Complex sentence: Water Resources Research, vol.47 WO7536, doi: 10.1029/2010/WR009697 While precipitation has generally increased since the early 1900s, the high variability in precipitation makes the identification of precipitation trends statistically difficult.
Split into simpler sentences: Water Resources Research, vol.47 WO7536, doi: 10.1029/2010/WR009697 While precipitation has generally increased, since the early 1900s. The high variability in precipitation makes the identification of precipitation trends statistically difficult.