فهرست مطالب

Desert - Volume:21 Issue: 2, Summer - Autumn 2016

Desert
Volume:21 Issue: 2, Summer - Autumn 2016

  • تاریخ انتشار: 1395/10/10
  • تعداد عناوین: 10
|
  • B. Behmanesh, A. Abedi Sarvestani, M. Sharafatmandrad *, M.R. Shahraki, A. Hajili Davaji Pages 105-113
    In recent years, large rangeland areas have been destroyed for various reasons, so that its negative impacts on local people's income and sustainable livelihood are become significant. Due to the fact that signs of negative or downward trends in the rangelands condition are being revealed prior to the complete degradation, a study was done to identify these sings and evaluate their importance in Saryqmish rangelands, Marave Tape County, Golestan Province, Iran. Data were gathered using direct and participant observations. Based on rangeland degradation indicators extracted from literature and interviews, a questionnaire was drawn up under which the respondents were asked to rate the importance of rangeland degradation indicators in two different scales: 5-point Likert-type scale and a 20-point scale. The results showed that "vegetation" with 68.9% and 53.3%, and "climate" with 48.9% and 77.8% are known as the indicators with medium and high importance in rangeland degradation, respectively. In other words, exploiters known climate and vegetation more important than other indicators in rangeland degradation. The results indicated that exploiters consider "reducing production plants" and "reduce the number of annual plants and grass" as the first priorities for assessing rangeland degradation Statistical comparison of the rangeland degradation indicators between authorized and unauthorized users pointed out that there were no significant differences between these two groups in assessed rangelands degradation indicators.
    Keywords: Rangelands, Degradation Indicators, Authorized Exploiters, Unauthorized Exploiters, Saryqmish
  • B. Shokati *, M.R. Asgharipour, A. Ghanbari, B. Feizizadeh Pages 115-131
    In the way of finding economic and tolerable plant to the arid and semi-arid climatic conditions and prevent desertification in these areas, this study aims to assess Agro-climatic suitability for producing Saffron in East-Azerbaijan province based on Geographic Information System (GIS) spatial analysis technique. For this goal, several criteria including soil conditions, climatological indicators, topography situation and agro-climatology criteria were taken into account of modeling process. For this to happen, standardization process was performed on criteria and weighting process was done by using of Analytic Hierarchy Process (AHP) approach. GIS based Multi-criteria Decision Analysis (MCDA) was employed for weighted overlapping of indicators and results were achieved based on GIS-MCDA method. Initial results indicated that East-Azerbaijan province has potential for cultivating of Saffron. Our research results indicated that about 42.7 percentage (1954416.9 ha) of this province has high suitability for Saffron producing. While, about 55.4 percentage (2537492.0 ha) of the study area has moderate suitability. In addition, about 1.8 percentage (84643.2 ha) of the study area represents low suitability. The results also indicated that, sum of sun hours and precipitation were supposed as important and limiting factors in the cultivation of this plant respectively. The founds of this research are great of importance for the purpose of regional planning in East-Azerbaijan province and also important in terms of developing methodology for precision agriculture which is one the main aspects of modern agriculture.
    Keywords: Analytic Hierarchy Process, Climate, Crocus sativus, GIS, Suitability assessment
  • N. Mashhadi *, M. Hanifehpoor, F. Amiraslani, Sh. Mohamadkhan Pages 133-141
    Aeolian process and subsequently soil erosion are key factors in dryland environments. Such phenomena are related not only to geoecological factors (lithology, topography, and climatology) but also to land-use and plant cover changes. Formation of new sand dunes in Damghan explains the development of human activities over the past. The aim of this study is to explain the land use changes and their contributions and impacts on Aeolian sediments in Damghan Region. The study was carried out using topographic and geologic maps, satellite imagery, aerial photographs, meteorological data, field observation and samplings. According to meteorological data, period of strong winds (May to Jun) were identified. This period is wind activity period. So, based on this period, unprotected soil surface by crop residues with the interpretation of satellite images was determined. The field samples were carried out from May to June 2008 when the wind was active. The study methods include sieving soil granulometry, and analyzing the particle size. Granulometric analyses were performed using conventional dry sieve method. The results of statistical analysis of grain size distribution showed that the mean and median of particle size were composed of coarse and very coarse sand particles. The study indicated that 90% of the agricultural lands contained more than 23% soil aggregates, where in areas with sensitive particles to erosion the Figure was 35%. It can be argued that agricultural land in study area are resistant to wind erosion.
