مجله مدیریت بیابان
پیاپی 2 (پاییز و زمستان 1392)

Wind erosion and sedimentation include detachment, transportation and deposition of soil particles by wind. To increase stability of soil surface and for soil conservation against wind erosion, artificial covers can be used, along with vegetation cover. Among artificial covers, one can use industrial residuals. Steel slag is a by-product of iron and steel industries which is produced in massive amount in Isfahan and contains valuable combinations and material. The study area is Harand plain in east of Isfahan which is one of the most critical erosion sites in Isfahan province. The experiment treatments included thicknesses at 2 levels (1 & 2 layers), cover percentage at 4 levels (25, 50, 75 and 100 percent), graining at 3 diameter levels (15-30, 30-45& 45-60 mm), wind velocity at 7 levels and their reciprocal effects. Test took place with 4 factorial replications and by completely random design, and then data got analyzed with Duncan & ANOVA tests in SPSS 15 and Excel. The results showed that steel slag increased the surface coarseness and therefore can control the erosion. Increasing area cover, size and graining of mulch, decline the soil loss. However there was no significant difference between the numbers of applied layers. It is citable that simultaneous increase in area percentage, size and diameter of slag decline the soil loss as well. According to the results, slag mulch can be used for erodible sediments control with 50% density, 30-45 mm graining and in one layer.

Kashan Erg is one of the most important sand seacomplexes in Iran. The Current research tried to determine the homogeneity of Kashan Erg through multivariate data analysis. Data was extracted by interpretation of aerial photographs, Google earth, field observations and morphologic map of the study area. Moreover, different statistical variables of aeolian sediment samples were conducted in different sand dunes. The granulometric parameters were also calculated based on the dry sieve analysis while mean diameter, sorting, skewness, kurtosis, d10, and d90 indices were calculated using GRADISTAT software. Wilks’ lambda and canonic coefficients results indicated that, among granulomtric data, skewness and kurtosis could distinguish different sand dunes types (accuracy of 57%). According to the above mentioned indices, the classification was performed using Hierarchical Cluster analysis. The results showed that the stabilized dunes were located in the separate group which related to the effect of vegetation establishment and ability of wind in transporting of fine particles of these areas. Also, bivariate plots used for evaluating the homogeneity of the sand dunes which indicated d10 and d90 parameters as a discriminant factors for graphical and visually separation, but not statistically. Findings revealed that by using quantitative multivariate methods for sand dunes classification, less experimental insights can affect the results.

Assessment of natural resources projects is one of the most basic problems that are done to program the upcoming applied plans and management of these fields in different countries. In this study, the assessment of watershed operation in Tochal watershed basin was carried out through some primary studies and then integrating them together. In addition to watershed operation, was studied biological operation in study region. According to pizometric statistics wells in studied area, was appraised to improvement of water resources in before and after of Implementation of operation. At first, the efficiency percentage was determined for each of the applied structures by evaluating the condition of structures through field study. The aim of the execution of biological operation has been increase of the rate of permeability in construction operation, in addition of consolidation of sediment in area. The result of reviews show, the efficiency percentage of gabion, stone – cement, and the other structures were 75, 66, and 14. 8 respectively. In biological operation, some activities are offered, for example, nothing Spades, working Plant, seeding, drilling and protection. that among of this the proposed operation is executed: 10 hectare for working plant,1000 hectare for drilling, 700 hectare for seeding and 500 hectare for protection. The biological operation has just done for erosion controlling and soil conservation the volume of the precipitation behind the structures was calculated as 49775. 3 m3 and most of the structure capacity to control precipitation was for sediment control. Also with considering climatic parameters, SPI index statistical period was drawn. With drawing underground water hydrograph, the performance of biological and structural operation was considered in increasing of underground water level. The average of discharge has increased 30.36 liter/second.

Desertification consists of land degradation in arid, semi-arid and dry sub-humid areas induced by climate change and human activities. For evaluation and mapping of desertification many research have been conducted leading to regional and local models. In this research, among different existing methods, IMDPA‌ model was selected and desertification intensity of Garmsar plain was evaluated based on 2 criteria and 6 indices including: climate (precipitation, drought and aridity index) and water (groundwater table depletion, electrical conductivity, sodium absorption ratio) over four periods; 1995-1997, 1997-2003, 2003-2009 and 2010-2012. Each criterion was assessed based on the selected indices resulted in qualitative mapping of each criterion based on geometric average of the indices. Finally, desertification map of the region was extracted using geometric average of criteria for each period. Thematic databases, with a 1:50000 scale resolutions were integrated and elaborated in ArcGIS9.3. The results showed that during the periods, four indices including groundwater table depletion, electrical conductivity, aridity index and precipitation index have the most significant effects on desertification with the values of 3.81, 3.17, 3.11 and 3.09, respectively. Also two indices including Sodium absorption ratio and drought have the least effect on desertification with the values of 1.17, 1.63 of the Plain, respectively. Also, analysis of desertification criteria in Garmsar region showed that among studied criteria, water criteria have had the most effect on land degradation and desertification since 1994.

This study deal with investigation of the effect factors on dryness of planted Haloxylon considering the importance of its role in soil stabilization especially mobile sands and also enormous costs were done for biological developments. For this research one peer site from planted Haloxylon area, 5 vigor Haloxylon sets, 5 semi-vigor Haloxylon set and 5 wilted Haloxylon sets were chosen based on plants appearance in the study site. Haloxylon shrubs were cut from the ground and the leaves were separated, then ratio of leaf to stem, therefore this ratio become an indicator of given vegetation. From 15 total selected Haloxylon sets, 15 samples of shots and 15 samples of roots were taken for conducting chemical tests and value of sodium, calcium, magnesium, potassium, and phosphorus were determined in the laboratory based on the standard methods. The effects of measured factors on plant vitality index were evaluated by univariate analysis of variance. The results suggest that with regards to the important role of phosphorus, potassium, calcium and magnesium in plants, their shortage in shoots reduce vigor index.

This study investigated the changes of proline, soluble sugar, Na, K and N in Atriplex lentiformis, Halostachys belangeriana and Tamarix rammossma over two seasons (winter and summer) in the field conditions. Five plants all in the same sizes and forms from each species in Chahafzal area of Yazd province were collected and the above mentioned indices were measured. Results showed that the highest amount of proline and sugar were found in Halostachys belangeriana and Atriplex lentiformis, respectively. Meanwhile, the amount of proline in all plant over summer was significantly more than winter. The amount of proline in summer in Halostchys belengeriana was also equal to 3.2 mg/gfw. In Atriplex lentiformis and Tamarix rammossma, the amount of sugar in summer was significantly more than winter. The highest amount of sugar was found in Atriplex in summer measurement which was equal to 6.8 mg/gdw. In contrast to two mentioned species, sugar content of Halostchys belengeriana in winter was more than summer. The amount of N and K were not significant in any of the species. Na in Halostchys belengeriana was significantly high compared with two other species. It is concluded that these halophyte species tolerate with different mechanisms to cope with salinity and drought stresses.