Zulkiflee Ibrahim

Sediment phosphorus loadings uncertainty using fuzzy-logic in detention pond at Southern Malaysia

This study vitalized the uncertainty and fuzzy rules consideration in the detention pond sediment phosphorus loadings estimation .Sediment phosphorus is pollutant of primary concern as it may result in adverse environmental effect of the hydrological systems.Detention pond establishmentbecome a practical control measures to improve the downstream water quality.The purpose of this study is to estimate the sediment phosphorus loadingsuncertainty for the detention pond at UniversitiTeknologi Malaysia (UTM) using Fuzzy Logic MUSLE-IHACRES model.The IHACRES model was used to predict the streamflow into the detention pond that later be used in the MUSLE model.The streamflow modelling using IHACRES model showed that the largest bias was -1.2157 mm/day and the smallest bias is -0.0265 mm/day. The highest r2 value was 0.9204 while the lowest was 0.7813. Both statistics showed that the model was able to perform well. The resultsfrom MUSLE-IHACRES model showed that the maximum value ofsediment yield was 254.88 tons/ha /yr and minimum value was 84.40 tons/ha/yr.This study also forecast accumulated sediment loads and depth using MUSLE-IHACRES over 10-100 years. The highestfrequencyor most likely range of sediment phosphorus wasless than 350 ton/year (257tons/ha/year). The average phosphorus content in sediment obtained was 34.0 mg/g and the sediment phosphorus loadings estimated using fuzzy logic was 28.72ton/year.The sediment phosphorus distribution investigated using Fuzzy Logic was presented. Suggested control measures need to be established as the sediment deposition is degrading the pondand approaching the Eutrophic Status.