University of Tehran Desert 2008-0875 17 1 2012 06 01 Optimal Planning for Water Resources Allocation (Case study: Hableh Roud Basin, Iran) 1 8 32005 10.22059/jdesert.2012.32005 EN Arash Malekian Assistant Professor, Faculty of Natural Resources, University of Tehran, Karaj, Iran M. Mahdavi Professor, University of Tehran, Karaj, Iran M. Kholghi Associate Professor, University of Tehran, Karaj, Iran Gh.R. Zehtabian Professor, University of Tehran, Karaj, Iran M. Mohseni Saravi Professor, University of Tehran, Karaj, Iran H. Rouhani Assistant Professor, Gonbad Kavoos High Education Center, Gonbad Kavoos, Iran Journal Article 2007 05 23 The world is facing severe challenges in meeting the rapidly growing demand for water resources. In addition, irrigation water which is the largest use of water in most developing countries and arid and semi arid regions, will likely have to be diverted increasingly to meet the needs of the households in urban areas and industry sectors whilst remaining a prime engine of agricultural growth. A Linear Programming (LP) model has been developed to allocate the land and water resources to different crop activities for maximizing the net return. Application of the model for the irrigation water management revealed that in winter, 89.4% of available channel water was utilized, out of which 55.9% and 18.5% were allocated for wheat and barley, respectively .The remaining 25.6% channel water was allocated for cotton and watermelon. Since there were enough channel water supplies in this season, only 10.6% of available groundwater was utilized. In the absence of constraint on conjunctive use, there would have been no groundwater exploitation, and 100% of the channel water, which is much cheaper than groundwater, could have been utilized, if required. During summer season, the entire quantities of water available in channel as well as groundwater resources were utilized. In this season, as there was limited channel water supply, considerable part of the irrigation requirement was met from available groundwater. Based on the LP analysis, out of total available channel water, 43.2% was allocated to cotton cropping, which was most profitable as compared to all other crop activities, followed by 38.3%, 9.5% and 9% to crop activities including watermelon, barely and wheat, respectively. Out of total available groundwater, 65.8% was allocated to cotton whose irrigation water need was high and the remaining 34.2% was shared by wheat, barley and watermelon cropping activities. The model predicts that in the case of changes in irrigation water supply, it will be economic to change the cropping pattern.

University of Tehran Desert 2008-0875 17 1 2012 06 01 Evaluation of the Effects of Vegetation Characteristics on Desertification (Case Study: Northern Hableh Roud, Iran) 9 13 32006 10.22059/jdesert.2012.32006 EN H. Azarnivand Associate Professor, Faculty of Natural Resources, University of Tehran, Karaj, Iran M.A. Zare Chahouki Associate Professor, Faculty of Natural Resources, University of Tehran, Karaj, Iran H. Joneidi Assistant Professort, University of Kurdestan, Sanandaj, Iran Journal Article 2008 02 03 One of the characteristics in Iranian Model of Desertification Potential Assessment (IMDPA) is vegetation. Since vegetation is very important factor in the degradation of land, so some indices were determined for this item in order to evaluate desertification potential of arid, semi arid and arid sub humid areas of Iran. The indices included vegetation condition, exploit and revegetation. To calibrate the vegetation item in the IMDPA model, above mentioned indices were assessed in Northern Hableh Rood region as semi arid and arid sub humid region. To do this, in the first stage unit work map of the study area was prepared based on slope, land use and geological maps. Scores of indices were recorded in different study units. At last, using the following formula, VI  3VCI *VUI *VRI , final score of vegetation character (VI) was determined in the study area based on IMDPA. After scoring vegetation character, desertification intensity map for vegetation character including four low, medium, intensive and very intensive classes was prepared. The map showed that 62.2%, 37.2% and 0.6% of the study area are considered as low, medium and high desertification intensity class, respectively. There wasn't very high class based on vegetation character.

