• فهرس المقالات Rainfall simulator and Runoff

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        1 - Influence of Pasture and Rainfed Agriculture Land Uses on Soil Loss in Dojag-Chay Subwatershed (Ardabil Province- NW Iran)
        R. Talaei A. Jafari Ardakani F. Azimi R. Bayat M. Parehkar
        One of the main resonator factors in watershed soil erosion is inappropriateland management including conversion of pasture land to dry-land farming.Unfortunately, the changes of Gara Su watershed usages have been very common.Thus, in order to understand the influence o أکثر
        One of the main resonator factors in watershed soil erosion is inappropriateland management including conversion of pasture land to dry-land farming.Unfortunately, the changes of Gara Su watershed usages have been very common.Thus, in order to understand the influence of land use on runoff rate and soil loss, soillosses were investigated and determined under both pasture and dry-land agriculturesat sub-watershed of Dojag chay in southern west Qara Su Basin (within Ardebilprovince). In this Research, using a drop maker rainfall simulator device, 18treatments under the said watershed were conducted using an artificial rain with theintensity of 6 mm/ min for 6 minutes and soil loss rate was measured due to therainfall in two user types in dry-land and rangeland under natural humidity conditionsand approximately the same as the raining season in three slope classes of 5 to 12, 12to 20 and greater than 20. The results showed that with the cultivation, cultivatedsoils get empty and their porosity and permeability increase so, with the increase ofwater penetration ability, their runoff compared to the pasture lands starts with delay.Comparing the amount of runoff shows that after runoff gets started in rain-fedagriculture lands, the flowing speed and amount of water become more than those ofpasture lands and the statistical analysis also verified the significant relationship,especially in slopes of more than 20% between the amount of soil loss and land use.The soil loss under rain-fed agriculture was 8.8 times more than the pasture. As thesoil loss was compared for different slope classes of 5-12, 12-20, and more than 20slope percent, the results indicated that the soil losses under rain-fed agriculture were4.5, 5.6, and 12 times more than the pasture. The study results, therefore, can beutilized for proper management of area through devoting necessary attention intoland uses. تفاصيل المقالة