    Keywords: Damghan, Granulometry, Soil Aggregates, Human Activities, Sensitive Particles
  • Kh. Khermandar *, A. Mahdavi, S. Ahmady Asbchin Pages 143-154
    In desert reclamation strainer plants can be used for improvement and decrease pollution of soil and water. This technology can be used to remove both inorganic and organic contaminants in soil. In this study, one year old Acacia victoriae seedlings were exposed to Pb (NO3)2 in 5 different concentrations; 0, 50, 250, 500 and 1000 mg Pb L-1 for 45 days in two growing seasons. Subsequently, the heavy metal concentrations were measured in different plant tissues by Atomic Absorption Spectroscopy (AAS) for two growing periods. In addition, some physiological and morphological parameters (root and plant length, root diameter, leave area, dry weight, chlorophyll a, band total) were measured. Based on the results, the visible toxicity symptoms (chlorosis and necrosis) appeared only to the highest concentration (1000 mg Pb L−1) in both growing seasons. The results also showed that application highest concentration of Pbreduced the physiological and morphological parameters as compared to the control seedlings. The accumulation of Pbwas influenced by the Pbconcentration in the growth medium and the growing seasons as well. With respect to the more accumulation of Pbin the roots tissues than aboveground tissues, indicating A.victoriae as a good option for phytostabilization of Pbcontaminated soils. Furthermore if A.victoriae is planted for Pb phytoextraction, therefore the harvest of aboveground should be done at the fall season. Meanwhile concentrations of Pb in the aboveground parts were more than roots at the fall season. In conclusion A.victoriae a native to the arid zone appeared to be hyper tolerate, accumulate high concentrations of Pb and it could be regarded as a potential accumulator. In addition A.victoriae have high application value in repairing Pb contaminated soils and is suitable and effective choice to be used as a tool of phytoremediation in industrial sites of the arid zones. Our findings suggest that A.victoriae has the advantages of high capacity for adaptation to poor, easy cultivation, deep root system, high tolerance to the drought, saline soils and Pb and could use as candidate plant for environmetals monitoring.
    Keywords: Lead, Phytoextraction, Phytostabilization, Soil pollution, Toxicity symptom
  • Gh.R. Zehtabian, A. Salajegheh, A. Malekian, N. Boroomand, A. Azareh* Pages 155-164
    Climate change is found to be the most important global issue in the 21st century, so to monitor its trend is of great importance. Atmospheric General Circulation Models because of their large scale computational grid are not able to predict climatic parameters on a point scale, so small scale methods should be adapted. Among downscaling methods, statistical methods are used as they are easy to run. Two famous models, ClimGen and SDSM, were studied for daily total precipitation and temperature data in Qazvin station. For this purpose, three steps of models calibration, verification and simulation, in Qazvin station were performed and model performances in terms of similarities in produced data with those using parameters such as root mean square error (RMSE), coefficient of determination (R2) and Nash coefficient (NSE) were assessed. The results in climatic range showed that Climgen outperform in rainfall data generation while SDSM outperforms in simulating average temperatures. However, both models have high potential to simulate temperature and precipitation.
    Keywords: Rainfall, Average temperature, Climate change, SDSM model, Climgen model, Qazvin plain
  • A. Afzali, H. Keshtkar *, S. Pakzad, N. Moazami, E. Azizabadi Farahani, A. Golpaygani, E. Khosrojerdi, Z. Yousefi, M. Taghinaghilou Pages 165-172
    Drought monitoring is a fundamental component of drought risk management. It is normally performed using various drought indices that are effectively continuous functions of rainfall and other hydrometeorological variables. In many instances, drought indices are used for monitoring purposes. Geostatistical methods allow the interpolation of spatially referenced data and the prediction of values for arbitrary points in the area of interest. In this research, several interpolation methods, including ordinary kriging (OK), indicator kriging (IK), residual kriging (RK), probability kriging (PK), simple kriging (SK), universal kriging (UK), and inverse distance weighted (IDW) techniques were assessed for the derivation of maps of drought indices at 19 climatic stations in Zayandehroud River Basin of Iran. Monthly rainfall data of period 1989 to 2013 were taken from 19 meteorological stations. The results showed that based on the used error criteria, kriging methods were chosen as the best method for spatial analysis of the drought indices and also, the lowest error (RMSE) and R2 is related to the kriging method. The results showed that SK and OK were more suitable for the spatial analysis of the Z-Score Index (ZSI) and the Standard Precipitation Index (SPI) index. The mean errors (RMSE) of kriging methods for ZSI and SPI indices were 0.40 and 0.19 respectively.
