腾格里沙漠民勤沙丘CO_2浓度与昼夜变化规律研究  

Study on the Change of Dune CO_2 Concentration in the Autumn at Minqin in Tengger Desert

作　　者：邵天杰[1] 赵景波[1,2] 郁科科[1] 董治宝[1,3] 

机构地区：[1]陕西师范大学旅游与环境学院,西安710062 [2]中国科学院地球环境研究所黄土与第四纪地质国家重点实验室,西安710075 [3]中国科学院寒区旱区环境与工程研究所,兰州730000

出　　处：《环境科学》2010年第12期3004-3010,共7页Environmental Science

基　　金：教育部长江学者特聘教授基金项目(801813);国家自然科学基金项目(40672108);中国科学院黄土与第四纪地质国家重点实验室项目(SKLLQG0606)

摘　　要：为查明沙漠区CO2浓度和对大气CO2的影响以及在全球碳循环中的作用,利用红外CO2监测仪于2009年9月对腾格里沙漠民勤实验点不同类型不同深度的沙层CO2含量变化进行了昼夜连续观测.根据12个钻孔CO2浓度的昼夜观测结果可知,民勤沙漠区不同观测点CO2浓度差异较大,各观测点昼夜CO2浓度变化在310×10-6～2 630×10-6之间;夜间沙层CO2浓度低,白天CO2浓度高;CO2浓度在深度上也有明显的差异,不同深度CO2浓度由大到小的顺序是:4 m(3m)>2 m>1m;与温带半湿润的西安地区相比,位于极端干旱区的民勤沙漠区CO2浓度显著低;CO2浓度昼夜变化明显,从当日09:00左右到次日09:00左右均呈现由低到高再到低的变化规律;在沙层水分一定的条件下,昼夜温度变化是造成沙层CO2浓度昼夜变化的主要原因,两者呈显著正相关关系;含水量较高沙层CO2浓度明显高于含水量较低沙层,沙层含水量高低是决定沙层CO2浓度的主要因素;4 m深度以上沙层CO2浓度均高于地表空气CO2浓度,表明极端干旱的沙漠区可能是CO2的来源区,也指示环境恶劣的裸露流动沙丘微生物活动产生的沙层CO2浓度仍然超过了大气CO2浓度.In order to find out the CO2 concentration of the desert area, the influence of it on the CO2in the atmosphere and the role that it played on the global carbon cycle, the research team utilized in September 2009 infrared CO2 monitor to observe the CO2concentration of the 12 drill holes day and night in Minqin desert area in the Tengger desert. The difference of various observation spots＇ CO2 concentration of the desert area in the Tengger desert area is relatively big. The CO2concentration at night is low but high in the daytime and the CO2concentration at each observation spot changes from 310×10^-6to 2 630 ×10^-6. The CO2 concentration is also obviously different in depth and the CO2eoncentration at different depths in order of size is as follows： 4 m（3m） 〉 2 m 〉1m. Compared with Xi＇ an area where is in the temperate and semi-humid region, the CO2concentration of the desert area in Tengger desert is very low. The diurnal variation of CO：concentration of the desert area in Tengger desert is obvious, and from the day 09：00am to 09：00am the next day, the CO2concentrations at different depths which rang from lm to 4 m present the regularity that it changes from low to high, and then from high to low. The diurnal variation in temperature is the main reason that causes the change of the CO2concentration in the sand layer, both of which have the positive correlation. The sand layer＇s CO2 concentration with higher water content is obviously higher than that with lower water content. The moisture content of sand layer is the main factor of the CO2 concentration. The CO2 concentration above 4m in the desert area is higher than that above the surface, which maybe indicates that the CO2from the highest desert area is also the resource of CO2in the atmosphere.

关 键 词：腾格里沙漠 沙层CO2浓度 昼夜变化规律 CO2释放 影响因素 

分 类 号：X144[环境科学与工程—环境科学]