长期土壤酸化模型(LTSAM)

Long term soil acidification model (LTSAM)

以碱总量守恒为基础，以Ｕｌｒｉｃｈ缓冲范围为模型主要框架建立了兼能描述酸性与石灰性土壤长期酸化反应过程的动态模型．经与ＳＭＡＲＴ模型在理论设计和模拟结果两方面作对比之后，又利用新建模型以北京地区典型褐土为例进行了硫沉降与酸（Ｈ＋）沉降的对比计算．结果表明：（１）ＬＴＳＡＭ模型能够很好地反映土壤缓冲酸的主要机制．（２）模式运行即稳定又省时．（３）大气硫沉降不同于酸沉降．也就是说，硫沉降改变时，阳离子（尤其是主要离子）沉降量的变化应当加以考虑．

A new dynamic model which can depict the long term calcareous and non calcareous soil response to atmospheric acid deposition has been developed based on the continuity of alkalinity and Ulrich buffer ranges. After comparing LTSAM with SMART (simulation model for acidification's regional trends) in model designs and modelling results, we have given two acidic deposition scenarios to simulate acidification of typical drab soil in Beijing area in order to show discrepancy between acid (H +) deposition and sulphuric (S) deposition in assessment of effects of acidic deposition on the ecosystems. The result indicates that:(1) LTSAM can describe dominant soil buffer mechanisms (e.g.carbonate buffer range, exchange buffer range, and aluminum buffer range) as well as SMART. (2) LTSAM is proved stable and time saving.(3) changes in atmospheric deposition of base cations should be considered while an increase or a decrease in S deposition occurs.