三峡库区消落带土壤物理性质变化

Changes of the Soil Physical Properties in Hydro-Fluctuation Belt of the Three Gorges Reservoir

连续2年对三峡库区消落带土壤物理性质定位监测,研究三峡水库水位涨落对消落带土壤物理性质的影响。结果表明:消落带经受2个水位涨落周年影响区域比未受水位涨落影响区域的土壤密度增加了0.7%～4.6%,土壤总孔隙度、毛管孔隙度和非毛管孔隙度分别减少0.2%～7.5%,0.6%～4.0%和32%～60.8%,最大持水量、毛管持水量及田间持水量分别减少0.6%～15.1%,0.7%～11.9%和0.3%～12.5%。虽然各项物理指标表现出较为明显的变化趋势,但是差异不显著(P>0.05);经受3个水位涨落周年影响区域比未受水位涨落影响区域的土壤密度增加7%～17%;土壤总孔隙度减少18%～21%,毛管孔隙度减少11.3%～24.3%,非毛管孔隙度减少35%～53%,土壤最大持水量降低28%～31%,毛管持水量降低26%～31%,田间持水量降低26%～32%。消落带受水位影响区域和未受水位影响区域各土层的土壤物理指标均差异显著(P<0.05)。

In order to understand any influence of water level fluctuating on the soil physical properties in hydrofluctuation belt of the three gorges reservoir. fixed-location monitoring was made for two years. The results showed that after two years with the water level fluctuating,the bulk density increased by 0. 7% 4. 6% and total porosity,capillary porosity,non-capillary respectively decreased by 0. 2% 7. 5% ,0. 6% 4. 0% ,32% 60. 8% and the maximum moisture capacity,capillary moisture capacity and field capacity respectively decreased by 0. 6% 15. 1% ,0. 7% 11. 9% ,0. 3% 12. 5% . The soil physical properties obviously varied,but the differences were not significant （ P〉0. 05）. After the water level fluctuating for three years,the bulk density increased by 7% 17% in comparison with the non-submerged zones,the total porosity decreased by 18% 21% ,the capillary porosity decreased by 11. 3% 24. 3% , the non-capillary porosity decreased by 35% 53% ,the maximum moisture capacity decreased by 28% 31% ,the capillary moisture capacity decreased by 26% 31% ,and the field capacity decreased by 26% 32% . There were significant （P〈0. 05） differences in the soil physical indicators between the non-submerged zones and the submerged zones in each soli layer.