بررسي اثر مقدار بارش بر مقاومت خاكپوش ويناس در سرعت‌هاي مختلف باد در كنترل فرسايش بادي

eva‎luating the Effect of Rainfall on the Resistanse of vinas Soil Cover at Different Wind Speed in Contorolling Wind Erosion

زمين شناسي

One of the most important and dangerous environmental crises in arid and semi-arid regions is the destructive phenomenon of desertification and wind erosion. Generally, in areas with dry, fine-grained soil and poor vegetation, the wind speed exceeds the tolerance threshold of the soil and wind erosion occurs more intensely in which is associated with the occurrence of dust storms and the dispersion of fine dust. This can have negative effects on the health of people who are exposed to this air. Wind erosion is a serious issue globally, particularly in low-precipitation regions. Iran, due to its arid climate, specific ecological conditions, and geographical location, faces this challenge acutely. Isfahan Province, located in central Iran, is particularly affected by wind erosion due to its warm and semi-arid climate, hosting numerous wind erosion hotspots. One such hotspot is the Sajzi Plain, located 35 kilometers east of Isfahan, which is consistently impacted by wind erosion. Consequently, controlling wind erosion and stabilizing the regionʹs soil to prevent dust storms is considered a critical measure. One widely utilized method for controlling wind erosion and stabilizing shifting sands is the application of various types of mulch. In Iran, oil-based mulches have been extensively used over recent years to stabilize soil and shifting sands. However, the detrimental environmental effects of petroleum-based mulches have drawn attention in recent years to polymers and biologically derived mulches from plant sources. One of the materials currently being considered for soil and sand stabilization is vinasse. Vinasse, a by-product of sugarcane processing, has a low pH, high salinity, and substantial amounts of potassium, calcium, sodium and magnesium. Moreover, vinasse lacks toxic compounds and demonstrates better environmental compatibility compared to some other mulches. This study aims to eva‎luate the effectiveness of vinasse in controlling wind erosion and stabilizing shifting sands in the Sajzi Plain under the influence of wind and rain. Additionally, the impact of this mulch on the particle size distribution of the regionʹs soil is examined. To conduct this research, 10 grams of vinasse per square meter were applied to the soil in the study area. Subsequently, the treated samples, along with control samples, were exposed to three wind speeds (6, 9, and 12 meters per second) with three repetitions for each speed inside a wind tunnel, and the erosion rates were measured. A particle size distribution test for soil crusts was also conducted on both treated and control samples. The samples were then subjected to simulated rainfall, and after rainfall exposure, the samples were again tested in the wind tunnel under the same wind speeds (6, 9, and 12 meters per second) to reassess soil erosion rates. Additionally, particle size distribution tests were performed on the crusts formed after rainfall. The results indicate that the erosion rates of samples treated with vinasse solution were significantly lower than those of the control samples, and rainfall had no adverse effect on the performance of vinasse. Also, there has not been much change in soil granularity.

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