DESERTIFICATION AND CLIMATE CHANGE: THE GEOGRAPHICAL DETERMINISM OF RÍO NEGRO SOUTHERN REGION

J.M.ZEBERIO; D.M.MARTIN; R. DEL BARRIO; NICOLÁS A. FELLENZ

CABA

Taller; Adaptación al cambio climático en sectores clave en América del Sur; 2012

UBA

Development of Río Negro province southern region depends on environmental services of its ecosystems, which are primarily influenced by thermal and hydric conditions. Prolonged droughts trigger natural and anthropogenic agents processes and actions such as soil erosion, changes in vegetation and quantity quality water availability. In this paper are described and evaluated climate conditions, thermal and hydric, and some groundwater quality parameters in relation to regional development potential. Daily temperature and rainfall data of Maquinchao (41o25´S;68o73´W); rainfall data of Ing.Jacobacci (41o30´S;69o58´W), Comallo (41o25´S;70o27´W) and Sierra Colorada (40o58´S;67o80´W), and groundwater quality analysis during May and June 2012 in different locations of the region were used with this aim. For each location annual normal rainfall, deciles 2nd and 8th, interannual variability, trends by decades series partition and rainfall probabilities ≤ 150 mm as indicators of severe hydric restrictions were calculated. Maquinchao temperatures were used to calculate normal average, January maximum average and absolute, July minimum average and absolute, trends by decades series partition, chances of maximum absolute temperatures above 36 ° C (January) and minimum absolute less than - 20 ° C (July). Results indicate annual average temperatures lower than 10 ° C, July minimum average - 3.9 ° C and probabilities of occurrence of 20% July absolute minimum temperatures ≤ - 20 ° C and probabilities of annual rainfall ≤150 mm from 50% to 20% according to the considered location. Both, hydric and thermal restrictions, displayed increasing incidence in the last decade. In turn, ground water quality analyses indicate high arsenic levels which exceed sometimes up to 100 times as recommended by Argentine food code. Thus, the results indicate a strong environmental constraint to regional development.