Geography and Environmental Sustainability
Year:2017 | Volume:7 | Issue:23 |Papers Count:7

As a major component of hydrological، geomorphological، and ecological functioning of rivers، suspended sediment has been identified as the leading direct cause of river instabilities. Therefore، recognizing the variability of rivers is essential to manage water resources and environmental issues. As a result، 5 storms were sampled and analyzed for 4 months in Mereg watershed from 2015 to 2016. Sampling was taken in 2 hours interval and suspended sediment concentration was obtained in the laboratory by filtration method. Estimation of temporal variation of suspended sediment during storm was carried out using sediment rating curves. Different approaches were used to prepare sediment rating، including hysteresis pattern، hydrological and seasonal separation. Measured floods have the peak flows from 1. 38 to 49. 40 m3/s covering a suitable range of low to high peak flows in this river. Moreover، the peak suspended sediment concentration measured in these storms was from 1 to 15. 2 g / l. The average suspended sediment load in the study period was 15، 919 tons. Measurement of suspended sediment during winter and spring showed that the generation and transportation of suspended sediment in spring is higher than winter in the studied watershed. The fitted relationships on all rating curves was valid and had a determine coefficient higher than 0. 5 and estimated error below 50%. The results show that rating curve can provide acceptable estimate of suspended sediment load in the Mereg River without the need for classification or segmentation of rating curve. IntroductionSediment entrance into rivers causes many problems، including the reduction of reservoirs capacity by sedimentation and the increase of turbidity in water supply systems. In many catchments، short and intense precipitation events are responsible for a large part of the total sediment transport. Therefore، recognizing the variability in different scale of sediment supply، especially in flood scale، is considered very important to manage and understand the river and water structure systems. The lack of proper and adequate data has led to the use of sediment rating curves and regression relations to estimate suspended sediment loads، widely. Due to the lack of data or scattered data، it is very difficult to study suspended sediment in the rivers of Iran. The studying temporal variation of suspended sediment، especially during storms، to achieve sustainable river management is very necessary. The present study aims at investigating intra-storm and seasonal variations of suspended sediment during rainfall and assessing the sediment curve approach in estimating sediment load in storm base in Merg River watershed in Kermanshah province. Materials and MethodsMereg watershed with 1446 square kilometers area is located in the west of Iran، Kermanshah province. It is a relatively mountainous region with the average altitude of 1524 meters. The average slope of the basin is about 6%. The length of Mereg River to hydrometric station of Khers Abad is 121. 34 km. To conduct the present study and to prepare suspended sediment and flow data، sampling of water and sediment was carried out at Khers Abad hydrometric station in two seasons، the winter of 2015 and the spring of 2016. At the time of rainfall، sampling was done simultaneously with runoff and rising water levels in the river at intervals of 2 to 4 hours. The method of filter paper was used to measure suspended sediment. Discharges associated with sediment samples were also calculated using the discharge-water stage relationship of the Regional Water Organization Station. Sediment curve approach was used to estimate suspended sediment. Separate curves for rising and falling limbs of hydrographs، seasonal data (winter and spring) and hysteresis patterns were developed and compared with sediment rating curve of the whole data. In addition to the coefficient of determination، the estimate relative error was also used to evaluate the sediment rating curves. Results and DiscussionFive events were chosen from January to May، 2016. Storms had a peak discharge of 1. 38 to 40. 49 (m3/s)، which covers a wide range of low-to-high peak floods in Mereg river. The amount of rainfall is significantly different from 5. 27 to 109 mm، as، it led to the average discharges with different values from 0. 79 to 10. 9 (m3/s). Different rates of discharge have led to different amounts of mean and maximum sediment concentration in these storms; as a result، the suspended sediment concentration ranges from 0. 31 to 4. 54 (gr/lit) and the maximum concentration from 1 to 15. 5 (gr/lit) was obtained. The development of the hysteresis pattern of sediment showed that two events had the pattern of figure 8، and the other storms had a clockwise or anticlockwise pattern. All of the events were fitted well with a sediment rating curve with a high-level determination coefficient. The highest determination coefficient (96%) was for the event on 04/06/2016 and the lowest (57%) was for 04/13/2016. Due to poor estimates in its rising limb، the largest uncertainty (75. 68%) was for the event of 04/13/2016. The relative error of events is less than 50%، except for the event of 04/13/2016. In addition، the sediment rating curve was established for all measured events in the study period، seasonal events and all the data. They were also evaluated based on the determination coefficient and estimation error. According to the results، the relative error of sediment rating curve of the total data is about 32% which is within acceptable range. The measurement of suspended sediment during the winter and spring season showed that the sediment transport rate in spring events is higher than winter events. Establishing the sediment hysteresis patterns showed that most of the measured events had a clockwise and anticlockwise pattern، indicating the dominance of one of the sources of sediment (hillslope or waterway) in each storm. Although، the fitted relationships on the total measured rainfall data have a determination coefficient greater than 0. 5، the separation of the rising and falling limbs of hydrograph and developing sediment rating curve for them improved the determination coefficient but، it was not able to increase the accuracy of the rating curves. The calculation of the estimation error indicates that there is no difference، and in some cases، the error is raised by creating a separate curve for the rising and falling limbs. Although the relative error and the difference between observed and estimated values have increased with the hydrological separation of the rating curve، ، the relative error is still less than 50%. The integration of all data has a rating curve with a lower determination coefficient than the rating curve of the each storm. The rating curve of seasonal data cannot affect the accuracy of rating curves or reduce the relative error. ConclusionDuring the study period، the hydrological regime of Merg River showed a lot of variability. Based on the analyzed samples، the total amount of suspended sediment transported during the study period (4 months) was 15919 tons. The sediment transport process in two measured seasons has almost the same pattern، according to the results، without data classification or separation; the rating curve can provide an acceptable estimate of the suspended sediment load.

