جستجوی مقالات مرتبط با کلیدواژه "استان اردبیل" در نشریات گروه "آبخیزداری، بیابان، محیط زیست، مرتع"

It is impossible to manage water resources in basins without the accurate determination of the peak flood discharge. Therefore, this study was carried out to determine the peak flood discharge for the return period of 10, 25, 50, and 100 years using RSM model in Darrehrood sub-basins with 12900 km2 area in Ardebil Province. Flow data of 16 hydrometric stations were collected in a statistical period of 15 years (2001-2005) and statistical deficiencies in the joint period were eliminated by using regression methods between hydrometric stations. Floods were calculated with different return periods. Also, physiographic characteristics of sub-basins that affect flood rate including area, slope, shape factor, height average, concentration time, and curve number were achieved using ArcGIS10.2 and WMS7.1 (watershed modeling system). The Goodness of Fit (R2) in the return periods of 10, 25, 50, and 100 years was estimated to be 96, 97, 95, and 94%, respectively. This indicates the model's high accuracy to predict the peak discharge in the sub-basins using the basin physiographic parameters. Model performance indexes of the model evaluation for return period of 10, 25, 50 and 100 years were calculated respectively including root mean square error (RMSE)  of 20.99, 7.16, 29.05, 39.55, relative percentage error (ε) of 52.7, 37.7, 45.1, 49.13, mean absolute error (MAE) of 0.52, 0.45, 0.48, 0.55, coefficient of residual mass (CRM) of 0.28, 0.16, 0.56, 0.82, and model efficiency (EF) of 0.74, 0.85, 0.71, 0.75. Cross-validation diagrams showed that RSM model was very suitable for the whole return periods. Paired t-test showed that the difference between predicted and actual values in different return periods was not significant (P< 0.01). The results of this study showed that the RSM has good accuracy for estimating floods in sub-basins of Ardebil Province.

Primary production and the contribution of each of the life forms of rangeland ecosystems are key features. The purpose of this study was to determine the effect of rainfall and temperature changes on the amount of total production and life forms: grasses, forbs and shrubs in Sabalan,s rangelands. For determining of annual primary production (Full bloom stage), different species using one square meter plots by cutting and weighting method in different elevation was harvested in 6 plant types (totally 216 plots). Rainfall classes and temperature parameters were determined using the data of weather stations and derived relevant gradient. Then, climatic parameters for plots was derived by considering the position of sampling plots. Correlation between the life forms and total production with rainfall and temperature parameters were analyzed using multivariate regression method in SPSS16 software. Results show that, climatic parameters with the life forms production of grasses (P<0.01), forbs (P<0.01) and shrubs (P<0.01) have significant relationship, however there was no significant relationship between total production and selected climatic factors. Moreover, results show that the production of grasses are more affected by climatic factors in comparison with the other two life forms and have significant differences in different classes. Additionally, forbs production is more than shrubs affected by the selected climatic factors. The result of study can be used for the calculate primary production in mountain region, supply-demand balance of forage, biomass, health Ecosystem, Ecological balance and carbon sequestration.

By evaluating land use change and land cover, it is possible to plan and land manage to reduce the impact of alteration and degradation of exploitations. The purpose of this study was to evaluate land use changes in Ardabil province between 1987 and 2015 using Thematic Mapper (TM) sensor of Landsat 5 and Operational Land Imager (OLI) sensor of Landsat 8 satellite images. Firstly, the efficiency of the object-based classification method was evaluated using ground control points, error matrix, and comparing total accuracy and kappa coefficients for the resulting maps. Total accuracy and Kappa coefficients for 1987 were 82.3% and 0.70, and 2015 were 94% and 0.90, respectively. Change detection results showed that from 1987 to 2015, rangelands decreased by 4.2%, equivalent to 75039.3 hectares and forests decreased by 0.5%, equivalent to 9393.7 hectares compared to the total province area and irrigation farming increased by 3.1%, equivalent to 55276.8 hectares, residential areas increased by 0.8%, equivalent to 14989.7 hectares and dry farming increased by 0.7%, equivalent to 12632.4 hectares compared to the total province area. The most significant changes that occurred from 1987 to 2015 were the conversion of rangelands to dry farming with 13.8%, equivalent to 141794.2 hectares and irrigation farming lands with 4.8%, equivalent to 49836.9 hectares of rangelands, irrigation farming to dry farming with 7.7%, equivalent to 11464.8 hectares and forests to rangelands with 6.1%, equivalent to 1059.9 hectares which indicate that the requirement of a serious revision of the management policies.

