By the comparative analysis of mean flood process and characteristic volume before and after harness ,it shows that though the mean process rainfall after harness is bigger than that before harness, the peak flood and flood volume tend to decrease, and the sediment amount is decreased at 20 percent, and the flood rises and falls slowly.

Air-lift performance was investigated experimentally for different air injection method,the discharged liquid flux,discharged particle mass,concentration of particles and efficiency were tested by changing the number of air injection nozzle,angle of injection and arrangement of air pipe.

Air-lift performance is investigated experimentally for different jet nozzles,the discharged liquid flux,discharged particle mass,concentration of particles and efficiency are tested by changing the number of jet nozzles.

Characteristics and impact factors of sediment concentration in lower reaches of three great rivers of Hainan province in the recent 40 years;

Influence of variations in suspended sediment concentration and grain size on sediment deposition of Yichang-Hankou reach of Yangtze River;

Relationship between quartz component and sediment concentration and calculation on the year occurrence number of wearing sediment concentration in Shantou Bay;

To solve them,ways to calculate section average silt content through the result from ADCP device are studied.

After three centrifugal pump impeller being tested within the silt laden flow with sand content of 0 to 88 kg/m3, the variation pattern of hydraulic characteristics chart are alalyzed, the relstionship of the head, efficiency and discharge is discussed the effect of silt content on energy characteristics of centrifugal pumps is alalyzed.

5 L/min:with the smaller gradient and discharge,the erosion processes are characteristic of undulation,randomicity and intermittence,and the fluctuation amplitude of the silt content is very large;with t.

The sediment quality guidelines for waters by the National Oceanographic and Atmospheric Administration (NOAA) of USA are employed to evaluate degree of sediment contamination by the heavy metals and arsenic, and the standar.

Sediment quality in waters not only affect the benthic organism, but also has close relation with the water quality due to the frequent pollutant interchanges between the sediment and overlaying water.