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Abstract: This study investigated the spatial and temporal variability of daily minimum, mean and maximum temperature and the diurnal temperature range (DTR) in the Yangtze River Basin (YRB) during 1961–2010. Three variability patterns of daily minimum temperature and four variability patterns of daily mean and maximum temperatures were detected. Results indicate that the rugged topography causes more complex temperature variability in the mid YRB, and daily mean temperature shows more complex variability rather than daily minimum and maximum temperatures. Under the control of both topography and atmospheric circle, three temperature variables have mean values decreasing spatially with longitude, although the Sichuan Basin has larger mean values compared with the surrounding areas, and there are smaller variations in the Jinsha River Basin relative to other areas. The variations of three temperature variables became smaller over time. After the 1980s, the three temperature variables show upward trends in most areas of YRB, except in the Jinsha River Basin where complex temperature trends appeared. In the five decades, both negative and positive magnitudes of DTR were detected, reflecting the different upward speeds of daily minimum and maximum temperatures in different areas of YRB. Rapid urbanization caused notably increasing temperature and DTR in the 2000s at the Wuhan and Shanghai urban agglomerations. In summary, the Dongting and Poyang Lake basins and the Yangtze River Delta in YRB are more sensitive and susceptible to climate change. [Copyright &y& Elsevier]

Variability of the climate in the headwater drainage basins of the Yangtze River and Yellow River during 1961-2010 was investigated by examining four typical climatic variables: daily minimum, mean, and maximum temperatures and daily precipitation. The results indicate that the temporal trends vary among the climatic variables and the time periods examined. The increase in daily minimum temperature began later than the daily mean and maximum temperatures, but the increase rate of the former was relatively greater after 1985. The abrupt increases in precipitation that occurred near 1978 were much clearer than the three temperature variables. Four dominant periodicities (3, 7, 11, and 18-20 yr) of temperature and precipitation were identified, and these variation patterns directly determined the periodic discharge variations in the two rivers. Under climate change impacts, periodic variations in temperature and precipitation at long temporal scales were intensified after the 1980s. Comparatively, climate change more severely impacts the minimum temperature and precipitation than the maximum and mean temperatures in the study area, and the variability of daily precipitation is more complex than the three temperature variables. Overall, the headwater drainage basin of the Yellow River is more susceptible to climate change compared with the other basin. After 2008, the increase rate of temperature (especially the daily mean and minimum temperatures) became greater, and precipitation showed a downward trend in the study areas. These trends are unfavorable for the safety of water resources and for eco-environmental safety in the two basins. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, the variability of daily temperature in the Yangtze River Delta (YRD) for the period 1958–2007 was investigated by selecting three typical temperature variables (daily minimum, mean and maximum temperatures) and the diurnal temperature range (DTR). Three variability patterns of daily mean temperature and two variability patterns of daily minimum and maximum temperatures were first classed, and then statistical properties of three temperature variables in 1958–1985 and 1986–2007 were analyzed. After that, temporal trends of three temperature variables and DTR were detected. Finally, the impacts of urbanization on the variability of daily temperature were investigated. Results indicate that: (1) daily mean temperature shows more complex variability than daily minimum and maximum temperatures; (2) in 1986–2007 three temperature variables have bigger mean values but smaller C v (coefficient of variance) values, and are more close to normal probability distribution; (3) three temperature variables show positive trends in 1986–2007, and the increase of daily mean temperature is more due to the increase of daily minimum temperature in the northern YRD but due to daily maximum temperature in the mid and southern YRD; (4) in the mid and southern YRD, daily maximum temperature has bigger increasing magnitude than daily minimum temperature in 1986–2007, causing positive trend of DTR; and (5) rapid urbanization causes normal distribution of three temperature variables, and notably increasing magnitude of daily temperature and DTR in 1986–2007 at the lower reaches of the Yangtze River and the Hangzhou Bay. [Copyright &y& Elsevier]