Mathematical Modeling of Fish Behavior to Hydraulic Environments in Agricultural Canal

鱼类行为是评价开发活动对河流生态系统影响的重要指标之一，也是评估河流改善功能的重要指标。过去的生态学研究试图解释鱼类在自然栖息地的偏好，我们的研究是针对开发一种方法，这种评估与数值模拟技术的帮助。我们研究的最终目标是通过鱼群模型和水工建筑物周围实测水力数据的数值模拟来评估鱼类在水力环境中的偏好。本研究通过水槽实验和数值模拟，对农业渠道中鱼类在不同水力环境下的行为进行了数学模型的研究。首先，通过水槽实验，对日本小黄鱼的集群行为进行了研究。 关于我们 青鳉（Oryzias latipes）。在实验中引入了几个特征变量来量化鱼群的全局结构和典型特征：最近邻距离、极化和扩展。利用混沌工程中提出的分形维数、回归映射和关联维数等参数来表征鱼类个体在给定环境中的神经应变，并分别采用牛顿动力学模型和行为模式模型对鱼缸中的集群行为进行了模拟。两种模型的比较表明，行为模式模型能更准确地再现真实的鱼群特征变量。人工神经网络模型还可以模拟水箱实验中获得的学校行为。最后，进行了明渠水力实验，以确定水深、流速和屏蔽系数等水力环境的偏好曲线。少

Fish behavior is one of the essential indicators, not only for evaluating the water environments following the impact of development activities on river ecosystems, but also for estimating the functional aspects of river improvement. In contrast to the past ecological studies that have tried to explain the preferences of fish from field measurements in a natural habitat, our study is directed toward developing a methodology for such evaluations with the aid of numerical simulation techniques. The final goal of our study is to evaluate the fish preference in a hydraulic environment by numerical simulations with a fish school model and the observed hydraulic data around the hydraulic structures. In this project, mathematical models for predicting the fish behavior to various hydraulic environments in agricultural canals have been examined by using water tank experiments and numerical simulations.First, the water tank experiments were executed to characterize the schooling behavior of Jap … More anese Medaka fish (Oryzias latipes). Several characteristic variables were introduced to quantify the global structure and the typical characteristics of a fish school in the experiments : the nearest neighbor distance, the polarization and the expanse. The fractal dimension, the return map and the correlation dimension, which are the parameters proposed in the field of chaos engineering, were also used to characterize the nervous strain of fish individuals in the given environment.Next, the Newtonian dynamics model and the behavioral pattern model were investigated to simulate the schooling behavior obtained in the water tank. The comparison of both models showed that the behavioral pattern model could reproduce the characteristic variables of real fish school more accurately. The artificial neural network model could also simulate the schooling behavior obtained in the water tank experimentsFinally, the hydraulic experiments using an open channel were carried out in order to determine the preference curves for the hydraulic environments such as the water depth, the flow velocity and the shield factor. Less