Journal of Environmental Hydrology
ISSN 1058-3912


Electronic Journal of the International Association for Environmental Hydrology

JEH Volume 16 (2008), Paper 7    Posted January 31, 2008
PHOSPHORUS LOADING ESTIMATION USING A FUZZY VOLLENWEIDER- IHACRES MODEL, MALAYSIA

Supiah Shamsudin1
Ling How Ing1
Azmi Ab Rahman2

1Faculty of Civil Engineering
2Faculty of Management and Human Resource Development
Universiti Teknologi Malaysia


ABSTRACT
Eutrophication processes degrade lake or reservoir systems if not monitored and managed properly. This study estimates the phosphorus loadings for the Layang reservoir using the Vollenweider-IHACRES model. The IHACRES model was used to predict streamflow to the reservoir for the Vollenweider model. A fuzzy membership function was then used to describe phosphorus content, hydraulic loadings, and the phosphorus loadings representing the current conditions of the reservoir. The most likely range of phosphorus content was 0.1 to 0.3 mg/l and hydraulic loading was 1350 to 1400 m/yr. The average phosphorus content was 0.214 mg/l and average hydraulic loading was 1452 m/yr. The average calculated phosphorus loading was 0.6 g/m2/yr (18.02 tons/year), within the estimated range of 0.26 to 0.81 g/m2/yr (7.81 ton/yr to 24.28 ton/yr). The average daily inflow from the IHACRES model ranged from 4.95 to 2.99 m3/s. The bias from the IHACRES model ranged from -0.5546 to -0.0076 mm/day. The R2 values ranged from 0.9925 to 0.9208. Both statistics, in terms of bias and R2 value, show that the model is able to perform well.

Reference: Shamsudin, S., L.H. Ing, and A.A. Rahman. 2008. Phosphorus loading estimation using a fuzzy Vollenweider- IHACRES model, Malaysia. Journal of Environmental Hydrology, Vol. 16, Paper 7.
CONTACT:
Supiah Shamsudin
Universiti Teknologi Malaysia
81310, UTM-Skudai
Johor, Malaysia


E-mail: supiah_utm@yahoo.com



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