计数模型在池塘养殖游憩服务价值评估中的应用
Application of count models in estimating recreational values of pond aquaculture
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摘要: 随着社会经济的快速发展, 休闲渔业正在逐渐成为渔业产业经济发展的新方向。近十年来, 上海地区加大了对休闲渔业的投入, 使得该地区池塘养殖系统更加具有游憩服务价值。目前对池塘养殖游憩资源价值的研究相对较少, 对相应的评估方法及其在池塘养殖游憩价值评估中的适用性也需进一步探讨。由于对评估方法研究的滞后, 池塘养殖系统中的游憩服务价值往往得不到科学揭示。基于对青浦、嘉定、奉贤3区的实证调查结果, 本文以上海市为例, 使用计数模型的个人旅游成本法估算这3个地区的池塘养殖游憩价值, 进而将泊松模型和负二项模型进行对比研究, 并将本文得到的青浦地区池塘养殖游憩价值结果与前期研究成果进行比较, 探讨两种模型在池塘养殖评价中的有效性及个人旅游成本(ITCM)与区域旅游成本(ZTCM)两种方法在此类评估中的稳定性。研究发现: ①不同模型对池塘养殖游憩价值的评估结果存在差异, 总体来看负二项模型优于泊松模型。②个人旅游成本法与区域旅游成本法估计结果比值为4.98︰1, 分别以两种方法估算值作为养殖池塘系统游憩价值的上限值和下限值比较合适。③基于计数模型的个人旅行成本法评估青浦、嘉定和奉贤地区的池塘养殖游憩服务价值分别约为20 863.34 元·hm-2·a -1、57 997.03元·hm-2·a -1和522.73元·hm-2·a -1。建议有关各方重新认识池塘养殖休憩价值, 继续加大休闲渔业支持力度, 保护该地区的池塘养殖生态系统, 以促进旅游及池塘养殖产业的可持续发展, 提高渔民收入水平。Abstract: With the rapid development of the third industry, recreational fishery has become one of significant sectors of fishery economy in China. At the same time, the increasing investment in the recent decade on the recreational fishery has made this industry more valuable in Shanghai. The literatures show that there are a few researches focused on the recreational values of pond aquaculture ecosystems, and the suitability of methods and models which may be used to analyze these values should be estimated. Owing to the lag of researches on the estimation methods, these eco-service values were not scientifically explained. Based on the investigation in Qingpu, Jiading and Fengxian, three suburban districts of Shanghai, this paper estimated the recreational values of the pond aquaculture ecosystems in these areas with count models of individual travel cost method (ITCM). The effectiveness of Poisson Model and Negative Binomial Regression Model were compared. The estimated value of the pond aquaculture ecosystems in Qingpu District this time and those results of former studies in the same area was also compared to analyze the stability of individual travel cost method (ITCM) and the zone travel cost method (ZTCM). The results showed that: ① estimated values of pond aquaculture ecosystems were sensitive to the models used, Negative Binomial Regression Model was more effective than Poisson Model when the data had discrete characteristics; ② it was feasible to use the estimated values by individual travel cost method and zone travel cost method as the upper and lower limits of pond aquaculture ecosystem services values respectively, the ratio of the values estimated by the two methods was 4.98︰1; ③ the recreational values in the three districts were approximately 20 863.34 Yuan·hm-2·a -1, 57 997.03 Yuan·hm-2·a -1 and 522.73 Yuan·hm-2·a -1, respectively. The results suggest that stakeholders should recognize the existence and importance of these types of ecosystem services values, support the development of recreational fishery, protect the pond aquaculture ecosystems, and make full use of these ecosystems to promote the sustainable development of tour industry and aquaculture and increase fish farmers' income in these areas.