A quantitative method is presented to evaluate the ability of plants for rill and gully erosion control in the Moghan region in the province of Ardabil. This research was carried out during a five-year period (2016-2020). Five indicators, namely, stem density (SD), topsoil erosion-reducing potential of plant roots during the concentrated flow erosion (RSD), sediment obstruction potential (SOP), index of plant stiffness (MEI), and root cohesion (Cr) were calculated for 20 native plants of the region (SD=1.411×10-4 – 0.28, RSD=6.68×10-24 – 10.1076, SOP=8.275×10-5 – 0.696, MEI=1.69×10-6 – 27.134 N, Cr=5.432×10-4 – 34.626 Pa). Tamarix ramosissima Ledeb., Salsola dendroides Pall.,Artemisia fragrans Willd., Stipa arabica Trin. & Rupr. var. arabica, Alhagi camelorum Fisch., Verbascum stachydifome Boiss. & Buhse., Festuca ovina L., and Melica altissima L. are very appropriate species for controlling rill and gully erosion. Festuca ovina L., Stipa arabica Trin. & Rupr. var. arabica and Melica altissima L.have a distinct potential to obstruct sediment inflow into channels at the gully outlets. As each species has a particular ability in one or more of the indices, combined planting of selected plant species may be more effective in erosion control. The results of this study may be used in adjacent regions and under similar cold-semiarid and cold-arid environments.

Ethnobotany is a science that studies the relation between a particular ethnic or culture groups in a particular area with the native plants. This research studies the ethnobotany and indigenous knowledge on medicinal and food plants of Darwishchai Sarein local poeple. The ethnobotanical knowledge of residents of 5 villages namely Verniab, AliDashi, Vargeh Saran, Ujour and Alvares was investigated. Required information on the use of medicinal and food plants was collected using open-ended questionnaires. knowledgeable persons in a discourse-based manner were selected for filling the forms. Results showed the 57 medicinal and food species in the study area are used by local communities. These plants belonged to 21 plant families. The most species belonged to Asteraceae, Lamiaceae, Rosaceae, Fabaceae and Apiaceae, respectively with 12, 9, 7, 5 and 3 species. The results also showed that from the 57 species, 27 are categorized as medicinal  and 30 are put in both medicinal and food caregories. The most and least used organs were leaf (41%) and flag (1%), respectively. Residents in the watershed are using the herbs as brewed for 68.42 percent of the plants used. Usage of food plants is mostly in soups, 19.3%. According to the results, most medicinal plants are used to prevent the colds and coughs (35%). Resuts of the research could be used for medicinal and food plants management in the region. In addition it shows that the knowledge of elderlies ahould be respected and used.

The aim of this study was to investigate the ecological factors affecting the distribution of four Trifolium repense, T. pratense, T. micranthum and T. compestre species in Fandoghlou rangelands of Namin county in Ardabil province. Sampling was conducted in six sites with the presence and absence of species at random. Topographic, climatic, land cover and density of selected species were recorded. From each transect, soil samples were taken from the root activity depth the parameters of acidity, electrical conductivity, soil texture, lime, calcium, magnesium, sodium, phosphorus, potassium, organic matter, propagated clay and soil moisture content were measured. A significant difference was observed between the environmental factors on presence and absence of studied species by one-way ANOVA and comparison of the mean of the measured characteristics with Duncan test. To determine the importance of the variables in different sites and the species distribution, Linear Discriminant Analysis (LDA) was used. Results showed that there were significant different between the factors of electrical conductivity, slope, sodium, organic matter (p<0.01) and factors of elevation, rainfall, temperature, acidity, potassium, phosphorus, clay, silt, dispersible clay and bare soil (p<0.05) in sites of presence and absence of species. According to the results of the LDA, four functions were justified as 78.50, 15.60, 5.80, 0.10 %, respectively and totally 100% of the total variance of the data were justified. Four factors (temperature, electrical conductivity, potassium and clay) were identified as the most important factors in the distribution of the T. repense, T. pratense, T. micranthum, T. compestre species.

