Piping formation and distribution in the semi-arid Northern Negev environment: A new conceptual model

Abstract

Soil piping is a complex erosion process caused by subsurface water flow. We studied the effects of soil cracks and hillslope aspects on piping development and spatial distribution, and introduce a conceptual model of piping development in semi-arid environments. The model addresses factors that substantially influence piping formation: rainfall regime, solar radiation, soil properties, and geospatial characteristics extracted from unmanned aerial vehicle scans. To provide evidence for the ideas presented in the conceptual model, 322 pipes were sampled and measured in the field. Soil texture, sodium, calcium magnesium and organic matter contents, and sodium adsorption ratio (SAR) were analyzed using standard laboratory methods. Our results demonstrate the profound effects of subsurface soil properties on piping-formation processes but do not fully explain substantial differences in spatial distribution between north- and south-facing slopes. However, the synergy of soil properties, rainfall data, and simulated differences in heat flux between aspects led to the development of a landscape with considerably more pipes in the south-facing slopes.