Mehdi Vatakhah; Mohammad Tavosi
Abstract
Today, the use of surface water to meet various human requirements such as drinking, agriculture and industry has endangered the health of this river ecosystem and its role in the natural system. The minimum environmental flow in the river provides a safe level of protection for the water-dependent environment. ...
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Today, the use of surface water to meet various human requirements such as drinking, agriculture and industry has endangered the health of this river ecosystem and its role in the natural system. The minimum environmental flow in the river provides a safe level of protection for the water-dependent environment. In the present study, the environmental flow requirement of three stations of Cheshmeh Langan River located in Isfahan province were calculated by two hydraulic methods: slope and maximum curvature of wetted perimeter. The results showed that both slope and curvature methods estimate the same minimum environmental flow requirement. So that the difference between the two methods in S1 station was about 0.07m3/s. According to the discharge measured at station S1, minimum environmental flow requirement is provided in all months except December. While the measured discharge at S2 and S4 stations cannot provide the minimum environmental flow requirement due to the impact of the dam and water transfer in any of the months. The flow of 0.39 m3/s for the first station (S1) and 1.44 an 1.68 m3/s for the second and third stations, respectively has been proposed as the minimum environmental flow requirement of Cheshmeh Langan River. The results of this study showed that the environmental flow requirement can be estimated using hydraulic method in data scarce.
Ahmad Hajarian
Abstract
The purpose of this article is to investigate the obstacles and challenges of rangeland ecotourism from the perspective of experts and stakeholders using the Delphi method and confirmatory factor analysis.The present research is applied research in terms of purpose and descriptive-analytical research ...
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The purpose of this article is to investigate the obstacles and challenges of rangeland ecotourism from the perspective of experts and stakeholders using the Delphi method and confirmatory factor analysis.The present research is applied research in terms of purpose and descriptive-analytical research in nature and has a quantitative qualitative approach. The statistical population of the study consists of two groups. The first group included experts and the second group included stakeholders. The sample size for the first group was selected using snowball or chain sampling of 28 people and the second group is based on the statistics of about 1000 people in rural areas of Isfahan province, which was determined based on Cochran's formula of 276 people.Data analysis was performed using SPSS software version 23. In order to identify the existing challenges of rangeland ecotourism in rural communities of Isfahan province, Delphi technique was used. The results in the qualitative part of the research indicated that the most important challenges facing rangeland ecotourism are structural and managerial factors, policy-making, financial and economic factors, individual-personality, research and information. In the quantitative part, using confirmatory factor analysis, there are 5 factors, which are: financial and economic factors, managerial and structural factors, weakness of laws and comprehensive policy, research and information, and individual and personality factors, respectively, which is 78.73. Explains the percentage of total variance.
azadeh bazrmanesh; Mostafa Tarkesh; Hossein Bashari; Saeid Poormanafi
Abstract
In order to model the potential habitat of Bromus tomentellus Boiss and study the effect of climate change on the habitat of this species in Isfahan province method of modeling maximum entropy (MAXENT) were used. The species event data were determined by random categorization method using field visits ...
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In order to model the potential habitat of Bromus tomentellus Boiss and study the effect of climate change on the habitat of this species in Isfahan province method of modeling maximum entropy (MAXENT) were used. The species event data were determined by random categorization method using field visits and geographic information system including 60 rangeland locations as educational points. Also, 20 points of occurrence were surveyed using GPS in the western region of Isfahan as points of assessment. 22 environmental layers including 3 physiographic variables and 19 climate variables derived from temperature and rainfall were used in the modeling process. Using by Maxent, the relationship between species incidence and environmental factors was determined. Then, the effect of climate change using cluster variables of CCSM4 general circulation model was evaluated under two scenarios RCP2.6 (optimistic) and RCP8.5 (pessimistic) on geographic distribution of Br.tomentellus Boiss. Regarding the photo curves, the specie’s behavior relative to the environmental variables of Br.tomentellus Boiss in the range of 2500 to 3500 altitudes, slope 10 to 30 degrees, annual precipitation is 240 to 260 mm and the average temperature is 8 to 10 ° C are more likely to occur. The habitat of the species studied during the two periods of 2050 and 2070, it was observed that under the optimistic scenario, 46.1 square kilometers to the appropriate level of the habitat of the Br.tomentellus Boiss is increased and under a pessimistic scenario, about 35.74 km2 is reduced from the appropriate level of habitat of this species.
S. Saadati; S. Soltani; S. eslamian
Volume 62, Issue 2 , October 2009, , Pages 257-270
Abstract
Drought is universal phenomenon that can occur everywhere and can cause harmful impacts on human beings and natural ecosystems. Thus, it is very important to study drought character ristics part of for water resources management. In this study, the Standardized Precipitation Index (SPI) is used for drought ...
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Drought is universal phenomenon that can occur everywhere and can cause harmful impacts on human beings and natural ecosystems. Thus, it is very important to study drought character ristics part of for water resources management. In this study, the Standardized Precipitation Index (SPI) is used for drought frequency analysis in Isfahan province. After collecting the precipitation data in the province stations and removing those stations with incomplete data, frequency analysis of drought was carried out by 12-month SPI time series scale end of March. Then, the maps of drought return periods were prepared and analyzed by SURFER software. These maps show that moderate and severe drought with long return period mainly in the west the province and extreme drought events in the east and north east of the province with short return periods which indicate high sensitivity and the necessity for suitable managing programs to deal with the problem of drought.