Quantification of water balance using a lysimeter in Mexico

Abstract

Under conditions of high pressure on water resources, it is essential to quantify the water balance. There are tools to perform the water balance, but unfortunately, they are expensive and hardly accessible in developing countries. The objective of this study was to quantify the water balance using a low-cost lysimeter (LCL). Rainfall was measured using rain gauge. Soil water content (and infiltration were measured in the LCL, which was out in the open. The site of study was a place in La Malinche volcano (Mexico). Evaporation was calculated using the water balance equation. In order to evaluate the LCL efficiency, measurements were registered for two years (2015-2016). The distribution of the rainfall data was assessed using Kolmogorov-Smirnov test (K-S). The Mann-Whitney test (M-W) was used to compare rainfall, and infiltration for the two years. HYDRUS-1D software was used to simulate soil water storage () in the LCL. The efficiency of HYDRUS-1D was evaluated with Nash-Sutcliffe test (N-S). The total annual rainfall was 992.1 mm for 2015 and 1025.1 mm for 2016. The K-S test showed that rainfall data had exponential distribution in both years. The M-W test evidenced that rainfall, and infiltration were not significantly different (p>0.05) for the two years. Rainwater infiltration was 6.4% for 2015 and 5.9% for 2016. Most of the rainfall was evaporated, reaching percentages around 94%. N-S test showed that there was a good simulation of the LCL by HYDRUS-1D software. The water balance indicated that currently, La Malinche recharge area is insufficient to compensate the water consumption of Puebla and Tlaxcala. The use of low cost lysimeter would be of great help in expanding basin-scale water balance studies.