Blue tide, upwelling of anoxic water, is a serious water pollution problem in Tokyo Bay. To evaluate each source of anoxic water in navigation channels and dreged trenches, we first proposed a practical method for estimating the amount of sulfide in each water using a measured value of sulfide at the bottom and measured vertical profiles of pH and ORP. We then set an intial condition of sulfide distribution in each water and peformed numerical simulation of upwelling of sulfide using a primitive equation model with nesting. Through the numerical experiments, we can evaluate the contribution of each water to the magnitude and area of the outbreak of blue tide along with its upwelling processes.