Detrended Fluctuation Analysis of Precipitation Time Series in Yuanmou Dry-hot Basin over the Last 50 Years

The dry-hot valley is a special kind of degradation ecosystem region; the precipitation is a key factor to its landscape change. Based on the method of Detrended Fluctuation Analysis (DFA), the authors analyzed the variation trends of precipitation time series in Yuanmou Dry-hot Basin over the last 50 years. At the same time, the DFA exponent spectra of moving series from 1978 to 2006 were analyzed. The results shows that precipitation time series in Yuanmou Dry-hot Basin,which has obvious Hurst effect, has relative weak persistence and relative strong randomness. Vegetation coverage change in the dry-hot valley can explain the temporal evolution dynamics of precipitation shown by the DFA exponent spectra of moving series from 1978 to 2006 in Yuanmou Dry-hot Basin.