Trend and correlation analysis of air temperature, precipitation, evaporation and discharge (1968–2009) in the Liu River, Zhangwu, Liaoning, China

Climatic changes may have significant impacts on terrestrial hydrological processes. It is essential to study the correlation between climate and hydrology of the Liu River, because the river is crucial for the local agriculture and industry development. The change range, trend and correlation analysis of air temperature, precipitation, evaporation and discharge during 1968-2009 in the Liu River ( Zhangwu county) were carried out. The results showed inter-year change range of air temperature for the high flow period, precipitation and discharge for the level flow period and evaporation for the low flow period were relative stable. The trends of air temperature and discharge series for every period were significant positive and negative respectively and that of evaporation series for the level flow period was significant negative. Correlation analysis indicated a marked drop in discharge with increased air temperature and reduced precipitation, furthermore, the effect of evaporation on discharge was different for different period.