Geotecnologias na estimativa do índice de erosividade da chuva para a microrregião de Sinop - MT

Abstract

In fact, agriculture is a critical part of food security in the world. The agricultural sector is very important for brazilian economy being responsible for 44% of exports. This fact proves that soil convervation studies are necessary to agricultural development and food availability. The rain is able to degrade the soil, being an important factor in erosion studies. This work aims to compare precipitation obtained from remote sensing and rainfall station to calculate the rainfall erosivity index for the microregion of Sinop, Mato Grosso. This work was done by using data from 15 stations concerning to 9 years: 1985, 1986, 1996, 1997, 1998, 1999, 2000, 2001, 2005, and CHIRPS rainfall data were obtained from Google Earth Engine in the microregion of Sinop. The comparison was done between rainfall and CHIRPS data through Pearson correlation, RMSE and pluviometric differences. The EI30 factor was calculated by means of the linear regression adjusted equation for a county in the whole study area. The interpolation method Inverse Distance Weighted (IDW) was applied aiming at data spatialization to obtain the final rainfall erosivity maps. The results showed that exists correlation between CHIRPS data and rainfall station data, in a monthly scale, for every station in the range of 0,85 to 0,98. Through the differences between CHIRPS and station data, was possible to define a dry and a rainy season. The maps showed a period of intense rainfall erosivity from october to march and EI30 factor ranged along the microregion from 13.500 MJ.mm(ha.h.ano)1 to 15.600 MJ.mm(ha.h.ano)-1 .