ha (39,65%) for AUA, 230,84 ha (5,15%) for APP and 252,13 ha (4,85%) for ACP. The environmental deterioration average for the sub-basin was 61, 3%. Summarizing, it is recommended that the environmental zoning be a tool to be applied by the government agences, because it optimizes the organization of the territorial space as well as the preservation of the natural resources.