doctoralThesis
Influência dos extremos climáticos e do balanço hídrico na produtividade agrícola
Fecha
2021-04-30Registro en:
VALE, Tásia Moura Cardoso do. Influência dos extremos climáticos e do balanço hídrico na produtividade agrícola. 2021. 140f. Tese (Doutorado em Ciências Climáticas) - Centro de Ciências Exatas e da Terra, Universidade Federal do Rio Grande do Norte, Natal, 2021.
Autor
Vale, Tásia Moura Cardoso do
Resumen
In a scenario of climate change, the current levels of productivity, under broad
environmental conditions, production per harvested area is intrinsically linked to issues
of water availability in the soil. Understanding climate influence and water balance on
agricultural productivity can assist in the performance of practices in the field and
policies to reduce climate-related vulnerability. In this perspective, the objective of this
thesis is to analyze the behavior of the productivity of the crops: cassava, corn and
beans in view of the climatic variability and water balance, in the Northeast Region of
Brazil. Two articles were developed: the first identifies space-time patterns of daily
precipitation, verifying associations with crop yields, in the state of Rio Grande do
Norte, 1980 to 2013; the second analyzes the Climatological Normal Water Balance
and the sequential and its relationship with crop productivity in the Northeast region of
Brazil, 1990 to 2019.Daily and climatic data provided by Xavier et al. (2015), from
1980 to 2013 and data from the Era Retrospective Analysis for Research and
Applications version 2 (MERRA-2) from the Global Modeling and Assimilation Office
(GMAO) with the support of the modeling program of America's Space Agency
(NASA), for the period from 1990 to 2019. Various statistical methods were used:
correlation analysis, Mann Kendall trend test, Cluster analysis, Tukey test, Factor
Analysis, among others. The first study observed from moderate to strong positive and
significant correlations of precipitation indicators with the productivity of subsistence
agriculture, its trends, regions of greater agricultural aptitude and better periods
indicated for the beginning of planting, according to the climatology of each region of
the state of Rio Grande do Norte. The second study evaluated, based on the
Thornthwaite climate classification of the Moisture Index, six typologies: Arid (28
municipalities); Semiarid (746 municipalities); Dry Sub-humid (536 municipalities);
Sub-humid (389 municipalities), Humid B1 (73 municipalities) and Humid B2 (20
municipalities). The results showed an increase in radiation, temperature and
evapotranspiration, mainly in the humid regions of the NEB. There was also an
increase in water deficiency in SON and, consequently, a reduction in storage in all
regions during the DJF period. It was found that in the two most humid regions, evapotranspiration and temperature correlated positively with the yields of beans and
corn, while in the less humid areas, storage and water surplus had greater positive
associations with agricultural productivity. According to the monthly climatological
water balance, the periods of greatest water capacity for the regions were different
between January and April. It is concluded, therefore, that the understanding of the
behavior of the water balance variables and their relationship with agricultural
productivity help in management strategies associated with climatic variations / trends, especially for the purposes of agricultural and hydrological planning and for irrigation
projects for farmers and local managers in Northeast Brazil.