鄂尔多斯高原近48a降水及蒸发特征分析

Characteristics of precipitation and evaporation in the Ordos Plateau in recent 48 years

利用鄂尔多斯高原1961-2008年降水和蒸发时间序列分析表明,研究区降水量和蒸发量总体特征是皆向减少趋势发展,但降水在各年代都呈下降趋势,而蒸发在波动中向减少趋势发展。以Morlet小波函数为工具,分析得出研究区内降水和蒸发都存在多时间尺度特征,其中降水在8-9年和14-16年的时间尺度下正负交替震荡特征最明显,而蒸发在12-14年和21-22年时间尺度下信号最强。进一步分析表明,区内降水存在约3年、6年、9年和13年左右的周期,且未来几年内在经历短暂的降水偏少期后,将呈增多趋势;而蒸发量在未来几年内仍将减少。上述分析成果,对于进一步研究区内水资源演变特征,指导水资源合理开发利用具有十分重要的意义。

Based on the time series of the precipitation and evaporation from 1961 to 2008,the characteristics of climate change in Ordos Plateau were analyzed.The results showed that both of precipitation and evaporation were decreased during recent 48 years.It is interesting that the precipitation was always decreased but the evaporation decreased with fluctuation on per decade time-step.Furthermore,by using the Morlet wavelet function,we found that multi-time sale existed.The signal of precipitation under two time periods,8 to 9 year and 14 to 16 year was strong and alternation between positive and negative fluctuated obviously,and time periods about 3 years,6 years,9 years and 13years.furthermore,the precipitation will increase after few years of arid period.The multi-time scale character was different in the evaporation time series that there were two strong signal of 12 to 14 years and 21 to 22 years and the evaporation will still decrease in the next 10 years.The analysis results offer evidences to further study on water resources evolvement and guide to exploit water resource reasonably.