@InProceedings{BormaLimaOmet:2019:SoMoVa,
author = "Borma, Laura de Simone and Lima, Jos{\'e} Romualdo and Ometto,
Jean Pierre Henry Balbaud",
affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and
{Universidade Federal Rural de Pernambuco (UFRPE)} and {Instituto
Nacional de Pesquisas Espaciais (INPE)}",
title = "Soil moisture variation along a toposequence in the northeast
Brazilian caatinga",
year = "2019",
organization = "EGU General Assembly",
abstract = "Soil moisture variations and soil water potentials are crucial to
understand the plant behavior under water stress conditions. Such
kind of data are also valuable for modeling efforts in hydrology,
ecophysiology, soil-plantatmosphere interactions and earth system
models. Here we present soil moisture variation along the
hydrological year of 2015 for 4 different soil profiles along a
topographic gradient in the Brazilian caatinga, Sao Joao site,
northeast Brazil, Pernambuco state. The data were collected using
Sentek probes, Enviroscan type, in sandy soil profiles of 0.4 m
(P1), 0.5 m (P2), 0.9 m (P3) and 1.10 m (P4), from the bottom to
the top of an instrumented hillslope of around 1 km length. Along
this topographic gradient, the maximum depth of probes
installation occurred due to the existence of an impenetrable
layer, commonly found in some areas of the Caatinga biome. Our
results show that, during the rainy season, in the deepest soil
profile (P4) from the upper part of the slope, soil moisture
reached the maximum of 16% at the top layer (0.1-0.4 m soil
depths), while below 0.4 m depth, the maximum soil moisture
registered during rainy season were 6%. However, during the dry
period, soil moisture at the top (0.1-0.4 m soil depths) decreased
to values below 1 %, while the deeper soil layers (below 0.70 m)
maintained moisture content at values around 4% for the whole dry
period. In the shallower soil profile (P4), soil moisture also
reached the maximum of 16% in the wet season along the whole soil
profile. In the dry period, however, the top layer presented
maximum soil content of 1% while the bottom (0.4 m) maintain
moisture content of around 4%, similar to the deepest layer of the
P4 profile. Similar behavior was found for the intermediate soil
profiles (P2 and P3), suggesting that, independently of the depth
of the soil profile, soil moisture at the interface
soil/atmosphere present values below 1% in the dry season while at
the interface sandy soil/impenetrable layer, moisture is
maintained at around 3-5%. For the next steps, these results will
be analyzed in terms of rainfall rates, soil physical properties
and water storage in order to understand the water balance dynamic
for different soil depths above the impenetrable soil layer.",
conference-location = "Vienna, Austria",
conference-year = "07-12 apr.",
language = "en",
targetfile = "EGU2019-18249-1.pdf",
urlaccessdate = "03 jun. 2024"
}