Potential Impacts of Land Use Changes on Water Resources in a Tropical Headwater Catchment

Magda Stella De Melo Martins,Vera Lúcia Abdala,Regina Maria Bessa Santos,Marcelo Zanata,Luís Filipe Sanches Fernandes,Teresa Cristina Tarlé Pissarra,Fernando António Leal Pacheco,Carlos Alberto Valera

doi:10.3390/w13223249

Abstract

The main objective of this study was to investigate the relationships between land use and future scenarios of land changes on water runoff and groundwater storage in an Environmental Protection Area (EPAs) watershed. The methodology was based on the application of the Soil and Water Assessment Tool (SWAT) hydrological modelling to investigate flow simulations in current land use and in two future scenarios (forest and pasture). The performance of goodness-of-fit indicators in the calibration (NSE = 0.82, R2 = 0.85, PBIAS = 11.9% and RSR = 0.42) and validation (NSE = 0.70, R2 = 0.72, PBIAS = −4% and RSR = 0.55) was classified as good and very good, respectively. The model accurately reproduced the inter-annual distribution of rainfall. The spatial distribution of average annual surface flow, lateral flow, and groundwater flow were different between sub-basins. The future scenario on land use change to forest (FRSE) and pasture (PAST) differed during the year, with greater changes on rainy and dry seasons. FRSE increase of 64.5% in area led to decreased surface runoff, total runoff, and soil water; and increased lateral flow, groundwater, and evapotranspiration. The effect of the natural vegetation cover on soil moisture content is still unclear. The hydrological model indicated the main areas of optimal spatial water flow. Considering economic values, those areas should encourage the development of government policies based on incentive platforms that can improve environmental soil and water sustainability by establishing payment for environmental services (PES).

Highlights

The extent of land use land changes (LULC) in tropical headwater catchment can result in the deterioration of many natural materials as a result of a human actions that directly affect the water and soil resources
The streamflow was calibrated to a 5-year period (1982–1987) and validated to a 4-year period (2006–2010), both monthly
This study shows a way of looking at the effect of land use change in watersheds on the volume of water available, as a subsidy to payments for ecosystem services (PES) system, that can come about with the establishment of catchments on springs, and the hydrological benefits that will come from productive pasture potential of land to be changed into forest land with more biodiversity and hydrological functioning

Summary

Introduction

The extent of land use land changes (LULC) in tropical headwater catchment can result in the deterioration of many natural materials as a result of a human actions that directly affect the water and soil resources. Each land use production unit varies in its effect on environmental attributes [12], and impact the hydrologic cycle, affecting people’s living. During the last few decades there has been an increase in world population and LULC impact on soil and water resources [6,9,11,12], and a better improved land organization is important to better distinguish the watershed factors of the ecosystem balance. Understanding the potential impacts on water and soil resources is challenging and enables consideration of the aspects on how LULC varies in space and time to apply better management practices

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Discussion

Conclusion