Effects of rainfall pattern changes due to global warming on soil water erosion in grasslands and other vegetation types in the state of Zacatecas, Mexico

Abstract

Temperature and precipitation anomalies were used to assess it for the 2021-2080 period, based on an assembly of 11 global circulation models, in order to generate future temperature and precipitation maps based on the reference climatology of the 1961-2010 period. In the state of Zacatecas, the grassland area has current average erosion values of approximately 16.3 t/ha, estimated using the RUSLE model. In other types of vegetation or land use as shrubs, forest or agricultural areas, values are even higher (50.74, 65.99, 161.39, t/ha/yr, respectively). The application of the ensemble model in RCP 4.5 and RCP 8.5 indicates that there will be an increase in temperature and a decrease in rainfall. In a scenario with less effect of global warming (SPC 4.5), a gradual reduction of grassland water erosion is expected, compared to 2010 of 2.3 % in 2030 (15.67 t/ha/yr) to 5.8 8% (15.18 t/ha /yr) in 2070. In the same period up to 2070, the rate of decline of water erosion is 14.1 kg/ha/yr. RCP 8.5, which was designed for a condition of continuous emission of greenhouse gases, exhibits even greater reduction values and for 2070 it establishes a decrease of 13.0 %, with an erosion reduction rate of 31.5 kg/ha/yr. Other types of vegetation and land use showed the same tendency to decrease, although at higher rates. The scenario of water erosion reduction seems favorable; however, an increase in soil loss values due to wind erosion in the arid regions of northern Zacatecas is not ruled out. The assessment of levels of water erosion contributes to the ordering of land use to reduce levels of degradation and desertification.