Researchers from the Institute of Geography of the Ministry of Science and Education of the Republic of Azerbaijan and a visiting researcher from Kazakhstan have conducted monitoring of landslide processes in the Atachay River basin.

  On June 7, 2026, Dr. Stara Tarikhazar, Head of the “Geomorphology and Paleogeography” Laboratory of the Institute of Geography, and Saniya Beisenbayeva, a researcher from the Republic of Kazakhstan undertaking an internship to conduct scientific research for her dissertation and gain experience from Azerbaijani specialists in studying hazardous exogenous processes, carried out monitoring of landslide activity in the Atachay River basin.

  This area is not only one of the regions most exposed to landslide hazards, but also serves as a source of material feeding debris-flow events. Mud-stone debris flows are frequently observed in the Atachay River, which is explained by the lithological composition of the mountain basin, consisting of flysch deposits that include limestone, marl, calcareous sandstone, and other sedimentary layers.

  The main factor determining the development of exodynamic processes is the presence of longitudinal morphostructures. These morphostructures differ in absolute and relative elevations, degree of relief dissection, slope steepness, and other characteristics. The Altiaghaj and Khizi plateaus represent the dominant positive relief forms in the area. Synclinal peaks play a significant role in landslide formation because their concave surfaces facilitate the accumulation of atmospheric precipitation and recharge of groundwater. Strong stresses associated with sharply inclined strata lead to the formation of numerous fractures, which are further widened by erosion. Atmospheric water penetrates through these fractures into deeper parts of the slopes, moistening fractured clay rocks, causing them to swell, acquire plastic properties, and eventually slide.

   Thus, favorable geological and geomorphological conditions-including synclinal peaks, tectonic faults and fractures, seismicity reaching 7-8 points, steep north-facing slopes (25° and more), lithological characteristics such as highly fractured clay-marl rocks, and climatic conditions characterized by 400–600 mm of annual precipitation concentrated mainly in spring and autumn, together with abundant groundwater—create ideal conditions for the widespread development of landslides in the Atachay basin. Most of these landslides occur at elevations above 800 meters. The largest and most clearly expressed landslide flows in the modern relief are the Yukhari Findighan, Bakhishly, and Khalanjan landslides.

   In addition, landslides are often triggered and intensified by human activity. The Khizi–Altiaghaj road, which is 20 km long, two-lane, 7 m wide, and classified as a Category IV highway, was constructed along a watershed divide. During construction, slopes exceeding 3 m in height were cut. Heavy rainfall increased the water saturation of the slope-forming rocks, resulting in deformation and damage to the asphalt pavement. Numerous cracks ranging from several centimeters to 50 meters in length and 10-40 cm in depth, as well as subsidence phenomena, were recorded along the road.

   Furthermore, rainfall in the Khizi Mountains has contributed to the development of erosion gullies, karst-suffosion depressions, and minor landslide deformations. Rainwater accumulated in fractures and penetrated into deeper layers, washing away fine clay particles through mechanical suffosion and enlarging filtration pathways. As a result, weakened areas experienced surface subsidence. Karst-suffosion processes were observed on mountain slopes in chain-like and clustered forms, as well as within depressions, indicating that relief development is controlled by geological structure and that surface landforms are largely determined by the underlying geological framework.

   The area is mainly composed of Upper Cretaceous and Paleogene terrigenous-carbonate and flysch deposits, including strongly deformed multicolored and gray clays, marls, and thin-bedded siltstones. Water accumulates within impermeable clay layers. Numerous fine-dispersed particles (dust-sized and clay fractions) are subject to mechanical suffosion, leading to the formation of underground voids.

  Bedded and fractured limestones, calcareous sandstones, and marly carbonates facilitate chemical dissolution processes. Due to the intense folding of the Khizi zone, these rocks have developed a dense network of tectonic fractures. Instead of flowing across the surface, rainwater infiltrates into the subsurface, resulting in the formation of chain-like depressions closely associated with tectonic fractures.

  The Quaternary deluvial-proluvial deposits forming the surface cover consist of loose loams and sandy loams enriched with gravel and limestone fragments. This cover layer reaches a thickness of 10-15 meters. It is within these deposits that subsidence processes and erosion gullies are most actively developed.