关键词: 河谷型地区, 近地层风环境, 气候舒适度, GIS, 空间分析

Abstract:

Taking the valley type city(Lanzhou) and its surrounding area as the study region, we establised the climate evaluation system which was suitable for valley-city based on the GIS technology and wind environment characteristics, and the system included six grade indexes, the study region was divided into four areas. Main conclusions are as follows:(1) The area with classification index value of 2 or 3 included the east part of Lanzhou, the southern of Yuzhong, the most of Dongxiang and the southwestern of Lintao, where annual average relative humidity was below 45%, annual average wind speed and temperature ranged from 1.5 to 2.5 m/s and from 7 to 11 ℃, respectively, and the altitute was about 2 000 to 2 500 meters, the climate comfort degree was poor. (2) The area with classification index value of 1, there were suitable temperature, wind speed and relative humidity, and better wind connectivity, but in the most parts of west Lanzhou, northwest Yongdeng and north Yuzhong there were higher wind speed and lower temperature. (3) The area with classification index value of 0 included the west Lanzhou, the southeast and north Ledu, the most parts of Dongxiang and northwest Lintao, where there were very comfortable and appropriate altitude, good vegetation and cool climate. (4) The area with classification index value of -1 and -2, including the mountaintops of the Xinglong Mountain and Maxian Mountain in Yuzhong, the mountaintops around Minhe and Ledu, which belong to the cooler and slightly comfortable area. The research results can provide certain scientific reference and theoretical support for the local to deal with the climate change, carry out the town planning and ecological environment protection planning.

Key words: valley-region, wind environment near surface layer, climate comfort degree, GIS, spatial analysis