• 论文 •

### EVAPOTRANSPIRATION OF LOW-LYING PRAIRIE WETLAND IN MIDDLE REACHES OF HEIHE RIVER IN NORTHWEST CHINA

WU Jin-kui1, DING Yong-jian1, WANG Gen-xu2, SHEN Yong-ping1, Yusuke YAMAZAKI3, Jumpei KUBOTA3

1. 1. Cold and A rid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences,Lanzhou 730000, P. R. China;The Laboratory of Climate Study of China Metrological Administration, Beijing 100041, P. R. China;
2. Cold and A rid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences,Lanzhou 730000, P. R. China;
3. Research Institute for Humanity and Nature, Kyoto, 602-0778, Japan
• 收稿日期:2005-08-10 出版日期:2005-12-20 发布日期:2011-12-15
• 作者简介:WU Jin-kui (1970- ), male, a native of Huining of Gansu Province, Ph.D. candidate, specialized in water resources and water environment in arid areas. E-mail: jkwu@lzb.ac.cn
• 基金资助:

Under the auspices of the Sino-Japan Cooperation Project and the Special Fund of China Metrological Administration(No. CCSF-2005-2-QH39)

### EVAPOTRANSPIRATION OF LOW-LYING PRAIRIE WETLAND IN MIDDLE REACHES OF HEIHE RIVER IN NORTHWEST CHINA

WU Jin-kui1, DING Yong-jian1, WANG Gen-xu2, SHEN Yong-ping1, Yusuke YAMAZAKI3, Jumpei KUBOTA3

1. 1. Cold and A rid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences,Lanzhou 730000, P. R. China;The Laboratory of Climate Study of China Metrological Administration, Beijing 100041, P. R. China;
2. Cold and A rid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences,Lanzhou 730000, P. R. China;
3. Research Institute for Humanity and Nature, Kyoto, 602-0778, Japan
• Received:2005-08-10 Online:2005-12-20 Published:2011-12-15

Low-lying prairie wetland, which has characteristics of both grassland and wetland, has irreplaceable ecological fmctions in inland river basins of Northwest China. Owing to its small-scale distribution, so far, the observation and research on it are rare. The estimation ofevapotranspiration is significant to ecological and environmental construction, scientific management of pasture and protection of wetland. For studying the evapotranspiration (ET) of low-lying prairie wetland in the middle reaches of the Heihe River, an inland river, in Northwest China, the automatic weather station in Linze Ecological Experimental Station of Lanzhou University (39°1'3"N, 100°03'2"E), Linze, Gansu Province,was selected as a case study. Based on meteorological data collected, Bowen-Ratio Energy Balance (BREB) method was used to calculate the evapotranspiration (ET) of low-lying prairie wetland. The analysis results showed that in a whole year (September 2003 -August 2004), the total ET was 611.mm and mean daily 1.67mm/d. The ET varied with different growing stages. In non-growing stage (NGS), initial growing stage (IGS), middle growing stage (MGS) and end growing stage (EGS), the ET was 0.7, 2.01, 3.82 and 1.49mm/d, with a percentage of total ET of 18.26%, 9.20%, 61.83% and 10.71% respectively. In March, ET began to increase. But in April, the ET increased most. After that, it increased gradually and got the maximal value in July. From then on, the ET decreased gradually. In September, the ET decreased rapidly. With the ending of growing and the freezing of soil, the ET stopped from the middle of November to February in next year. Hourly ET analysis showed that at 8:00 a.m. (during MGS at 7:00 a.m.), the evapotranspiration began, at 13:00 p.m.got its maximal value and at 19:00 p.m. (during MGS at 20:00 p.m.), the evapotranspiration stopped. The intensity of ET in sunny day was much larger than that in cloudy day in the same growing stage.

Abstract:

Low-lying prairie wetland, which has characteristics of both grassland and wetland, has irreplaceable ecological fmctions in inland river basins of Northwest China. Owing to its small-scale distribution, so far, the observation and research on it are rare. The estimation ofevapotranspiration is significant to ecological and environmental construction, scientific management of pasture and protection of wetland. For studying the evapotranspiration (ET) of low-lying prairie wetland in the middle reaches of the Heihe River, an inland river, in Northwest China, the automatic weather station in Linze Ecological Experimental Station of Lanzhou University (39°1'3"N, 100°03'2"E), Linze, Gansu Province,was selected as a case study. Based on meteorological data collected, Bowen-Ratio Energy Balance (BREB) method was used to calculate the evapotranspiration (ET) of low-lying prairie wetland. The analysis results showed that in a whole year (September 2003 -August 2004), the total ET was 611.mm and mean daily 1.67mm/d. The ET varied with different growing stages. In non-growing stage (NGS), initial growing stage (IGS), middle growing stage (MGS) and end growing stage (EGS), the ET was 0.7, 2.01, 3.82 and 1.49mm/d, with a percentage of total ET of 18.26%, 9.20%, 61.83% and 10.71% respectively. In March, ET began to increase. But in April, the ET increased most. After that, it increased gradually and got the maximal value in July. From then on, the ET decreased gradually. In September, the ET decreased rapidly. With the ending of growing and the freezing of soil, the ET stopped from the middle of November to February in next year. Hourly ET analysis showed that at 8:00 a.m. (during MGS at 7:00 a.m.), the evapotranspiration began, at 13:00 p.m.got its maximal value and at 19:00 p.m. (during MGS at 20:00 p.m.), the evapotranspiration stopped. The intensity of ET in sunny day was much larger than that in cloudy day in the same growing stage.