Analysis Of Hydrological Characteristics And Runoff Retrieval In Jialing River Basin

The Jialing River is an important tributary of the Yangtze River,which has the largest reserves of hydropower resources in China.Its watershed area is the largest among the tributaries of the Yangtze River,reaching 160,000 km2.The water volume is second only to the Minjiang River,and flows through Shaanxi,Gansu,and Sichuan.Into the Yangtze River in Chongqing.Changes in the runoff of the Jialing River affect the ecological environment in the basin and the economic development of the economic zones along the river.The precipitation in the Jialing River basin is affected by the monsoon and is unevenly distributed throughout the year.Frequent human activities cause frequent landslides and debris flows in mountainous areas in the basin.The water and soil loss is particularly serious,and the river has high sediment content and is the river with the highest sediment content in the Yangtze River system.This study provides a reference for the hydrological parameters when simulating the hydrological process of the river basin by extracting and analyzing the hydrological characteristics of the Jialing River basin.It is also the basis for the research and development of water and soil loss in the basin.This paper first uses the spatial analysis function of gis technology to extract basic information such as watersheds,sub-catchments,river networks,and river system grades in the Jialing River Basin based on dem data.The river morphological parameters such as watershed area,river network density,and main tributaries are calculated.Length,etc.to analyze the average ratio of the main tributary channels and the fractal dimension coefficients of the entire river system.Secondly,the precipitation data from the Jialing River Basin in 1979-2017 and the Beibei,Wusheng,Tingzikou,Wudu,Luoxidu,and Xiaoheba were analyzed.The multi-year average runoff data of the six hydrological stations during the period of 1979-2017 analyzes the spatial distr ibution characteristics,interannual and seasonal changes of the water resources in the Jialing River Basin,and the causes.The annual runoff coefficients of the hydrological station control areas in the river basin are calculated.With the monthly runoff coefficient,using the runoff coefficient in combination with precipitat ion,the runoff of the hydrological stations in the river basin during the period of lack of measurement is inversely calculated,which provides a reference for the study of the relationship between precipitation and runoff in the Jialing River basin.(1)The river network density in the Jialing River Basin(above Beibei Station)is 0.197 km / km2,the river network density is the largest in the Minjiang River Basin(above Xiaoheba)is 0.206 km / km2,and the smallest is the Bailong River Basin(above Wudu)at 0.182 km / km2.The river network density in the basins above Wusheng Station,Tingzikou Station,and Luoxidu Station are 0.193 km / km2,0.189 km / km2,and 0.197 km / km2,respectively.(2)The total length of the main stream of the Jialing River is 1198.5km.According to the Stellar classification method,the water system in the basin is divided into 7 levels,the bifurcation ratio of each level of water system is 2.33-4.27,and the river length is 1.73-2.41.The fractal dimension of the water system of the Jialing River basin is calculated.The value is 1.73,which indicates that the river development in this basin is in its prime.(3)Using the longitudinal profile of the main stream of the Jialing River Basin and the three major tributaries of the Qujiang,Minjiang,and Bailong Rivers,the average channel ratio drop of the main tributaries was calculated.The maximum channel ratio drop was 5.24 ‰ in the Bailong River,and the smallest channel river was 1.01 ‰.It is 4.25 ‰,and the average ratio of the main stream drops to 1.7 ‰.The channel ratio descends from southeast to northwest as the terrain changes.(4)The annual average runoff coefficient of the Jialing River Basin is 0.44,the largest in the sub-watershed controlled by each hydrological station is 0.66 above Xiaoheba,the smallest is 0.37 in the middle stream(Wusheng to Tingzikou),Tingzikou Station(except Wudu),Wudu The runoff coefficients of the watershed above the station and Luoxidu station are 0.43,0.48,and 0.57,respectively.The runoff coefficient has a negative correlation with the density of the river network,and the correlation coefficient is-0.93.The monthly runoff coefficient calculated from the monthly average runoff has a phenomenon of greater than 1 in the monthly runoff coefficients of Beibei,Wusheng,Tingzikou,and Wudu,and the closer to the upper reaches of the river,The more months the monthly runoff coefficient is greater than 1.(5)The precipitation in the Jialing River Basin combined with the average runoff coefficient for many years,the average runoff of Liushui Hydrological Station in the basin from 1979 to 2017 was retrieved,and the monthly average runoff of Beibei,Wusheng,Tingzikou,and Wudu stations were calculated.The results show that using the The total monthly runoff of the four hydrological stations calculated from the annual average runoff coefficient is slightly different from the measured total annual runoff for many years,but the annual water distribution is different.The high-value area of the measured runoff is higher than the high-value area of the precipitation.There is a lag.(6)Comparing and analyzing the hydrological characteristics of the Bailong River and the upper reaches of the Jialing River,it is found that the Bailong River is better than the upper reaches of the Jialing River in terms of river length,precipitation,and catchment area,but the water system in the upper stream of the Jialing River is more developed.The search of Zhengyuan provides a reference.