@Article{MartinsKaBaFaLoNo:2019:ImSuWa,
author = "Martins, Vitor S. and Kaleita, Amy and Barbosa, Cl{\'a}udio
Clemente Faria and Fassoni-andrade, Alice C. and Lobo, Felipe de
Lucia and Novo, Evlyn M{\'a}rcia Le{\~a}o de Moraes",
affiliation = "{Iowa State University (ISU)} and {Iowa State University (ISU)}
and {Instituto Nacional de Pesquisas Espaciais (INPE)} and
{Universidade Federal do Rio Grande do Sul (UFRGS)} and {Instituto
Nacional de Pesquisas Espaciais (INPE)} and {Instituto Nacional de
Pesquisas Espaciais (INPE)}",
title = "Remote sensing of large reservoir in the drought years:
Implications on surface water change and turbidity variability of
Sobradinho reservoir (Northeast Brazil)",
journal = "Remote Sensing Applications: Society and Environment",
year = "2019",
volume = "13",
pages = "275--288",
month = "Jan.",
keywords = "inland water, Surface water change, Drought e\ff,,ects,
Atmospheric correction, Landsat-8.",
abstract = "Sobradinho reservoir has been suffering a severe water loss caused
by multi-year drought in the Northeast Brazil. This reservoir
contributes to the socio-economic development of the semi-arid
region, and the monitoring of water shortage is crucial for people
living in this climate-vulnerable region. In this study, we
evaluate the surface water change and turbidity variability of
Sobradinho reservoir during recent drought years (20132017). A
time-series dataset was created using 109 Landsat-8 OLI images for
mapping the water extent in the reservoir. A non-linear regression
between measured turbidity and surface reflectance (red band) was
developed and applied for turbidity retrievals. Additionally, we
performed a long-term precipitation analysis (17-year) to assess
the rainfall deficit over the catchment area. Our results show
that the annual precipitation regimes are below the long-term
average during 20122017 period, except 2013. We also found that
negative anomalies occur during 26 out of 36 months between 2014
and 2016, mostly in the rainy season. Since the rainfall regimes
and river discharges are the major drivers for water recharge,
these drought years have a critical impact on the reservoir level.
According to our results, the water surface receded about 2073 km2
(out of total 3303 km2) during September 2017; this represents a
reduction of 62.8% in the total water extent. The surface water
change is spatially distinct across the reservoir. For instance,
the upper section of the reservoir was almost totally dried during
September 2017, and the water coverage was ~8% (91.25 km2 out of
1128 km2). Although other sections had a relatively low water
change (reduction of ~40%), the losses are significant in terms of
area (~1035.5 km2). The receding of water extent affects the
people living near to the reservoir, and local communities are
more distant from water (up to 13 km). We also observed that the
turbidity is seasonally dependent, and water clarity presents a
strong variability between rainy and dry seasons. In general, the
turbidity levels vary from clear water (020 NTU) during the dry
season to turbid condition (>50 NTU) during the rainy season. A
lack of access to clean and safe drinking water in some periods
might be harmful to humans, livestock and domestic animals.
Finally, this research contributes to the assessment of
drought-related impacts in the Sobradinho, the largest reservoir
in the Northeast Brazil. The water shortage is a recurring concern
in the semi-arid region, and the remote sensing techniques provide
spatially explicit information to enhance the livelihood
resilience during drought years.",
doi = "10.1016/j.rsase.2018.11.006",
url = "http://dx.doi.org/10.1016/j.rsase.2018.11.006",
issn = "2352-9385",
language = "en",
targetfile = "martins_remote.pdf",
urlaccessdate = "20 set. 2024"
}