Spatio-temporal relations between temperature and precipitation regimes: Implications for temperature-induced changes in the hydrological cycle

Abstract

Changes in the precipitation regime as a result of temperature changes are important for water resources management and management of water-related natural hazards. In this study, daily temperature and precipitation datasets from 590 stations from across China are analyzed to investigate possible relations between precipitation and temperature regimes in both space and time. The K-means method is applied to group 590 stations into 4 homogenous sub-regions and then trends are detected by the modified Mann–Kendall test. The field significance test and false discovery rate approaches are used to determine spatial correlations. Results show that: (1) significant increases in temperature extremes are detected across China. However, the magnitude of increase in the minimum temperature is larger than that in the maximum temperature. The warming in China is reflected mainly by the remarkable increase in the minimum temperature; (2) precipitation changes are extremely uneven in both space and time. Generally, a wetting tendency is detected in western China, and a drying tendency in northeastern China annually and in summer. In winter, however, a wetting tendency is observed; and (3) different regional responses of precipitation extremes to increasing temperature can be identified across China. Under the influence of increasing temperature, precipitation is intensifying in southeastern China and winter is having a wetting tendency. The responses of changes in weak precipitation extremes to climate warming are comparatively complicated and diverse. Even then it can be confirmed that increasing temperature tends to trigger the intensification of precipitation. Temporal and spatial changes of water vapor divergence can well aid in the interpretation of seasonal and spatial alterations of precipitation regimes. Temperature changes can influence precipitation changes by altering thermo-dynamic properties of air mass and hence the moisture transportation.