Nadia Kamali; Hossein Azarnivand; Shervin Ahmadi; Mohammad Ali Zare Chahouki; Ahmad Sadeghipour
Abstract
This study was conducted to evaluate the effect of polymer mulches and plant mulch on some soil physical properties. For this purpose, effects of synthetic polymer, natural polymer, natural - synthetic polymer, and litter, On some physical properties of soil at two depths (0-5 cm and 5-30 cm) and two ...
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This study was conducted to evaluate the effect of polymer mulches and plant mulch on some soil physical properties. For this purpose, effects of synthetic polymer, natural polymer, natural - synthetic polymer, and litter, On some physical properties of soil at two depths (0-5 cm and 5-30 cm) and two time periods in a completely randomized design with four replications was studied. 10*10 meter experimental plots were considered and mulches covered 2 cm of the soil surface in each plot. The results showed that the use of mulches in the first week of applying, affected the bulk density (3.6% increase in synthetic polymer), porosity (6.01% increase in synthetic polymer), temperature (2.52% increase in litter and 1.85 decrease in natural polymer) and humidity (16.67% increase in synthetic polymer) at the layer of 0-5 cm, Soil moisture (16.67% increase in synthetic polymer) was also affected at the depth of 5-30 cm. Six months after the experiment began, mulches were applied, made a significant difference compared to control in the bulk density (4.81% and 2.12% decrease in synthetic polymer for 1st and 2nd layers respectively), porosity (8.23% increase in synthetic polymer for 1st layer and 4.12% increase in natural - synthetic polymer for 2nd layer) and moisture content of both surface and beneath soil (103.53% and 48.6% increase in natural - synthetic polymer for 1st and 2nd layers respectively), also the electrical conductivity of the first depth of soil (6.23% decrease in natural - synthetic polymer) was affected.
Hamed Eskandari Damaneh; Gholamreza Zehtabian; Hassan Khosravi; Hossein Azarnivand; Aliakbar Barati
Abstract
The present research aims to assess climate change in the Minab plain and its effect on groundwater level variability in the future period. Climate change was explored by the climatic model CanESM2 using the SDSM4.2 software package, and the effect of climate change on groundwater resources was quantitatively ...
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The present research aims to assess climate change in the Minab plain and its effect on groundwater level variability in the future period. Climate change was explored by the climatic model CanESM2 using the SDSM4.2 software package, and the effect of climate change on groundwater resources was quantitatively modeled in the GMS10.0.5 software package under the emission scenarios of RCP2.6, RCP4.5, and RCP8.5. The results for the effect of climate change in the future period in the context of these scenarios showed that temperature will increase by 1.88ºC, 2.60ºC, and 4.28ºC and precipitation will decrease by 34.19%, 42.08%, and 59.43% versus the reference year, respectively. The results for the application of the climatic scenarios using the groundwater model revealed that due to the decline of precipitation in this period, mean groundwater level balance in the future periods leading to 2019, 2024, 2029, and 2035 versus the reference year (2003-2004) will be -13.99, -19.003, -22.70, and -25.61 m/yr in RCP2.6, -13.99, -18.95, -22.75, and -24.73 m/yr in RCP4.5, and -14.23, -19.22, -22.003, and -25.46 m/yr in RCP8.5, respectively. This shows that the drawdown will be being aggravated over time. Finally, this decline of precipitation and rise in temperature due to climate change and the subsequent increase in water abstraction for different uses will result in the growing depletion of the groundwater tables in Minab. So, it is recommended to planners and authorities to adopt strategies for adaptation to new climatic conditions and water scarcity and accommodate themselves with future conditions.
Ahmad Gillvare; Gholamreza Zehtabian; Hassan Khosravi; Hossein Azarnivand; Salman Zare
Abstract
Due to the importance of vegetation cover in these areas, the aim of this study was to investigate the effect of drought, on vegetation of HablehRood watershed.Initially, NDVI index obtained from MODIS sensor was used to study vegetation cover and then SPI index based on rainfall data of two basins in ...
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Due to the importance of vegetation cover in these areas, the aim of this study was to investigate the effect of drought, on vegetation of HablehRood watershed.Initially, NDVI index obtained from MODIS sensor was used to study vegetation cover and then SPI index based on rainfall data of two basins in two arid and semi-humid climates was used for drought assessment (2001-2018) using image processing methods. The results showed that during this 18-year period, 53% of the region had droughts on average. Also during the period 2001-2003, drought was more severe than other periods (2003-2018). In addition, the highest vegetation index occurred in 2005, indicating that vegetation was affected by rainfall fluctuations in the region. The correlation matrix between the three indices indicated that NDVI had the same correlation with SPI and annual rainfall. The results of this correlation in dry and semi-humid climates showed that the correlation was 0.38 and 0.25, respectively. These results indicate that this relationship is positive and robust in different climates of a region؟. On the other hand, drought class is mainly located in dry and semi-humid climates, with 55.55% and 50% in relatively normal drought class, respectively. Based on the above, it can be concluded that using remote sensing data can monitor the response of semi-humid and dry arid ecosystems to climate change. The study also showed that arid and semi-arid regions are highly susceptible to climate change and human anomalies. Therefore, the destruction of these lands will have many environmental and economic consequences.
