Spatiotemporal Analysis of Meteorological Elements on the Loess Plateau during 1961 - 2009

Based on meteorological data from 48 monitoring stations during 1961-2009,the spatial distribution and temporal trends of meteorological elements on the Loess Plateau were analyzed with Inverse Distance Weighted Interpolation and Mann-Kendall methods.Results show that the meteorological elements on the Loess Plateau spatially distributed with an obvious gradients.Precipitation and mean temperature decreased while mean wind speed and sunshine hours increased from southeast to northwest,relative humidity decreased while reference evapotranspiration increased from south to north.Monotonic trends were detected on most stations for each meteorological element;however,the numbers of stations with significant trends were different.About 98% of stations had significant upward trends in mean temperature,60% of stations had significant downward trends in sunshine hours and wind speed and upward trends in reference evapotranspiration,40% of stations had significant downward trends in relative humidity,and 30% of stations had significant downward trends in precipitation.Interdecadal variation existed in each meteorological element.Relative humidity decreased significantly since 2004;precipitation decreased,mean temperature and reference evapotranspiration increased significantly since the 1990s;the significant decrease in sunshine hours and wind speed was from the 1980s.Some new changing trends in climate were detected on the Loess Plateau,which might cause some uncertainties for the sustainable development of this region;therefore,more attention should be paid to this issue.