مجله مدیریت بیابان
پیاپی 4 (پاییز و زمستان 1393)

Based on the scientific literature in the realm of sustainable water resources management, some researchers have highlighted the impacts of economic, social and environmental driving-forces, yet ignored analysis of effective strategic internal and external factors through the basin. Meanwhile, the others have considered strategic factors rather than sustainable development paradigm. Therefore, the current research has constructed a framework to promote the quantitative policy-making by using the internal and external strategic matrix along with the sustainable development together in Lake Urmia Basin. Due to the fact that, conventional quantitative strategic planning matrix (QSPM) could not involve above mentioned considerations simultaneously, the Modified QSPM (MQSPM) was proposed to include the socio-economic and environmental factors besides internal and external factors. According to the results, the most attractive policy belonged to Conservative strategies (included weaknesses and opportunities). Moreover, capability of watershed management to deal with 10 out of 13 weaknesses was not satisfying. The potential of regional watershed management to deal with 11 economic, five social, and nine environmental challenges contributed to the weaknesses was estimated inappropriate. In addition, climate change and drought were not evaluated as the most critical threat of the basin, while economic crises and low investment security was determined as the most critical threat. Actions’ ranking for environmental security conservation indicated that high ranks belonged to the integrated watershed management. Due to the simplicity and suitable performance of MQSPM, this matrix is suggested for future research work on identifying and evaluating the strategic factors.

Nowadays, desertification is one of the important ecological crises affecting the world. We require a proper understanding of causes and processes of desertification to control the serious phenomenon in the global and regional scales. In comprehensive management, the monitoring content is systematic collection and storage of data from activities and strategies that provide assessment and report about the overall condition of the study area. In this study, using AHP and GIS techniques, the desertification process was assessed by IMDPA model in 7864.5 ha of Zarabad region in the southeastern Iran. The results of analysis showed that desertification benchmarks and indicators in the three periods had a nonlinear trend of desertification process in the region so that the numerical value is equal to 2.73 in the period 2001-2004 but In the period 2004-2007 the figure has decreased that is show decreasing trend of desertification in recent years and the main reason for the improvement was climatic parameters such as rainfall. The numerical value in the period 2007-2010 is 2.55 shows an increasing trend of desertification. As the result show that climate benchmark is dominant over three periods and classified in high grade. Among the indicators studied, Transou aridity index and annual precipitation index had the maximum effect with the values of 3.81 and 3.4 while sodium absorption ratio value ​​was 1.17 with the least impact on desertification. Among two water quality indices in the area, the electrical conductivity has greater influence than sodium absorption ratio that it directly related to the increased exploitation of groundwater and increased salinity in the studied region.

Application of provenance method by tracers or fingerprinting has been demonstrated as a successful and effective way to determine the sediment sources. According to this method, physical, geochemical and biogenic features of sediment are used to determine the sediment sources and their importance. The main aim of this research is determining the contribution of different facies using the hybrid model in sediment supply for sand dunes of Ashkzar erg. For this aim, 65 surface samples from the sources region facies and 8 samples from the sand dunes were collected and the particles less than 62.5 micron, as the target, were tested. In order to measure the geochemical elements including rare earth elements (REE) and trace element, the ICP-AES was used. Then, ICP-MS was used to measure Strontium (87Sr & 86Sr) and Neodymium (143Nd & 144Nd) isotopes. The indices of rare earth elements were calculated and the elements, REE indices and isotopes were used as tracer. Then, initial choice and optimal combination of tracers were done by the statistical methods including one-way ANOVA, Kruskal-Wallis and discrimination analysis. Finally, contribution of the various facies on sediments supply was determined using hybrid models. The results showed that Rubidium (Rb), Cerium (Ce) and Strontium (Sr) were determined as the optimal combination. Moreover, the results of hybrid models showed that the distribution facies of fine sandy plains & dry river bed, fans & dry river bed, Kelot, farmlands, Neogene marl hills and Sebkha were 27, 22.7, 24.4, 13.26, 6.4 and 6.24 % respectively. Performance of the model was 0.999 indicating it's accurate and appropriate results.

Spraying petroleum mulch has been one of the common measures of mobile sand stabilization endeavors over the last three decades. However, the consequences of mulch on the endemic vegetation species, vegetation recovery and soil attributes improvements have not been fully understood. This study seeks examining the effects of petroleum mulch on the sandy deserts of Sarakhs located in Khorasan Razavi province. The sampling was arranged as the randomized-systematically by dividing the area of operation into control and treatment plots and the sampling was performed in the key areas of each plot. Nine transects of 50 meters were placed and vegetation cover, density of two dominant species (viz. Astragalus squarosus & Convolvolus hamadae) as well as the total vegetation cover was recorded. Moreover, 220 plants were selected and examined for their dry and green matter. Four soil profiles in each plot were sampled at the depths of 0-20 and 20-80 cm and the samples were further analyzed for their organic matter content. Data analysis was performed using the independent t-test which showed no difference between the treatment and control plots for their total vegetation and species cover. Even though the density of As sq. was lower in the treatment plot of all plants especially As sq, were in good condition and enjoying considerable volumes. While the situation for plants in the control plot were harsh where most plants were drying. The current status in the treatment plot has resulted in a significant rise in the level of organic matter at the depth of 20-80 cm in the mulched areas.

Soil carbon sequestration and storage is one of the important methods to reduce the atmospheric carbon dioxide and mitigating climate change effects. Therefore, with identification of the effective factors on carbon storage can be helpful to improve soil fertility and environmental protection. Therefore, this study was conducted to investigate the effects of some soil physical factors on soil organic carbon (SOC) storage content in drylands of Sarfiroozabad watershed, Kermanshah province, Iran. So, the watershed was separated into homogeneous zones and soil sampling was performed using a randomized systematic method in the units. The samples were transported to the laboratory and texture, TNV%, gravel% and organic carbon were analyzed to determine the SOC storage. Then, using stepwise regression, cluster and factor analysis, the effective factors on carbon storage were studied. The results of cluster analysis showed three variables such as TNV%, Silt% and SP%, are effective on SOC storage and the regression model with this three variables can predict 33 percent of the soil carbon storage variability with a correlation coefficient of 0.574. Also, cluster analysis to predict the effects of physical factors on carbon storage is important with EF= 0.32. Therefore, it was proven that the soil factors are more effective than climate and topography factors to predict SOC storage. It shows that improving the soil conditions and correct management, to keep soil carbon stocks should be given more attention.

In this study, IMDPA model was used to assess desertification phenomena regarding the importance of agriculture in Mehran plain. Climatic and hydrologic criteria were selected to consider over two periods 2002-2007 and 2008-2012. Two climatic indices (Precipitation index and SPI) and three hydrologic indices (Groundwater level depletion, EC and TDS) were chosen to quantify climatic and hydrologic criteria, with which desertification intensity was calculated and classified for mapping by Arc GIS 9.03. Desertification intensity was classified in four classes including negligible and low, medium, high and very high. According to the results, among studied indices, SPI with the values of 2.45 and 2.78 and the groundwater level depletion with the values of 3.68 and 3.97 were the most effective factors. The results of analysis indicated that drought, decreased precipitation and groundwater level depletion cause an increase in desertification in Mehran Plain.