img

官方微信

高级检索

中国沙漠 ›› 2012, Vol. 32 ›› Issue (4): 1154-1162.

• 生态经济 • 上一篇    下一篇

民勤与周边土地覆盖变化及对沙尘模拟结果的影响

蔡迪花, 赵建华, 李耀辉, 段海霞, 郭 铌, 杨启国   

  1. 中国气象局兰州干旱气象研究所 甘肃省干旱气候变化与减灾重点实验室/中国气象局干旱气候变化与减灾重点开放实验室,甘肃 兰州 730020
  • 收稿日期:2011-06-22 修回日期:2011-11-18 出版日期:2012-07-20 发布日期:2011-11-18

Land Cover Changes and Their Influences on Dust Transportation Simulated Using GRAPES-SDM in Minqin and Its Surrounding Area, Gansu, China

CAI Di-hua, ZHAO Jian-hua, LI Yao-hui, DUAN Hai-xia, GUO Ni, YANG Qi-guo   

  1. Key laboratory of Arid Climatic Change and Reducing Disaster of Gansu Province/Key Open Laboratory of Arid Climatic Change and Disaster Reduction of Chinese Meteorological Administration, Institute of Arid Meteorology, Chinese Meteorological Administration, Lanzhou 730020, China
  • Received:2011-06-22 Revised:2011-11-18 Online:2012-07-20 Published:2011-11-18

摘要: 利用民勤与周边地区2005年的Landsat-5 TM影像和1∶25万的DEM资料,在ArcGIS的支持下,对GRAPES_SDM沙尘模式中原有的20世纪80年代的地面信息进行更新与对比,在此基础上就2010年4月23日至25日的沙尘天气过程进行土地覆盖更新前后的数值模拟对比试验,并结合民勤站的沙尘浓度观测数据对模拟结果进行评价分析。结果表明,与模式中原有的土地覆盖信息相比,民勤及周边地区2005年的沙地、草地、耕地、水体、湿地面积明显减少,城乡用地变化不大;土地覆盖变化影响了模式输出的起沙通量和沙尘浓度的范围与强度。一方面,土地覆盖的更新使得起沙总体上有所减弱,且影响程度随过程的增强而逐渐增大。另一方面,土地覆盖变化对地面沙尘浓度的影响具有初期性、移动性和尺度适应性,同时也显著地改变了沙尘浓度的垂直分布。此外,起沙过程中土地覆盖信息的更新有利于民勤站沙尘浓度模拟值接近观测值,表明沙尘模式中的土地覆盖信息应该具有现势性。

关键词: 沙尘暴, 土地覆盖变化, GRAPES_SDM模式, 数值模拟, 民勤及周边地区

Abstract: Supported by GIS techniques, the land cover data were obtained on the basis of Landsat-5 TM images derived in 2005 and DEM data (1∶250 000) in Minqin and its surrounding area, Gansu of China. Comparison between the new land cover data and the original data of 1980s used in GRAPES_SDM model was then carried out. Finally, numerical simulation for a severe dust storm process occurred from 23 to 25 April, 2010 in Northwest China was conducted based on the two times of land cover data, respectively, and the simulation results were thereupon compared and evaluated by combining the observation data of the Minqin weather station. It was found out that the areas of sandy land, grassland, cropland, inland water area, and wetland decreased obviously in Minqin and its surrounding area, while urban and rural construction land changed little compared with the original land cover data used in the model. The results also showed that changes of land cover affected model outputs in extent and intensity of surface dust emission and dust concentration: On the one hand, the updating of land cover data made dust emission weaken in general, and the impact on dust emission increased with the enhancement of dust storm intensity. On the other hand, the influences of land cover changes on surface dust concentration were primeval, ambulant, and scale adaptive, which also obviously altered the distribution of dust concentration in vertical direction. What's more, the updating of land cover data is benefit to make the simulated value of surface dust concentration during dust emission in Minqin closer to the observations, implying that the land cover data used in the model should be updated in time.

Key words: dust storm, land cover change, GRAPES_SDM model, numerical simulation, Minqin and its surrounding area

中图分类号: