干旱区典型流域人工与天然绿洲相互转化过程与适宜比例——以开都-孔雀河流域为例

Artificial and Natural Oasis Mutual Converting Process and the Proper Ration in the Typical Basin of Arid Land——Taking the Kaidu-Kongque River Basin as an Example

利用1990、2000、2010年Landsat TM/ETM遥感影像,基于RS/GIS技术,分别提取土地利用/覆被类型信息,分析1990-2010年,开都-孔雀河流域人工绿洲和天然绿洲的变化规律及其比例,探讨该区人工绿洲和天然绿洲的适宜配比。结果表明:(1)1990-2010年,开都-孔雀河流域的人工绿洲呈不断扩张,天然绿洲面积不断缩小,表现为人工绿洲替代天然绿洲的趋势,1990-2010年人工绿洲面积增长2 895.1 km2,扩张速度为144.8 km2/a,天然绿洲减少面积1 946.4 km2,减小速度为97.32 km2/a。(2)1990-2010年,在人工绿洲扩张过程中,人工绿洲各土地利用要素变化也存在很大差异,1990-2000年,人工水库面积增长速度最快,年均增长速度为15.86%,建筑用地最慢,增长速递为2.88%;2000-2010年,果园面积的年均增长速度最快达37.1%。(3)近20 a开都-孔雀河流域人工绿洲面积呈增涨趋势,而天然绿洲面积呈下降趋势;人工与天然绿洲面积比例在近20 a呈增加的趋势,在1990、2000、2010年,人工与天然绿洲面积比值分别是2∶8、3∶7、4∶6。

Based on the Landsat TM/ETM remote sensing image of Kaidu-kongque-river basin, by using RS/GIS technology, this paper extracts the land use/cover type information of 1990, 2000 and 2010, analyzes the changing rule and the area ratio of the artificial and the natural oasis in Kaidu-kongque-river Basin, and discusses the suitable area ratio of the artificial and natural oasis. The results show that ： ①The artificial oasis was expanding, natural oasis area was shrinking in Kaidu-kongque-fiver basin from 1990 to 2010. The artificial oasis area increased by 2 895.1 km2 in 1990-2010, the expansion speed was 144.8 km2/a, the natural oasis area decreased by 1 946.4 km2, and the decreasing rate was 97.32 km2/a. ② In the process of artificial oasis expansion, land using types in artificial oasis also changed greatly from 1990 to 2010; artificial reservoir area was growing fastest, with an average annual growing rate of 15.86% from 1990 to 2010. Orchard area was growing fastest and with the annual growth of 37.1% from 2000 to 2010. ③The artificial oasis area in Kaidu-kongque-river Basin took on an increasing trend and the natural oasis area took on a declining trend in recent 20 years, the ratio of artificial oasis area and natural oasis area were 2 ： 8. 3 ： 7 and 4 ： 6 resoeetively.