Sedimentation Study at Setiu Wetland by using GIS Technology (AV SWAT): Emphasis on Suspended Sediment Concentration (SSC)
This study was done in order to identify total of sediment load at Setiu Wetland by using AVSWAT model. AVSWAT is very appropriate to simulate the sediment yield monthly. It was built to overcome the problem of long term simulation and prediction of quantity and sources point of sediment yield into catchments area based on land cover and soil type. Furthermore, the aim of the study also to get the correlation value between SSC and sediment load data for SSC prediction by using AVSWAT in the future without come to the field. 8 years data has been used in the AVSWAT analysis from 2000 to 2007 to ensure the preciseness of the result. To improve the accuracy, AVSWAT out put data have been compared with SSC and current velocity data which got manually at Sungai Setiu. Filtration technique have been use to measure the suspended sediment concentration. To remove the organic matter the sample was burned in furnace at temperature 550oC The study shows the total sediment load at Setiu Wetland was decrease by the year together with the declining of total precipitation. Total of sediment load at 2007 is 10739490 metric tonne. 2563149 metric tonne less comparing with year 2006. Correlation between sediment load and SSC based on month is 0.8462. While, the correlation between SWAT simulation of flow out and current velocity by current meter is 0.8177. Both of comparison shows the correlation is very significant. There are 4 main factors that’s play important role to determine the total of sediment load in water. Firstly, total of precipitation which related with current velocity and surface run off. The stronger current contains more energy to transport of sediment. Beside that, the variation of land use or land cover support different quantity of sediment into sub-basin. The study shows, sub basin which was engaged with urbanization, farming and deforestration/forestration contribute more sediment rather than covered area or evergreen forest. Whereas soil characteristic which have more sand in ratio support less of sediment comparing with silt and clay.