FOSS4GNL 2025

Dune slacks are low-lying depressions within dune ecosystems that exhibit unique microclimates, forming cold air pools during nighttime. This nocturnal cooling varies between slacks due to differences in their geomorphological characteristics, influencing local biodiversity and the broader ecosystem.

This study focuses on the automated detection of dune slacks using freely available geospatial data in QGIS. A dynamic thresholding parameter will be developed to accurately delineate dune slacks based different attributes. Following detection, each slack will be indexed and ranked according to geomorphological parameters to indicate their relative thermal behavior—ranging from coldest to warmest.

The methodology will integrate LiDAR-derived Digital Terrain Models (DTMs), in-situ temperature measurements, and other open-source spatial datasets. This approach not only streamlines the identification of dune slacks but also lays the groundwork for informed conservation strategies and deeper ecological insights into climate-sensitive dune environments.

Urban areas pose significant challenges for hydrological modeling due to their modified landscapes and often flat topography, which disrupt natural drainage and create zones where water cannot flow or discharge effectively. Using QGIS, we can identify such stagnant areas where water accumulates without natural outflow. For these trapped water zones, conventional drainage is impractical, necessitating alternative strategies such as targeted infiltration systems, permeable surfaces, or green infrastructure to manage runoff.

Moreover, through stream network generation and catchment delineation, we can identify vulnerable residential structures and backyard areas due to high accumulation while determining their exact contributing drainage zones. This analysis reveals both accumulation hotspots and their specific upstream source areas. Such comprehensive understanding enables development of coordinated solutions that simultaneously address flood-prone sites and their contributing catchments, leading to more effective urban water management.