Development of a geospatial framework for monitoring and assessing desertification in Kebbi state, Nigeria
Terrestrial degradation nowadays presents one of the devastating environmental problems of the earth caused by natural as well as man-made factors. According to UNCCD, almost one-third of the world agricultural land is facing a degradation phenomenon. Desertification phenomenon is threatening...
Saved in:
| Main Author: | |
|---|---|
| Format: | Thesis |
| Language: | English |
| Published: |
2018
|
| Subjects: | |
| Online Access: | http://psasir.upm.edu.my/id/eprint/75813/1/FH%202018%2012%20IR.pdf |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | Terrestrial degradation nowadays presents one of the devastating environmental
problems of the earth caused by natural as well as man-made factors. According to
UNCCD, almost one-third of the world agricultural land is facing a degradation
phenomenon. Desertification phenomenon is threatening Kebbi state with huge
drawback relating to the diminishing of ecosystem services and negative
socioeconomic impact on community livelihood. However, the extent, trends and
severity of desertification in Kebbi state has neither fully recognised, nor the rate of its
development is accurately documented. Subsequently, the primary aim of the study is
to develop a geospatial framework to monitor and assess land degradation in the area
with specific emphasis on quantifying land cover (LC) change and vegetation depletion
from 1986-2016, modelling the LC change for the year 2026 and characterising
desertification sensitivity in the area.
Remotely sensed data were classified into five thematic LC classes namely dense
vegetation (DV), shrubs land (SL), farmland (FL), bare/grassland (BGL) and water
body (WB). The Driver-Pressure-State-Impact-Response (DPSIR) framework was
used for better understanding of the drivers, the state of the environmental condition,
the causes and the impact of the LC changes. Modelling the future (2016-2026) LC of
the area was conducted using the CA-Markov model. Desertification sensitivity of the
area was assessed using Mediterranean Desertification and Land Use-Environmental
Sensitivity Area Index (MEDALUS-EASI) methodology.
The analysis of LC change from 1986-2016, indicates a gradual decrease of DV by
about 61%, the downturn in the SL by about 25.7%. BGL has increased by about
18.2% while FL increases by 35.9%. WB remains unchanged. The drivers of the
change are mainly the demand for farming land as the population increases as well as
socio-economic stresses.The pressures of the change include expansion of farming land and the use of wood as
fuelwood, construction material and other domestic use. The state of the condition
indicates a decline in vegetated and shrubland, however; farming land and bare
grassland are increasing. The impacts include severe land degradation, soil erosion, the
decline in the provision of ecosystem goods and services and biodiversity loss. The
responses include afforestation programs by government and Non-Governmental
Organisations (NGO’s) however, communities and individuals organise an annual tree
planting campaign. The future LC prediction (2026) illustrates that FL and DV may
probably increase while SL and BGL may probably decline. WB may decrease
slightly. The spatial assessment of desertification sensitivity of the area indicates that
36% of the area is not affected. 17%, 30%, 15 % fall within a low, moderately and
sensitive categories respectively. Only 1% of the area is highly sensitive to
desertification. The impact of the different quality index to the desertification in the
area show that climatic indices have a high impact on desertification in the area
(r2=0.64) followed by soil indices (r2=0.47) and human indicators to desertification
(r2=0.45). Vegetation indices have the least impact to the desertification in the area
with (r2=0.38).
It is recommended that Governmental and NGO’s should make an essential strategic
plan for the continued in-depth assessment and monitoring of land degradation using
advanced tools. Adaptation and mitigation measures such as agroforestry system of
farming, robust afforestation and land restoration activities need to be strengthened.
Environmental education needs to be integrated into both primary and post-primary
teaching curricula to enhance environmental awareness. There is also the need to
improve the livelihood of the rural people by providing alternative income and
domestic energy sources since they depend heavily on natural resources for sustenance.
The novelty of the study laid on the integration of remote sensing and GIS, the
MEDALUS-EASI and the DPSIR frameworks for developing a unique and
explanatory platform for modelling LC cover trend and magnitude of land degradation
in the area. |
|---|