HYDROLOGICAL BALANCE EVALUATION OF THE SUB-BASINS BACOACHI RIVER, LA MANGA STREAM AND LOS PÁPAGOS STREAM AT THE UPPER MIDDLE REGION OF THE BACOACHI RIVER BASIN IN SONORA, MEXICO

Economical and social development of this region depends on the knowledge gathered about the behaviour and utilization of the groundwater and surface water. Since this resource has great value for human consumption and agricultural development, sound water management should be based on a quantitavie understanding of the state of the resource.

The objetives of evaluation are: 1) To set the hydraulic state in relation to the lithology of the area, 2) To investigate the behaviour of hydrodynamic and piezometric levels, 3) To analyze the behaviour of water in relation to its use and 4) To analyze the existing uses in the region, both physical characteristics and equipmen for such utilization.

So far, there are measurements of precipitation, actual evapotranspiration and infiltration. Maps, graphs and tables are also presented as part of this evaluation process. The progress of the project is presented in accordance with a hydrogeological model that allows more accuracy on the evaluation for this specific area.

As part of the hydrogeological evaluation of this project, the tools used include a geophysical census for water use, Vertical Electrical Sounding to determine major geological structures and magnetometry to determine the most favorable spots water catchemnts, and determine the principal geological structures in the area.

Results on the áreas of major exploitation and groundwater recharge zones are expected in order to make more responsible decisions on the use of this resourse. So far some groundwater flow directions have been detected. Also, it has been determined that the thickmess of aquifers lies between 20 m and 500 m near the deeper areas and that the static levels range from 8 m to 85 m of depth.