基于属性识别模型的退耕地土壤水分综合评价

Comprehensive Evaluation of Soil Moisture of Abandoned Cropland Based on Attribute Recognition Model

运用基于熵权的属性识别模型,对延河流域不同退耕年限土壤水分进行综合评价。结果表明:从不同退耕年限土壤水分的变异趋势来看,受耕作和施肥影响,退耕初期,土壤水分含量相对较高,随着退耕年限的延长,土壤水分总体呈下降趋势,表层的土壤水分比深层的土壤水分更快地损失了,土壤水分变异系数随着土层深度的增加呈减小趋势;随着退耕年限的增加,各土层土壤水分指标权重变化程度有很大差别,变异程度相当的土层之间土壤水分权重大小会随着退耕年限的变化发生反转。不同退耕年限土壤水分属性测度值均未达到速效水平,大部分处于难效水平。说明研究区土壤水分贫乏,有必要提高该地区的土壤水分水平。属性识别模型评价方法在很大程度上减小了主观因素的影响,评价结果直观实用,能为土壤水分综合评价提供有力的技术支撑。

Atribute recognition model based on entropy weight was used to evaluate the soil moisture of abandoned cropland of different years in Yanhe Watershed.The results showed that from trend of variation of soil moisture abandoned cropland of different years,by the farming and fertilizer effects in the early farmland,content of soil moisture was higher relatively.With prolonged,in overall,soil moisture was downward trend,and soil moisture in toplayer lost more quickly than that in deep layers.The coefficient variation of soil moisture was reduced trend with increase of soil depth.The powers of soil moisture in considerable degree of between soil layers could be reversed with the length of abandoned cropland.In general,the soil moisture of abandoned cropland is at lower level in Yanhe Watershed,it is necessary to improve soil moisture in this region.The method of attribute recognition model can reduce the impact of subjective factors to large extent.This method of results which are visual and practical can provide powerful technical support for comprehensive evaluation of soil moisture.