فهرست مطالب

Environmental Resources Research - Volume:6 Issue: 1, Winter - Spring 2018

Journal of Environmental Resources Research
Volume:6 Issue: 1, Winter - Spring 2018

  • تاریخ انتشار: 1397/02/25
  • تعداد عناوین: 7
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  • H. Siroosi *, G.A. Heshmati, H.R. Naseri Pages 1-14
    Identification of ecosystem thresholds is a way to predict future changes and taking the best management practices in restoration processes. Thresholds are an integral part of nonlinear responses of ecosystems to disturbances such as climate change or human activities. In this study, structural threshold of the total patch area and mean patch width in a grazing gradient were identified using the nonlinear function and the concept of threshold of potential concern. Other structural features including number of grass, shrub and forb patches were also measured. The result showed that three-parametric sigmoid functions had the highest ability to predict structural changes in ecosystem structure within a grazing gradient radiating out from the livestock stock night corral (camp). The result also showed that 1 to 2 Km radius from the livestock camp is the critical threshold in ecosystem structure based on total patch area, landscape organization index and mean patch width fitting to a sigmoid function. Generally, the area within 2 Km from the camp needed to receive emergency remedial management actions. The present study showed that the concept of threshold of potential concern is a useful and early way to predict the thresholds in the ecosystem for management actions. Also, the present study revealed that threeparameter sigmoid function provides a much better fit to structural data than other nonlinear functions.
    Keywords: Ecosystem, Structure, threshold, concern, sigmoid
  • S. Arabamiry * Pages 15-24
    The current paper seeks to estimate the value of management attributes in Perhentian Island Marine Park (PIMP). In order to collect the data, Choice Modelling (CM) questionnaires were used. After some checking with the related software and based on the literature and previous studies and suggestions, an experimental design was developed. Four ecological attributes and four relevant management processes for PIMP were selected. The results indicated that the respondents are concerned about conservational and relevant management process attributes. In the basic model, the main attributes were divided into two parts. The coefficients had prior expected signs, and they were statistically significant at 1% level. The findings can be utilized by Department of Marine Park Malaysia (DMPM). Based on the concept of ecotourism, local population benefits and marine resources maintenance are important besides fulfilling the satisfaction of visitors.
    Keywords: Perhentian Island Marine Park, Choice Modeling, Management attributes, Ecotourism
  • M.R. Azizzadeh *, Kh. Javan Pages 25-40
    Climate extremes have more direct and significant impact than average state on social and ecological systems. In this study temporal and spatial distribution of extreme precipitation events were analyzed based on the daily precipitation data of seven meteorological stations in the Lake Urmia Basin in Iran from 1987 to 2014. Eleven indices of precipitation extremes were selected and calculated using the RClimDex software. The Mann-Kendall test was employed to assess trend in extreme precipitation indices, and the Sen's Estimator test was used to determine the slope of the significant trends. Results demonstrate that consecutive dry days (CDD) exhibit an increasing trend. The other indices of precipitation extremes, Consecutive wet days (CWD), heavy precipitation days (R10mm), heavier precipitation days (R20mm), heaviest precipitation days (R25mm), maximum 1-day precipitation (RX1day), maximum 5-day precipitation (RX5day), very wet day precipitation (R95), extremely wet day precipitation (R99), simple daily intensity index (SDII), and wet-day precipitation (PRCPTOT) show decreasing trend and time of change in most indices starting from 1995-1996. However, all the linear trends for each index are not statistically significant. Decreasing trends in precipitation days were greater than those in precipitation indices. The slope of trends in extreme precipitation indices showed that the highest slope of the decreasing trend occurred in wet-day precipitation, consecutive dry days and very wet day precipitation. Spatial distribution for precipitation extremes exhibited a declining trend in most regions in the Lake Urmia Basin. Furthermore, the extreme precipitation indexes had positive correlations with the annual total precipitation, and their correlation coefficients were statistically significant at the 1% significance level, except for consecutive dry days.
    Keywords: Precipitation extremes, Spatial, temporal distribution, Mann-Kendall test, Sen's Estimator test, Lake Urmia Basin
  • H. Niknahad Gharmakher *, A. Esfandyari, H. Rezaei Pages 41-50