University of Tehran Desert 2008-0875 17 1 2012 06 01 The Impacts of Different Kinds of Dust Storms in Hot and Dry Climate, A Case Study in Sistan Region 15 25 32007 10.22059/jdesert.2012.32007 EN A. Pahlavanravi Faculty of Natural Resources, University of Zabol, Zabol, Iran A. Miri Faculty of Natural Resources, University of Zabol, Zabol, Iran H. Ahmadi Islamic Azad University, Science and Research Branch, Tehran, Iran M.R. Ekhtesasi Faculty of Natural Resources, University of Yazd, Yazd, Iran Journal Article 2009 06 12 Dust storms are catastrophic natural disasters that beside other disasters frequency occur in the arid and semiarid regions worldwide. Drought occurrence, climate aridity, dryness of the Hamoun Lake cause strong winds to below. These conditions have been prepared for dust storms in Sistan region. The damages to Sistan society have been measured using different criteria. The result shows that, peak of dust storms takes place at 10:30 am and the particular minimum was recorded at 6:30 pm. The maximal frequency of dust storms has been occurred in June and July. Since the dust storms cause extensive damages, an attempt has been made to quantify the damage costs using an analyticaldescriptive method based on questionnaires completed by the local community and organizations. The cumulative losses in terms of physical damage and loss of productive man-hours have been estimated US$ 99.190 million, over a five year period between 2000-2005.

University of Tehran Desert 2008-0875 17 1 2012 06 01 Statistical and Geostatistical Appraisal of Spatial Variability of Aggregate Stability and Aggregate-Associated Organic Carbon Content on a Catchment Scale in a Semi-arid Region, Central Iran 27 39 32008 10.22059/jdesert.2012.32008 EN H.R. Motaghian PhD. Student, College of Agriculture, Shahrekord University, Shahrekord, Iran J. Mohammadi Assoc. Prof., College of Agriculture, Shahrekord University, Shahrekord, Iran Journal Article 2009 08 31 In a semiarid region of central Iran, effects of parent materials, physiography and landscape position, land use, and management practices on association of organic carbon with secondary (aggregates) particles and aggregate stability can have important consequences in terms of carbon sequestration and budgeting, deciding on the proper land use strategy and suitable soil conservation practices. It was used wet sieved aggregates to evaluate the effects of different factors on soil aggregate stability and organic carbon concentration within three aggregate size fractions (>2 mm, 1-2 mm, <1 mm). 111 soil samples were collected to measure water stable aggregates (WSA), aggregate organic carbon concentration (OC), and mean weight diameter (MWD). Some other related soil and terrain properties including bulk density, infiltration rate, saturated hydraulic conductivity and erodibility index were also measured. Analyses of variance indicated that water stability of aggregates was influenced by aggregate size. Higher percentage of water stable aggregates was found for microaggregates (< 1 mm), followed by mesoaggregates (1 to 2 mm). Aggregate organic carbon content was highest in mesoaggregates (9 g kg-1), followed by microaggregates (7 g kg-1), while the least OC concentration was found in macroaggregates (3 g kg-1). Both aggregate size fraction and slope aspect significantly impacted aggregate organic carbon concentration. Although a significant effect of aggregate size on aggregate organic carbon content was found, however, our findings did not support the model of aggregate hierarchy. Both MWD and GMD were significantly impacted by aggregate size fractions. Geostatistical analysis showed that the measured soil attributes exhibited differences in their spatial patterns in both magnitude and space at each aggregate size fractions. The relative nugget variance for most aggregate-associated properties was lower than 45%. The range for water stable aggregates was almost similar (3 km) for the three studied aggregate size classes. The range for aggregate-associated organic carbon contents ranged from about 3 km for macroaggregates to about 6.5 km for mesoaggregates. Kriged maps of predicted WSA, OC and MWD for the three studied aggregate size fractions showed clear spatial patterns. However, a close spatial similarity (coregionalization) was observed between WSA and MWD.

University of Tehran Desert 2008-0875 17 1 2012 06 01 Flood Flow Frequency Model Selection Using L-moment Method in Arid and Semi Arid Regions of Iran 41 48 32009 10.22059/jdesert.2012.32009 EN A.R. Keshtkar Assistant Professor, International Desert Research Center (IDRC), University of Tehran, Tehran, Iran A. Salajegheh Associate Professor, Faculty of Natural Resources, University of Tehran, Karaj, Iran M. Najafi Hajivar MSc. Graduate, Natural Resources and Watershed Management Office, Koohrang, Iran Journal Article 2009 11 03 Statistical frequency analysis is the most common procedure for the analysis of flood data at a gauged location that in first step it is needed to select a model to represent the population. Among them, the central moment has been the most common and widely used, and with the using of computers, the application of the maximum likelihood has increased. This research was carried out in order to recognition of suitable probability distributions with pervious common methods. In order to investigate of suitable probability distribution for flood flow, using L-moment method through the existing hydrometric stations in the region, 17 hydrometric stations were selected for peak discharges data studies. According to results of this research for peak discharge, LP3 distribution and ordinary moment method, P3 distribution and L-moment method, LN2 and LN3 distributions and ordinary method have been suitable distinguished for 53%, 35%, 6% and 6% of stations, respectively. We concluded that L-moment method is suitable to determine peak series probability distributions in the Iran central plateau and P3 is the best probability distribution for modeling peak series in this region.

