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连续型Schaefer产量模型和BP网络模型在渔业中的应用研究
The Study between Continuous Schaefer-Form Production Model and BP Network Model in Fishery
【作者】 高晓;
【导师】 张家波;
【作者基本信息】 华中农业大学 , 渔业资源, 2009, 硕士
【摘要】 在渔业资源评估中,传统的评估模型有产量模型、消耗模型和年龄结构模型。随着计算机技术的发展,地理信息系统、遥感技术和人工神经网络技术型等逐步应用到渔业资源的评估和预测当中。剩余产量模型(surplus production model)是现代渔业资源评估和管理的主要理论模型之一。该模型不像动态模型考虑资源群体的年龄结构等因素,它把资源群体的补充、生长和自然死亡综合起来作为资源群体大小的一个单变函数进行分析,然后推导出我们所需要的剩余产量模型的数学公式。剩余产量模型(surplusproduction model)具有简单的形式和所需数据和参数相对较少的特点,在渔业研究中可以被简单的应用,并且它估计的管理参数(最大持续产量和最佳捕捞努力量)比较容易得出和理解,为渔业动态研究提供不同的思路。BP网络模型是近年来新兴的评估方法,因其高度并行性、自适性和自学习功能而备受人们关注。本研究以丹江口水库翘嘴鲌资源和东海区总渔获量为例,对连续型Schaefer模型和BP网络模型进行了比较研究,研究内容和主要结果如下:(1)利用连续型Schaefer模型及丹江口水库翘嘴鲌的产量和捕捞努力量估算Bi(初始生物量)、r(种群内禀增长率)、K(最大环境容纳量)、q(可捕系数),MSY(最大可持续产量)和相应的fMSY(最适捕捞努力量),得到结果为:B1=186302 kg,r=0.1965,K=2200429 kg,q=0.2123,MSY=113216 kg,fMSY=458172。(2)利用连续型Schaefer模型对东海区总渔获量进行评估,估算结果为:B1=12236567 t,K=29546790,q=0.398,MSY=4109876 t,fMSY=13.63。(3)利用BP神经网络模型建立丹江口水库翘嘴鲌渔获量预测系统,利用1981~1985年渔获量作为可信度比较指标,估算结果为:1981~1985年渔获量预测值分别为108150kg,119339kg,126845kg,114010kg,109652kg。(4)利用BP神经网络模型建立东海区年总渔获量预测系统,利用1991~1995年渔获量作为可信度比较指标,估算结果为:1991~1995年渔获量预测值分别为4094768t,4709258t,5349900t,6349296t,7314227t。(5)比较两种模型在不同渔业应用中的评价结果准确度。参数估计偏差值为:在丹江口水库中,B1:9.7,r:2.7,K:3.9,q:2.3,MSY:1.6,fMSY:1.0;在东海区渔业中:B1:17,r:8.8,K:12,q:7.5,MSY:1.7,fMSY:1.3。渔获量预测值与真实值之间的误差率结果为:在丹江口水库中,1981~1985年依次是0.0672,0.0621,0.0503,0.0341,0.0485;在东海区渔业中,1991~1995年依次是0.0040,0.052 1,0.0745,0.0736,0.0767。
【Abstract】 In fish stock assessment,traditional models have three main types,there are production models,depletion models,and age-structured models.With the development of computer technology,geographic information system、remote sensing technology and artificial neural networks technology gradually applied to the assessment and prediction of fisheries resources.Surplus production models are major academic models in assessment and management of modern fishery resources.Surplus production models can be simply used in fishery assessment because of their simplicity and relatively undemanding data needs.Surplus-production models generally do not incorporate age structure which is useful for fish population dynamics.These models are of particular value when the catch can not be aged,or can not be aged precisely.Moreover, Surplus-production models are classical methods to predict the MSY(maximum sustainable yield) for fisheries management,which is one of the major fisheries management goals.BP neural network model is emerging in recent years,because of its high degree of parallelism,adaptive self-leaming function,it has people’s attention.In this study,the author using the Culter alburnus resources in DanJiangkou Reservoir and the annual fish catch in East China Sea as an example,to compare Schaefer model and BP model,the contents and main results as follows:(1) Using the continuous Schaefer model and C.alburnus resources in DanJiangkou Reservoir to estimate B1(initial biomass),r(innate rate of increase),K (environmental carrying capacity),q(quotiety of catch),MSY(maximum sustainable fishing yield) and fMSY.The results are:B1=186302 kg,K=2200429 kg,q=0.2123, MSY=113216 kg,fMSY=458172.(2) Using the continuous Schaefer model to estimate the total catch in East China.Sea,results are:B1=12236567 t,K=29546790,q=0.398,MSY=4109876 tk fMSY=13.63.(3) Using the BP neural network model to build an yield prediction model for DanJiangkou Reservoir,using the data from 1981 to 1985 as indicate of comparison, the results are:predictive value from 1981 to 1985 followed by 108150 kg,119339 kg, 126845 kg,114010 kg,109652 kg.(4) Using the BP neural network model to build an yield prediction model for East China Sea,using the data from 1991 to 1995 as indicate of comparison,the results are:predictive value from 1991 to 1995 followed by 4094768 t,4709258 t, 5349900 t,6349296 t,7314227t.(5) Compare the results’ accuracy of assessment using Schaefer model and BP model in different fisheries.Deviation of parameters are: in DanJiangkou Reservoir,B1:9.7,r:2.7,K:3.9,q:2.3,MSY:1.6,fMSY:1.0; in East China Sea:B1:17,r:8.8,K:12,q:7.5,MSY:1.7,fMSY:1.3. The error rate between predictive value and true value are:in DanJiangkou Reservoir, from 1981 to 1985 followed by 0.0672,0.0621,0.0503,0.0341,0.0485;in East China Sea:from 1991 to 1995 followed by 0.0040,0.0521,0.0745,0.0736,0.0767.
- 【网络出版投稿人】 华中农业大学 【网络出版年期】2010年 07期
- 【分类号】S951.2
- 【被引频次】2
- 【下载频次】171