基于模糊数学法的新建绿地土壤物理性能评价

Evaluation of Soil Physical Properties of New Green Spaces Based on Fuzzy Mathematical Method

城市绿地土壤的物理性能影响着城市生态系统的运行,为了研究城市绿地建设过程中不同层次土壤的物理性能,以西安植物园新区为典型案例,选取容重、总孔隙度、毛管孔隙度、非毛管孔隙度、田间持水量、自然含水量等6个指标,结合模糊数学法以及SPSS17.0与Excel软件对各层土壤的物理性能(Q)进行评价。结果显示,西安植物园新区表层土壤(0~25 cm)、浅层土壤(25~50 cm)、中层土壤(50~70 cm)、深层土壤(70~90 cm)的Q值分别为21.69、61.24、71.19、66.89;分别处于极差水平、较差水平、良好水平、较差水平。平均Q值为55.25,处于较差水平。表层土壤与浅层土壤Q值过低的原因在于重型机械的重复碾压,碾压力对中层土的影响较小。随着土层深度的增加,深层土壤的Q值相对中层有所下降。各影响因子的权重比较显示,土壤容重是影响各层土壤物理性能优劣的重要因素,但随着土层的加深,土壤容重的权重逐渐降低。自然含水量的权重随着土层的加深呈现逐步上升的趋势。

Physical properties of soil in urban green spaces（UGS） have great influence on ecosystem functions.To study physical properties of different soil levels of green spaces, soil samples in Xi＇an Botanic Garden werecollected, six indexes were chosen, including bulk density, total porosity, capillary porosity, non-capillaryporosity, water holding capacity and soil moisture content, Q value of soil samples were evaluated with fuzzymathematical method, SPSS17.0 and Excel. The results showed that Q values of soil samples of topsoil（0-25 cm）,surface soil（25-50 cm）, middle soil（50-70 cm） and deep soil（70-90 cm） were 21.69, 61.24, 71.19, 66.89,which indicated that they were in extremely low level, lower level, good level and lower level, respectively. Theaverage Q value was 55.25, which indicated that the soil was in lower level. The reason of low Q value intopsoil and surface soil was that the soil was repeatedly rolled by heavy machinery during the construction. Theeffect on middle soil was lower. The Q value of deep soil was lower than that of middle soil along with theincrease of soil depth. The comparison of the weight of the indexes showed that bulk density was the mainindex affecting the physical property. The bulk density decreased with the increase of soil depth. However, theweight of natural water content increased with the increase of soil depth.