As a major component of hydrological، geomorphological، and ecological functioning of rivers، suspended sediment has been identified as the leading direct cause of river instabilities. Therefore، recognizing the variability of rivers is essential to manage water resources and environmental issues. As a result، 5 storms were sampled and analyzed for 4 months in Mereg watershed from 2015 to 2016. Sampling was taken in 2 hours interval and suspended sediment concentration was obtained in the laboratory by filtration method. Estimation of temporal variation of suspended sediment during storm was carried out using sediment rating curves. Different approaches were used to prepare sediment rating، including hysteresis pattern، hydrological and seasonal separation. Measured floods have the peak flows from 1. 38 to 49. 40 m3/s covering a suitable range of low to high peak flows in this river. Moreover، the peak suspended sediment concentration measured in these storms was from 1 to 15. 2 g / l. The average suspended sediment load in the study period was 15، 919 tons. Measurement of suspended sediment during winter and spring showed that the generation and transportation of suspended sediment in spring is higher than winter in the studied watershed. The fitted relationships on all rating curves was valid and had a determine coefficient higher than 0. 5 and estimated error below 50%. The results show that rating curve can provide acceptable estimate of suspended sediment load in the Mereg River without the need for classification or segmentation of rating curve.

Nowadays، dispersal of Persian fallow dear (Dama mesopotamica) is restricted to the forests and woodlands near Dez and Karkheh rivers in southwestern Iran. However، there are no reliable data for the species from these regions in recent years. The present study aims to assess the knowledge of local communities and the importance of the endangered species from the perspective of the human communities. A total of 500 respondents belong to 27 localities (situated in Dezful، Shush and Andimeshk counties) surrounding the study area were interviewed representing different local communities. The respondents were selected randomly to avoid serious bias. The findings showed that more than 56% of the respondents did not even know that the fallow deer is one of the wildlife species in the study area. About 16. 4 percent of people (mainly older people) claimed to have seen the species in natural habitats of Dez and Karkhe protected areas. Moreover، roughly 73 percent of respondents claimed that they have a high willingness to observe the Persian fallow deer in natural habitats of the study area. In this respect، more than half of participants are willing to pay from one to 1. 5 dollars per one to observe deer in the protected areas. The majority of respondents (86. 4%) believed that poaching and habitat destruction are the most important factors threatening the Persian fallow deer in the study area. Gaurenteed sustainable conservation is of high importance for most people (67. 8%). The willingness to pay in order to establish a fund for conservation of Persian fallow deer was estimated between one to seven dollars annually. Raising community awareness of Persian fallow deer biology and its national and global importance، introducing the species as a flagship and using community-based management were recommended as suitable conservation strategies for the Persian fallow deer.

Drought is an inseparable part of climatic fluctuations which caused a lot of damages to different sections annually. Prediction of drought is recognized really useful in management of crisis and reduction of damages due to its the effect on different parts of environment، agricultural sections، natural resources، and wild life. In this research، monthly drought in 12 synoptic stations located in southeast of Iran during 1980-2014 were calculated based on SPI index، Then، using Markov chain method، monthly drought during 2015-2020 were predicted. Based on the results، in the most synoptic stations، normal، moderate dry and severe dry classes of drought have the highest frequency of occurrence. Transition probability matrix showed that، in all synoptic stations، probability of passing from a specific drought condition to the same drought condition and probability of passing from wet conditions to dry conditions were high، but the probability of passing from the dry conditions to wet conditions were low. Results of prediction in different synoptic stations with different of accuracy level (In Iran Shahe، Zabol، Zahedan، Bam and Saravan stations accuracy of prediction were 75%، In Jask، Kerman، Bandar Abbas and Shahr Babak stations accuracy of prediction were 79. 1% and In Bandar Lengeh، Chahbahar and Sirjan stations the accuracy of prediction were 83. 3%، ) showed that، from 2015 to 2020 the normal، moderate and severe drought classes will be the highest probability of drought occurrence. In the study area، the classes of drought (from 1 to 7) are 13. 3، 25. 81، 26. 74، 36. 11، 4. 75، 2. 87 respectively and 0. 69 percent of predicted months will be appropriated.

