THE EFFECT OF LAND CONVERSION ON SOIL QUALITY IN A SEMI-ARID ENVIRONMENT: THE CASE OF SCRUBLAND TO PERMANENT CULTIVATION

Abstract

The study assessed the effects of land conversion in a semi-arid environment. Remote 
Sensing, GIS and field-based technologies were integrated to assess the effects of Land 
use/Land cover changes from 1986 to 2011on soil quality in parts of Katsina state, 
northern Nigeria as an area demarcated for the study. Four Landsat satellite image scenes 
with the same Path and Row numbers (189/051) for 1986, ETM of 1996, ETM+ of 2006 
and ETM+ of 2016 were used for LULC change detection and analysis. Ground– truth 
exercise was conducted to gather field data useful for the classification of the satellite 
images of the area. GPS points used for both training sample set for the classification and 
reference data for accuracy assessment were collected. Supervised Classification 
procedure was used to classify the entire sub set images separately for 1986, 1996, 2006 
and 2011. Post-classification comparison of classified land use/land cover statistics was 
employed using cross tabulation approach in detecting and assessing changes of the 
various LULC parameters in this study. It was observed that textural composition of the 
soil at top and sub surface layers in this change scenario area vary from 78% to 80% with 
1.63 and 0.98 standard deviations respectively. Mean silt values of soils in this change 
scenario vary from 16% at the top layer and 14% at the sub surface layers, with 1.25 and 
0.91 standard deviations. Similarly, mean clay values of soils at the top and sub surface 
layers of soils remained 6% with 1.11 and 0.29 standard deviations. Satellite imageries 
provided a good source of information for detecting changes in land use/land cover in the 
study area. 
Keywords: Lan