Drought identification is crucial to water resources management and planning. Different drought indices have been developed and their complexity and applicability vary. The objectives of this research are to develop a new integrated drought index with the capability of identification of drought and to further customize drought categorization for cold climate regions. Specifically, a new hydroclimatic aggregate drought index (HADI) is developed by coupling with a grid-based hydrologic model and applying the R-mode correlation-based principal component analysis. The HADI is a composite drought index, which assesses the anomalies of rainfall, surface runoff, snowmelt, and soil moisture in the root zone. Furthermore, joint probability distribution function of drought frequencies and classes as well as conditional expectation are used for drought categorization. The HADI was applied to the Red River of the North Basin (RRB) and its performance was evaluated by comparing with the Palmer Drought Severity Index (PDSI) and the U.S. Drought Monitor (USDM) products. Based on the impacts of drought on agriculture, the HADI outperformed the PDSI in identification of droughts in the RRB. Although the HADI and USDM showed a good agreement in identification of drought periods, the drought area coverages for each drought category from the two methods differed. The new customized drought categorization based on variable threshold levels accounted for the variations in both time and geographical locations. The new HADI, together with the customized drought categorization, is able to provide more accurate drought identification and characterization, especially for cold climate regions.

干旱识别对于水资源管理和规划至关重要。已经开发了不同的干旱指数，它们的复杂性和适用性各不相同。这项研究的目的是开发一种具有干旱识别能力的新的综合干旱指数，并进一步针对寒冷气候地区定制干旱分类。具体而言，通过结合基于网格的水文模型并应用基于R模式相关性的主成分分析，开发了新的水文气候总干旱指数（HADI）。HADI是综合干旱指数，用于评估根部地区的降雨，地表径流，融雪和土壤湿度的异常情况。此外，干旱频率和类别以及条件期望的联合概率分布函数用于干旱分类。将HADI应用于北部盆地的红河（RRB），并通过与Palmer干旱严重性指数（PDSI）和美国干旱监测器（USDM）产品进行比较来评估其性能。基于干旱对农业的影响，在确定RRB中的干旱方面，HADI优于PDSI。尽管HADI和USDM在确定干旱时期方面显示出很好的一致性，但是两种方法对每种干旱类别的干旱区域覆盖率都不同。基于可变阈值水平的新的定制干旱分类解决了时间和地理位置的变化。新的HADI以及定制的干旱分类，