Application of SLEMSA and USLE erosion models for potential erosion hazard mapping in South-eastern Nigeria.

摘要

Two potential erosion hazard maps of Anambra and Enugu States of Nigeria were developed by the application of SLEMSA [Soil Loss Estimation Model for Southern Africa] and USLE [Universal Soil Loss Equation] erosion models. The purpose was to ascertain which of these models is more applicable to the study area. Information was obtained from the soil map of the area, topographic map sheets of 1:50 000, aerial photographs, and rainfall data. In each case five erosion hazard classes were developed. Forthe SLEMSA the erosion hazard unit (EHU) categories are moderate (<100), moderately high (101-250), high (251-500); very high (501-1000) and extremely high (>1000). The USLE model is categorised into very slight (<50 t/ha per year); slight (50-150 t/ha per year); moderate (151-500 t/ha per year); severe (501-1500 t/ha per year), and very severe (>1500 t/ha per year). A combination of potential soil loss of USLE and the interception factor of SLEMSA gave more realistic soil loss values, although the USLEmodel reflected the actual field situations better.