The climate and climatological water balance of Brazilian semi-arid mountainous areas and inland depression

Abstract

This research aimed to carry out a comparative climatic analysis between high-altitude areas and those located in the inland depression according to climatic indices of aridity. This analysis chose the following municipalities: the high-altitude Guaramiranga/CE, Campos Sales/CE, Lagoa Nova/RN, Martins/RN, Monteiro/PB, Areia/PB, Triunfo/PE and Garanhuns/PE and the low-altitude Crateús/CE, Sobral/CE, Mossoró/RN, Caicó/RN, São Gonçalo/PB, Patos/PB, Petrolina/PE, and Cabrobó/PE. In order to gather both the climate analysis & its agricultural suitability, it was necessary to apply climatic indices of aridity and water availability for vegetation. The time series spanned from 1981 to 2010 and included precipitation and air temperature data and estimates of potential evapotranspiration. Data were obtained from the Brazilian National Institute of Meteorology. This study found a marked difference between the climatic conditions in elevated areas and those in lower altitudes in the Brazilian semi-arid, especially on water deficit and the prevailing high temperatures in the inland depression. Mountainous areas generally have a more humid climate than the depression due to orographic effects. However, this condition is not the rule due to the influence of other geographical factors of the climate. This study also observed that higher areas have a more climatically favorable conditions for the natural development of vegetation (and, therefore, for potential agricultural activities) than lower areas.

Keywords

• High-altitude climates. Climate indices. Aridity indices. Northeastern Brazil.