Surface water balance at the Chapingo River basin: rainfall intercepted by vegetation and water infiltration into the soil

Resumen

Objective: To estimate the surface water balance in the Chapingo River microbasin in the years 2014, 2016, 2017, and 2018, based on information collected on rainfall and runoff, the use of interception simulation models, and the estimation of the of infiltration as a remainder of the balance.

Design/Methodology/Approach: During the 2014, 2016, 2017, and 2018 wet seasons, the water balance in unit sheet was estimated based on rainfall and runoff data, mathematical interception simulation models, and estimation of infiltration as a remainder of the balance.

Results: The highest interception rate was recorded in 2014, with a shorter range and lower dispersion of rainfall, while the lowest interception occurred in 2018 with opposite rainfall characteristics. A linear relationship was found, in two years, between rainfall and surface runoff with R² greater than 0.81. The interception rate was lower in the oyamel fir forest (7.7-9.3%), while the variation in interception between grasslands, pine forests, oak forests, and agricultural areas ranged from 20% to 23%. The remaining infiltration water represented between 85.5% and 88.2% of the rainfall.

Study Limitations/Implications: Determining the temporal evolution of the interception and humidity in the soil is necessary to specify the potential recharge to the aquifer.

Findings/Conclusions: Interception is the main vehicle by which water reaches the ground in areas covered by vegetation. Rainfall intensity has a negative impact on interception and infiltration. The basin under study offers a high recharge potential to the Texcoco aquifer.