Análise da Taxa de secagem da umidade do solo na bacia experimental do riacho Guaraíra

Abstract

Natural soil moisture is related to the water present in the highest part of the soil. This variable is a fundamental aspect in the generation of surface runoff, evaporation estimate, infiltration processes, and other factors that might interfere in the water balance of a region. In this way, the soil moisture is perceived in both hydrological, biological and biogeochemical processes. In this study, the main goal is to analyze the behavior of decreasing soil moisture throughout time, here denominated as drying rate. For this purpose, we used hydrological monitoring data from the Guaraíra Experimental Basin, which is located in the coastal region of Brazilian Northeast, being representative of this area. The soil moisture values are measured by TDR (Time Domain Reflectometry) probes, installed vertically at five points in the experimental basin. The period of data selected for the survey was six years from station 01 and eleven years from station 02, between the years of 2004 and 2016. In order to analyze the soil moisture variability during the soil drying process, in both dry and wet periods, drying events were identified and the different peculiarities of each variable were investigated. Classification criteria were also established in order to distinguish periods and events with different characteristics, to perform descriptive statistics analyzes through box-plot diagrams for each category. Divergent results were observed for the different dry rate intervals and periods of the drying rate events. In the dry periods, the behavior of soil water loss was with a potential trend throughout the event for both stations. In the wet period, this tendency was maintained for one of the monitored stations, however, for the other one noticed a linear behavior, with relative linearity throughout the event. In this way, it is possible to emphasize the importance of this study, since in the same experimental basin the soil moisture dynamics differs. And to predict how water loss per soil occurs, observing specific characteristics of the area, is useful for numerous unfolding of the water resources management, such as irrigation and agriculture.