关键词: 人工绿洲, 生态建设, 试验研究, 额济纳旗

Abstract: The test study was conducted on the gobi area near the lower reaches of the Heihe River, where climate belongs to continental extremely dry type. Taking local circumstance and urgent need as starting point, and the rehabilitation and improvement of ecological environment as goal, the paper seeks ways to rebuilt and enlarge the oases in desert region. The test began at the year of 1982. The technical measures include: ① making use of river water during ice melting season to irrigate and fill groundwater;② accumulating sands by digging ditches for planting to improve soil texture; ③ selecting local tree species suitable to the environment to heighten the survival rate;④ afforestating with trees and shrubs integrately; and ⑤ controlling sand by enclosure and pl anting alternatively. From 1982 to 1996, the area of enclosure added up to more than 1 300 km², that of afforestation to 978 km² and that of natural recover accelerated by man made function to 222 km². The average preserving rate of trees planted during 1981~1989 is 61.3%, the average closing degree of these forest lands is 0.4. The coverage degrees of shrubs and grasses are 15.1% and 40.8% respectively. The construction of the artificial oasis has turned the bare gobi to green and showed ecological, economic and social benefits more obviously wit h time. The wind speed in woodland decreased by 48.3% compared with that at front of forest belt and 55.3% compared with that over gobi. During late June, the daily mean air temperature in woodland is 0.5℃ lower than that in gobi, but the ground surface temperature has a larger lower value of 6.3℃. The relative humidity rises from 14% near gobi surface to 2.9% in the woodland. Meanwhile, large amount of sand particles and dusts are retained by forest belt, which accelerates the processes of soil formation. There is a 9.5 cm soil surface layer in a woodland after 15 years from afforestation. The successive construction of artificial oasis has not only brought about direct and indirect economic benefit, but also encouraged the farmers and herdsmen to preserve and establish ecological environment.

Key words: Artificial oasis, Ecological construction, Test study, Ejin Banner