Estimation of soil erosion using USLE and GIS in the locality of Tzicatlacoyan, Puebla, Mexico

摘要

Deforestation and conversion of natural grasslands to agricultural land constitute two of the main threats to soil and water conservation, causing erosion, and likely, desertification. The objective of this study was to estimate the erosion of the soil in the locality of Tzicatlacoyan, applying the Universal Soil Loss Equation (USLE) through Geographic Information Systems (GIS). The results indicated that Tzicatlacoyan faces risk of soil erosion with an average annual rate of 117.18 t/ha.year, due to natural factors and anthropogenic activities such as the use of agricultural land without appropriate conservation practices. Four classes of soil erosion risk were identified, according to the rate of erosion (A) in t/ha.year: extreme risk (114 >= A <= 234.36), severe risk (59 >= A < 114), moderate risk (23 >= A < 59), and low risk (A < 23). Most of the area (180.96 km(2), 64.83%) was characterised by the low risk of erosion, while a small part (11.64 km(2), 4.17%) of the study area showed extreme risk. The results indicated that 13.33% of the territory of Tzicatlacoyan present values of soil loss exceeding tolerable. The assessment of the soil erosion using the USLE model and GIS might allow land users to make better decisions about the use and conservation of the soil and the ecosystem, adding scientific criteria to their traditional knowledge.