1 Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China; College of Geology and Exploration Engineering, Xinjiang University, Urumqi, 830046, China; 2 Graduate School of Chinese Academy of Sciences, Beijing 100039, China
Spatial heterogeneity for grain size distribution of eolian sand soil on longitudinal dunes in the southern Gurbantunggut Desert
1 Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China; College of Geology and Exploration Engineering, Xinjiang University, Urumqi, 830046, China; 2 Graduate School of Chinese Academy of Sciences, Beijing 100039, China
摘要 The grain size composition, distribution characteristics and spatial variation of eolian sand soil on distinct positions across two longitudinal dunes and interdune areas were studied by means of conventional grain size analysis and geostatistical methods. In the study, 184 samples of eolian sand soil from the 0-30cm layer were systemically collected and measured from two longitudinal dunes and interdunes in the southern Gurbantunggut Desert. The results show that the dominant grain sizes are fine and very fine sands, and the differences of grain size compositions between the distinct geomorphologic positions are significant. The contents of clay and silt are highest on the interdune areas and lowest on the crests, and higher on the leeward slopes than on the windward slopes. The contents of very fine and fine sands are highest on the windward slopes and lowest on the crests. The contents of medium, coarse and very coarse sands are lowest on the interdune lands, and highest on the crests, and are identical on the two slopes. The coarser sizes (φ1) and mean sizes (Mz) for eolian sand soil all have a varying tendency from fine to coarse sizes with interdune area → leeward slope → windward slope → crest, and the sorting (σ) are poorly to well sorted. The results of geostatistical analysis reveal that φ1, Mz and σ values are moderately to strongly spatially autocorrelated. The values of the spatially correlated ranges are φ1＜σ＜Mz. The spatial variation for these grain size parameters is significant across the longitudinal dune landscape. From the crests towards the bottom of the slope, there is a varying gradient of zonal distribution, and the gradient values on the leeward slopes are larger than sites on the windward slopes.
Abstract: The grain size composition, distribution characteristics and spatial variation of eolian sand soil on distinct positions across two longitudinal dunes and interdune areas were studied by means of conventional grain size analysis and geostatistical methods. In the study, 184 samples of eolian sand soil from the 0-30cm layer were systemically collected and measured from two longitudinal dunes and interdunes in the southern Gurbantunggut Desert. The results show that the dominant grain sizes are fine and very fine sands, and the differences of grain size compositions between the distinct geomorphologic positions are significant. The contents of clay and silt are highest on the interdune areas and lowest on the crests, and higher on the leeward slopes than on the windward slopes. The contents of very fine and fine sands are highest on the windward slopes and lowest on the crests. The contents of medium, coarse and very coarse sands are lowest on the interdune lands, and highest on the crests, and are identical on the two slopes. The coarser sizes (φ1) and mean sizes (Mz) for eolian sand soil all have a varying tendency from fine to coarse sizes with interdune area → leeward slope → windward slope → crest, and the sorting (σ) are poorly to well sorted. The results of geostatistical analysis reveal that φ1, Mz and σ values are moderately to strongly spatially autocorrelated. The values of the spatially correlated ranges are φ1＜σ＜Mz. The spatial variation for these grain size parameters is significant across the longitudinal dune landscape. From the crests towards the bottom of the slope, there is a varying gradient of zonal distribution, and the gradient values on the leeward slopes are larger than sites on the windward slopes.
基金资助: National Basic Research Program of China (2009CB825105) and the Forestry Bureau of Fukang City
通讯作者:
YiBing QIAN
E-mail: dt6@ms.xjb.ac.cn
引用本文:
YiBing QIAN, ZhaoNing WU, HaiFeng YANG, Chao JIANG. Spatial heterogeneity for grain size distribution of eolian sand soil on longitudinal dunes in the southern Gurbantunggut Desert[J]. 干旱区科学, 10.3724/SP.J.1227.00026.
YiBing QIAN, ZhaoNing WU, HaiFeng YANG, Chao JIANG. Spatial heterogeneity for grain size distribution of eolian sand soil on longitudinal dunes in the southern Gurbantunggut Desert. Journal of Arid Land, 2009, 1(1): 26-33.
