Effects of Soil Compaction by Animal Trampling on Growth of \u3cem\u3eAgropyron Repens\u3c/em\u3e

Animal trampling is the most important factor that increases soil compaction beyond the soil elastic property in rangelands under heavy grazing intensities (Lull, 1959). The complicated ecological interactions in a rangeland ecosystem make it difficult to predict the impact of trampling under different conditions. However, soil properties and vegetation composition are sensitive to different grazing management practices. This research, which was carried out in simulated conditions, sought to establish the contribution of soil compaction resulting from animal trampling over a long period to the decline in rangeland condition

Effects of impervious surfaces and urban development on runoff generation and flood hazard in the Hajighoshan watershed

Urbanization is a pervasive global trend. The development of residential areas and road network in Hajighoshan watershed (northern Iran) has been observed in the recent several decades. The objective of this study is the quantitative investigation of the effects of impervious surfaces development and urban development on runoff generation and flood hazard. The study of urban area development was carried out using aerial photos, topographic maps and satellite images. Also a rainfall-runoff model was presented using GIS (HEC-GeoHMS extension) and HEC-HMS model. Then, the model was optimized with initial loss and SCS-Lag parameters. The optimized model was evaluated using the other 4 events of flood .In the next stage, the development of impervious surfaces was included in the validated hydrologic model and their effects on intensifying runoff generation and flood hazard was investigated quantitatively during the recent forty years. The results showed that the runoff generation potential has increased in Hajighoshan watershed because of urban development during forty years ago

Artificial neural network technique for rainfall temporal distribution simulation (Case study: Kechik region)

Artificial neural networks (ANNs) have become one of the most promising tools for rainfall simulation since a few years ago. However, most of the researchers have focused on rainfall intensity records as well as on watersheds, which generally are utilized as input records of other hydro-meteorological variables. The present study was conducted in Kechik station, Golestan Province (northern Iran). The normal multi-layer perceptron form of ANN (MLP–ANN) was selected as the baseline ANN model. The efficiency of GDX, CG and L–M training algorithms were compared to improve computed performances. The inputs of ANN included temperature, evaporation, air pressure, humidity and wind velocity in a 10 minute increment The results revealed that the L–M algorithm was more efficient than the CG and GDX algorithm, so it was used for training six ANN models for rainfall intensity forecasting. The results showed that all of the parameters were proper inputs for simulating rainfall, but temperature, evaporation and moisture were the most important factors in rainfall occurrence

Meteorological drought analysis using copula theory and drought indicators under climate change scenarios (RCP)

AbstractThe study was carried out to assess meteorological drought on the basis of the standardized precipitation index (SPI) and standardized precipitation evapotranspiration index (SPEI) evaluated in future climate scenarios. Yazd province, located in an arid region in the centre of Iran, was chosen for analysis. The study area has just one synoptic station with a long‐term record (56 years). The impact of climate change on future drought was examined by using the CanESM2 of the CMIP5 model under three scenarios, that is, representative concentration pathways RCP2.6, RCP4.5 and RCP8.5. Given that a drought is defined by several dependent variables, the evaluation of this phenomenon should be based on a multivariate analysis. For this purpose, two main characteristics of drought (severity and duration) were extracted by run theory in a past (1961–2016) and future (2017–2100) period based on the SPI and SPEI, and studied using copula theory. Three functions, that is, Frank, Gaussian and Gumbel copula, were selected to fit with drought severity and duration. The results of the bivariate analysis using copula showed that, according to both indicators, the study area will experience droughts with greater severity and duration in future as compared with the historical period, and the drought represented by the SPEI is more severe than that associated with the SPI. Also, drought simulated using the RCP8.5 scenario was more severe than when using the other two scenarios. Finally, droughts with a longer return period will become more frequent in future

Prediction of Breast Cancer Risk in Women over 35 Years Old Living in Villages of Zanjan: A Study Based on Gail Model

Background: Breast cancer is one of the most important malignancies in both developed and developing countries. Objectives: To reduce the burden of this disease, the prediction of individuals at risk and implementation of efficient preventive interventions can be effective. The present study was aimed at investigating five-year and lifetime risks of the breast cancer in a rural community in Zanjan province, Iran. Methods: A total of 435 subjects aged 35 years old were randomly selected using systematic randomization in a rural community in Zanjan. The participation rate was 92.4% (402 women). Data collection instrument was a questionnaire in which all associated variables of Gail model and demographic information were included. The data were analyzed using SPSS software version 18, and mean cancer risks were reported. Results: Family history of breast cancer and history of breast biopsy were found to be positive in 3.5% and 0.3% of participants, respectively. Out of all participants, 84.3% were under 60 years old and 13.2% were illiterate. Five-year and lifetime mean risks were fund to be 0.74% and 7.6%, respectively. About 2% of the participants had a higher cancer risk>1.66%. Conclusion: The findings demonstrated that based on the Gail model, the lifetime risk of the participants will be one out of 13 women. Given the lower estimations of Gail model in the prediction of breast cancer, we suggest general population interventions and high-risk strategies be implemented to decrease problems associated with the breast cancer in the future

Survey and feasibility study for the introduction of native fish and non- native fish for cage culture in the southern part of Caspian Sea

The aim of this study is the feasibility of introducing suitable species of fish (native and exotic) for rearing in cages in the southern region of the Caspian Sea. This study from the perspective of economic efficiency and maintaining ecology were analyzed. The results showed that the southern Caspian Sea has the ability to aquaculture fish. However, due to the yearly temperature variations of water (from surface to a depth of 50 meters), the talent of aquaculture area is preferred for fish in cold water than warm water fish due to possibility rearing over the years. The survey showed that the current conditions and due to unfavorable changes in the ecology of the area in the last decade, the use of non-native fish culture in cages is not recommended. Many species of native fish are suitable for rearing in cages. Nevertheless, there is no infrastructure suitable for the production of all of them. Therefore, respectively species of Salmo caspius, Huso huso and Common carp of Caspian Sea for cultivation of in cages was suggested. In the current situation, this fish for their ability to grow faster than the need for selectivity. It is noteworthy that detailed environmental assessments and species risk assessments before the final introduction of any fish species (native and exotic) for rearing in cages in the Caspian Sea ecosystem is essential

Economic study of the rainwater collection system in drought conditions

Collecting rainwater is one way to make life easier for local communities during periods of drought. The lack of uniform distribution of rainfall in all seasons makes it necessary to store the water needed by households. Iran is one of the arid and semiarid countries facing water scarcity problems, but in the city of Taleghan, average annual rainfall is above the national average. The roof surfaces were used to measure the quantity of water stored. The surface which can be created on the roofs of houses has been calculated using the SPOT 5 satellite. It has a total accuracy and a kappa coefficient of 91.2 and 88.5, respectively. While there are many benefits of the rainwater collection system, the results of this study showed that the economic benefits are different. If the estimated life of the rainwater collection system is 10 years and annual inflation increases at least 41% each year, this system is not economic. The initial capital requirement for a rainwater collection system was estimated at $ 679 ± 278. The results show that the costs of setting up a rainwater collection system and at least the 18% yearly financial interest on bank deposits are not equal. Besides the results show that the high cost of building the rainwater collection system is linked to the storage tank and it needs the government's financial support