학술논문
基于弯道水力特性的蛙道构建与数值模拟研究 / Construction and Simulation of Frog-ways Based on Hydraulic Characteristics of Curved Channels
Document Type
Academic Journal
Author
毕博; 陈菁; 陈丹; 洪大林; 金秋; 王小军; 毕利东; BI Bo; CHEN Jing; CHEN Dan; HONG Da-lin; JIN Qiu; WANG Xiao-jun; BI Li-dong
Source
中国农村水利水电 / China Rural Water and Hydropower. (1):8-15
Subject
Language
Chinese
ISSN
1007-2284
Abstract
为有效提高渠系水利用系数和耕地利用率,灌区末级渠系普遍采取硬质化建设,又因受到渠道规模和防渗要求的约束,生态化改造相对匮乏.为解决灌溉渠道造成的稻作区两栖动物生境破碎化问题,结合灌区末级渠系输配水的实际情况,创新性地将弯道水力特性应用于灌溉渠道生物通道研究,通过建立硬质化农渠弯道的三维水流模型并开展数值模拟试验,模拟了不同弯道处于稳定输水条件下的水力特性,分析了水流结构对渠内蛙类运动轨迹的影响,提出了弯段生物通道的设计方法,并通过水流数值模拟和水头损失计算,评估了设置蛙道对蛙类逃脱效果和渠道输水效率的影响.结果表明:90°弯道出弯断面的纵向流速分布和横向环流结构有助于黑斑蛙利用水动力条件逃脱,并由此提出蛙道位置和结构形式的设计方法;结构变化对水流流态和输水效率并无明显影响,水流结构有利于渠内蛙类逃脱,最大沿程水头损失约为3.83×10-4 m,能够同时保证蛙类迁移效率和水流安全通畅.研究成果可为灌溉渠道生态修复提供理论依据和技术支持.
Green and sustainable development of irrigated agriculture and protection of agricultural biodiversity are the inevitable require-ments for the construction of modern irrigated districts in China.However,in order to ensure the efficient utilization of irrigation water,the construction of irrigation channels has been dominated by hard engineering,which has caused the loss and fragmentation of amphibian habi-tat,and the damage for ecological environment of the irrigation districts.The construction of amphibian corridors in irrigation channels is an important way to improve the connectivity of agricultural landscape and the migration efficiency of frogs in farmland.This paper innovatively applies the hydraulic characteristics of curved channels to the research on ecological channels,builds the curved irrigation channel models,conducts numerical simulation experiment,analyzes the trajectory of frogs at the curved irrigation channels,proposes the design of engi-neered modifications to allow frogs to escape from field concrete ditches.To evaluate the effects of engineered modification on the effective-ness of frog-ways and the water transfer efficiency of irrigation channels,the paper compares the water flow pattern and calculates the head loss.By carrying out numerical simulation tests,the paper obtains the flow movement law of the concrete-lined irrigation channels with differ-ent bend angles,and the flow dynamic axis and velocity distribution are compared.As a result,the slow flow zone and the transverse circula-tion are found.The locations suitable for amphibian corridors to be built vary when the curvature of the curve changes.The numerical simula-tion and head loss calculation results show that the amphibian corridors in the bend has no obvious influence on flow pattern and water trans-fer efficiency,and the head loss in bend is about 3.83×10-4 m,which can ensure the safe and unobstructed water flow.This study is expected to provide a scientific reference and technical support for the ecological reconstruction of end irrigation channel systems.
Green and sustainable development of irrigated agriculture and protection of agricultural biodiversity are the inevitable require-ments for the construction of modern irrigated districts in China.However,in order to ensure the efficient utilization of irrigation water,the construction of irrigation channels has been dominated by hard engineering,which has caused the loss and fragmentation of amphibian habi-tat,and the damage for ecological environment of the irrigation districts.The construction of amphibian corridors in irrigation channels is an important way to improve the connectivity of agricultural landscape and the migration efficiency of frogs in farmland.This paper innovatively applies the hydraulic characteristics of curved channels to the research on ecological channels,builds the curved irrigation channel models,conducts numerical simulation experiment,analyzes the trajectory of frogs at the curved irrigation channels,proposes the design of engi-neered modifications to allow frogs to escape from field concrete ditches.To evaluate the effects of engineered modification on the effective-ness of frog-ways and the water transfer efficiency of irrigation channels,the paper compares the water flow pattern and calculates the head loss.By carrying out numerical simulation tests,the paper obtains the flow movement law of the concrete-lined irrigation channels with differ-ent bend angles,and the flow dynamic axis and velocity distribution are compared.As a result,the slow flow zone and the transverse circula-tion are found.The locations suitable for amphibian corridors to be built vary when the curvature of the curve changes.The numerical simula-tion and head loss calculation results show that the amphibian corridors in the bend has no obvious influence on flow pattern and water trans-fer efficiency,and the head loss in bend is about 3.83×10-4 m,which can ensure the safe and unobstructed water flow.This study is expected to provide a scientific reference and technical support for the ecological reconstruction of end irrigation channel systems.