Spatio-Temporal Characteristics of Meteorological Drought in Liaoning Province Based on Z Index
基于Z指数的辽宁省气象干旱时空特性分析

Based on the daily precipitation data from 21 meteorological stations in Liaoning province during 1958~2008, the drought and water logging indexes of single station were calculated by the method of normalized Z index in this paper. According to these data, the drought and flood grades were determined and the grade sequence was established. Besides, the annual and spring meteorological drought characteristics in recent 51 years were analyzed from perspectives of time and space. The conclusions are as follows:1) From the point of view of time, the drought and water logging occur alternately in terms of inter-annual variation; the drought occurs on an average of two years, and the continuing meteorological drought occurs easily with more severe extent; there are nine years of primary cycle on Liaoning Province’s annual drought grade; drought frequency is the largest in northwest Liaoning province, and reaches minimum in southern part; spring drought is the most serious in terms of seasonal variation in Liaoning Province, with 18 years of drought out of 51 years. There are about three years of primary cycle on spring drought grade; drought frequency is largest in the middle and the north-west of Liaoning, and is smallest in southern part; 2) From the perspective of space, the distribution of inter-annual drought in Liaoning Province is more concentrated. Overall, it decreases from northwest to southeast. Northern and southern part are severe drought-prone areas, southwest is drought-prone area, and the partial drought-prone areas are more dispersed. The distribution of drought in spring is more dispersed, with north-western part is severe drought-prone area, northern and southern parts are drought-prone areas and the partial drought-prone areas are numerous and more dispersed. The research results correspond with the actual situation in the main, so they can provide a theoretical basis for relevant departments in Liaoning Province to develop appropriate drought countermeasures based on the regional drought characteristics.