Impacts of future deforestation and climate change on the hydrology of the Amazon Basin: a multi-model analysis with a new set of land-cover change scenarios - Sorbonne Université Access content directly
Journal Articles Hydrology and Earth System Sciences Year : 2017

Impacts of future deforestation and climate change on the hydrology of the Amazon Basin: a multi-model analysis with a new set of land-cover change scenarios

Juan Pablo Boisier
  • Function : Author
  • PersonId : 936896
Ana Paula Dutra Aguiar
  • Function : Author
Hester Biemans
  • Function : Author
David Galbraith
  • Function : Author
Bart Kruijt
German Poveda
  • Function : Author
Anja Rammig
Daniel Andres Rodriguez
  • Function : Author
Graciela Tejada
  • Function : Author
Kirsten Thonicke
Rita C. S. von Randow
  • Function : Author
Ke Zhang
  • Function : Author
Hans Verbeeck

Abstract

Deforestation in Amazon is expected to decrease evapotranspiration (ET) and to increase soil moisture and river discharge under prevailing energy-limited conditions. The magnitude and sign of the response of ET to deforestation depend both on the magnitude and regional patterns of land-cover change (LCC), as well as on climate change and CO 2 levels. On the one hand, elevated CO 2 decreases leaf-scale transpiration, but this effect could be offset by increased foliar area density. Using three regional LCC scenarios specifically established for the Brazilian and Boli-vian Amazon, we investigate the impacts of climate change and deforestation on the surface hydrology of the Amazon Basin for this century, taking 2009 as a reference. For each LCC scenario, three land surface models (LSMs), LPJmL-DGVM, INLAND-DGVM and ORCHIDEE, are forced by bias-corrected climate simulated by three general circulation models (GCMs) of the IPCC 4th Assessment Report (AR4). On average, over the Amazon Basin with no deforestation, the GCM results indicate a temperature increase of 3.3 • C by 2100 which drives up the evaporative demand, whereby Published by Copernicus Publications on behalf of the European Geosciences Union. 1456 M. Guimberteau et al.: Impacts of future deforestation and climate change on the Amazon hydrology precipitation increases by 8.5%, with a large uncertainty across GCMs. In the case of no deforestation, we found that ET and runoff increase by 5.0 and 14 %, respectively. However, in southeast Amazonia, precipitation decreases by 10 % at the end of the dry season and the three LSMs produce a 6 % decrease of ET, which is less than precipitation, so that runoff decreases by 22%. For instance, the minimum river discharge of the Rio Tapajós is reduced by 31 % in 2100. To study the additional effect of deforestation, we prescribed to the LSMs three contrasted LCC scenarios, with a forest decline going from 7 to 34 % over this century. All three scenarios partly offset the climate-induced increase of ET, and runoff increases over the entire Amazon. In the southeast , however, deforestation amplifies the decrease of ET at the end of dry season, leading to a large increase of runoff (up to +27 % in the extreme deforestation case), offsetting the negative effect of climate change, thus balancing the decrease of low flows in the Rio Tapajós. These projections are associated with large uncertainties, which we attribute separately to the differences in LSMs, GCMs and to the uncertain range of deforestation. At the subcatchment scale, the uncertainty range on ET changes is shown to first depend on GCMs, while the uncertainty of runoff projections is predominantly induced by LSM structural differences. By contrast , we found that the uncertainty in both ET and runoff changes attributable to uncertain future deforestation is low.
Fichier principal
Vignette du fichier
Guimberteau_2017_hess_Amaz_deforestation.pdf (9.41 Mo) Télécharger le fichier
Origin : Publisher files allowed on an open archive
Loading...

Dates and versions

hal-02165378 , version 1 (25-06-2019)

Identifiers

Cite

Matthieu Guimberteau, Philippe Ciais, Agnès Ducharne, Juan Pablo Boisier, Ana Paula Dutra Aguiar, et al.. Impacts of future deforestation and climate change on the hydrology of the Amazon Basin: a multi-model analysis with a new set of land-cover change scenarios. Hydrology and Earth System Sciences, 2017, 21 (3), pp.1455-1475. ⟨10.5194/hess-21-1455-2017⟩. ⟨hal-02165378⟩
923 View
309 Download

Altmetric

Share

Gmail Facebook X LinkedIn More