The aim of this study was to assess the rangeland health of North Sabalan in three-elevation classes (less than 1500, 1500 to 2100, and 2100 to 2700 meters), which were the representative of rural, rural-nomad, and nomad rangelands, using the landscape function analysis (LFA) in Ardabil province. For sampling, three 50-meter transects were established in each elevation class according to the uniformity of the habitat and distribution of patches. Using the LFA framework, three characteristics including stability, infiltration and nutrient cycling of soil surface were determined using 11 indicators. Statistical analysis of data was conducted using the LFA method and instructions of Tongway and Hindley in Excel software. The soil stability index for vegetation life forms in the elevation class of 2100 to 2700 m was more than that of the other two elevation classes, with significant difference (P>0.05); however, there was no significant difference between the first and the second class .Comparison of the infiltration and nutrient cycling indices for vegetation life forms in the elevation class of 2100 to 2700 m was also more than those of the other two elevation classes with significant differences (P<0.05). The stability index in the third elevation class (72.35) and in the second class (48.75), the infiltration index in the third elevation class (73.31) and in the first elevation class (15.99), and the nutrient cycling index in the third elevation class (78.75) and in the first elevation class (10.12) had the highest and least values, respectively. Overall, the health condition of the third elevation class was better than the other two classes. By examining the functional characteristics of ecological patches, we can identify the vegetation indicators affecting rangeland health, and then conduct proper management to protect that ecosystem.

Knowing the ecological characteristics of plants and consequently changes in forage production during the season of grazing for grazing management is essential. Therefore, understanding the annual and monthly production of different rangeland types is essential for efficient and effective forage management. Consequently, relationships between forage production and climatic variables should be considered. For this purpose, the annual forage production was measured in the research exclosure of Arshaq Site rangelands in Ardabil province during 2007-2010 by clipping and weighing method. The monthly rainfall in this period was calculated using Mashkin-Shahr synoptic station data and then the amount of cumulative rainfall in winter and spring of each year was calculated. Afterward, the relationship between production and winter and spring rainfall as well as rainfall of different months of winter and spring was studied separately. Statistical analysis was performed using SAS software. According to the results, the average forage production during four years was calculated of which 28.95% belonged to Artemisia fragrans, 26.35% to Kochia prostrate, 19.55% to Stipa hohenackeriana, 4.77% to Astragalus brachyodonuts and 20.38% to the other species. Analysis of variance showed that the production of species among years were significant (P<0.01). In terms of stability (interactions of year × month), Artemisia fragrans and Kochia prostrata were stable, with a high yield; however, Astragalus brachyodonuts and Stipa hohenackeriana were stable with a low yield.

Considering the harmful effects of drought, it is important to recognize and evaluate the frequency of low flow. Analysis of low flow is a method for estimating hydrologic drought. In this study, 33 hydrometric stations used in Ardebil province for hydrological droughts survey. The purpose of this study was to analyze the intensity of the low flow (hydrologic drought) using the gamma distribution of two parameter and the relationship between low flow with the percentage of occurrences and the return periods and plotting the curves in different basins have discharge statistics in Ardebil province. The results of this study showed, with increasing the return period, the intensity of the low flow decreases and the severity of drought increases. The discharge values at the two-year return period change from 0.01 to 0.95 at the stations of the booran and atashghah respectively. In the return period of 100 years, the low flow rate at Bouran and Nair stations are the lowest (0) and maximum (0.21) of the value respectively. Since the occurrence of drought causes significant damage to the economic, social, political and environmental sectors of the country, consideration of this phenomenon is necessary in order to achieve the goals of sustainable development.

Preference evaluation of four species of perennial forage grasses including Alopecurus textilis L., Festuca ovina L. and F. sulcata L. and Agropyron trichophorum. In order to use for improvement and restoration of rangelands, seeds of species were collected from of Ardebil province. After seed germination test and preparing of seed bed. This eyperiment was done based on Randomized completely block design with 3 replicates in dryland conditions from 2010 -2014 in Ardabil station. After plants establishment and end of growing, crown cover Total height, seedling vigority, forage and seed production. Analysis variance of data was done using SAS software and the mean comparison with Duncan method at 5% level. The results showed that, the species in term of studied traits, had significant difference exept survival, The highest height, crown cover and forage production. Be longes to Agropyron trichophorum, The highest seedling vigority belodes to Agropyron trichophorum and Festuca sulcata finally, Therefore these con be used in improvement and developmend procces of pasture in arid and semi arid region.

The purpose of this study was to investigate the relationship between rangeland aboveground production based on total aboveground production and life forms of grasses, forbs, and shrubs with 25-year temperature and precipitation data, the year before sampling, and the year of sampling in Hir and Neur rangelands in Ardabil province. To determine the aboveground production, the amount of production was estimated using the harvesting method in one square meter plots (totally 330 plots) in three elevation classes under the range of 1446-2750 meters. Temperature and precipitation were calculated for each plot. Aboveground production maps were prepared in a GIS environment using extracted regression equations. The results showed that over the years, precipitation decreased and temperature increased, and aboveground production also decreased in relation to those climatic factors. Moreover, there is a significant relationship (P<0.01) between the aboveground production of life forms and total aboveground production with climatic factors, and aboveground production of grasses and total have a direct relationship with precipitation; however the maximum aboveground production of forbs was recorded in the middle ranges and maximum aboveground production of shrubs was recorded in the higher ranges of annual precipitation. Grasses and total aboveground production had an inverse relationship with temperature, and the maximum aboveground production of forbs and shrubs was recorded in the middle and lower ranges of annual temperatures, respectively. According to the accuracy of derived regression equations, the maps prepared by climatic data of 1394 and 1395 were better than 25-year climate data. The results of this study can be used for the supply-demand balance of aboveground production, biomass accounts, and ecosystem carbon balance indicator that is potentially an important tool for sustainable development.

