[Objective] Addressing the increasing demands for disaster prevention and mitigation，it is essential not only to enhance the accuracy of rainstorm forecasting but also to assess in advance the potential disaster-causing risks posed by rainstorms. In contrast to evaluation models that rely on uniform topographic factors，this study aims to reflect the distinct disaster mechanisms of mountain torrents and urban waterlogging，thereby accurately revealing the comprehensive risk patterns of regional flood disasters caused by rainstorms. [Methods] By assigning specific topographic factors to mountain torrents and urban waterlogging respectively，this study develops a refined disaster-causing risk model that integrates hazard-inducing factors and disaster-specific hazard-inducing environments. The model enables mechanism-based zonation of the hazard-inducing environments for both disaster types and the integration of comprehensive risks. Taking Qinhuangdao as the empirical area，the validity of the proposed model is verified. [Results] （1） Fine-scale modeling of the hazard-formative environment effectively distinguishes the disaster-prone contexts for flash floods and urban waterlogging. The flat central-southern plains，characterized by concentrated urban and agricultural land，show a high hazard-formative environmental index for urban waterlogging，while the mountainous northern and northeastern areas，with significant topographic relief and dense river networks，exhibit a high index for flash floods. （2） The comprehensive high-risk zones for torrential rain disasters in Qinhuangdao are mainly located in the central part of the city，representing areas where high hazard intensity overlaps with highly sensitive disaster-prone environments. （3） The comprehensive risk index of historical rainstorm events shows correlation coefficients R of 0.721，0.698，and 0.724 with direct economic loss （GDP），affected population，and affected crop area，respectively，all passing the significance test at α=0.05. The correlation coefficient R between the comprehensive disaster index and the comprehensive risk index across counties （districts） reaches 0.912，passing the significance test at α=0.01，indicating that the model has good indicative significance for actual disaster situations. [Conclusions] The refined comprehensive risk model developed in this study，which integrates hazard-inducing factors and disaster-specific hazard-forming environments，effectively captures the differential mechanisms of mountain torrents and urban waterlogging. This model not only offers a unified framework for accurately delineating the regional pattern of comprehensive rainstorm and flood risk，providing a paradigm for flood risk assessment in analogous regions，but also can be applied to dynamic risk assessment for single hazard-inducing processes.