暴雨条件下北京山区主要乔木蓄水能力研究

利用大型称重式蒸渗仪记录2012年7月21-22日北京暴雨全过程下土体水重的变化,分析不同树种土体水重的增幅和总量的差异.同时运用土壤三参数测定仪对蒸渗仪的不同深度土体中土壤含水率进行观测,分析降雨过程中各层含水率的动态变化.结果表明,暴雨条件下蒸渗仪土体水重呈先猛增后缓增的趋势,五角枫的土体水重增加最多,渗漏量最少；油松土体水重增加最少,渗漏量最多.土体水重大小依次为:五角枫＞侧柏＞空地＞油松.不同深度土层在暴雨过程中都有水分猛增的过程,表层土发生较早,且增幅大；深层土发生晚,增幅小.五角枫各层土体的含水率最高,油松的最低,含水量大小依次为:五角枫＞空地＞侧柏＞油松.

Water Storage of Main Trees Under Storm Conditions in Beijing Mountain Area

The differences of growth and total soil mass water amount among different tree species were studied by large-scale weighing lysimeter in the whole process of rainstorm in Beijing from 21to 22July in 2012.At the same time,soil moisture content was measured in different depths of soil mass by soil three-parameter determinator and dynamic changes of the moisture content of every layers in soil mass were analyzed in the whole rainfall process.Results showed that soil mass water content in lysimeter presented the trend of slow growth after a jump under the rainstorm conditions.Soil mass water content for Acer elegantulum gained the most and leakage was the least,while for Pinus tabuliformis,just the opposite.The soil mass water content decreased in the order of A.elegantulum>Platycladus orientalis>space>P.tabuliformis.In different soil layers,they had a jump of moisture in rainstorm process.The jump in topsoil occurred earlier and increased more,while in deep soil layers,the opposite.At the end of rainfall,the soil moisture content of every layer for A.elegantulum was the most and P.tabuliformis was the least.The soil moisture content decreased in the order of A.elegantulum>space>P.orientalis>P.tabuliformis.