According to proportion of land use structure of Bijie region, the model is applied to simulate , annual average sediment transport modulus of the whole region's rivers are obtained which is 628.47 t/km~2·a.
Based on the data of annual average sediment transport modulus that 4 mountain river hydrological stations of Liuchong river, Shancha river, Chishui river, and Yeji river,monitored in Bijie region of Guizhou Province, and land use structure of these rivers basin, the BP artificial neural network model is set up.
⑤ With the large area and high standard ecological environment construction of the small watershed,the sediment transport modulus had been obvious decreased in small watershed in 1990 to 2004.There is the obvious decrease effect of the in sediment transport in vegetation recovery and rebuilding.
According to analysis on measured data of rainfall, runoff and sediment transport and contrast research between different valley, it shows that the dam system has very notable sediment control effect. Presently the annual mean sediment reduction profit is 78.6%, the valley sediment transport modulus has been reduced to 2 060 t/km 2 from 18 000 t/km 2 before harnessing, the flooding sediment is basically controlled. The dam system is relatively stable.
The result indicated that runoff depth and flood peak modulus are in connection with sediment transport modulus. Runoff erosivity has good relationship with sediment transport modulus. Runoff erosivity can reflect ability of eroding soil and transport sediment.
To effectively control soil erosion in semiarid, especially in hilly-gullied areas and make sediment transport modulus reduce to less than 6000 t/km2, it is rather difficult by merely relying on natural restoration of forest.
The construction of dam system in Jiuyuangou valley since 1953 undergoes about four stages including experimental Demonstration, development, reconstruction and improvement. It has constructed 263 blank of dam reservoirs, 282 hm 2 of silt lands and 20 085 00 m 3 of silts have been controlled. According to analysis on measured data of rainfall, runoff and sediment transport and contrast research between different valley, it shows that the dam system has very notable sediment control e...
Sediment amount data from two hundred and twenty two hydrological stations in China are first used to make the isoline map of long term average sediment transport modulus of China based on GIS software, ARC/INFO, database system software, and visual foxpro. Then the distribution of sediment transport and deposition in a great scale in China is analyzed and the areas for different sediment transport intensity are calculated.
Based on the data of annual average sediment transport modulus that 4 mountain river hydrological stations of Liuchong river, Shancha river, Chishui river, and Yeji river,monitored in Bijie region of Guizhou Province, and land use structure of these rivers basin, the BP artificial neural network model is set up. According to proportion of land use structure of Bijie region, the model is applied to simulate , annual average sediment transport modulus of the whole region's ...