نشریه محیط زیست طبیعی
سال هفتاد و یکم شماره 4 (زمستان 1397)

The volume of fabric wastes throughout the world is constantly increasing. A significant proportion of these wastes are recoverable or compostable, but in our country there is no other way of burning and landfilling for the management of these wastes. Among the various types of fabrics, some have greater biodegradability and can be decomposed at the acceptable rates under controlled conditions. In this study, the disintegration of rayon fabric was investigated under composting conditions. During the composting process, temperature, moisture and aeration were controlled and by sampling at the certain times, changes in some operating parameters such as temperature, moisture and pH were investigated. Structural and morphological changes of the linen fabric before and after disintegration were investigated by FTIR spectra and scanning electron microscopy (SEM). At the end of the process, by measuring the weight loss due to organic matter conversion, the disintegration of this fabric was evaluated and the maturation of resulting compost was investigated by a germination test. The results revealed the breakdown of hydrogen bonds in the fabric. The samples weight loss at the end of the test showed that the rayon fabric is biodegradable under composting conditions, and due to the germination test, the resulting compost maturity is at the acceptable level.

Water resource development plans (such as dams) has the numerous environmental effects, which altering the natural regime of river and river flow reduction is the most important. One of the most important environmental challenges in water resources planning is river water rights estimation affected by natural variables, understanding the importance of protecting water resources, variety biological and ecosystems related to river flow. Environmental flows is meaning time, quality and amount of required current to protect freshwater, estuarine ecosystems, human welfare and livelihoods related to water. The main aim of this study is estimation of environmental water right Gorganrood river (Aq Qala station) based on 33-year period, using hydrological methods Tennant, Tessman, aquatic base flow, flow duration curve and duration curve change in different months of years. The results show that at least the Gorganrood river flow (Aq Qala station) to provide environmental flows using the above methods, respectively should equal to 27/2, 8/1, 51/5, 47/4 and 33/3 (class C) cubic meters per second. This study has shown that in the absence of information on the ecological, hydrological indices can be used for preliminary estimation of environmental flows.

One of the biggest needs facing most societies today is the lack of fresh water. Lack of safe water resources and high costs of treatment plans often prevent communities' access to this vital need. Therefore providing a reliable method that the elimination of industrial pollution, low cost and environmentally is very necessary. This study aimed to investigate the removal of hexavalent chromium from waste water by absorbing roots, stems and leaves of barberry was done. The initial pH, reaction time, absorption weight and initial concentration of chromium was the most important parameters that in this study examined in each adsorbent. The results showed that the removal efficiency of hexavalent chromium by increasing pH and initial chromium concentration decreases, in the event that increase the amount of particulate absorbent and adsorbent contact time with the solution containing chromium ion, removal rate increases and then reaches a state of equilibrium. It was also observed that the absorbent roots of barberry with less than two other absorbent removal rate is higher. Therefore, use of low-cost agricultural waste is very helpful in order to remove the heavy metals chromium and reuse of water for agriculture in the country.

Faecal standing crop pellet group counts have been widely used in forested habitats to estimate deer population size. To convert pellet group density to deer density, Knowledge of disappearance rate of pellet groups is necessary. The disappearance rate of pellet groups may be different in different environments and can affect the accuracy of abundance estimation. We estimated decomposition and disappearance rate of Persian fallow deer (Dama mesopotamica) pellet groups in Dasht-e-Naz wildlife refuge, northern Iran, over a 12-month period. Labeling and monitoring pellet groups for decay was conducted at strip transects. Mean time ± SD to pellet group decomposition and pellet group disappearance were 94.84 ± 5.59 SE and 45.79 ± 2.71 days, respectively. Pellet groups persisted longest in summer and shortest in spring. The time to pellet group decomposition was significantly correlated with daily evaporation, mean daily air temperature and mean wind speed. The deposition of pellet groups became equal to their decay from 70-140th days and from 270-310th days since the start of the experiment suggesting a steady state system of the dung on the ground.

Climatic conditions has an important factor in regarding tourism planning. Tourists are looking for a favorable climates (i.e. comfort climate) where people feel neither dissatisfied of climatic discomfort. The most suitable time to have recreation is when climatic indicators reach the levels of comforts and satisfactions of the human beings. In this current investigations, by considering the climatic information of touring destinations that it’s so important in suitable sitation regarding climatic conditions in Monj customary unit, Chaharmahal and Bakhtiari province. Then a recreational suitability map from a climatic point of view was provided. In this investigation the environmental cooling power index, (i.e. Baker’s index) was calculated by using the average monthly temperature and by measuring wind speed. The measurement of wind speed in Lordegan meteorological station was examined by considering the nearest station to the case study. The results of current investigation indicated that the highest temperatures belong to July and August and January and February have the lowest temperatures. Also, the amount of Baker’s index regarding bioclimatic conditions ranges from 10 to 20 in April, October, November, December, and March and have a suitable natural condition too. Also, the highest suitability is in the elevation ranges consisting of 1894-2094, 2294-2494, and 2494-2694. In all of the three elevation ranges, 9 months of the current year have a natural suitable bioclimatic conditions in the case study. It is based on this investigation, eight months of the current year have the highest recreational suitability comprising 3065.90 hectares and 64.4 percentage of the case study region.

