Essential Site Maintenance: Authorea-powered sites will be updated circa 15:00-17:00 Eastern on Tuesday 5 November.
There should be no interruption to normal services, but please contact us at [email protected] in case you face any issues.

loading page

Landcover Dynamics and their Influence on the Seasonal and Interannual Hydrology of an Amazonian Floodplain Using Hydrological Model and Satellite
  • +3
  • Tainá Sampaio Xavier Conchy Rocha,
  • Sebastien PINEL,
  • Lucas Garcia Magalhães Peres,
  • Joecila Santos Da Silva,
  • Eduardo Antonio Ríos‑Villamizar,
  • Marie-Paule Bonnet
Tainá Sampaio Xavier Conchy Rocha
Universidade do Estado do Amazonas

Corresponding Author:[email protected]

Author Profile
Sebastien PINEL
Universidade do Estado do Amazonas
Author Profile
Lucas Garcia Magalhães Peres
Universidade de Brasilia
Author Profile
Joecila Santos Da Silva
Universidade do Estado do Amazonas
Author Profile
Eduardo Antonio Ríos‑Villamizar
Universidade do Estado do Amazonas
Author Profile
Marie-Paule Bonnet
Institut de Recherche pour le Developpement Delegation Regionale Occitanie
Author Profile

Abstract

The spatio-temporal land cover dynamics of a medium‐size floodplain system along the Amazon/Solimões River (Janauacá Lake, 786 km 2) and their hydrological impacts are studied through remote sensing and modeling. Hence, the analysis of 5 satellite-derived land cover maps (1972-2016 period) reveals a decrease in natural environments (from 65% to 35%) to the benefit of anthropic classes (from 17% to 51%) through deforestation vectors (two highways and lake banks). Deforestation is a non-stationary process with significant increase over specific subperiods (1972-1986, and 2005-2016). It occurs in stages with conversions into secondary vegetation then into non-natural environments. 7 land cover scenarios (5 satellite-derived, 1 deforested and 1 forest, used as reference) are used as inputs to run simulations with the same meteorology over the 2006-2018 period. Beside high ( ≥ 24%) and low ( ≤ 7%) interannual variability of runoff-rainfall ratio (RRR) and evapotranspiration (ET), the numerical experiments evidence, on an annual scale, the RRR decreases and the ET increases with deforestation increases. Deforested scenario suggests a convergence: for the RRR, around 0.34 (-87%) and for the ET, around 1146 mm.yr -1 (+6%). At the seasonal scale, the landuse/landcover changes (LUCC) induce positive wet season ET anomaly (<9%) and large negative dry season RRR anomaly (-87%). The highest LUCC-induced disturbances (from -15% to 18%) in the FP mixture are recorded at seasonal scale, during LW and RW and, at interannual scale, during dry and normal HY. The LUCC-induced disturbances patterns of FP mixture mainly concern river and runoff. They are different regarding the hydrological period or HY type. Our experiments suggest the existence of a tipping point between present land cover (2016) and fully deforested cover associated with reversal phenomena and enhancing of seasonal and interannual LUCC-induced disturbance. At last, the model shows the LUCC augment the vulnerability associated with drought periods.