Comparative Analysis of Difference between MeasuredData and Legacy Data of Clay in Manas County

Wei Ying; Wu Hongqi; Zhang Wentai; Xuan Junwei

doi:10.14083/j.issn.1001-4942.2018.05.020

Abstract：Taking Manas County as research area and based on the measured data of 54 soil survey sam-ples, we compared and analyzed the difference of soil clay content between 1:50000 Xinjiang Soil Database of Manas County (XSD), 1:1000000 China Dataset of Soil Properties for Land Surface Modeling (LSM) and 1:1000000 Harmonized World Soil Database (HWSD).For the point data, the average absolute error and the average relative error of XSD were the largest, reaching 133.1 g/kg and 45.87％, respectively.All soil clay data of the three databases are quite different from those of the actual measurement results .The 1:50000 soil texture map of Manas County showed that it has clay soils , and the area was 141.8 km 2 .From the spatial distribution of soil clay in Manas County , we can see that there are differences between different databases in the same area.The area with soil clay content over 300 g/kg was 1621.7 km 2 in the HWSD and 104.3 km 2 in the XSD, but there was no clay soil area for LSM.Through comparing the differences among the three data -bases with the actual measuring , we found that XSD data was closer to the actual measured ones and was more reliable than LSM and HWSD data at county scale .