Comparison Of Meteoric Water Line Between Different Methods In Arid Northwest China

The relationship between ?¹⁸? and ?D is called meteoric water line. The formula of global meteoric water line is ?D=8?¹⁸?+10. Temperature, precipitation amount,vapour pressure and relative humidity influence meteoric water line discrepant main about in slope and intercept. Beside the affected by meteorological factors, another reason is closely related with the choice of arithmetic. In this paper, based on GNIP date in Hotan, Urumqi, Zhangye and precipitation isotope data in Altay, Houxia,Gaoshan, Yeniugou, using OLSR, RMA, MA, PWLSR, PWRMA and PWMA, the seven sites atmospheric water line be calculated in arid zone of northwest China.Compared and analyzed of meteoric water line in different arithmetic, combined with the feature of meteorological factors and geographical environment, the best method of meteoric water line be alternative, because of isotope site scarce and uneven distribution in study area, ECHAM simulated data be introduce to participate, the result showed that:?1?RMA and MA compared with OLSR, the slope gap in Houxia is small,while in Zhangye is large; RMA and MA compared with OLSR, the intercept gap in Houxia is still small, while in Urumqi is large. PWRMA compared with PWLSR, the slope gap in Gaoshan is small, while in Urumqi is large; PWMA compared with PWLSR, the slope gap in Gaoshan is small but in Zhangye is large. PWRMA and PWMA compared with PWLSR, the intercept gap in Houxia is small, while in Urumqi is large.?2?PWLSR?PWMA?compared with OLSR?MA?, the slope gap in Gaoshan is small, while in Zhangye is large; PWRMA relative to RMA, the slope gap in Gaoshan is small, while in Houxia is large. PWLSR?PWRMA?compared with OLSR?RMA?, the intercept gap in Yeniugou is small, while in Zhangye is large; PWMA relative to MA, the intercept gap in Yeniugou is small, while in Urumqi is large.?3?From the variation of the slope and intercept in different meteorological factors, slope and intercept of meteoric water line is strongly influenced by temperature, secondly is the impact of precipitation, the effect of relative humidityand vapor pressure without obvious than temperature and rainfall.?4?To compare result calculation by different arithmetic in ECHAM simulated data, unweighted arithmetic relative to the OLSR and weighted arithmetic relative to the PWLSR, the slope gap and intercept gap in Southern Xinjiang subregion is small,while in the area of northern Xinjiang is large, Alxa-Hexi area is largest. Weighted arithmetic and correspondence unweighted arithmetic, the slope gap and intercept gap in the area of northern Xinjiang is small, but in southern Xinjiang subregion and Alxa-Hexi area is not fixed. The slope gap and intercept gap change with arithmetic among southern Xinjiang subregion and Alxa-Hexi area.?5?To compare with meteoric water line calculation by different arithmetic,both measured data and ECHAM simulated data have a good consistency. The slope and intercept calculation by ECHAM simulated data is small than measured data in the area of northern Xinjiang. While slope and intercept calculation by ECHAM simulated data is large than measured data in southern Xinjiang subregion and Alxa-Hexi area.?6?rmSSEav have smaller value in arid zone of northwest China and Tianshan area with RMA and PWLSR than others, we can alternative RMA and PWLSR to calculate meteoric water line in arid zone of northwest China. However, climate is drought and precipitation is little in arid zone of northwest China, give the corresponding weights to different precipitation event, the influence on meteoric water line about small rainfall events can be reduced. Therefore, alternative PWLSR to calculate meteoric water line best.