Spatial and temporal variations of precipitation: case study of Zhanghe River Basin, P. R. China

From the day first droughts and over wettings remains important in the economic development of humankind. In this study, monthly and annual trends of precipitation were analyzed for eight different weather stations in the Zhanghe River Basin, China over 30 years period (1980–2010). Prior to applying MK (Mann-Kendall test), trend-free Pre-whitening (TFPW) approach was applied to eliminate serial correlations in the time series data. The Mann-Kendall and Sen's slope methods were used to ascertain the trends in the precipitation data. The results demonstrated both positive (increasing) as well as negative (decreasing) trends at the 90, 95 and 99 % significance levels. The present study further revealed that the variability in the spatial distribution of precipitation trends were highly significant. In the month of February, most of the stations had upward precipitation trends (99% significance level) whereas that of March showed a downward trend in the Anyang station (99 % significance level). This study mainly points out that there is a high probability of water scarcity occurrence in this region. The information provided in this study is therefore useful in drought assessment in this particular region. It is also concluded that the Mann-Kendall and Sen's tests are suitable for the precipitation trend analysis in the stud