Hamid Reza Saeidi Goraghani; Hossein Arzani; Hossein Azarnivand; Mehdi Ghorbani
Abstract
People's attitudes toward influence of natural resource management projects on their livelihood could be playing a role important in the sustainability of these projects. This paper accomplished with general aim to studying the attitude of rancher towards the effects of range and watershed plans in sustainable ...
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People's attitudes toward influence of natural resource management projects on their livelihood could be playing a role important in the sustainability of these projects. This paper accomplished with general aim to studying the attitude of rancher towards the effects of range and watershed plans in sustainable livelihoods capitals tribal families in Sarduieh of Jiroft county. In this regard, five allotments selected that they were done range management and watershed plans. Sampling was simple Random method and the number of samples was determined by Krejcie and Morgan of 48 ranchers. Data were collected via focus groups and interviews structured questionnaire that its validity and reliability were achieved at an acceptable level. Forms and questionnaires analyzed after the initial review and verify the accuracy of the data. For processing and extraction of quantitative and qualitative data used from software SPSS18 and using statistical techniques appropriate with measurement level of variables. The findings show that there was a significant relationship between natural-ecological capital, human-technical, social and sustainable livelihoods of farmers. The results from multiple regression analysis showed that totally 83% of the variance of sustainable livelihoods is determined by third variable including natural capital, social capital and human capital and technical. Also, the findings of this study showed that the highest standard regression coefficient was related to index of natural capital and ecological indicators.
Sahar Zakeri Anaraki; Gholamreza Zehtabian; Hassan Khosravi; Hossein Azarnivand; Arash Malekian
Abstract
Intergovernmental Panel on Climate Change report shows that the world average temperature has increased to 0.6 ° C ± 0.2 ° C in the twentieth century. Therefore, long-term prediction of climate variables and the consideration of measures to mitigate the adverse effects of climate change ...
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Intergovernmental Panel on Climate Change report shows that the world average temperature has increased to 0.6 ° C ± 0.2 ° C in the twentieth century. Therefore, long-term prediction of climate variables and the consideration of measures to mitigate the adverse effects of climate change is evident. The SDSM model was used to downscale observation data of the minimum and maximum temperatures of the Vazvan Meyme station in Isfahan province. The CanESM2 global model data under new emission scenarios: RCP2.6, RCP4.5, and RCP8.5 are used to predict the near future (2006-2036), mid-term (2037-2078) and far-away future (2079-2100). The studies show the ability of the SDSM model to model maximum and minimum temperatures in the base period. The results of this study necessary indicate that as we get closer to the 21st century, the minimum and the maximum temperatures increase in the area of study. The average maximum temperature changes will have the highest increase under the RCP8.5 scenarios in the (2079-2100), in July, which will reach 7.9 ° C. The average changes in minimum temperature show the highest increase in August under the RCP8.5 scenarios. Therefore, considering that this temperature increase in future periods will affect the status of the study area, water resources, and natural resources. Planners and authorities of the relevant departments will take the necessary measures, such as measures to correct irrigation systems, methods for reducing evaporation and improving the cultivation system, to adjust the damage caused by heating or adapt to the new climatic conditions.
Shahram Yousefi Khanghah; Hossein Azarnivand; Mohammad Ali Zare Chahouki; Mohammad Jafari; Hamidreza Naseri
Abstract
The establishment of vegetation is the best way to manage degraded and at risk of degradation lands. Considering that the planting in arid lands is very costly because of ecological restrictions, so experts are looking for methods that increase the percentage of the seedlings establishment and reduce ...
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The establishment of vegetation is the best way to manage degraded and at risk of degradation lands. Considering that the planting in arid lands is very costly because of ecological restrictions, so experts are looking for methods that increase the percentage of the seedlings establishment and reduce the cost of planting, in this regard the correct use of amendments is very important. The study area is located in Nazarabad City in southwest of Alborz province. In this study, the amendments including mineral biochar, arbuscular mycorrhiza fungi and acrylic resin polymer each in four levels were used at the base of Nitraria schoberi seedlings. The soil characteristics of the area was determined at the start of planting. After one year with counting the number of live seedlings, the percentage of establishment for each treatment was calculated. Economical estimates were calculated based on cost-benefit and calculated separately for each treatment. The results showed that there was a significant difference at the 5% level between the amendments and the control. Mycorrhizae had the highest (70%) and the control and biochar 4 treatments had the least (40%) percent of establishment. Economically, mycorrhizal 2, polymer 2 and biochar 1 treatments were the most optimal treatments for each amendment, respectively. The used amendments had different effects on the establishment of seedlings, so that the percentage of establishment increased with increasing level of mycorrhiza use, but with increasing level of polymer and biochar use, negative effects were observed and the percentage of seedling establishment decreased.
