| Temporal and spatial variation characteristics of temperature, precipitation,runoff and available rainfall resource in the region from Sanmenxia to Huayuankouover the last 50 years were analyzed firstly. Runoff calculation formula wasdeveloped considering the relationship between natural runoff and climatic factors.And in further, effects of climate change and human activities on runoff were studied.And results indicate that: (1) Regional precipitation mainly concentrates in the floodseason from July to September. Annual precipitation after 1986 has decreased by10% to 30% of that in previous period. (2) In the recent 50 years, temperature hasbeen rising, especially winter temperature and spring temperature in Qinhe Riverbasin. (3) Annual runoff has been presented decreasing trend. Natural runoff after1986 has decreased by 10%～40% of that in previous period. And the correspondingrecorded annual runoff and flood season runoff have decreased by 41.6% and 54.8%respectively. (4) Regional runoff is mainly from rainfall. Runoff variation has notonly been affected by human activities, but also been influenced by changes inrainfall and temperature. (5) Available precipitation resource is a comprehensiveindicator which has considered multiple climatic factors, and it has closerrelationship with runoff than any other single meteorological factor. (6) Since 1986,regional runoff reduction is consequence of climate change and human activities. (7)The proportion between effects induced by climate change and human activities isdifferent in different period, which in later 1980s and the recent 5 years is about 3:1,but in 1990s, it is 45%:55%.
|
PDF Full Text Request