Vahid Chitsaz; Seyed Bagher Fatemi; Zabihollah Eskandari
Abstract
Nowadays, application of remote sensing is common in soil conservation and erosion projects and most of them are used aerial photogarphs and desipte of the numerous advantages, there are some limitations. In this study, replacemen of moderate-resolution satellite data instead of aerial photographs has ...
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Nowadays, application of remote sensing is common in soil conservation and erosion projects and most of them are used aerial photogarphs and desipte of the numerous advantages, there are some limitations. In this study, replacemen of moderate-resolution satellite data instead of aerial photographs has been investigated with emphasis on processing of satellite images and using image filters and the purpose of soil erosion figures detection. Finaly, image processing of area are prepared with maximum capability vitual interpretation of effects associated with erosion, after the study design, atmospheric and geometric corrections and perform pre-processing and initial processing on ETM+ and ASTER images. In order to evaluate the efficiency of filters for detection and identification of soil erosion were used low-pass and high-pass filters such as filters, median, mean, High Pass, Gaussian, Laplacian, Sobel and linear filters on ASTER and ETM images in the part of the Esfahan Dastkan basin. According to the results, using of low pass filters are not recommended because of the resolution reduction of soil erosion. High-Pass filters can be partialy appeard the edages of image and can be help to visual interpretation (especially in combination with the original image). Use of filters is recommended in combination with the image and as an aid to vitual interpretation, due to problems of application the fiters for separate soil erosion units. Regard to the dimension of soil erosion (rill and gully) and compared to the spatial resolution of the used sensor in this study, the erosions are not clearly appeared in the picture and application various image filters to automatically discover and exploit of these effects can not be efficiently. Resolution images of ASTER and ETM+ are not responsive for mapping erosion by using automated method and should be looked for a solution of semi-automated and visual interpretation. Also, because of the similarity between the spectral and geometrical picture was not found a major difference in the results. Therefore, it is recommended to produce a susceptibility map of erosion or erosion risk map instead the variouse types of regional soil erosion.
Zabihollah Eskandari; Fathollah Ghayour; Amir Hossein Sherbaf
Abstract
Water deficiency in arid regions especially in Iran, generally reduces the cultivation and considered as a major limitation in green cover re-establishment process in deserted areas. This study aims to overcome on drought and to achieve a strategic way of increasing the water use efficiency and reduction ...
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Water deficiency in arid regions especially in Iran, generally reduces the cultivation and considered as a major limitation in green cover re-establishment process in deserted areas. This study aims to overcome on drought and to achieve a strategic way of increasing the water use efficiency and reduction of costs. This study is carried out in a wind-eroded part of Aran and Bidgol county of Isfahan province, Iran and two species of Haloxylon and Nitraria sp were cultivated in treated and check soils in mentioned area. The treatments were adding five of two kinds of polymer water absorbent to the soil of root environment. The check samples were irrigated every 14 days once and the treated ones every 14, 28, 35 and 42 days once. During two years of study, the moisture of root environment was measured in all samples. In third year the amount of live seedlings were also accounted. The statistical analysis showed that there is a significant difference between the treated and check samples in all irrigation periods in significance level of 5%. In other words, increasing of irrigation period in treated samples compared with check treatment hold more moisture in root environment. Mean comparison between treatments showed no differences in volumetric moisture of 21 compared with 28 and 28 compared with 42 irrigation periods. And also there was no difference between two absorbent in all treatments. The increasing rate of live seedlings, after 3 years, between treated and check samples represents that the polymers give a good establishing circumstance to young seedlings. In other words it is resulted that these water absorbents are capable of reducing the moisture stress in root area of irrigation periods and increase the rate of established seedlings. We assume that Aquasorb polymers and TC are successfully increasing the water holding capacity of soils in green cover re-establishing activities of deserted areas. With increasing the water holding capacity they also reduce also the costs by 50-70 percent.
