魏欢欢 李晓东 许龙

摘要 [目的] 通过对土壤冻融过程中电导率特征分析及模拟，为季节性冻土条件下精细农业的发展提供指导作用。[方法] 主要通过EM50采集的土壤温度、土壤湿度、土壤电导率数据，对土壤冻融过程中表层土壤电导率的变化特征进行了分析。[结果] 土壤电导率并不是随土壤剖面深度的增加而增大，而是土壤剖面20 cm处的土壤电导率最大，并且在土壤融冻期土壤电导率随时间呈现增-减-增-减的变化趋势。通过建立BP神经网络模型对土壤电导率进行模拟预测，得出的土壤电导率模拟值与观测值拟合程度高。[结论]BP神经网络模型可以对土壤电导率的实际观测进行辅助和验证。

关键词 土壤冻融过程;土壤电导率;BP神经网络模型;变化特征

中图分类号 S152  文献标识码 A  文章编号 0517-6611（2015）03-075-03

Analysis and Simulation of Soil Electrical Conductivity Characteristics in Soil Freezing and Thawing Process

WEI Huanhuan¹，LI Xiaodong1，2*，XU Long1，3

（1.College of Resources and Environmental Sciences of Xinjiang University， Urumqi， Xinjiang 830046; 2.Tourism College of Xinjiang University， Urumqi， Xinjiang 830046; 3.Aasis Ecological Key Laboratory of The Ministry of Education of Xinjiang University， Urumqi， Xinjiang 830046）

Abstract [Objective] The research aimed to analyze the variation characteristics of soil electrical conductivity and simulating in the process of soil freezing and thawing .It could provide important guiding significance for the development of precision agriculture under the condition of seasonal frozen soil. [Method] The variation characteristics of soil electrical conductivity of surface soil in freezing and thawing process through large numbers of data concluding soil temperature， soil humidity and soil electrical conductivity were mainly analyzed. [Result] The soil electrical conductivity isnt increased with the increase of the depth of soil profile， but it was the biggest when the soil profile was 20 cm. At the same time， soil electrical conductivity presented the trend of increasedecreaseincreasedecrease in the soil freezing period. BP neural network model was established for simulating and predicting. It was concluded that fitting degrees of simulated values and observed values were high. [Conclusion] BP neural network model could assist and validate the soil electrical conductivity.

Key words Soil freezing and thawing process; Soil electrical conductivity; BP neural network model; Variation characteristics

基金項目 国家自然科学基金面上项目“天山北坡典型流域积雪-冻土水热耦合中融水产汇流机制研究”（41171023）;重点项目“干旱区湖泊流域陆面过程及人类活动适应性—以艾比湖流域为例”（41130531）;水利部公益性行业科研专项经费项目（201301103）。

作者简介 魏欢欢（1988- ），女，河南巩义人，硕士研究生，研究方向：地理学。*通讯作者，副教授，博士，硕士生导师，从事地理学、旅游规划与管理方面的研究。

收稿日期 20141119

当前，全球面临着资源紧张、能源短缺的重大挑战。如何协调发挥土壤的生产功能、生态工程建设支撑功能和全球变暖缓解功能，是现代土壤学为人类可持续发展应做的重要工作。季节性冻土和融化层在温度年变化层的上部，更接近地表，对气候变化更敏感，反应更迅速。……