Rainfall-induced shallow landslides occurring along slopes of mountains around the city of Naples (southern Italy), characterized by pyroclastic covers laying upon fractured limestone bedrock, pose serious threat to settlements and towns located at their foot. Although the triggering mechanism, related to suction reduction in the initially unsaturated soil cover is quite clear, there is still debate about the hydrological processes which predispose the slopes to failure. In this paper, the predisposing factors are analyzed with reference to two intense storms, both with about 300 mm rainfall, occurred in the same period of the year in 1999 and 2019. The two storms triggered several shallow landslides in an area of few km² of the northeast-facing slopes of Partenio Mountains. The two events are compared analyzing both the characteristics of antecedent and event precipitations, as well as simulating the response of the slopes to rainfall with the help of a mathematical model. Specifically, two slopes are analyzed: one, near the town of Cervinara, where landslides were triggered only in 1999; another, near the town of San Martino Valle Caudina, where landslides occurred during both the events. The results of the model simulations indicate that rainstorm duration (shorter in 1999) and antecedent precipitation during the weeks before the event (smaller in 1999) are the main reasons of the different responses of the slopes to the two rainfall events. In fact, both drier initial conditions at the base of the soil cover and shorter storm duration limit the possibility of drainage of infiltrating water out of the soil cover through the soil-bedrock interface, thus favoring the suction reduction required for slope failure. The obtained results provide a key for the interpretation of landslides, often occurring in late autumn-early winter in the area.

那不勒斯市（意大利南部）周围山坡上发生的降雨诱发的浅层滑坡，其特征是火山碎屑覆盖在破碎的石灰岩基岩上，对位于其脚下的定居点和城镇构成了严重威胁。尽管与减少非饱和土层中的吸力有关的触发机制是很清楚的，但仍存在关于使坡度易陷于破坏的水文过程的争论。本文针对1999年和2019年同一时期发生的两次强降雨，分别降雨约300 mm，对诱发因素进行了分析。这两次暴风在几公里²的范围内引发了几次浅层滑坡。Partenio山的东北坡。比较了两个事件，分析了前期和事件降水的特征，并借助数学模型模拟了斜坡对降雨的响应。具体来说，分析了两个斜坡：一个在切尔维纳拉（Cervinara）镇附近，该镇仅在1999年才引发滑坡。另一处靠近圣马蒂诺瓦莱科多纳（San Martino Valle Caudina）镇，在两次活动中都发生了山体滑坡。模型模拟的结果表明，暴雨持续时间（1999年较短）和事件发生前几周的前期降水（1999年较小）是斜坡对两次降雨事件反应不同的主要原因。实际上，土层底部较干燥的初始条件和较短的风暴持续时间都限制了渗透水通过土-基岩界面从土层中排出的可能性，因此有利于减少边坡破坏所需的吸力。所获得的结果为解释山体滑坡提供了关键，山体滑坡通常发生在该地区的深秋和初冬。