摘要本文主要解决在以保护环境、实现可持续性捕捞的发展前提下，针对鳀鱼的捕捞方案提出合理的方法，来实现最大产量或者最佳效益，同时作为参考依据提供给渔业部门制定规则。                     

针对问题一的情况，在能够实现可持续捕捞的情况下,达到最高的年收获量。将鳀鱼划分为4个年龄段,独立建立微分方程,得到每个龄组鳀鱼的数量与时间的相对关系式,再把每年刚开始时渔场中各年龄组鱼群的总条数不变为约束条件,以总捕捞量最大作为目标函数,建立非线性规划模型，运用MATLAB中的软件求出：当3龄鱼、4龄鱼的捕捞强度系数分别为时，捕捞3龄鱼、4龄鱼所对应的条数为、条，这个时候的总捕捞量最大为：。并且得到对应的年初各年龄组鱼群的总条数分别为、、、条。86254

针对问题二的情况，按照所要求的条件，使得5年来总收获量最高。以第5年末1龄鱼的数量和第1年初的数量的相对误差值小于10%作为5年后鱼群生产能力没有遭受到太大的破坏的指标。利用第一情况中所计算出的各年龄鱼数量随时间的关系式，把鱼群未受到太大破坏的生产能力为约束条件，5年总捕捞量的最大值为目标函数，建立一个非线性规划模型，运用LINGO软件求得：3龄鱼、4龄鱼的捕捞强度分别为时，每年的捕捞量大约等于： 、、、、。此时5年捕捞总量最大约等于：，并且得到每年初的各年龄组中的鱼群数量。

毕业论文关键词：优化方程；非线性优化模型；可持续捕捞；捕捞量

Abstract This paper is mainly used to solve in to protect the environment and achieve sustainable fishing development under the premise, for anchovy fishing scheme put forward reasonable methods, to achieve the maximum yield and optimum benefit。 At the same time as the reference provides to the fisheries department rules。

In view of the situation, in the case of sustainable fishing, to achieve the highest annual harvest。The anchovy pision for four ages, independent differential equations are established。 To get the time and quantity of each age group of anchovy relative relation, and the beginning of the year fishing grounds in the age group of fish the total number of unchanged as the constraint condition, the total catch maximum as the objective function, a nonlinear programming model。Use of MATLAB software to find out: when the 3 age of fish, the 4 age of the fish's fishing intensity coefficient is too, fishing 3 age fish, the number of fish corresponding to the age of 4, the total amount of fish at this time is the maximum:、, And the total number of fish in each age group at the beginning of the year was、、、, respectively。

In view of the problems in the second case, according to the required conditions, making 5 years total yield is the highest。 To the end of the fifth number in one year old fish and the beginning of a number of relative error value is less than 10% for 5 years after fish production capacity does not suffer too much damage indicators。

The use of calculated in the first case the age of fish with the time, the fish has not been too much damage production capacity as the constraint condition, 5 years total catch maximum value as the objective function, a nonlinear programming model is established, using the lingo software to seek: 3 years old fish, fishing intensity of 4 year old fish were too, annual amount of fishing is approximately equal to the 、、、、。At this point, the total amount of fishing for 5 years is approximately equal to:,And get the number of schools of fish in each age group at the beginning of each year。

Keywords: Optimization model; nonlinear optimization model; Sustainable fishing：Fishing capacity

目  录

第一章 绪论