197: Observed Trends in Hydrologic Cycle Components

摘要: Documentation of change in the Earth's climate is accomplished by assessing rates, magnitude, and distribution changes various elements system, such as components hydrologic cycle. The present section reviews general character precipitation, streamflow, evaporation determined using systematically collected data through end twentieth century. Precipitation over global land areas increased about 2% during century, streamflow also exhibited widespread increases. There was good agreement regionally between observed precipitation increases appear to have occurred most commonly higher intensity categories (>50 mm per day), while were overwhelmingly low moderate range flows. No systematic peak streamflows. These findings indicate that a intensification cycle but this did not result extremes. Keywords: evaporation; hydrologic cycle; precipitation; streamflow; trends