University of Tehran Desert 2008-0875 17 1 2012 06 01 Study of Dust Storm Synoptical Patterns in Southwest of Iran 49 55 32010 10.22059/jdesert.2012.32010 EN E. Fattahi Faculty member, Atmospheric Science & Meteorological Research Center, Tehran, Iran K. Noohi Faculty member, Atmospheric Science & Meteorological Research Center, Tehran, Iran H. Shiravand Lorestan Meteorological Research Center, Khorram Abad, Iran Journal Article 2009 11 15 As widespread deserts is located in west and southwest of Iran plateau, dust storms form due to west and southwest systems over Syria or Iraq as well as Arabian Peninsula. These systems severely affect west and southwest regions. Sometimes the fine dusts transmit to central, north east, and east regions. In this study for investigating dusty synoptical patterns, meteorological data at 5 synoptic stations were studied during recent ten years. Mean daily sea level pressure data were selected from the NCEP reanalysis data encompassing the region from 20°-60°N latitude by 20°-80°E longitude, with a 2.5 spatial resolution and for the 10 year period 1961-2003 in dusty days. Selected territory is located in a geographical situation that covers all the effecting systems on Iran. For classification and delineate synoptical patterns Principal Component Analysis (PCA) and clustering method were used. Results showed that in this region, days with dust have three general circulation patterns. Analyzing these patterns show that there is a trough which restricted to 30-45°E longitude in 850 hPa chart, and at least one relatively strong low pressure over Arabian Peninsula in sea level pressure extending to the west, south west and the study region. This study shows that above aspects are the major specifications of dusty days.

University of Tehran Desert 2008-0875 17 1 2012 06 01 Grain Size and Shape of Sand Grains in Ergs of Iran 57 64 32011 10.22059/jdesert.2012.32011 EN Sh. Mohammadkhan Assistant Prof., International Desert Research Center, University of Tehran, Tehran, Iran Journal Article 2010 05 23 Large areas of Iran are under the influence of wind erosion thus it is important that we recognize three zones of removal, transportation and deposition. The deposition zone is very important due to more damages and tangible effects. In this study we try to obtain a comprehensive idea to Persian desert with use of laboratory facilities, remote sensing, GIS and field surveying. We survey 28 ergs in this study that they have 6410600 ha area. Area of sand dune is 4172500 ha and we analysis 66 samples from them. the range of grain size is 4000 micron to less than 62 μ. 11% from samples have max grain size of 4000 μ, 3% 1700 μ, 5% 1180 μ13% 600 μ, 58% 300 μ, 9% 150μ, 2% 62μ. 28% samples had min grain size of 75μ, 13% 62μ, and 59% less than 62μ. 3% samples had mod of 600μ, 3% 300μ, 59% 150μ, 30%75μ and 3% 62μ. The samples were transport 1 to 5 km, 2% were transport 5 to 20 km, 72% were transport 20 to 50 km and 23% were transport 50 to 200 km. skewness coefficient of normal charts are -0.2 to 2.95 and most coefficients is in range of 2 that shown fine grain.

