Knowledge of phosphorus (P) variation regularity of sediment-water system has important influence on water pollution. Thus P variation regularity of top-sediment affected by some factors such as type of sediment (sandy and silty), background value of sedi Knowledge of phosphorus (P) variation regularity of sediment-water system has important influence on water pollution. Thus P variation regularity of top-sediment affected by some factors such as type of sediment (sandy and silty), background value of sedi