In recent years, hydrological drought has become more and more frequent, which has caused serious ecological and environmental problems. This paper is taking Guizhou province of China as an example to analyze the geomorphologic distribution and temporal-spatial evolution of hydrological droughts, and to study driving mechanisms of both the rainfall in drought periods and geomorphologic factors on the hydrological droughts, based on the hydrometeorological data from the 2000 to 2010, and the TM and DEM data. The results show that (1) the rainfall and its temporal-spatial distribution have less impacts on the hydrological droughts and its temporal-spatial distribution, showing the obvious phase characteristics, and the regional hydrological droughts are more serious in the south than in the north, and the less serious in the east than in the west; and (3) in terms of the overall distribution of landform types, the mountain, hill and basin have less impacts on hydrological droughts; in terms of the distribution of single geomorphic type, hydrological droughts are significantly influenced by the high-medium mountain, deep-high hill and high basin, where the hydrological droughts are relatively lighter. While there are more serious areas in the low basin, shallow-low hill and low mountain.

The occurrences of atmospheric precipitation and runoff do not coincide with each other, but rather demonstrate a certain lag in time. Meanwhile the lagged time and intensity are affected by the water storage capacities, which is related to the occurrence of droughts. This paper will develop the lagging index (LI) based on the measured data of 56 rainfall stations and 11 hydrological stations in the Central Guizhou of China, and analyze the spatio-temporal evolution characteristics of rainfall-runoff. The studies show that (1) the lagged effect of runoff to rainfall in the Central Guizhou of China mainly shows the 3 lagged periods with the lagged distribution areas accounting for more than 80% of the total areas. (2) The order of spatio-temporal distribution differences of the lagged intensities is the lagged period 2（Cv=0.62）

The occurrence of atmospheric precipitation and runoff is not at the same time, and a certain lag in time, and its lagged time and intensity are affected by the water storage capacities, which is related to the occurrence of droughts. This paper will develop the lagging index (LI) based on the measured data of 56 rainfall stations and 11 hydrological stations in the Central Guizhou of China, and analyze the spatio-temporal evolution characteristics of rainfall-runoff. The studies show that (1) the lagged effect of runoff to rainfall in the Central Guizhou of China mainly shows the lagged 3 periods with the lagged distribution areas accounting for more than 80% of the total areas. (2) The order of spatio-temporal distribution differences of the lagged intensities is the lagged period 2（Cv=0.62）