Pedosphere 21(6): 793--801, 2011
ISSN 1002-0160/CN 32-1315/P
©2011 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Spatio-temporal variability of soil salinity in alluvial plain of the lower reaches of the Yellow River—A case study |
LI Kai-Li1,2,3, CHEN Jie4 , TAN Man-Zhi1, ZHAO Bing-Zi1, MI Shu-Xiao1,2 and SHI Xue-Zheng1 |
1 State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China)
2 Graduate University of Chinese Academy of Sciences, Beijing 100049 (China)
3 Department of Geography, Jiangsu Institute of Education, Nanjing 210013 (China)
4 School of Water Conservation and Environment, Zhengzhou University, Zhengzhou 450000 (China) |
| ABSTRACT |
| Soil salinity and hydrologic datasets were assembled to analyze the spatio-temporal variability of salinization in Fengqiu County, Henan Province, China, in the alluvial plain of the lower reaches of the Yellow River. The saline soil and groundwater depth data of the county in 1981 were obtained to serve as a historical reference. Electrical conductivity (EC) of 293 surface soil samples taken from 2 km × 2 km grids in 2007 and 40 soil profiles acquired in 2008 was analyzed and used for comparative mapping. Ordinary kriging was applied to predict EC at unobserved locations to derive the horizontal and vertical distribution patterns and variation of soil salinity. Groundwater table data from 22 observation wells in 2008 were collected and used as input for regression kriging to predict the maximum groundwater depth of the county in 2008. Changes in the groundwater level of Fengqiu County in 27 years from 1981 to 2008 was calculated. Two quantitative criteria, the mean error or bias (ME) and the mean squared error (MSE), were computed to assess the estimation accuracy of the kriging predictions. The results demonstrated that the soil salinity in the upper soil layers decreased dramatically and the taxonomically defined saline soils were present only in a few micro-landscapes after 27 years. Presently, the soils with relatively elevated salt content were mainly distributed in depressions along the Yellow River bed. The reduction in surface soil salinity corresponded to the locations with deepened maximum groundwater depth. It could be concluded that groundwater table recession allowed water to move deeper into the soil profile, transporting salts with it, and thus played an important role in reducing soil salinity in this region. Accumulation of salts in the soil profiles at various depths below the surface indicated that secondary soil salinization would occur when the groundwater was not controlled at a safe depth. |
| Key Words: electrical conductivity, groundwater table, kriging, salinization, salt content |
| Citation: Li, K. L., Chen, J., Tan, M. Z., Zhao, B. Z., Mi, S. X. and Shi, X. Z. 2011. Spatio-temporal variability of soil salinity in alluvial plain of the lower reaches of the Yellow River—A case study. Pedosphere. 21(6): 793-801. |
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