Study On Water Diversion Quantity Of From Other Watersheds Into The Shiyang River Basin

The Shiyang River basin is one of three big inland river basins in Hexi Corridor,Gansu. Because of overdevelopment of water resources,vicious circle was resulted,which appear as the development on middle reaches occupies the downstream water,the downstream development occupies the ecology water,the conflict of supply and demand is severe day by day.The groundwater is over exploited seriously in Minqin,which brings about decline of water table continuously and causes water quality deterioration,the vegetation degenerates,the land desertification and the oasis shrinks.The survival of Minqin oasis has been threatened.The Shiyang River Basin has become the typical region of ecological environment degenerates in Northwest China.Therefore,it is of practical significance to analyze present situation of water resources in Shiyang River Basin,to seek the reasonable used pattern and water diversion quantity from other watersheds.At the same time,it also provides the scientific basis for the central and all levels of local authority to make strategic policy for Hexi Corridor,Gansu and for northwest China.The main conclusions and understands through analysis were obtained by the study,as follows:(l)According to the existed problems in the Shiyanghe River Basin,the Minqin Hongyashan irrigation district and Jinchang city were selected as reception area. Minqin Hongyashan irrigation district need water to protect the ecological environment,Jinchang city need water to solve development of the nickle industrial base(2)Based on the combination forecast thought,the grey theory, self-memory model and the BP neural network were used to predict the annual runoff of the water supply system,the result is rather ideal.(3)The ecological water requirement in the reception region was obtained:the ecological water requirement in Minqin Hongyashan irrigation district is 1.93×108m3 and the Jinchang irrigation district is 0.068×108m3.And the total water demand and supply at 2020 were sum up.(4)The need for the south-to-north water transfer project transferred water in making full use of the local water resources, under the premise of required water and users, and a comprehensive consideration of water diversion of water bear ability, mainly provides a gelatinous minqin ecological environment water and the singularity of city life, industrial water, by 2020, can satisfy the requirement of shiyang river basin requirements.