Analysis physical and chemical properties of soil and morphometric impacts on gully erosion

     It is widely known that the development of gullies causes the loss of a great amount of soil and can be considered as one of the principal causes of geo-environmental degradation. The study area of the present research is located in the eastern shores of Urmia Lake. This study sought to evaluate the rate of growth and effective factors on the area’s gully dynamic over a year. To achieve this goal, levels of Electrical Conductivity (EC), Sodium Adsorption Ratio (SAR), pH, types of soil, and morphometric analysis were used for categorizing and analyzing effective factors on the creation of gully erosion. In addition, as the climate index, the coefficient of moisture in the area’s formation for analyzing the area’s gully erosion potential was also employed as relevant indicators. The results based on climate indices show that the area’s gully erosion potential is high. Analyzing the taken samples’ structures indicated that the constructing components of geological formations provided highly appropriate conditions for vertical and horizontal leveling of gullies because of the weak building of aggregates in a way that the results of the morphometric monitoring of the gullies represent the area’s high growth speed and dynamicity. High accumulation of soluble salts especially high values of SAR and EC have led to dissolution erosion that provides the conditions for creating tunnel erosion. The results of the research showed gully erosion formation in the study area and its expansion due to two factors, climate factors together with the chemical and physical characteristics of ‌an area’s soils. The results of the present research are of great importance for gully erosion modeling tasks in the study area and can be used as the base of future researches for identifying the relevant criteria and indicators in gully erosions.