最优捕鱼策略问题

最优捕鱼策略问题最优捕鱼策略问题摘要问题一，我们考虑渔场生产过程中的各年龄组鱼群数量的制约因素，将其分为两大类，第1,2龄鱼群为一类，该鱼群数量变化只受自然死亡率制约；第3,4龄鱼群为一类，其数量变化在前8个月受捕捞强度和自然死亡率影响，后4个月只受自然死亡率的制约；可写出在某时刻各鱼群的数量表达式。捕捞只在前8个月进行，则年捕捞量为前8个月各时刻鱼群数量的积分。最后建立年总捕捞量的函数与生产过程中满足的关系式，转化为非线性规划模型，利用matlab软件求解。问题二，我们利用问题一中所得到的迭代方程，可迭代地求出第i年初各年龄组鱼群的数量；再根据问题一中的捕捞量表达式，可写出5年的捕捞总量表达式，以5年捕捞总量最大为前提，利用matlab软件求解出此时的捕捞强度，然后再验证在此捕捞强度下会不会使5年后鱼群的生产能力有太大的破坏。最后得出以下结论：可持续捕获条件下，捕捞强度为17.36时，达到最大捕捞总质量g1088.311；5年后鱼群的生产能力不会有太大的破坏条件下，捕捞强度为17.5,17.8k，达到最大最大捕捞总质量g1064.112。关键词：渔业；最大收益；捕捞策略；生产能力；生长率；matlab最优捕鱼策略问题OptimalFishingStrategyABSTRACTOneproblem,meetthefunctionofintegralquantityexpressions;weconsiderfisheriesproductionprocessintheagegroupoffishnumberofconstraints,itisdividedintotwomajorcategories,onthe1stand2ndinstarfishasaclass,thenumberoffishchangeonlybynaturalmortalityratecontrol;the3,4yearsoldfishasaclass,thenumberofchangesinthefirsteightmonthsoffishingintensityandnaturalmortality,after4monthsonlybynaturalmortalityconstraintscanbewritteninamomentthefish.Fishingonlyinthefirsteightmonths,thentheannualcatchesinthefirsteightmonthseachtimestocks.Finallyatotalfishingvolumeandproductionprocess,istransformedintoanonlinearprogrammingmodelbyMATLABsoftwaresolution.Twoproblem,weexploittheproblemintheiterativeequationthatcanbeiteratedtocalculatethenumberoffishineachagegroupatthebeginningofthei-th;accordingtotheproblemsincatchesofexpression,canwritewith5yearsoffishingaggregateexpressions,in5yearsoftotalfishingmaximumasthepremise,atthistimethefishingintensitywasobtainedbyusingMATLABsoftware,whicharethenvalidatedinthisfishingintensitydoesnotmake5yearsafterfishproductioncapacityhastoomuchdamage.Finallydrawsthefollowingconclusion:Sustainablecaptureconditions,fishingintensityof17.36toachievemaximumcatchtotalquality;5yearsafterfishproductioncapacitywillnothavetoomuchdamageconditions,thefishingintensity,achievethemaximumtotalfishingquality.Keyword：Fisheries；Maximumbenefit;Fishingstrategy;Throughput；Growthrate;Matlab最优捕鱼策略问题目录1绪论...........................................................................................................................................41.1研究背景及目的.............................................................................................................41.2研究方法.........................................................................................................................42最优捕鱼策略问题分析求解.........................................................................................-1-2.1问题的提出...................................................................................................................-1-2.2问题假设.......................................................................................................................-1-2.3符号说明.......................................................................................................................-2-2.4题中术语理解................................................................................................................-2-2.4.1自然死亡率........................................................................................................-2-2.4.2捕捞强度系数...................................................................................................-2-2.4.3成活率...............................................................................................................-3-2.5问题分析.......................................................................................................................-3-2.5.1问题一分析.......................................................................................................-3-2.5.2问题二分析.......................................................................................................-3-2.6模型建立.......................................................................................................................-4-2.6.1问题一模型........................................................................................................-4-2.6.2问题二模型.......................................................................................................-6-2.7模型求解........................................................................................................................-6-2.7.1问题一求解........................................................................................................-6-2.7.2问题二求解.......................................................................................................-8-2.8模型评价.....................................................................................................................-10-参考文献..................................................................................................................................-10-附录源程序清单..................................................................................................................-10-最优捕鱼策略问题1绪论1.1研究背景及目的本文以生态经济着眼，首先用微分方程组建立了基本模型，从理论上完整地描述了各年龄鱼的变化情况.其次，从基本模型出发，我们构造出年度最优模型，得到了可持续捕获应满足的条件及在此条件下可获得的年最高收获量，在抓寸“鱼的生产能力不受到太大破坏，进行详细分析和合理描述的基础上，巧妙构思，建立了承包期总产量模型，给出了公司应采取的浦捞策略及相应的承包期最高收获量.1.2研究方法可再生资源管理应