     The aim of this study was to investigate the effect of environmental factors on Prangos ferulacea Lindl. and P. pabularia Lindl. distribution in the rangelands of Ardabil province. Seven habitats of Prangos genus were identified, so that P. ferulacea was distributed in three habitats and P. papularia in two habitats. In each habitat, sampling sites were identified and in each site three transects of 100m  were established, and the density of the study species were recorded in ten plots of 4m2. Soil samples were taken from the depth of 0 to 30 cm at the start, middle and end of each transect. In the vicinity of each habitat, sampling was done in the same way. In sampling plots, elevation, slope, aspect, and soil characteristics such as organic matter, N, P, K, pH, EC, and texture were measured. To investigate the effects of environmental factors on the presence or absence of the study species and to compare the characteristics of the variables measured one-way ANOVA and Tukey test were used.Discriminant analysis was used to determine the degree of importance of the environmental variables measured in the distribution of the study species. Results showed that P. pabularia was distributed in the habitats with the high content of P, clay, EC, rainfall, sand, slope and pH; while P. ferulacea was distributed where the elevation was high but rainfall and the content of K were low. According to the results of discriminant analysis, variables such as EC, organic matter, K, elevation, slope, aspect, silt, clay, rainfall, and temperature were effective in discrimination of sites and species distribution. The results of the present study could be useful to propose the species for range management, improvement and reclamation.

Flood as a rapid and destructive event causes great human and economic losses in Iran and around the world, annually. This study aimed to assess the temporal trend and spatial changes of flood coefficient of Ardabil Province rivers using daily discharge of 22 hydrometric stations over a 22-year (1991 to 2011) of recorded data. The flood coefficient amount was calculated after subtracting the defined base flow resulted from the local minima technique. The non-parametric Mann-Kendall test was used to detect the temporal tend in the time series values. The recorded data length were divided into 5-year periods and the variations of changes of flow rate in different periods were analyzed. The significant differences were determined by using the Kruskal-Wallis statistical test. The results showed that changes of flood coefficient was significant (p<0.05) between different periods. The spatial changes of flood coefficient variation coefficient showed a similar spatial pattern in different studied periods and the highest variability were defined at North-East and West parts of the study area. The highest rate of flood coefficient was observed in Akbardavood station with the value of 0.8 in the fourth sub-period. According to the results of trend analysis, there is an increasing significant temporal trend in 6 stations, and one station had decreasing trend, while other stations had increasing trend with no statistical significance. The increasing trend of flood coefficient can be related to rainfall variations and land use change along with intensified use of extensive rangelands areas which increases the potential runoff and surface flow resulting increase in the flood coefficient in the studied statistics.

Vegetation changes rangelands, that usually occurs in the composition and structure of vegetation over time. On the other hand, human factors, especially rangeland management, play an important role in maintaining stability or degradation. The purpose of this study was to investigate the dynamics of vegetation under the local management was carried out from 2008 to 1391. To do this, main vegetative stepic regions of the factors related to crown cover, density and abundance were determined by multi-year and group species, during the three transects 500 m in 30 plots (5/1 × 5/1 meter) as well as soil moisture and organic carbon were measured. The results showed that a four-year period, In the vegetation of perennial grasses, such as Festuca ovina, Alopecurus aucheri, Bromus tomentellus and Koeleria caucasica their variation was due to rainfall in the growing season, there was no significant difference between study years. In shrub cover such as Onobrychis cornuta and Astragalus aureus were significantly different between years of study due to annual precipitation fluctuations and soil moisture moisture content. In perennial forbodies, such as Scorzonera radicosa, Polygonum alpetre and Veronica orientalis were affected by precipitation seasonal and there was a significant difference between years. Changes in soil organic carbon and the process is slow. Therefore the results of the survey year to year changes in vegetation,climate changes and soil moisture also how the soil erosion condition can as an appropriate guide for the correct current methods used for management of rangeland ecosystems.