Water Availability of São Francisco River Basin Based on a Space-Borne Geodetic Sensor

Tengke Sun,Xiufeng He,Samuel Andam-Akorful,Vagner Ferreira

doi:10.3390/w8050213

Abstract

Brazil has recently experienced one of its worst droughts in the last 80 years, with wide-ranging consequences for water supply restrictions, energy rationing, and agricultural losses. Northeast and Southeast Brazil, which share the São Francisco River basin (SFRB), have experienced serious precipitation reduction since 2011. We used terrestrial water-storage (TWS) fields, inverted from the Gravity Recovery and Climate Experiment (GRACE) mission measurements, to assess and quantify the ongoing drought over the SFRB. We found a water loss rate of 3.30 km3/year over the time-span of April 2002 to March 2015. In addition, the TWS drought index (TWSDI) showed the extension of the recent drought that has jeopardized the SFRB since January 2012, and which reached its maximum in July 2015 (the end of TWS time series). In this sense there seems to be a linkage between the TWSDI (wetness/dryness) and the El Niño Southern Oscillation (ENSO), in terms of the wavelet coherence, at the semi-annual and biennial bands, suggesting a relationship between the two. While acknowledging that further investigation is needed, we believe that our findings should contribute to the water management policies by quantifying the impact of this drought event over the SFRB.

Highlights

Drought, as an extreme hydrological event, has serious impact on humanity
The spatial pattern of total water-storage gains or losses estimated from Gravity Recovery and Climate Experiment (GRACE) data for Brazil covering the period of April 2002 to March 2015 (13 years of time span) is shown in Figure 2 in units of km3
The São Francisco River basin (SFRB) extends to almost one million square kilometers serving the northeast and much of the southeast of Brazil

Summary

Introduction

As an extreme hydrological event, has serious impact on humanity. Impacts include loss of life, crop failures and food shortages, health issues, and mass migration [1] and the consequences on society and the environment are far reaching. Tøttrup et al [2] have reported the impact of drought at the Horn of Africa on the phenology of the songbirds’ migrations to Europe. The environmental effects of droughts in Amazonia, a very humid region, have included forest fires, reductions of biomass, and forest mortality [3]. Despite its impacts drought remains a major threat causing extensive damage to the environment and the economy around the world. The global effects of droughts and extreme heat have cut average national cereal production by 9%–10% with more damage in developed countries than developing ones [4]

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Discussion

Conclusion