| 摘要: |
| 【目的】监测渭-库绿洲土壤盐渍化的空间分布特征，探究驱动因子作用机理，对当地因地制宜进行土壤盐渍化调控。【方法】采用决策树、克里金插值和灰色关联度分析研究了渭-库绿洲土壤盐渍化的剖面分布特征，着重分析了样本点海拔、植被覆盖度、地下水位、TWI（地形湿度指数）、地下水矿化度5个驱动因子对土壤盐渍化的影响。【结果】①研究区表层土壤（0~10 cm）属于重度盐渍化土壤，10~20、20~40、40~60 cm各深度剖面土壤属于中度盐渍化土壤。土壤EC1:5有强的空间变异性，其分布格局受灌溉等人为驱动因素的影响较大。②绿洲内部（即耕作区）表层土壤属于非盐渍化区域，绿洲东部10~20、20~40、40~60 cm土层有轻、中度的盐渍化现象。绿洲内部表层以下土壤盐分高于表层，绿洲存在潜在的盐渍化风险。耕作区外围绿洲-荒漠交错带区域各剖面层均属于盐渍化区域，随着剖面深度的增加，盐渍化程度在不断减弱。③样本点海拔、植被覆盖度、地下水位、TWI、地下水矿化度与土壤EC1:5的灰色关联度大小次序为：0~10 cm土层：地下水矿化度>TWI>样本点的海拔>植被覆盖度>地下水位；10~20、20~40 cm土层：地下水矿化度>样本点的海拔>TWI>植被覆盖度>地下水位。【结论】渭-库绿洲土壤盐渍化主要分布在绿洲-荒漠交错带区域，土壤盐分表聚强烈，地下水矿化度是造成该研究区土壤盐渍化问题的首要原因。 |
| 关键词: 土壤盐分； 绿洲； 决策树； 克里金插值； 灰色关联分析 |
| DOI：doi：10.13522/j.cnki.ggps.20190026 |
| 分类号: |
| 基金项目: |
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| Soil Salt Distribution and the Factors Affect it in Ogan Kucha River Oasis |
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LI Yanju, DING Jianli, Mireguli Ainiwaer
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1. College of Resource and Environment Science, Xingjiang University, Urumqi 830046, China; 2. Key Laboratory of Wisdom City and Environmental Modeling Department of Education, Urumqi 830046, China; 3. Ministry of Education Key Laboratory of Qasis Ecology, Xingjiang University, Urumqi 830046, China
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| Abstract: |
| 【Objective】This paper studied the spatiotemporal dynamics of soil salt in the Ogan Kucha River oasis in attempts to unravel its underlying mechanisms and helping ameliorate soil salinization that affect agricultural production in this region. 【Method】 The studied area was a moderate salinized field in Ogan Kucha River Oasis, from which we measured salt content in 10~20, 20~40 and 40~60 cm soil respectively. Using decision tree, Kriging interpolation and grey relation analysis, we analyzed the role of elevation, vegetation coverage, depth of groundwater table, topographic wetness index (TWI) and groundwater salinity in formation of soil salinization.【Result】The top 0~10 cm soil was heavily salinized while the 10~60 cm soil as moderately salinized. The EC1:5 varied erratically over space, affected anthropologically by factors such as irrigation. The surface soil in the oasis was less salt-affected, and light-moderate salinization was found in 10~60 cm soil in the east part of the oasis. Soil salinity in sub-soil was higher than that in the top soil, indicating a risk of potential salinization. The oasis-desert ecotone in the periphery of tilled area was salinized and the salinity level decreased with depth. The EC1:5 in the top 0~10 cm soil was correlated to elevation, vegetation coverage, depth of groundwater table, TWI and groundwater salinity, ranked in groundwater salinity>TWI>elevation>vegetation coverage>groundwater level. For EC1:5 in 10~40 cm soil, and impact of these factors was ranked in groundwater salinity>elevation>TWI > vegetation coverage>groundwater level. The impact of these factors on EC1:5 in 40~60 cm was groundwater salinity> elevation>TWI>groundwater level>vegetation coverage. 【Conclusion】Soil salinization in Ogan Kucha River Oasis is mainly distributed in the oasis-desert ecotone and groundwater salinity is the primary cause of the soil salinization. |
| Key words: soil salinity; oasis; decision tree; Kriging; grey relation analysis |