The socio-economic and environmental consequences of dam construction can be irreversible. The ecosystem of reservoir dams is only examined prior to the construction and the effects of post-construction are not investigated. The main purpose of this qualitative-quantitative research is to estimate the economical-social effects of siazakh dam on the people living in the surrounding area. The research’ s statistical society in quantitative part includes the rural house supervisors (households). In this research، the whole population of 1659، including 350 family، was considered as the case study. By the Cochran formula، 183 of the households were determined، for including the error probability، 200 questionnaires were considered. Factor analysis and SPSS software packages were applied to analyze the data. The statistical society in qualitative part includes the councils (up and down streams)، regional water office and village office (n=41). The mind map diagram technique، content analyzing and GIS software are used in order to analyze data. According to the results of a multi-criteria analysis، the most important positive effects of this project were improving the region's agriculture، providing drinking water، increasing the irrigated area، controlling the flood، increasing land value، improving tourism and the income level. The most significant negative impacts were forced displacement of upstream، the demolition of the main occupations of the upstream (livestock، agriculture)، the creation of false occupations among residents، the destruction of mosques and schools، environmental damage and the cutting of trees and land ownership in upstream of the dam. The research shows the positive effects of the design on the bottom of the dam outweigh its negative effects، while the negative effects of the dam are more than its positive effects in the upstream of the dam. Irrigational cultivation in upstream of dam is decreased to half، while the area under cultivation got to 3. 5 fold in downstream of dam.

As a major threat to biodiversity، habitat fragmentation has increased the local extinction of species due to a function of inbreeding and demographic stochastic factors. Creating or maintaining of corridors among core areas of protected areas decreases the negative impacts of fragmented habitat. This study attempts to prioritize wildlife linkage areas among current protected areas of East Azerbaijan based on the biological importance and threat-opportunity. The prioritization process was done through assembling stakeholders’ opinions. Then، for the highest priority linkage، the focal species that are sensitive to habitat loss and fragmentation were determined based on the ideas of environmental officials. The distribution maps of focal species (Persian leopard، lynx، ibex، wild sheep، and two reptile species) were modeled based on four different modelling techniques: GLM، MARS، MaxEnt، and RF using species presences. Although all of the individual models showed good overall prediction accuracy for Persian leopard and ibex; MaxEnt and RF models indicated a good discrimination ability for wild sheep and only RF for lynx. However، no models had good prediction accuracy for reptiles (Coluber and Vipera; AUC < 0. 7). Models with good discriminate accuracy are finally summarized in an ensemble forecasting approach to estimate the distribution of suitable habitats for the species of interest. To identify potential routes among the protected areas، GIS methods we used (CorridorDesigner package) to identify a biologically best corridor for each focal species to move among these protected blocks. The findings of the present study indicated that making corridors among Marakan-Kiamaky protected areas is the first priority that is followed by identification of corridors between Dizmar-Kiamaky linkage. The delineated corridors for the highest priority linkage were consistent with field observations of Tabriz environmental officials from animal movements gathered for several years.

This is an exploratory and descriptive-analytical research. At first، this study aims to assess the status of the rural entrepreneurship ecosystem. Moreover، it assesses the role of each sub-systems of entrepreneurship ecosystem in the emergence of the conditions. The data were collected from literatures and field surveys (questionnaire and observation). The statistical community of current research includes local experts (such as members of Islamic councils of villages and villagers)، which consists of 3108 people. 341 people were selected as the sample by stratified sampling using Cochran method. In the first step، one-sample T-test in SPSS software is applied to analyze the questionnaires. The findings show that two subsystems، "Equity of Laws and Regulations" and "Entrepreneurship Education in Universities"، are just significant at the level of 0. 05 out of the 12 subsystems. Although these two sub-systems are favorable to the national pattern، but none of them perform well in the global model. As the second step، the role of each subsystems in the occurrence of existing conditions was analyzed using the factor analysis method in the LISREL software. It is observed that sub-ecosystems of "commercial and legal infrastructure" and "government programs for entrepreneurship" have maximum effect (by 91% and 75%)، and the sub-ecosystem of "social norms" has the minimum effect (by 43%) on the performance of rural entrepreneurship ecosystem.