5:15 PM - 7:15 PM
[HGG01-P05] Quantitative Analysis of Climate Disaster Risks of Hillslope Tea Gardens in Taiwan
Keywords: Bayesian network, Agronomic methods, TaiESM1, Altitude, SSP
Taiwan's tea industry, with a history spanning over a century, represents an important agricultural and cultural asset. Hillslope tea gardens in Taiwan, distributed across low to high altitudes, are highly sensitive to climatic conditions. With the intensification of global warming and the increasing frequency of extreme weather events, such as heatwaves, droughts, heavy rains, and colds, tea garden ecosystems face significant challenges, including impaired tea tree growth, elevated risks of pest and disease outbreaks, and increased management costs and economic pressure.
This study focuses on tea gardens located in Mingjian Township, Lugu Township, and Ren-ai Township in Nantou County in central Taiwan. A Bayesian Network (BN) model was employed to integrate meteorological data, gardens conditions, and tea farmers’ management practices to conduct a quantitative analysis of climate risks. The model utilized climate scenario data from the Sixth Assessment Report (AR6) of the Intergovernmental Panel on Climate Change (IPCC) in conjunction with the General Circulation Model, TaiESM1, to simulate the potential impacts of the three major climate risks, which are cold, drought, and heavy rain on the selected tea gardens. It also examined the interactions among risk factors and the risk characteristics of the tea gardens across different altitudes.
The results indicate that droughts cause primary climate risks on the tea gardens, significantly impairing tea tree growth and reducing tea leaf yield. The probability of drought occurrence exceeds 45% across all altitude zones, and as climate change intensifies, drought is likely to cause even greater losses. Cold have a more pronounced impact on tea trees growth at high altitudes, with a damage probability of 31%, higher than the 29.8% at mid-altitudes and 21.2% at low altitudes. However, during the winter dormancy period of tea trees, cold, while limiting growth potential, have minimal impact on yield, as this period falls outside the harvesting season.
In contrast, heavy rain poses the least risk to tea gardens. Data from the Central Weather Bureau indicate that between 2019 and 2023, there were only 53 days that met the criteria for torrential rain, resulting in a relatively minor impact. Furthermore, most tea farmers perceive the damage caused by heavy rain to tea gardens as less significant.
This study examines both the baseline and SSP585 scenarios. The results indicate that as climate conditions worsen, the risks of tea tree growth impairment and reduced tea yield increase. However, under different farming practices, the increase in risk for tea tree growth impairment is less pronounced, whereas the risk of reduced tea yield is amplified. Climate scenarios characterized by significantly higher greenhouse gas concentrations generally elevate the risks of both tea tree growth impairment and decreased tea yield. Regarding the reduction in tea yield, although the differences in risk occurrence between farming practices are not substantial overall, the impacts of meteorological disasters on tea yield vary between tea gardens employing agroecological farming and those using conventional farming at different elevations. With appropriate fertilization and irrigation measures, tea gardens using conventional farming can also exhibit greater resilience in coping with the impacts of climate change.
This research provides critical guidance for the long-term management of tea gardens, emphasizing the need to address the risks posed by extreme climate events, particularly drought, to mitigate the negative impacts of climate change on tea gardens. Tea gardens at different altitudes on hillslopes in central Taiwan should adopt tailored risk management strategies based on their specific geographical and climatic conditions. The proposed model serves as an effective tool for assessing the impacts of meteorological disasters under climate change scenarios on tea gardens, offering key references for enhancing the climate resilience and sustainable development of the tea industry.
This study focuses on tea gardens located in Mingjian Township, Lugu Township, and Ren-ai Township in Nantou County in central Taiwan. A Bayesian Network (BN) model was employed to integrate meteorological data, gardens conditions, and tea farmers’ management practices to conduct a quantitative analysis of climate risks. The model utilized climate scenario data from the Sixth Assessment Report (AR6) of the Intergovernmental Panel on Climate Change (IPCC) in conjunction with the General Circulation Model, TaiESM1, to simulate the potential impacts of the three major climate risks, which are cold, drought, and heavy rain on the selected tea gardens. It also examined the interactions among risk factors and the risk characteristics of the tea gardens across different altitudes.
The results indicate that droughts cause primary climate risks on the tea gardens, significantly impairing tea tree growth and reducing tea leaf yield. The probability of drought occurrence exceeds 45% across all altitude zones, and as climate change intensifies, drought is likely to cause even greater losses. Cold have a more pronounced impact on tea trees growth at high altitudes, with a damage probability of 31%, higher than the 29.8% at mid-altitudes and 21.2% at low altitudes. However, during the winter dormancy period of tea trees, cold, while limiting growth potential, have minimal impact on yield, as this period falls outside the harvesting season.
In contrast, heavy rain poses the least risk to tea gardens. Data from the Central Weather Bureau indicate that between 2019 and 2023, there were only 53 days that met the criteria for torrential rain, resulting in a relatively minor impact. Furthermore, most tea farmers perceive the damage caused by heavy rain to tea gardens as less significant.
This study examines both the baseline and SSP585 scenarios. The results indicate that as climate conditions worsen, the risks of tea tree growth impairment and reduced tea yield increase. However, under different farming practices, the increase in risk for tea tree growth impairment is less pronounced, whereas the risk of reduced tea yield is amplified. Climate scenarios characterized by significantly higher greenhouse gas concentrations generally elevate the risks of both tea tree growth impairment and decreased tea yield. Regarding the reduction in tea yield, although the differences in risk occurrence between farming practices are not substantial overall, the impacts of meteorological disasters on tea yield vary between tea gardens employing agroecological farming and those using conventional farming at different elevations. With appropriate fertilization and irrigation measures, tea gardens using conventional farming can also exhibit greater resilience in coping with the impacts of climate change.
This research provides critical guidance for the long-term management of tea gardens, emphasizing the need to address the risks posed by extreme climate events, particularly drought, to mitigate the negative impacts of climate change on tea gardens. Tea gardens at different altitudes on hillslopes in central Taiwan should adopt tailored risk management strategies based on their specific geographical and climatic conditions. The proposed model serves as an effective tool for assessing the impacts of meteorological disasters under climate change scenarios on tea gardens, offering key references for enhancing the climate resilience and sustainable development of the tea industry.