การประเมินมูลค่าเชิงนันทนาการของพื้นที่ชุ่มน้ำในประเทศไทย โดยวิธีการโอนมูลค่า

Abstract

Wetlands are very important natural resources that provide a wide range of services and make human well-being. In Thailand, wetlands are under pressure about losing and degeneration because some wetlands were converted to support social and economic development activities. To support public decision making, policy makers need to know the environmental value of wetland in order to assess the social cost of wetland conversion. However, there are several important wetlands in Thailand have not been valuated yet because a primary study of environmental valuation is budget and time-consuming. This study aimed to assess a recreational value of wetlands in Thailand using value transfer method which is secondary approach. This study collected 54 wetland valuation studies in Thailand and Asia during 1989 - 2012. The selected studies yielded 98 observations in total. For analysis, the recreational values of wetland was standardized to US$ per person per visit price 2012. The mean and median values were 76.79 and 10.44 US$ per person per visit respectively. The meta-regression was estimated by a multilevel modelling approach in order to control for authorship effects. In this study, it was proved that authorship effect was 18% of total variance in values. This implied that the variation in valued can be highly attributed to differences among authors. The estimated regression showed that the factors determining a recreational value of wetlands were (1) site characteristics, (2) socio-economic characteristics and (3) valuation methods. The size of wetland had significantly positive impact on the value. It was found that for types of recreational activities, boating tended to provide significantly lower value estimates. For socio-economic characteristic, it was shown that tourists’ income has a significantly positive relationship to the estimated value. For valuation method, Travel Cost Method (TCM) provided significantly high value estimates than other methods. Compared to other studies, the average transfer error from our meta-regression function was relatively high (147 %). For estimated meta-regression, it can use to estimate recreational value of wetland in Thailand, the values have range between 8.97 US$ - 60.72 US$ per person per visit or about 278.63 Baht - 1,887.30 Baht per person per visit. Therefore, benefit transferred values from our model should be carefully used and policy makers should consult experts if any modification is necessary.