It is desirable to propose a centralized coverage method when monitoring key areas under different pollution levels. Particle swarm optimization（ PSO） algorithm based on weighted factors adjustment is used

and compare effect of particle numbers on network coverage ability. According to the simulation results

the sensor nodes can achieve fast-adaptive and well-distributed deployment

as well as avoiding local optimal. With the increase of swarm size

coverage ability of the sensor network is becoming larger

however decreasing after 20. It is of high importance that key water area is covered by sensor nodes after uniformly deployment

hence ensuring the reliability of the water quality data.