The theme was based on studies about the physiographic aspects of the hydrographic basin of the upper Parnaíba River that drains the municipalities of Dom Aquino and Poxoréu. The greatest emphasis was given to the soil and water resources due to the importance for the municipalities in terms of their exploitation, and thus physical-chemical soil and water analyses were carried out for a better characterisation of this part of the river under consideration. This report contains the results obtained in the field, laboratory and office work carried out as part of the proposed studies, with geological/geomorphological/pedological and water mapping carried out on a regional scale of 1:100,000.