    Keywords: Drought, Spatial analysis, ZSI, SPI, Zayandehroud
  • H. Sarhadi, J. Daneshian*, S.A. Valadabadi, H. Heidari Sharafabad, Gh.R. Afsharmanesh Pages 173-180
    For investigation deficit irrigation and nitrogen application effect on nutrients uptake of henna ecotypes, this research was conducted in the form of split-split-plot on the basis of randomized complete block design with four replications in the Research Field of Islamic Azad University, Jiroft, Iran in 2013-2014. The main, sub and sub-sub plot were deficit irrigation (100, 75 and 50% of crop water requirement), ecotypes (Bami, Boushehri and Roudbari) and nitrogen amount (50, 100 and 150 kg/ha). Results revealed that deficit irrigation had a significant effect on calcium, sodium and potassium/sodium (α≤0.01), and on potassium (α≤0.05) absorption percent. Nitrogen application effect was significant for potassium and calcium/potassium absorption percent (α≤0.05). There was no significant difference between evaluated ecotypes. According to mean comparison results, decreasing irrigation level from 100 to 50% of water requirement has led to increase in calcium, potassium and sodium absorption percent; On the other hand, it led to decrease in potassium ratio to sodium. Increasing nitrogen amount from 50 up to 150 kg/ha caused decrease in potassium and finally increased calcium/potassium ratio. It seems that increasing potassium, calcium and sodium in drought stress condition is one of the strategies for drought tolerance. For more details and applied results, it is recommended to evaluate relation between growth and nutrients uptake under water deficit and nitrogen application
    Keywords: Henna, ecotype, water stress, Nitrogen, Nutrients absorption
  • A. Salehpour Jam*, M. Karimpour Reihan Pages 181-192
    Investigation of desertification trend requires an understanding of phenomena that create changes singly or action and reaction together in an area that these changes were led to the desertification and land degradation. In the investigation of pedological criterion affecting on land degradation in Alluvial Fans, first, the map of units was created by overlaying and crossing maps of slope classes, land use, geology and grid layer created by extension of ET Geo-Wizards in ArcGIS 10.3. In this research, three indices of erodibility, salinity and permeability of soil were considered and classified. Then, the weights of each criteria and consistency ratio were calculated by the AHP method. The TOPSIS method was used to prioritize the alternatives in this research. After calculating the weighted normalized values, Euclidean distances and the relative closeness to the ideal solution were calculated. The results show that the relative closeness to the ideal solution obtained from AHP-TOPSIS technique alters from 0.016 to 1.000. The alluvial fans in the research area were classified into three classes of I, II, and IV from the view point of pedological criterion affecting on desertification using AHP-TOPSIS technique. The obtained results showed that 74.18 % of the area is in the low desertification potential, and 3.37 % and 22.45 % are in the high and very high desertification potential, respectively.
    Keywords: Erodibility, Salinity, permeability, Priority, MCDM
  • S. Amini, A. Gandomkar *, M. Bagheri Bodaghabadi Pages 193-204
    There are various methods and models for land evaluation. These methods are classified according to the number of used resources. The best resources capabilities or potentials and land use can be found by analyzing one of the main resources, in the lands close relations to ecologic resources exist. Soil has a great potential for introducing the studied region specifications. Hence, it challenges the mistaken belief stating: “soil is only valid for agricultural applications and it is weak in measuring developing and planning domain.” The present study is done with the aim to achieve the best land use according to a single-factor (soil) model for tourism planning. A soil map was obtained using a combination of conventional and digital soil mapping methods. In conventional process soils were mapped using aerial photo interpretation and physiographic methods and in digital process an elevation model and satellite images were used. Based on the field works and laboratory analyses, the soil map included 13 soil units resulting 176 delineations. Tourism region needs more essential requirements rather than recreation area. Thus, an ecological capability evaluation model developed by Bagheri Bodaghabadi (2016) was employed to evaluate all delineations of the soil map using GIS. Finally, the best environmental planning was presented to design the study area for tourism usage. The results also showed there are moderate to high suitable classes for all tourism purposes, resulting the study area has potential to develop a tourism region. The most important limiting factors in the area include soil depth, slope and coarse fragment of soil. It was also suggested to use local models to evaluate the ecological capacity in the small area.
    Keywords: Single-factor evaluation, Soil map, Tourism, Land evaluation, land use planning
  • Z. Eslamian, M. Ghorbani *, T. Mesbahzade, H. Rafiee Pages 205-212
    Recently, natural resources economists have turned to valuation and appraisal of the contribution of natural resources to human’s welfare and they have made striking progress in valuing the environmental and ecological services of eco-systems. The present study investigated people’s willingness to pay (WTP) for participation in preservation and reclamation of Abuzeidabad desert area through contingent valuation method and by applying double dichotomous questionnaire. Logit regression model was applied for measuring willingness to pay and the parameters of this model were estimated based on maximum likelihood. It was revealed that variables including poultry farming and monthly income leave positive significant impact upon WTP but age, sex, job, farming, livestock raising, overgrazing, and proposed amount (bid) had negative effects on willingness to pay. Besides, family size (the number of family members) had negative effect on willingness to pay but it was not significant at acceptable significance level. The average amount ethical and consequentialists were willing to pay for preservation and reclamation of Abuzeidabad desert area was estimated 93986 and 95153, respectively. Therefore, ethical conduct must be institutionalized within families so as to prevent much extra expenses for preservation and development of environmental objectives.
    Keywords: Contingent valuation, Participation, Ethical beneficiaries, Consequentialist beneficiaries, Willingness to pay, Abuzeidabad district