Analysis Of Characteristics And Influencing Factors For River Runoff

As the basic condition of human survival and development, water is animportant resource and it has an irreplaceable role in the development ofindustry and agriculture. At the same time, water is the basis of the ecologicalsystem so that it also plays an important role in improving and maintaining thenormal operation of the ecological environment. With the rapid development ofeconomy and the rapid growth of population, the demand for water resources ismore than ever and people do not take the pollution of water serious, eventually,lead to the contradiction between supply and demand for water resources isbecoming more and more prominent in the process of social development,seriously affected the process of the development of human society in all aspects.The study of hydrological sequence helps to understand the trend of waterresources, provides scientific basis for the reasonable development andutilization of basin water resources and the protection of the ecological environment and also has important significance for the national economy, waterdepartment, social and economic development and people’s life and propertysafety which is within the scope that controlled by the reservoir.The runoff data of Zhangze reservoir from1956to2008as the researchobject in this paper to study the following items:(1) Analysis of runoff basiccharacteristic.(2) Trend analysis and aberrance point identification of runoffseries.(3) The fractal feature analysis of the runoff sequence.(4) Theinfluencing factors of reservoir inflow runoff analysis. Using the nonuniformcoefficient, annual distribution completely regulation coefficient, theconcentration ratio, variation range Cm, Gini coefficient, the interannualextreme value rate M, anomaly percentage, and so on, to analyze the basiccharacteristics of runoff change of Zhangze reservoir. Using the methods ofsliding t test, Yamamoto, Mann–Kendall, Cramer, Pettitt, Lepage and heuristicsegmentation algorithm (BG) to study the trend and aberrance pointidentification of inflow runoff. And on the basis of the heuristic algorithm (BG)combined with Hilbert transform (HHT) and average method to propose a newmutation point identification method, HHT-BG and A-BG method. By usingR/S method and the trend of fluctuation analysis (DFA) to discuss the fractalcharacteristics of inflow runoff in Zhangze reservoir. Using the methods of setpair analysis and related coefficient based on the analysis of the characteristicsof runoff to analyze the various factors that influence the inflow runoff. Theconclusions are as following: (1) The distribution of inflow change into the reservoir is not uniform,the months that reach a peak are March and August respectively, showed a "twinpeaks" distribution, the inflow runoff mainly concentrated in June to October.(2) The inflow runoff variation is greatly and the overall trend is reduced.The year of1976is the cut-off point, the volume of inflow runoff is increased atfirst and then to reduce from the year of1956to1976, and the inflow runoffdecreased suddenly in1976, while increase slowly from1978to2008.(3) The inflow runoff has significant fractal characteristics andlong-range correlation. The inflow runoff may has a declining trend in the future,which was like the trend of historical data.(4) Precipitation is the main factors that affects the inflow runoff changeof Zhangze reservoir, and it has significant correlation with inflow runoff;temperature change has a weak negative correlation with inflow runoff; thevolume of inflow runoff of Zhangze reservoir in the El Nino years or next yearhas the high probability to reduce, while the volume of inflow runoff of Zhangzereservoir in the La Nina years or next year has the high probability to increase;the greenhouse effect may lead to reduction of inflow runoff; with the increaseof the area of soil and water conservation management, the storage capacity ofbasin water is increased, the process of rainstorm to form runoff is reduced ordelayed, the amount of rainfall infiltration is increased, and the volume of inflowrunoff is reduced.