黑河上游坡面尺度土壤贮水量的时间稳定性

Temporal stability of soil water storage on slope in the upstream region of Heihe river

利用土壤水分速测仪,获得黑河上游天老池流域2014年5-9月祁连圆柏林、灌木林、青海云杉林3个坡面0~60 cm土壤深度坡面土壤贮水量,通过时间稳定性分析,研究该区域坡面尺度的时间稳定性特征.结果表明:土壤贮水量的季节变化趋势与降雨动态基本一致,坡向和植被类型共同影响着土壤水分的空间分布.累积概率分析认为祁连圆柏林的时间稳定性最高.通过平均相对偏差、平均相对偏差的标准差、时间稳定性指数、平均绝对偏差误差确定了坡面土壤水分平均状态的代表性测点.3个坡面土壤贮水量的Spearman秩相关系数基本都在P<0.01的水平上显著,具有强烈的时间稳定性,Spearman秩相关系数为分析区域土壤贮水量的时间稳定性分析提供了便捷途径.

Soil water storage time domain reflectometer （0-60 cm） on three slopes （those of Sabina przew- alskii, shrub and Qinghai spruce） was obtained by time domain reflectometer from May, 2014 to Septem- ber, 2014 in Tianlaochi watershed of the upstream region of the Heihe river. The temporal stability of the soil water storage was conducted through a temporal stability analysis and the results showed that soil wa- ter storage depended strongly on precipitation, as expected, and the spatial distribution of soil moisture was affected by slope features and vegetation types. The cumulative distribution analysis showed that Sa- bina przewalskii forest had the highest temporal stability. The mean relative difference, the deviation of the mean relative difference, the index of time stability and the mean absolute bias error were used to de- termine the representative points of soil water storage. Almost all slopes had strong temporal stability ac- cording to the Spearman rank correlation coefficient （P〈0.01）, which can provide a convenient method for analyzing the temporal stability of regional soil water storage.