Impacts of land use and land cover changes on hydrological processes and sediment yield determined using the SWAT model

• Published in: International journal of sediment research Vol. 37; no. 1; pp. 54 - 69
• Main Authors: Afonso de Oliveira Serrão, Edivaldo, Silva, Madson Tavares, Ferreira, Thomás Rocha, Paiva de Ataide, Lorena Conceição, Assis dos Santos, Cleber, Meiguins de Lima, Aline Maria, de Paulo Rodrigues da Silva, Vicente, de Assis Salviano de Sousa, Francisco, Cardoso Gomes, Denis José
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.02.2022; Academic Unit of Atmospheric Sciences,Federal University of Campina Grande,Campina Grande,PB,Brazil%Institute of Technology,Civil Engineering Graduate Program,Federal University of Par(a),PPGEC/ITEC/UFPA Bel?em,PA,Brazil%Earth System Science Center,National Institute of Space Research,S(a)o Jos(e) dos Campos,SP,Brazil%Institute of Geosciences,Federal University of Par(a),Bel?em,PA,Brazil%Department of Physics,Center for Natural and Exact Sciences,Federal University of Santa Maria,Santa Maria,RS,Brazil
• Subjects: Amazon basin; Hydrological modeling; Sediment yield; SWAT model; Sediment yield; SWAT model; Hydrological modeling; Amazon basin
• ISSN: 1001-6279
• DOI: 10.1016/j.ijsrc.2021.04.002

Land use and land cover (LULC) changes strongly affect local hydrology and sediment yields. The current study focused on a basin in the Brazilian Amazon and had the following three objectives: (1) to perform an effective diagnosis of flow and sediment yield, (2) to evaluate the impacts of LULC changes over the last 40 years on the hydro-sedimentological variables, and (3) to investigate the impacts of the possible trends or breaking points in the flow, surface runoff, and sediment yield series. The Soil and Water Assessment Tool (SWAT) model validation showed that the simulated results were consistent with the data measured in the dynamic reproduction of flow seasonality. Furthermore, changes in LULC altered surface runoff, sediment yield, and flow according to the Mann-Kendall and Pettitt non-parametric tests. It was also observed that the sub-basins in which pastureland is predominant are more susceptible to increased surface runoff and sediment yield. According to trend and homogeneity tests, these sub-basins had break points in the time series of these variables. On the other hand, in the sub-basins whose land cover is predominantly forest, the time series is homogeneous and trendless. The current study highlighted the impacts that 40 years of LULC changes in an Amazonian basin had on hydro-sedimentological variables, which, in turn, can play an important role in changing the hydrological cycle, consequently these changes can also impact diverse human activities in the region, such as agribusiness, livestock, energy production, food security, and public water supply. Thus, it is concluded that the SWAT model is a good estimator of hydro-sedimentological processes in Amazonian basins and can be used by decision makers in the management of water and environmental resources. [Display omitted] •Changes in land use impact sediment yield in the Amazon.•The SWAT model was calibrated and validated for an Amazon subbasin.•Soil types, land use, and slope are the main factors affecting sediment yield.•Subbasins dominated by pasture showed a positive trend and a break point.•Over 57% of forest areas have been converted to pasture on the IRW.