Background
The lower Jinsha River has abundant hydropower resources of strategic importance for the national economic development. The hydrological and sediment data are essential to the management of land resources and the development of rivers. However, the observation data and sampling data from field surveys are limited due to the complexity of bed load transport, coupled with inconvenient access to the river located in the canyon amid mountains. As the research on bed load transport in lower Jinsha River is almost blank, we are in duty bound to study and clarify regularity and quantity of bed load transport in lower Jinsha River and its tributaries. This comprehensive study examines bed load amounts in lower Jinsha River and its tributaries and gives the relationship between transport rate and water flow. It is of great significance for the safe operation and dispatch of the four giant cascade hydropower stations in the lower Jinsha River.
Contents
· Investigating gravel bed load quantity and its longitudinal variationin in the lower Jinsha River;
· Revealing the law of gravel bed load transport in the Jinsha River and establishing the gravel bed load transport equation; and
· Investigating gravel bed load transport in the tributaries of Jinsha River and suggesting calculation formula.
Achievements
· A comprehensive study on gravel bed load transport in the Jinsha River and its tributaries has been conducted through field investigation, numerical simulation, physical model test, flume test and lithologic analysis. In particular, the normal physical model and lithologic analysis facilitate the comparison of results obtained using various technical methods and increase the reliability of results;
· The gravel bed load quantity and its variation along the lower Jinsha River have been identified, determining the annual average gravel bed load quantity at the dam sites of the four cascade hydropower stations in the lower Jinsha River, and establishing the relationship between rate of gravel bed load transport and flow discharge in both inlet section (Sanduizi section) and outlet section (Pingshan section);
· The annual average gravel bed load amount for 19 major tributaries of the lower Jinsha River have been given, and the formula for calculating gravel bed load transport in typical tributaries are proposed; and
· The law of gravel bed load transport in the lower Jinsha River has been revealed, finding the obvious characteristics with main band of bed load transport and the relationship of band's location and width with river regime, bed morphology and flow pattern, and clarifying the size gradation relationship between bed load, upstream incoming sand and local bed material.
Application
The achievements have been widely used in the construction, impounding and dispatching regulation of Xiluodu and Xiangjiaba hydropower stations, ensuring safety in flood season during the construction period and initial impounding. The study fills in the void of bed load transport research on the lower Jinsha River and has important implication for bed load transport research on other similar mountainous rivers. It provides the background and basic information for land resources management and development and utilization of the lower Jinsha River.
On-site bed material sampling in the lower Jinsha River
Physical model test for bed load study
Study on law of bed load transport in the lower Jinsha River
Relationship between bed load transport rate and flow discharge
Schematic diagram of gravel bed load quantity in the lower Jinsha River and its tributaries
(Note: unit of data is 104t. Tributaries are 1-Yalong River,2-Longchuan River, 3-Menguo River, 4-Pulong River, 5-Shenyu River, 6-Pudu River, 7-Xiaojiang River, 8-Yili River, 9-Heishui River, 10-Xixi River, 11-Niulan River, 12-Lugao River, 13-Meigu River, 14-Xisujiao River, 15-Tuanjie River, 16-Xisha River, 17-Xining River, 18-Zhongdu River, 19-Dawen River)
