جستجوی مقالات مرتبط با کلیدواژه « اثرات زیست محیطی » در نشریات گروه « آبخیزداری، بیابان، محیط زیست، مرتع »

One of the natural and common hazards in recent years is the phenomenon of dust, which causes damage, especially to urban and human environments, and is very difficult to control and manage. One of the main and effective factors in the occurrence of this phenomenon is the geographical location and climatic conditions of the regions of origin and the areas affected by this phenomenon. In this research, which has been done in Hindijan City of Khuzestan Province, first, issues and problems have been identified based on library studies, questions from experts, referring to the research area. Then, the Driving force-Pressure-Status-Impact-Response (DPSIR) framework was used to analyze the most important factors that have caused the occurrence of dust in the city of Hindijan. The DPSIR framework is an analysis of the "cause-effect" relationship of factors for policy-making and management planning. In this study, the factors related to each of the components of the DPSIR framework were identified and prioritized using a questionnaire of experts with a Likert scale and based on nonparametric Friedman tests. Explain that, to complete the questionnaire of experts, experts from the Departments of Natural Resources, Environment, Regional Water and Agricultural Jihad of Khuzestan Province were surveyed. Results showed that population growth, agricultural development, livestock development, industrial development and climate change are important from maximum to minimum, respectively, the most important drivers affecting the occurrence of dust in the study area. Attention to both reactive and preventive responses has an important role in improving the situation and reducing the adverse effects of dust occurrence in the research area.

The purpose of this descriptive-correlation study was to investigate socio-economic and environmental impacts of the watershed management projects in Mahabad’s dam catchment. The research instrument was structural questionnaire with close-ended questions which its validity and reliability was confirmed. The target population of this study consisted of all householders who lived in Mahabad’s dam catchment (N=2458) out of which, according to Cochran’s formula, a number of 175 people were selected using cluster sampling in a simple randomization method (n=175). The descriptive results indicated the status of environmental, economic, and social impacts of watershed management in Mahabad’s dam catchment were at nearly high, nearly appropriate, nearly and low levels, respectively. These results also showed the main economic, environmental, and social impacts of watershed management were changing dry farming into irrigated farming, controlling flood, and attracting rural people’s participation, respectively. The results of Friedman test indicated environmental and social impacts were the most and the least amount of impacts of watershed management in Mahabad’s dam catchment, respectively. The results of correlation coefficient showed that there was the significantly positive relationship between land under cultivation and number of respondents’ household individual who participated in agricultural activities with impacts of watershed management in Mahabad’s dam catchment.

In recent years, a major contribution of the nitrogen needed for agricultural production was supplied from urea chemical fertilizer in Iran; this issue would lead to the serious environmental impacts. The aim of this study was to investigate the environmental impacts of the use of this important agricultural input through Life Cycle Assessment (LCA) methodology during 2007-2012. LCA in four sections including "the goal and scope definition”, “inventory analysis (inputs and outputs of the system)”, “impact assessment, and interpretation of the impacts were calculated. Investigation was performed on three impact categories such as global warming, acidification and eutrophication for terrestrial ecosystems. The obtained data analysis showed that approximately of 1.5%, 8.6% and 42.8% of the environmental consequences of impact categories including global warming, acidification and eutrophication for terrestrial ecosystems in Iran were related to the this input consumption, respectively. The amounts of weighted indices during the period for these impact categories were calculated 1160785, 11330566 and 25384073, respectively. Urea fertilizer consumption had the highest environmental hazards in terms of eutrophication for terrestrial ecosystems impact category. Therefore, management of the urea fertilizer consumption to minimize its environmental impacts and its replacement by non-chemical nitrogen resources is vital in agriculture sector of Iran.

In forest harvesting, there is an ongoing trend to increase constantly the size, power and load of logging machines. This may cause soil degradation in forest ecosystems as the passes of these machines modify important soil structural characteristics. The present study was conducted to traffic, trail slope, traffic frequency, and soil depth on bulk density and soil compaction due to tree-length logging method using rubber-tired skidder in Namkhaneh district in Kheyrud Forest. The level of soil compaction at eight levels of traffic (1, 4, 8, 10, 15, 20, 25, and 30 passes), four levels of slopes (0, 10, 1-10, and -20) and three soil depth (5, 15, 25 cm) were applied in three replicates consequently. Bulk densities were measured on the undisturbed surface (UD) and within the tracks (WT). Result showed that in four different slopes most bulk density increasing was occurred during the first few passes of skidder, although density continued to increase in amount and depth with the number of passes. About 5.2% of total area of harvesting unit were disturbed and compacted. Uphill skidding increases compaction more than downhill skidding. The increases in bulk density were still important at the maximum sampling depth of 20-30 cm. The results indicated that slope steepness had a strong effect on the soil physical properties and soil disturbance. Designated skid trails should be used to minimize the influence on the forest stand.