University of Tehran Desert 2008-0875 17 1 2012 06 01 Analyzing the Changes of Soil Erodibility Index (K) in the Soils of Arid Regions and the Effective Factors in Central Iran (Case Study: Yazd-Ardakan Plain) 65 75 32012 10.22059/jdesert.2012.32012 EN F. Fotouhi Msc. Graduatet, Yazd University, Yazd, Iran H.R. Azimzadeh Assistant prof., Yazd University, Yazd, Iran A. Talebi Assistant prof., Yazd University, Yazd, Iran M. R. Ekhtesasi Associate professor, Yazd University, Yazd, Iran Journal Article 2010 09 17 One of the main factors of water erosion is the natural characteristics of the soil called "erodibility" or "detachability". The present study aims to analyze the variations of soil erodibility factor in different plains and the factors related to it. Erodibility is one the key factors in some models of erosion and sediment such as Universal Soil Loss Equation (USLE), Revised USLE (RUSLE), and Modified USLE (MUSLE) and is a function of grain size distribution, organic matter, structure and infiltration. To this end, the index of soil erodibility was measured through field surveys in 37 spots in the faces of bare pediment, coalescing pediment, and concealed pediment plains using Wischmeier and Smith (1987) method. The infiltration of soil profile and the percentage of desert pavement in the field were measured as well. Soil grain size distribution, percentage of organic matter, soil structure, gravel volumetric content, lime, salinity, acidity, and sodium absorption rate were also measured in the laboratory. The statistical analysis indicated positive correlations of erodibility with silt, very fine sand (VFS), and negative correlation of this factor with gravel, sand, infiltration, organic matter, and lime. The results from Analysis of Variance (ANOVA) test also indicated that three factors of salinity, acidity, and sodium absorption rate are not significantly different in bare pediment, coalescing pediment, and concealed pediment plains. The results suggested that in natural conditions of soil surface, desert pavement plays its protective role and land use change through mixing the soil would thwart effect of the pavement. So, the erodibility of the soil in manipulated and mixed conditions increases up to 10 times.

University of Tehran Desert 2008-0875 17 1 2012 06 01 Land Suitability Evaluation for Alfalfa and Barley Based on FAO and Fuzzy Multi-Criteria Approaches in Iranian Arid Region 77 89 32013 10.22059/jdesert.2012.32013 EN N. Yaghmaeian Mahabadi College of Agriculture, Shahrekord University, Shahrekord, Iran J. Givi College of Agriculture, Shahrekord University, Shahrekord, Iran M. Naderi Khorasgani College of Agriculture, Shahrekord University, Shahrekord, Iran J. Mohammadi College of Agriculture, Shahrekord University, Shahrekord, Iran R.M. Poch Claret Dept. of Environment and Soil Science, University of Lleida, Lleida, Spain Journal Article 2010 12 25 The present research aims to apply several approaches for suitability evaluation of lands under cultivation of alfalfa and barley in Chaharmil mechanized farming center, Ardestan town, Isfahan province, Iran. Climatic and soil maps of the climate and soil data were provided in raster format. Land evaluation carried out using maximum limitation, parametric and multi-criteria (Analytical Hierarchy Process (AHP) and fuzzy AHP) approaches. Land indices, calculated by these methods were correlated with the observed yields. The best relationships were given by fuzzy AHP for alfalfa and barley, which illustrates the accuracy of this approach for land evaluation. The results of fuzzy AHP showed that the majority of the study area is potentially more suitable for alfalfa than for barley. The membership functions revealed that soil texture is the main constraint for alfalfa and barley production.

University of Tehran Desert 2008-0875 17 1 2012 06 01 Comparison the Amount of Existing Mineral Elements in Plant Aerial Parts, Litter and Soil of Three Range Species in Taleghan Region 91 97 32014 10.22059/jdesert.2012.32014 EN M. Saberi Faculty of Natural Resources, University of Zabol, Zabol, Iran M. Jafari Professor, Faculty of Natural Resources, University of Tehran, Karaj, Iran A. Tavili Associate Professor, Faculty of Natural Resources, University of Tehran, Karaj, Iran M.A. Zare Chahouki Associate Professor, Faculty of Natural Resources, University of Tehran, Karaj, Iran M. Tahmoures MSc. Graduate, Faculty of Natural Resources, University of Tehran, Karaj, Iran Journal Article 2010 12 26 The aim of this research was to compare the amounts of existing mineral elements in plant aerial parts, litter and soil of three range species (Bromus tomentellus, Psathyrostachys fragilis, Agropyron tauri) in order to investigate the litter effect of species on soil properties of Taleghan rangeland. The measured mineral elements include carbon, nitrogen, phosphorous and potassium. After selection of the appropriate plant species and suitable sites, random- systematic sampling method was used to plant aerial part, litter and soil sampling. Soil data were taken of 0-30 cm depth and in addition to above mineral elements, soil texture, EC, pH and lime percentage was measured in soils of the sites. The data was analyzed by analysis of variance (ANOVA), Duncan’s test and t-test. Results of analysis of variance of different elements showed that the amounts of nitrogen, carbon and C/N ratio of the species litter had significant differences, so that A. tauri had the highest concentration of nitrogen and B. tomentellus had those of Carbon and C/N ratio. Results also indicated that there are significant difference among the amounts of nitrogen, phosphorous and carbon in plant aerial part of the mentioned species (P<0.01). P. fragilis had the highest amount of nitrogen and both P. fragilis and B. tomentellus had higher amount of carbon and phosphorous than A. tauri. Soil under the species and control showed significant differences so that the mentioned species improve soil productivity. Totally, A. tauri had the highest litter quality and decomposition rate.

