494 / 2024-05-07 10:41:39

Ecological regulation and effectiveness evaluation of Elodea nuttallii controlling in the Danjiangkou-Wangfuzhou section of the Hanjiang

Wangfuzhou Reservoir; Elodea nuttallii; Ecological regulation; Effectiveness evaluation

Subtheme 3: Eco-hydraulics and Environment > Topic 1: Innovation and Development of Eco-hydraulics Theory

In order to scientifically and effectively control the excessive growth of Elodea nuttallii in the section from Danjiangkou to Wangfuzhou of the Hanjiang River, and to study the implementation effect of ecological regulation. The biomass survey method, distribution area statistics method, and mathematical model simulation method were used to analyze and evaluate the changes in total biomass, distribution area before and after the implementation of ecological regulation. Meanwhile, the demand for the discharge flow of Danjiangkou Reservoir was studied. The results showed that after implementing ecological regulation for 3 years, the total biomass of Elodea nuttallii decreased from 48000 tons in 2019 to 40.11 tons in 2022, and the distribution area decreased from 11.60 km² to 0.23 km², with a decrease of over 95%. The proportion of Elodea nuttallii biomass in the total biomass of submerged plants decreased from 99.99% to 17%, indicating a good ecological regulation effect. In spring, ecological scheduling should focus on moderate interference by increasing the extreme flow ratio, while in summer or autumn, ecological scheduling should focus on high flow velocity erosion by meeting the critical flow velocity of 0.14m/s.