The impact of the dry spells in the production of grains in the macro-region of Inhamuns – Ceará

Abstract

The agriculture, especially the subsistence one, is an economic activity dependent of the climate rhythm. This dependent relation is even more intense in the Northeast of Brazil (NEB) since it is a region which presents high variability of interannual and intraseasonal rainfall. Therefore, this paper aims at observing the intraseasonal behavior of the rainfall in the rainy period from 2003 to 2013 and its impact in the production of grains (corn and bean) in the macro-region of Sertões dos Inhamuns in Ceará. For this purpose, we have analyzed daily data from 16 rainfall stations that belong to the macro-region of Inhamuns and, from this analysis on, we have identified and classified the dry spells, considering consecutive days without both any rain or under 2mm. The results were grouped in three categories: dry spell class A (from 5 to 10 days); dry spell class B (from 11 to 15 days); and dry spell class C (over 15 days). Based on the agricultural productivity data we could observe the relation between the dry spells and the productivity. The results indicate that the dry spells A and C have a relation of correspondence with the production – dry spell A, a positive relation as C maintains a negative one. The dry spell C is the most determining in the productivity of the crops than the dry spell A. At last, through the correlation model of Pearson and estimated regression using the panel data, it was demonstrated that there is a significative relation between the dry spells class C and the drop in productivity in corn and bean crops.