University of Tehran Desert 2008-0875 17 1 2012 06 01 Wheat (Triticum aestivum L.) Growth and Yield as Influenced by Flooding and Salinity Stresses in Northern Iran 99 104 32015 10.22059/jdesert.2012.32015 EN H.R. Asgari Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran W. Cornelis Department of Soil Management, Ghent University, Ghent, Belgium P. Van Damme Department of Plant Production, Ghent University, Ghent, Belgium Journal Article 2011 08 15 Salinity and flooding are as two very important factors of soil degradation. They often occur together and can cause severe damage to plants. However, plant response to environmental stresses may vary with growth stage at which exposure occurs. A pot study was conducted in 2005-2006 in northern Aq Qala (northern Iran) to study combine effects of waterlogging and soil salinity at different growth stages on grain yield and some yield components of two Iranian spring wheat genotypes, i.e. Kouhdasht and Tajan. Two salinity treatments were applied, viz. a nonsaline (ECe = 3 dS m-1) and saline soil (ECe= 10 dS m-1). The six waterlogging treatments within each set consisted of: control (no waterlogging), and waterlogging applied at tillering (T); stem elongation (SE); booting (B); grain filling (GF); and two spells of waterlogging, i.e. at tillering and grain filling stages (T+GF). In this experiment, waterlogging was imposed by keeping pots in hypoxia conditions by adding water daily (during up to two weeks) to 110% of available water holding capacity. Results reveal that highest reduction in grain yield; thousand grain weight (TGW) and harvest index (HI) were observed through waterlogging at T+GF for both wheat genotypes. Nonsignificant changes in grain yield, TGW and HI were observed via waterlogging at B as compared to control. Kouhdasht showed better performance than Tajan under saline and saline × waterlogged conditions

University of Tehran Desert 2008-0875 17 1 2012 06 01 Study of the Effect of Management Criterion on Desertification Control (Case Study: Kashan) 105 109 32016 10.22059/jdesert.2012.32016 EN M.S. Ziaei Associate professor, Faculty of Management, Univ. of Tehran, Tehran, Iran R. Masoudi Ph.D. Student, Faculty of Natural Resources, University of Tehran, Karaj, Iran M. Ghodsi Ph.D. Student, Faculty of Geography, University of Tehran, Tehran, Iran H. Khosravi Ph.D. Graduate, Faculty of Natural Resources, University of Tehran, Karaj, Iran Journal Article 2012 04 30 Desertification is more related to social and anthropogenic issues than natural causes and it becomes more important over the time. Human effects on desertification could be classified as direct and indirect factors. This study has focused on the effect of management factor, as a dominant case, on desertification of Kashan region based on IMDPA (IMDPA: Iranian Model of Desertification for Potential Assessment) model. The geometric average weight was used in order to find out the numerical value of management factor and then; desertification status map of the area was prepared using GIS. The results showed that about 59.96 percent of the region, based on management criterion, is classified in the medium class of desertification which mostly covers central, northern, southeastern and western parts of the region. Meanwhile, irrigation systems, rangeland ploughing and the index of evaluation implemented activity having the numeral value of 3.52, 3.43 and 2.23 are the most important affecting factors on desertification, respectively. Increasing unwise human activities due to lack of sufficient knowledge on new irrigation and cultivation technologies has been resulted on accelerated degradation and consequent desertification. Then, combination of new extension and traditional knowledge, policy making and planning may lead to desertification control in the region.