    Phytoremediation is a well known heavy metals remediation technique for contaminated soils and water. The present study was aimed to evaluate the uptake and dry weight response of vetiver grass (Vetiveria zizanioides L.) subjected to different levels of cadmium (Cd) (0, 3, 6 and 12 mg/kg soil) and nickel (Ni) (0, 50, 100 and 200 mg/kg soil) stress. The experiment was conducted in pots using a completely randomized design with four replications for three months. Concentration of Ni and Cd was determined using atomic absorption spectrophotometer. The dried weight of aerial and underground parts of Vetiver grass individuals at the end of the experiment were used to compare plant weight response to different stresses. Statistical analysis was performed using version 18 of SPSS software and analysis of variance (ANOVA) and mean comparisons were completed through Tukey method. No restrictions on Cd uptake was observed in root and shoot of Vetiver grass, but in the case of Ni, its concentration in shoots of vetiver grass decreased with higher metal levels.The highest transfer factor (TF) among Ni treatments was observed at the lowest concentration (50 mg/L) and the highest TF among Cd treatments was observed at the highest concentration (12 mg/L). Results revealed that Ni and Cd had a significant (p 0.05) positive effect on shoot and root dry weight of Vetiver grass. Our results suggest capability of this plant for use in phytoextraction of Ni and phytostabilisation of Cd contaminated soils.
    Keywords: Contamination, Dry weight, Heavy metals, Remediation, Translocation factor
  • S. Alahdin *, H.R. Ghafouri, A. Haghighi Pages 51-68
    Allocation is the number-one cause of conflict in water resources, whether between sovereign nations, different user groups or neighboring basins. The inter-basin water transfer is a remedy to the negative issues of water shortage in drought-stricken regions. In a water transfer project, the receiving basin always benefits while the donor basin may suffer. In this work, to define an operating policy, a multi-reservoir multi-purpose system is simulated and optimized for a set of long-term historical records. A multi-objective optimization model is developed based on Non-Dominated Sorting Genetic Algorithm (NSGA-II). The optimization results define the best possible performance set for a twobasin system with the objectives of supplied water shortage minimization during droughts. In a multi-objective optimization problem, there is not a single solution that simultaneously optimizes all objectives. However, decision makers are concerned with finding a unique compromise solution that balances conflicting objectives in a socially acceptable manner. The game theory can identify and interpret the behaviors of parties in water resource problems and describe interactions of different parties who give priority to their own objectives, rather than system’s objective. Using the strategic form description for different moves or actions available in the optimum trade-off front, Nash equilibrium outcomes predicted by game theory narrow the results suggested by optimization method. In this study, the inter-basin water transfer project from Zohreh multi-reservoir multi-purpose system in southwestern Iran to the Persian Gulf coastal district is investigated using the proposed methodology.
    Keywords: Inter-Basin Water Transfer, Conflict Resolution, Rule-Curve, Multi-Objective Optimization, Nash Equilibrium, Quantal Response Equilibrium
  • Z. Maryanaji *, H. Merrikhpour, H. Abbasi, M. Darvishi Pages 69-78
    In this research air temperature characteristics of five meteorological stations located in the Hamedan region of Iran were analyzed. The main objective was to identify and assess the possible climate change of the region during the period 1980 to 2010. To this end, time series of the mean annual temperature were investigated using Mann-Kendall and Normalized Residual Mass Curve methods. The climatological stations were Hamedan, Ekbatan Dam, Dargazin, Nojeh and Varayaneh. The results showed that the Mann-Kendall and Normalized Residual Mass Curve tests were similar on detection of the trends. The mean annual temperatures of stations with the exception of Varayaneh and Darghazin showed significant rapid increasing trends. This study illustrates the identical results of the two different tests on climate change identification and more importantly a significant warming at the majority of stations in the region. These results provide useful information for long term planning in water management of the region.
    Keywords: Annual air temperature, Mann-Kendall, Normalized Residual Mass Curve
  • A. A. Shahbazi, A.R. Soffianian, N. Mirghaffari, H. Rezaei * Pages 79-87
    Use of chemical fertilizers, pesticides and sewage sludge in agriculture lands have increased soils trace metals concentration in many parts of the world. In This article we report the results of a study on impacts of agricultural activities on soil accumulation of Cadmium, Cobalt, Chromium, Copper, Nickel and Lead and risk of metal contamination in Hamedan Province using contamination factor. The soil samples were collected systematically from agriculture fields with cultivation period of 65, 35 and 20 years. The results showed the mean concentration of Cd, Co, Cr, Cu, Ni and Pb in the soils was increased with the cultivation period and a significant difference was seen between the concentrations of metals, except for Pb, in the soil under different cultivation periods. The trend of soils trace metal accumulation of Cd, Co, Cr and Cu was exponential, whereas for Ni and Pb, it was quadratic and linear, respectively. Also, based on the calculated contamination factors, the soils classified as none and none to medium class pollution were generally found in lands with more length of cultivation. The increase of trace metals concentration in the soil followed the increase in the use of fertilizers in the region. The cultivated soils thus provide a way for entrance of trace elements in the human’s food chain. Therefore, monitoring contaminated soils is necessary to control and prevent the risks from contaminated soils.
    Keywords: Accumulation trend, Agricultural activities, Contamination factor, Traces metal