Analysis On Soil And Water Conservation Achievements Of Benefits Of Runoff ? Sedimentation Reducing Of Typical Basins In Liaoning Province

In this study,we selected typical basins as research objects by mastering the implementation of soil and water conservation measures in Liaoning Province,and collected data of water and soil conservation measures,in order to reveal the change rule of runoff and sediment,analyze the benefits of runoff and sediment reduction,and study on the implementation of soil and water conservation measures in Liaoning Province,so as to provide a basis for the scientific and rational distribution of soil and water conservation measures.The main conclusions of this experiment were as follows:(1)The soil erosion area in Liaoning Province had a significant declining trend,with a total decrease of 27,500 square kilometers from 1986 to 2015.Among them,the most soil erosion area is Chaoyang City.It showed that Liaoning Province made great achievements for a long time in water and soil erosion.(2)Comparative analysis of implementation of soil and water conservation measures in all cities of Liaoning in different periods.The results showed that the measures of soil and water conservation in Liaoning are mainly distributed in western Liaoning,such as Chaoyang City,Huludao and Fuxin,and the soil conservation measures in eastern Liaoning are mainly distributed in Dandong.It was found that the measures of soil and water conservation in Chaoyang City and Dandong were typical basins in Liaoning province.At the same time,there were relatively complete basins in typical basins.So we could only choose to study the middle and upper reaches of the Daling River and the primary tributaries of the Ai River.(3)The characteristics of water and sediment changes in typical basins were as follows: The runoff and sediment yields in the upper and middle reaches of the Daling River had changed significantly during the last 60 years.There was a good linear relationship between them,and the runoff and sediment discharges showed a general downward trend,and the runoff was decreased.The trend was more pronounced.The variation of runoff showed 4 stages,which was high flow period-low water period-high flow period-low water period;The variation of sediment discharge also showed 4 stages,that was rising period-changing period-rising period-declining period,the declining phase was longer than rising one in changing period.In addition,the Daling River's water and sediment had periodic characteristics.The 26 a time scale was the first major cycle of the runoff change,and the 6a time scale was the first main cycle of the sediment transfer.(4)The effects of human activities on the reduction of water and sediment in the upper reaches of the Daling River and the primary tributaries of the Ai River all played a dominant role.In the middle and upper reaches of the Daling River,from 1993 to 2016,the average annual water reduction was 210 million cubic meter and the water reduction effect was 34.65%,the average annual amount of sediment decreased by human activities was 3.71 million tons and the sediment reduction effect was 55.61%.The average annual water reduction of the Ai River Basin was 280 million cubic meter from 1995 to 2015,the water reduction effect was 25.95%,and the average annual amount of sediment reduced by the human activities was 191 thousand tons,and the sediment reduction effect was 45.87%.Since the 1990 s,no matter whether it was the upper reaches of the Daling River or the primary branch of the Ai River,the implementation of water and soil conservation measures had achieved certain results.and the implementation of soil and water conservation measures in the Daling river basin had achieved even better results.