在氣候變遷威脅及人為高度發展下，水資源短缺且分配不均，臺灣近年來旱災事件頻率越加頻繁且嚴重，面對旱災缺水的危機，解析地下水時空變異特性是必要，建立旱災風險的預警與地下水永續利用之機制為重要的防減災策略。本研究分析各地區在旱災下之脆弱度 (Vulnerability)、危害度 (Hazard)、暴露度 (Exposure) 及風險度 (Risk)，以屏東平原為例，各風險度分別繪製成旱災風險分析圖，並建立風險指標及劃分成五個等級。脆弱度是應用訊號分析方法希爾伯特-黃轉換 (Hilbert Huang Transform, HHT) 解析地下水位時空變異特性及地下水之物理機制去量化敏感度 (Sensitivity) 及耐災力 (Resilience)，危害度是以標準化降雨指標 (Standardized Precipitation Index, SPI) 分析各地區之乾旱特性及強度，暴露度是以人口密度去量化民生用水的危機，風險度是綜合各旱災風險度之結果。本研究結果整合各項旱災風險度建立旱災風險系統，有效解析旱災的風險，透過旱災風險度之結果歸類主要時頻特性區域、各地區地下水的可利用性及各風險，旱災風險由東往西南漸高，東區在乾旱事件發生時，各項風險度皆較低，此處地下水的可利用性較高，西南區域之各項風險度綜合為最高風險區，旱災強度強、耐災力弱及民生用水高，此區之地下水資源可調用性低。本研究可協助決策者判斷乾旱風險，作為旱災救援管理、旱災韌性與風險管理及地下水資源永續發展的重要依據。;Under the threat of climate change and high artificial development, water resources are scarce and unevenly distributed. The frequency of drought events in Taiwan has become more frequent and serious in recent years. In the face of the drought and water shortage crisis, it is necessary to analyze the spatial and temporal variability of groundwater and establish the risk of drought. The mechanism of early warning and sustainable use of groundwater is an important strategy for disaster prevention. This study analyzes the Vulnerability, Hazard, Exposure, and Risk of drought in each region. Taking Pingtung Plain as an example, each risk is plotted as a drought risk analysis, establish risk indicators and divide them into five levels. Vulnerability is the application of signal analysis method Hilbert Huang Transform (HHT) to analyze the spatiotemporal variation characteristics of groundwater level and the physical mechanism of groundwater to quantify Sensitivity and Resilience. Hazard is the application of the Standardized Precipitation Index (SPI) is used to analyze the drought characteristics and intensity of each region. Exposure is based on the population density to quantify the crisis of livelihood water. Risk is the result of integrating each risk of drought. The results of this study integrate the various drought risks to establish a drought risk system, effectively analyze the risk of drought and classify the main time-frequency characteristics, the availability of groundwater and the risks in each region through the drought risk map. The risk of drought is increasing from east to southwest. When the drought occurs in the eastern region, the risks are low, and the availability of groundwater is high. The comprehensive risk of the southwest region is the highest risk zone. The drought intensity is strong, disaster tolerance is weak, and the water for people′s livelihood is high. The availability of groundwater resources in this area is low. The result of this study can provide relevant units as an important basis for groundwater disaster prevention and backup well network planning reference, groundwater drought resilience and risk assessment.
