The Application of GIS and Remote Sensing in a Spatiotemporal Analysis...
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Erosion processes ranging from −0.1 to −7.9 m/year have been recorded from
the coastal sections of Rufisque to Nianghal while accretion phenomenon of 0.11
to 4.94 m/year only occurred towards the locality of Toubab Dialaw which is still
eroded in some of its parts. The mean rate of coastline change was estimated
at −2.58 m/year, showing net regression compared to the 1978–1988 period.
However, the surface analysis illustrated by Figure 8 shows that the phenom‑
enon of erosion remained more important than accretion with a clear sedimentary
deficit.
From 1988 to 1998 the estimated eroded surface was about 80.552 ha on 2.865 ha
of accreted areas showing an important sedimentary deficit of 77.687 ha and a rate
of 8.05 ha/year of erosion and 0.28 ha/year of accretion. Even if the surface of eroded
areas has tremendously decreased compared to 1978–1988, erosion still remained
a serious problem in that time.
Shoreline Change Rate from 1998 to 2008 (Figs. 9, 10)
From 1998 to 2008, the mean rate of coastline change provided by the analysis
was estimated at 1.04 m/year. This indicates that this period was marked by import‑
ant accretion as shown in Figures 9 and 10.
Figure 9 shows that during this period, the coastline was obviously marked
by important accretion ranging from 0.1 to 7.29 m/year and less important erosion
from −0.1 to −5.88 m/year.
Fig. 9. Shoreline change rate from 1998 to 2008
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Erosion processes ranging from −0.1 to −7.9 m/year have been recorded from
the coastal sections of Rufisque to Nianghal while accretion phenomenon of 0.11
to 4.94 m/year only occurred towards the locality of Toubab Dialaw which is still
eroded in some of its parts. The mean rate of coastline change was estimated
at −2.58 m/year, showing net regression compared to the 1978–1988 period.
However, the surface analysis illustrated by Figure 8 shows that the phenom‑
enon of erosion remained more important than accretion with a clear sedimentary
deficit.
From 1988 to 1998 the estimated eroded surface was about 80.552 ha on 2.865 ha
of accreted areas showing an important sedimentary deficit of 77.687 ha and a rate
of 8.05 ha/year of erosion and 0.28 ha/year of accretion. Even if the surface of eroded
areas has tremendously decreased compared to 1978–1988, erosion still remained
a serious problem in that time.
Shoreline Change Rate from 1998 to 2008 (Figs. 9, 10)
From 1998 to 2008, the mean rate of coastline change provided by the analysis
was estimated at 1.04 m/year. This indicates that this period was marked by import‑
ant accretion as shown in Figures 9 and 10.
Figure 9 shows that during this period, the coastline was obviously marked
by important accretion ranging from 0.1 to 7.29 m/year and less important erosion
from −0.1 to −5.88 m/year.
Fig. 9. Shoreline change rate from 1998 to 2008