Modeling risk analysis for rice production due to agro-climate change and uncertainty in irrigation water

Paddy and Water Environment - This study proposes a risk analysis model for quantifying the insufficient risk of rice production due to the climate change and variation in irrigation water and...     

Estimating the inverse demand function for transferring agricultural water in Taiwan

Changing climate has increasingly exacerbated droughts and floods in Taiwan; therefore, it is important to understand the actual demand of transferring Taiwan’s agricultural water. This estimation model could help the water resource agencies to develop appropriate mechanisms for transferring agricultural water, as well as bargaining tools for water-related negotiations. In this study, an inverse demand function estimation model for transferring agricultural water was established, and the water usage statistics derived from the water charge agreements, covering the period from January 1989 to December 2006 and including drought and non-drought periods, regarding the charging of water management fees and water usage fees, was applied to the estimation model in our empirical research. The agreements were made between irrigation associations and water companies, industrial water users, and science and industrial parks, for the purposes of strengthening irrigation management, building usage, and disposal of remaining water. The empirical research was conducted to estimate the demand for transferring agricultural water using double-log regression model for panel data, and analyzed with random effects models for regular conditions and drought periods. The results showed that the inverse demand function developed in this study was able to pass Largrange multiplier test, and adjusted R ² for the regression were high, fitting the random effects model showing good compatibility with the sample selection. From the results, we can verify the estimation models to forecasting models. The significant results not only prove that the model could provide important market information for the commercialization of water resources, but water resource agencies could also make use of this important information to develop suitable mechanisms for transferring agricultural water, as well as bargaining tools for negotiation of water transactions.     

The price elasticity of transferring agricultural water to industrial water during non-drought period in Taiwan

In this study, the demand function for the transferring agricultural water to industrial water during non-drought period covering from January 1998 to December 2008 in Taiwan was estimated, and the water usage statistics derived from the short-term water charge agreements, regarding the charging of water management fees and water usage fees from the irrigation associations, were applied to the estimation in the empirical model. The results of the research are presented as follows: (a) the demand for transferring agricultural water into industrial water is non-elastic; the price elasticity is −0.368; (b) the transferred water volume decreases when the water price rises; (c) the transferred water volume also decreases when the wholesale price index of domestic products rises; (d) the buyer’s industry classification was the significant factor influencing the transfer water demand; (e) the different title of transferred water including: “building utilization cost” or that in “costs for enhanced irrigation management” was the significant factor influencing the transfer water demand; (f) type of repository of irrigation association for transferred water was the significant factor influencing the transfer water demand; (g) whether irrigation association enhances irrigation management was the significant factor influencing the transfer water demand; (h) the source of transferred water was the significant factor influencing the transfer water demand; (i) the method for water transfer was the significant factor influencing the transfer water demand; (j) more water transferred by the industry when the total population of Taiwan increases; (k) the transferred water volume rises when the groundwater level of the water transferred area rises; and (l) the areas for water transferred was the significant factor influencing the transfer water demand.     

Environmental multifunctionality of paddy fields in Taiwan: an application of contingent valuation method

This paper aims to evaluate the social value of the environmental multifunctionality of paddy fields in Taiwan; through individual consumers’ direct expressions of their perceived benefit and to provide the empirical data thus collected for the reference of the decision makers in the government. This study use contingent valuation method (CVM) to evaluates the value of environmental multifunctionality of paddy fields from the purposefully selected pool of samples in Taiwan. The result shows if judged by the threat that free trade poses to the retention of arable land, most respondents give a value of 114 NT/household/month to 115 NT/household/month for 1% reduction of arable land to be restored to the existing level; and168 NT/household/month to 181 NT/household/month for a reduction rate of 4%. There are 7,394,758 households in Taiwan. The aggregating result is 10,116,028,944 NT/year to 10,204,766,040 NT/year for 1% reduction of arable land to be restored to the existing level; and 14,907,832,128 NT/year to 16,061,414,376 NT/year for a reduction rate of 4%.

Modeling risk analysis for rice production due to agro-climate change in Taiwan

This study proposes a risk analysis model for the rice production due to climate change in terms of agro-climate indices (i.e., cumulative temperature anomaly, cumulative precipitation anomaly, cumulative sunlight anomaly, cumulative radiation anomaly, and E1 Niño). This risk analysis model is developed by incorporating the multivariate Monte Carlo simulation method, multivariate regression equation, and uncertainty analysis method (advanced first-order second-moment, AFOSM). The study area is composed of 15 counties/cities in Taiwan, East Asia. The data set for the model development and applicability contains 27 years of annual rice productions and agro-climate indices in addition to cultivation areas. Through the proposed risk analysis model, it can be seen that the rice production in Taiwan is especially sensitive to temperature, precipitation, and sunlight. Also, on average, improving performance by reducing insufficient rice risk can rise by 80 % when the rice production increases from 3 × 10⁴ to 3 × 10⁵ tons.