Research On The Law Of Social Hydrology Coupling In Yanhe River

The impact of climate change and human activities on the global ecological environment is becoming more and more obvious,especially the impact on the temporal and spatial distribution of surface water resources and various factors(runoff,sediment load)in the water cycle,which has attracted wide attention all over the world.Yanhe river is level tributaries of the Yellow River basin,in recent years,human activity makes the Yanhe river basin sediment was significantly decreased,existing research is mainly focused on the natural factors or soil and water conservation measures on the influence of sediment discharge,few from the perspective of the development of social and economic impact on the sediment discharge,explore the relationship between the social development and sediment changes.Based on the meteorological data,sediment data and social economic data,through the Mann-Kendall mutation test,double mass curve,multivariate regression research methods such as social and economic development and the coupling between the law of sediment discharge mechanism for further understanding human activities have important meaning,at the same time the basin soil erosion prevention and control has a certain reference value.1)The meteorological and hydrological elements of Yanhe River basin from 1981 to 2016 were analyzed,and it was found that the temperature in Yanhe River Basin showed an overall trend of rise,and the rainfall first decreased and then increased,with a relatively stable change degree.At the same time,sediment transport and maximum sediment concentration showed a significant downward trend,among which the annual variation of sediment transport was greatly different.The mutational test of Mann-Kendall was used to determine that 2006 was the mutational year of sediment transport in Yanhe River Basin.2)By analyzing the social and economic development factors of Yanhe River Basin,it is found that the total population of Yanhe River Basin is increasing,among which the rural population is decreasing,the urban population is increasing and the urbanization rate is increasing.The commonly used cultivated land area is decreasing at the rate of 397.3 hectares/year,and 98.5 km2 of cultivated land is converted into forest and grass land every year.The secondary and tertiary industries in Yanhe River basin are developing rapidly and the proportion of the output value of the primary industry in the total output value is gradually decreasing.3)Through the calculation of the double accumulation curve,the contribution rate of rainfall to the reduction of sediment transport is-23.2%,and that of human activities is 123.2%.The main reason for this is the increase of rainfall in recent ten years,which should have resulted in the phenomenon of "increasing sediment",but human activities have significantly reduced sediment transport.The analysis shows that the sediment blocking effect of warping dam is decreasing in recent years,and the main reason for the decrease of sediment transport is the improvement of vegetation coverage.Economic development,industrial restructuring and urbanization mainly affect the area of cultivated land and then the amount of sediment transport in the river basin.4)By analyzing the social hydrological relationship of Yanhe River Basin,it is found that there is a mutual feedback relationship between social development and sediment transport.SPSS software was used to carry out multiple regression analysis and path analysis on the factors affecting the variation of sediment transport,and it was found that the difference of per capita income had the greatest impact on sediment transport,followed by the cumulative sediment control of silt DAMS,and the urbanization rate had the least impact.At the same time,with the increase of economic development and urbanization rate,sediment transport continues to decline.5)The obtained multiple regression equation and the soil loss equation(RUSLE)were simultaneously used to simulate the sediment transport in Yanhe River Basin.The results showed that the soil loss equation was more accurate,but the multiple regression equation had more comprehensive and predictable factors.The forecast analysis of sediment transport in the next ten years shows that when the social and economic development is stable and the silt dam keeps the function of sediment containment,the sediment transport will not increase significantly.