策勒绿洲沙漠过渡带小气候的空间差异

对策勒2011年1—12月4个不同下垫面的风速、温度、湿度、光合有效辐射的月差异进行分析,同时选取夏季晴天天气作为背景,比较沙尘暴、扬沙、浮尘、阴雨天时4个下垫面气象要素的差异。结果标明:与流沙地相比,绿洲-沙漠过渡带半固定沙地、固定沙地、绿洲内部2.0 m高处的6月平均风速依次减少了25.22%、27.93%、65.27%,12月绿洲内部0.5 m高处平均气温分别高于流沙地、半固定沙地、固定沙地1.39 ℃、1.21 ℃、2.70 ℃。5—10月4个下垫面之间温、湿度差异较春、冬季显著,7月流沙前沿2.0 m高处平均气温分别比半固定沙地、固定沙地、绿洲内部高0.35 ℃、1.61 ℃、3.75 ℃。沙尘暴天气下4个下垫面之间的风速差值依次小于扬沙、浮尘、阴雨、晴天天气下;在浮尘和晴天天气下,气温从流沙前沿到绿洲内部逐渐减低,相对湿度逐渐增加;沙尘暴和阴雨天气下各下垫面的气温和相对湿度无明显差异,扬沙天气下各下垫面之间温、湿度差异大于阴天天气,但小于浮尘和晴天天气;4个下垫面之间的光合有效辐射（PAR）在沙尘暴天气下差异最为明显,浮尘和阴雨天气下4个下垫面之间的PAR接近,晴天天气下各点PAR明显大于扬沙天气下,且各下垫面之间差异大于扬沙天气下的差异。

Spatial Difference of Microclimate in the Oasis-Desert Ecotone in Cele,Xinjiang, China

Analysis was done to the differences in time and space of monthly wind velocity, temperature, relative humidity and photosynthetically active radiation in four different underlying surfaces between ecotone and oasis in 2011. Additionally, a fine day in summer were chosen to synchronously analyze meteorological factors by comparing with sand-storm day, floating dust day, blown sand day and wet day. The results showed that: the monthly wind velocity in semi-fixed sandy land, fixed sandy land and oasis at the height of 2 m was 25.22%, 27.93% and 65.27% less, respectively, than that in mobile sandy land in June; the monthly temperature at the height of 0.5 m in oasis was higher than the rest three sites by 1.39 ℃, 1.21 ℃ and 2.70 ℃, respectively; the difference of temperature and relative humidity between May and October between the four underlying surfaces was greater than that of winter and spring; in July, the monthly temperature at the height of 2 m in mobile sandy land was higher than semi-fixed sandy land, fixed sandy land, oasis by 0.35 ℃, 1.61 ℃, 3.75 ℃, respectively; the wind velocity in sand-dust storm day was less than blown sand day, floating dust weather and wet day in turn; the air temperature in blown dust weather and fine day decreased gradually from mobile sandy land to oasis; while the relative humidity increased gradually and the difference between the four sites; the difference of air temperature and relative humidity at the four sites in sand storm weather and wet and cheerless weather was not obvious; difference of air temperature and relative humidity between blown sand day was more than that in wet day and less than that in blown dust day and fine day; difference of photosynthetically active radiation between the four sites was most obvious in day with sand-dust storm, there was no obvious difference between the day with blown dust and wet day.