water Article Identification of the Space-Time Variability of Hydrological Drought in the Arid Region of Northwestern China Huaijun Wang 1,2,*, Zhongsheng Chen 3, Yaning Chen 4, Yingping Pan 5 and Ru Feng 1 1 School of Urban and Environment Science, Huaiyin Normal University, Huaian 223300, China;
[email protected] 2 Research Center for Climate change, Ministry of water resources, Nanjing Hydraulic Research Institute, Nanjing 210029, China 3 Department of Land and Resources, China West Normal University, Nanchong 637002, China;
[email protected] 4 State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences (CAS), Urumqi 830011, China;
[email protected] 5 Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China;
[email protected] * Correspondence:
[email protected]; Tel./Fax: +86-517-8352-5089 Received: 11 April 2019; Accepted: 16 May 2019; Published: 20 May 2019 Abstract: Drought monitoring is crucial to water resource management and strategic planning. Thus, the objective of this study is to identify the space-time variability of hydrological drought across the broad arid region of northwestern China. Seven distributions were applied to fitting monthly streamflow records of 16 gauging stations from 10 rivers. Finally, the general logistic distribution was selected as the most appropriate one to compute the Standardized Streamflow Index (SSI). The severity and duration of hydrological droughts were also captured from the SSI series. Moreover, we investigate the relationship between hydrological drought (SSI) and meteorological drought (Standardized Precipitation-Evapotranspiration Index (SPEI)) at different time scales.