桃園市暴雨水減災的假設市場價格及其空間迴歸分析

Contingent Valuation and Spatial Regression Model of Stormwater Disaster Reduction for Taoyuan City

胡志平(Chich-Ping Hu)

《地理學報》 100期 (2021/12) Pp. 39-69

https://doi.org/10.6161/jgs.202112_(100).0003

摘要

減少不透水表面，是政府解決水患最優先要提出的政策。不透水表面的減少而降低淹水災害的風險，所帶來的社會效益，不只改善地區的福祉，更會擴散影響到相鄰地區。減災空間效益的間接效應，可以透過居民問卷詢價得到需求函數，進一步分析求得。本文以桃園市為研究對象，設計雙界二分評價問卷，並且利用受訪者回答都市暴雨水減災的願付價格的資料，建立減災願付價格函數。願付價格是透過問卷調查的資料，利用區間迴歸法建立暴雨水減災函數，估計解釋變數的邊際效應及預測減災效益，再利用空間迴歸模型，分析減災的空間外部效應。研究結果如後說明，1.居民屬性：年齡、教育程度、所得與環境財特質，會影響暴雨水災風險降低的願付價值。少部分居民，無論如何都不願意支付費用，最主要的原因是缺乏足夠風險訊息與認知，而且不相信政府能有效地達成風險降低的目標。2.桃園市暴雨水減災的總效益，在最大概似估計法計算後，最高為中壢區的6.93億元，其次為桃園區的6.01億元，龜山區、蘆竹區、楊梅區、龍潭區的願付價值分別是2.48億元、2.55億元、2.72億元、2.81億元，其他分區則分布在930萬元至0.97億元。3.暴雨水減災願付價格Moran's I等於-0.277，顯示暴雨水管理的社會福祉的空間特質，具有分散的效應。集中配置資源，才會形成聚集經濟的效果。分散的社會福祉效應，代表空間聚集經濟效應相對缺乏。4.空間迴歸模型操作結果顯示，暴雨水減災存在空間外部性，坡度、高度、耕地面積等地區的脆弱性愈高，減災效益愈高。相鄰分區的管理規費效益、海拔高度、耕地面積、平均收入，會負面的外溢至各分區，而且外溢數量愈多，暴雨水降低的效益減少愈多。

關鍵字

暴雨水 ； 減災 ； 不透水表面 ； 空間迴歸模型

並列摘要

Reducing impervious surfaces is the Taoyuan City government's highest priority in addressing floods. Reduction of impervious surfaces can reduce the risk of flooding disasters, and the resulting social benefits not only improve the well-being of the district, but also affect the adjacent areas. The indirect influence of disaster reduction can be achieved through the resident’s questionnaire inquiry and further analysis. This study designs a doubled-bound dichotomous choice questionnaire to ask residents of Taoyuan City, Taiwan about their willingness to pay for urban stormwater disaster reduction, and establishes the disaster reduction demand function from the survey results. Based on the questionnaire survey data, interval regression analysis is performed to estimate the marginal effect of stormwater disaster reduction and forecast the disaster reduction benefit, and then the spatial regression model is employed to analyze the spatial effect of disaster reduction. The following conclusions are drawn from the analytical results. 1) A resident's attributes including age, education level, income and environmental features affect the willingness to pay for the risk reduction from stormwater flooding. A small number of residents are unwilling to pay fees anyway for the reason of lack of sufficient risk information and awareness, and they do not believe that the government can effectively achieve the goal of risk reduction. 2) The total benefit of stormwater disaster reduction in Taoyuan City, based on maximum likelihood estimation, is NT$693,000,000 in Zhongli District, followed by NT$601,000,000 in Taoyuan District, Guishan District, Luzhu District, Yangmei District and Longtan District are willing to pay NT$248,000,000, NT$255,000,000, NT$72,000,000 million dollars and NT$281,000,000 respectively, while other districts range between NT$9,300,000 and NT$97,000,000. 3. The Moran's I of willingness to pay for stormwater disaster reduction is equal to -0.277, which illustrates the spatial characteristics of distribution for the social well-being of stormwater management with decentralized effect. Centralized allocation of resources accumulates the effect of an agglomeration economy. The decentralized social welfare effect represents the relative lack of spatial agglomeration economic effect. 4) The results of the spatial regression model show that the process of stormwater disaster reduction has spatial externalities. A higher vulnerability caused by slope, height, and cultivated land area is implies a greater potential benefit from disaster reduction. The benefits of management fees, altitude, arable land area and average income from neighboring districts spill over negatively to each district, and more spillovers mean increased benefit of storm water reduction.

並列關鍵字

Stormwater ； disaster reduction ； impervious surfaces ； spatial regression model

參考文獻

詹滿色、傅祖壇 [Zhan, M. S., and Z. T. Fu] 2007。臺灣漁產品HACCP安全認證的價值評估一雙界二分假設市場評估法之應用 [Tai wan yu chan pin HACCP an quan ren zheng de jia zhi ping gu- Shuang jie er fen jia she shi chang ping gu fa zhi ying yong; HACCP on seafood in Taiwan-A double-bounded dichotomous choice contingent valuation] 。農業經濟叢刊 [Nong ye jing ji cong kan; Taiwanese Agricultural Economic Review] 13 (2): 168-88, doi: 10.6196/TAER.2007.12.2.1

蕭代基、錢玉蘭、蔡麗雪 [Xiao, D. J., Y. L. Qian, and L. X. Cai] 1998。淡水河系水質與景觀改善效益之評估 [Dan shui he xi shui zhi yu jing guan gai shan xiao yi zhi ping gu] 。經濟研究 Jing ji yan jiu; Taipei Economic Inquiry] 35 (1): 29-59, doi: 10.29765/TEI.199801.0002

吳珮瑛，鄧福麟 [Wu, P. Y., and F. L. Deng] 2003。黑面琵鷺保護區生態旅遊規劃方案下居民參與和願付價值關係之檢討 [Hei mian pi lu bao hu qu sheng tai lü you gui hua fang an xia ju min can yu he yuan fu jia zhi guan xi zhi jian tao; Examining of the relationship between citizen participation and willingness to pay for the ecotourism program design for the Black-Faced Spoonbill Protected Area in Taiwan] 。戶外遊憩研究 Hu wai you qi yan jiu; Journal of Outdoor Recreation Study] 16 (4): 41-70, doi: 10.6130/JORS.2003.16(4)3

Ando, A. W., C. L. Cadavid, N. R. Netusil, and B. Parthum. 2020. Willingness-to-volunteer and stability of preferences between cities: Estimating the benefits of stormwater management. Journal of Environmental Economics and Management 99: 102274, doi: 10.1016/j.jeem.2019.102274

Arnold Jr., C. L., and C. J. Gibbons. 1996. Impervious surface coverage: The emergence of a key environmental indicator. Journal of the American Planning Association 62 (2): 243-58, doi: 10.1080/019443696089 75688