3.2. Mud accumulation
Constructed fences significantly enhanced deposition of sediment
in the study area. Mud accumulation was significant different
between fence treatments and control (t = 3.81; P = 0.002 < 0.05).
Three years after construction, 44 cm of mud had been deposited in
treatment 1 (wave barrier fence) and 42 cm in treatment 2 (silt trap
fence). In contrast, only 0.3 cm of mud was accumulated in the
control area, and only within 5 m of the shore. In both fence
treatments, mud accumulated mostly in the
first year (29 cm in
treatment 1 and 33 cm in treatment 2) and slowed down in the
second and third year (Fig. 6).
Fig. 7 shows that there was a strong dynamic of the sediment
accretion and erosion processes in the study site. In the fence areas,
mud mainly deposited in the wet season and continued
accumulating in the dry season. In contrast, a depth layer
(17 cm) of sediment in the open (control) area that was accelerated
at the earlier months of the wet season but it was washed away
within one to two months at the end of this season.