Search

In this study, we investigate the combined effect of different rainfall‐runoff event types and antecedent soil moisture (ASM) on runoff processes in the headwater elementary discharge area of a small forested upland catchment. The study focuses on (i) the relationship between soil moisture thresholds and runoff generation; (ii) the combined effect of ASM and tree vicinity and (iii) the relationship between different rainfall‐runoff event types and different types of runoff (baseflow and stormflow). The results suggest that ASM has a strong impact on local runoff generation processes. Soil water content (35%–36%) threshold exceedance was related to stormflow runoff generation caused by the activation of quick preferential flow paths in the soil during storm events, especially in the upper and the deepest soil layers. At the same time, unexpected non‐linear increases in baseflow runoff ratios were documented during dry, precipitation‐free, periods and when the 31%–34% soil moisture threshold was exceeded, presumably due to the hydrological connection of farther slope areas during these conditions. Multiple stormflow periods, which exhibited the lowest runoff coefficient, were the most significant events in terms of water retention and soil water recharge due to increased vertical hydrological connectivity enabling more rapid transport to deeper soil layers. However, this rainfall type occurred least often over the study period. The important role of forest stands (individual trees) in creating spatial patterns of soil moisture and preferential infiltration paths to deeper soil layers was also confirmed. These results contribute towards a better conceptualisation of hydrological behaviour in elementary headwater discharge areas and highlight the potential dangers associated with expected increases in extreme weather events. [ABSTRACT FROM AUTHOR]

The aim of this article is to present the basic theses about the function and potential of infiltration pits under culvert mouths on forest roads. The methodology consisted of a combination of literature review and own in situ experiments. Experimental verification was carried out on sections of forest roads on two training forest enterprises (TFE) at Kostelec nad Černými lesy and Masarykův les Křtiny (Czech Republic). At each location, two infiltration pits were built in a paired design with a uniform retention volume. One of the pits was always located under a pipe culvert. The control pit was located approx. 30 m far from it, in the same pedological and vegetation conditions without a centralized inflow. Measurements from the study period (autumn 2022) indicated that the infiltration pits under the culverts had unexpectedly low efficiency in retaining and infiltrating surface runoff. Mostly, due to the fact that in the analyzed period the surface runoff was minimal, even though precipitation did occur. During the study period, the infiltration pits did not reach the expected potential to support the hydric regime of the landscape. [ABSTRACT FROM AUTHOR]