فهرست مطالب hamzeh saeidian

The effects of flood spreading according to soil type and climate on vegetation cover of tree and rangeland species show different changes. The aim of this study was to investigate the periodic changes of vegetation including fruitful and non-fruitful cultivated trees and rangeland species in the Bam Abbarik flood spreading station. In this study, in order to perform forest studies, first the operation of locating the plots, selecting and marking the bases and preparing the certificate was carried out and rectangular parts of 350 square meters with random - systematic distribution were used. Also, in rangeland studies, 1×1 plots were used to measure canopy coved percentage and density and were recorded in the relevant tables. For measuring dry forage production, cut-off and weighing method were used. The results showed that Eucalyptus bases in this aquifer with density of 531 bases in hectare have an average height of 3.62 m and trunk diameter mean at collar site of 18 cm and the crown diameter average 3.6 m. In the study of rangeland cover, the effect of vegetative type, vegetative form, and interaction between vegetative type and vegetative form on crown was significant. Also, the effect of vegetative form, interaction of vegetative type in channel, channel interaction in vegetative form and vegetative form and channel interaction in this experiment were significant on plant density.

The type and intensity of soil erosion in a region generally depend on climatic conditions, ups and downs, soil and land use. Of these, land use is most important. Using different systems of ploughing after unconscious and non-scientific change of land use affects soil physicochemical characteristics. This fact especially in marginal lands and mountainous regions is more visible. In order to investigate sensitivity to soil loss and erosion in various land uses of Aghajary deposits, part of Margha catchment with an area of 1609 hectares in Izeh city was selected. This was to determine the relationship between soil loss by rain simulator and some soil physicochemical characteristics like percentage of very fine sand, sand, clay, silt, pH, Ec, moisture, Calcium Carbonate and organic materials in different land uses. Then, sediment sampling in 7 points, three replicates and in various intensities of 0.75, 1 and 1.25 millimeters in minute in range, residential and agricultural land uses was done using rain simulator. In order to investigate effective factors in sediment production and erosion, samples of soil layers (in depth range of 0-20 cm meters) equal to the number of sediments were taken. For statistical analysis, EXCEL and SPSS 11.5 software were used. In total, the amount of runoff in residential land use was highest and in agriculture land use was lowest. The amount of sediment in agriculture land use was highest and in residential land use was lowest. Then, the most important factors in sediment yield were diagnosed by multi regression. The results showed that sediment yield and erodibility in land uses have meaningful differences in various intensities of precipitation. Regression models showed that in the production of sediment in various land uses, from among the measured factors, silt, sand very fine, lime, Ec, organic materials and pH had the greatest role. Sand percentage in the residential land use, and very fine sand and organic matter in agriculture land use had the most important role in sediment production. But in range land use, moisture percentage and pH had the biggest role in sediment production.