A New Method for Estimating the Instream Ecological Water Requirement--Ecological Hydraulic Radius Approach
This essay proposes an ecological hydraulic radius approach (EHRA) which considers both the watercourse information (including hydraulic radius, roughness coefficient and hydraulic gradient) and the required stream velocity necessary for maintenance of certain ecological functions all together. The EHRA not only meets the requirement of flow velocity for adequate fish spawning migration, but also is applicable to the ecological flows in regard with other ecological issues (such as the calculation of the instream flow requirements for transporting sediment (IFRTS) and for pollution self-purification, etc.). It has been illuminated that the computational process taking the estimation of ecological water requirement of Zhuba Hydrologyical Station watercourse in Niqu branch of the Yalong River as an example. The result shows that the Zhuba Hydrological Station ecological water requirement calculated by EHRA lies between the minimum and favorable instream ecological water requirement (IEWR) calculated by the Tennant approach. This is due to the fact that the ecological flow velocity (such as the fish spawning migration flow velocity) was taken into consideration, producing results applicable to the practical situation. Moreover we defined the permitting flow velocity by the conception of IFRTS, also put forward the ecological hydraulic radius approach (EHRA) to estimate IFRTS. The result shows that the IFRTS occupied 29.7％~59.5％ of annual mean discharge in flood season, the average of IFRTS is about 100.2m 3/s during 1966~1987, it is close to the IFRTS 90m 3/s calculated by IFRTS conception. Hence, it is feasible to calculate IFRTS by using EHRA.
Ecological Hydraulic Radius (HER) Instream Ecological Water Requirement (IEWR) Instream Flow Requirements for Transporting Sediment (IFRTS) permitting flow velocity
Liu Changming Men Baohui
Key Laboratory of Water and Sediment, Beijing Normal University, MOE and IGSNRR, CAS, Beijing 100101 Department of Hydraulic and Hydropower Engineering, North China Electric Power University, Beijing 1
国际会议
山东东营
英文
207-215
2007-10-16（万方平台首次上网日期，不代表论文的发表时间）