Little is known about altitudinal distribution of lizards in Iran. In the present study we studied distribution pattern of members of family Lacertidae along the eleveatinal gradient in Iran. To determine environmental drivers of distribution pattern of 48 lizard species, all known valid members of family Lacertidae, along elevational gradient in Iran. Firstly, we classified Iran digital elevation model (DEM) based on 100m intervals, that resulted in 56 altitudinal bands and number of species in each band was recorded. Secondly, we extracted mean value of following variables; altitude, slop, area, solar radiation index (SRI), normalized differences vegetation index (NDVI), annual precipitation, precipitation of wettest month, precipitation of driest month precipitation, precipitation of wettest quarter, precipitation of driest quarter, and precipitation of warmest quarter, and using VIF measure correlated variables were removed. Finally, we performed a multiple regression and found that area and precipitation of warmest quarter are the most important drivers of distribution pattern of family Lacertidae along elevational gradient in Iran. General distribution pattern of family Lacertidae was unimodal and maximum number of species living from 1475 m to 1675 m.

Rainfall-runoff hydrological models are important tools in water resources projects. Generally, performance of this group of models is dependent on the proper selection of parameters. Accordingly, several methods have been developed to estimate hydrological parameters. The present study aimed to compare the performance of conceptual hydrologic models such as TANK, SIMHYD and AWBM which benefit from the indirect model parameters estimation approach in discharge simulation of Babolroud watershed, Mazandaran province, Iran. The automatic calibration process of these models was designed using genetic evolutionary search algorithm and objective functions (NSE and RMSE) as error thresholds determinants. Hence, meteorological and hydrological data consist of temperature, evapotranspiration, precipitation and discharge (in daily scale) were gathered from authorities. Input data was also divided into warm-up, train and test steps after preliminary validation and recovery. Based on the results, NSE metric introduced TANK model as the best simulator respectively for train and test step (0.59 to 0.72). Depends on RMSE metric, SIMHYD (0.83) and TANK (0.15) models were introduced as the best simulator respectively for train and test step either. According to the catchment flow signatures, general simulation of low-flow (excluding the Model TANK), mean-flow and high-flow were conducted with acceptable agreement. While simulation of the flow duration curve slope which represents an intensity of changes (excluding TANK model in train step), did not provide acceptable results. Given the weaknesses and strengths of the proposed models, they can be used as an acceptable simulator in water resources management especially in terms of ungauged basins, after preliminary verification in different climatic conditions.

One of the most conflict species in Iran is the grey wolf (Canis lupus). Unfortunately conflict between grey wolf and local communities were increased in Hamden province. So that, recently, 60 incidents of wolf attacks on local communities, mostly children (70 %), and more than100 incidents of wolf attack on livestock were documented. One of the effective management for conflict mitigation is determining local communities' attitude and structure (Social, Cultural, etc.). Although, most mitigation studies investigated only the technical aspects of conflict reduction. In this research we studied an important factor that effect on vulnerability of local communities towards wolf attacks in Hamadan province. To do this, we designed 400 questionnaire and interview with local communities in counties of Hamadan province. Using binary logistic regression we analyzed these data. Our result showed that most important factors on vulnerability of local communities included: Number of guarding dogs, herd size, releasing of domestic carcass near rural area, waste management and translocation of wolves to remote area (wild zoo or protected areas). As well as the number of guarding dogs, risk of wolf attacks to local communities would be decreased. Local communities believing, releasing of domestic carcass near the rural area lead to attractive wolves, would meet less vulnerability. Empirical results indicated that local communities managing their waste, risk of wolf attacks to will be reduce. Larger herd size lead to high encounter rates with wolves. People that agree with translocation of wolves from areas of high livestock density to remote area will be less vulnerable. Management implications to mitigate conflicts between wolf and local communities were discussed.

Water pollution with heavy metals is considered as a serious health problem in terms of human health risks. Therefore, it is important to remove these contaminants from polluted environments. In present study, a carbon nanocomposite was made of graphene oxide and activated carbon prepared from lignocellulosic waste and then optimum conditions for lead removal were investigated using Taguchi method and the effect of four effective factors on adsorption, including different adsorbent doses, pH values, initial concentrations and contact times were investigated at 5 levels. The iodine number of the nanocomposite was determined 920 mg/g. The maximum efficiency of lead removal by carbon nanocomposite was determined at a 0.5 g/L of adsorbent dose, pH=6, initial lead concentration of 50 mg/L and contact time=60 min. The produced nanocomposite in this study has a high potential for removal of lead from aqueous solution and can be proposed as a cheap absorbent for treatment of lead contaminated wastewater.

Fires in natural areas are one of the factors decreasing forested area of northern Iran. In this study, forest and rangelands susceptibility to fire were analyzed using data-driven methods over Mazandaran Province. Fourteen important environmental and anthropogenic parameters influencing forest and rangelands susceptibility to fire were used to model probability of fire susceptibility. Binary logistic regression and artificial neural network, as two well-known data driven methods was then used to evaluate environmental and anthropogenic performance on landfire and map of forest fire susceptibility estimates were prepared in GIS environment. The area under the successive rate curve (AUSC) showed that ANN method modeled forest fire susceptibility with an accuracy of around 88% and BLR with 85%. 21.6% of the total area of Mazandaran province is located in areas with high and very high susceptibility levels of forest and rangeland fire. Overall, ANN method showed promising results to estimate landfire susceptibility. The forestry and rangelands fire susceptibility map presented in this study can be used as a basic map of the strategic planing in Mazandaran province to reduce probability fire damages.