Reza Siahmansour; Nadia Kamali
Abstract
Fire is the fastest cause of extensive changes in vegetation. The purpose of this research is to examine some of these changes. SO, after determining key area of four 200m transects and a distance of 100 m from each other, 10 plots 1m2 fixed on each of them, formed sample units in each field. This site ...
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Fire is the fastest cause of extensive changes in vegetation. The purpose of this research is to examine some of these changes. SO, after determining key area of four 200m transects and a distance of 100 m from each other, 10 plots 1m2 fixed on each of them, formed sample units in each field. This site burned in 2011 and 2013, in 2018 and 2019, random-systematic statistical collection was carried out in it. Results showed, in fire treatment the dominance of production and cover is with invader plants. Production of this class 52.05 and 209.1gr/m2 has been preserved in burnt area compared to control. Also, annual grasses have significant average difference in terms of production and canopy compared to other species. However, annual forbs had 1.5 times more production in fire than control. Although the amount of production in burnt area is more than control but, it doesnt mean an increase in the amount of allowable forage. The plant type in the burned fundamental change compared to the control by replacing annuals instead of permanent species. As result production, density and canopy cover of different palatability classes and growing forms also found fundamental changes. Fire is cause of changing in rangeland condition from excellent to average, the trend is positive in both treatments. The management of burnt fields is very specialized, and according to the existing conditions, it is strongly not recommended to create a fire either intentionally or accidentally in this area is vegetation zone form of Iran.
Haniyeh Rezaie; Sharareh Pourebrahim; Mohammad Karimadini
Abstract
Due to the ability of land use/cover changes monitoring and predicting to understand the performance and health of ecosystems, this purposed method can provide possibility of sustainable land use management and planning, especially in the rapid change areas without master/land use plan. The present study ...
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Due to the ability of land use/cover changes monitoring and predicting to understand the performance and health of ecosystems, this purposed method can provide possibility of sustainable land use management and planning, especially in the rapid change areas without master/land use plan. The present study has aimed to introduce Google Earth Engine to evaluate the pattern of land changes during 2006- 2021 and predict the pattern of future changes by using an integrated model based on Cellular automata and Markov chain using Google Earth Engine system. Three Landsat images (2006, 2014 and 2021) were classified using the support vector machine classifier method, and were simulated using the integrated model of cellular automata and Markov chain. In order to evaluate the accuracy of the predicted map of 2021, the classified map of the same year was applied. The accuracy of classified and simulated maps was Kno=0.812, Klocation=0.816, Kstandard=0.786 respectively. Evaluation of the land use/cover changes shows that between 2006 and 2035, the buildup areas will reach from 4839.01 hectares to 7199.76 hectares with increasing of 2360.75 hectares. These results indicate the necessity of land use planning principles. Simulation models can reduce the risks of long-term decision-making in land use management and Google Earth Engine can reduce the time and cost for classification and satellite image processing.
Mehrnoosh Ghadimi; Nadia Hajihasani; Arash Malekian; Ebrahim Moghimi
Abstract
Sub-basin prioritization and morphometric characterization analysis is one of the efficient and low-cost tools in identifying flood hazards. The purpose of this study is to Prioritize the flood potential of watershed sub-basins using morphometric parameters, combines of model statistical correlation ...
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Sub-basin prioritization and morphometric characterization analysis is one of the efficient and low-cost tools in identifying flood hazards. The purpose of this study is to Prioritize the flood potential of watershed sub-basins using morphometric parameters, combines of model statistical correlation and multi-criteria decision making systems. 17 morphometric parameters including slope, elevation, curvature, Ruggedness number, elongation coefficient, circularity coefficient, equivalent rectangle, drainage density, Stream Length, coefficient Permeability, concentration time, duration-intensity of precipitation, land cover, land use, geology, Bifurcation Raito, Length of overland flow were studied. the relationship between parameters and weighting results showed that in AHP in climate and Morphotopography (slope, height, curvature, number of roughness) was one of the important factors of flooding. In ANP method, slope and concentration time (0.11) duration-intensity of rainfall (0.12) has become one of the most important factors in flooding. Ranking in AHP method showed that the sub-basins of Imamzadeh Davood, Taloon and Doab to Respectively with the highest score (0.74, 0.50, 0.38) and in the ANP method with the highest score (0.97, 0.51, 0.48) in the sub-basins of Imamzadeh Davood, Talun and Sangan They are located in the first to third places and the intensity of flooding in them is higher than other sub-basins. According to the results, relationship between the equivalent rectangle (width) and the circularity showed a strong correlation between these two variables.
Milad Momtazi Burojeni; Fereydoon Sarmadian
Abstract
Soil resource management is essential to maintain community production and the environment. Soil is usually used to produce agricultural products and livestock fodder. As a result, the mapping of high-resolution digital maps is crucial for the distribution of soil and soil properties and land management. ...
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Soil resource management is essential to maintain community production and the environment. Soil is usually used to produce agricultural products and livestock fodder. As a result, the mapping of high-resolution digital maps is crucial for the distribution of soil and soil properties and land management. The decision tree model is a widely used method for predicting soil class in digital soil mapping studies. This study aimed to provide a digital soil mapping in four levels of taxonomy using a decision tree with Boost-reinforced C5.0 algorithm using satellite data and digital Elevation Model and geological maps as environmental variables in 41,000 hectares of Abyek Area. This area was identified using randomized gridding of the geographic location of 128 soil profiles and then described, sampled, and classified. In this research, using the principal component analysis method on environmental variables, 20 environmental variables were selected as the representative of stacking factors for modeling. Multiresolution Valley Flatness Index is the most important environmental variable that was selected as input for the model. The results of the overall accuracy of the integrated model for predicting taxonomic levels of the Order, Suborder, great group, and subgroup were shown to be 89%, 85%, 58%, and 58%, respectively. The study also examined the effect of the boosting technique on the tree model, which showed that all taxonomic levels were better predicted by using the boost model than when no boosting was used and boosting resulted in an increase in overall accuracy and kappa coefficient It turned out.
Seyedeh khadijeh Mahdavi; Maedeh Yousefian; Mohammad Reza Shahraki; Reza Ourmaz
Abstract
The need to decentralize government at the local level can guarantee the participation of rangeland beneficiaries. So the present study has analyzed the perceptions of rangeland beneficiaries of participatory governance in Incheh salt marshes in Golestan province. The research is descriptive-survey and ...
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The need to decentralize government at the local level can guarantee the participation of rangeland beneficiaries. So the present study has analyzed the perceptions of rangeland beneficiaries of participatory governance in Incheh salt marshes in Golestan province. The research is descriptive-survey and statistical population consists of 120 beneficiaries, 92 of whom were selected as the sample size. The questionnaire was the main tool of data collection and participatory governance was evaluated with 32 items in the form of 9 components. The validity of the questionnaire was obtained by experts and its reliability was obtained by calculating the Cronbach's alpha coefficient. Statistical calculations based on SPSS25. The results showed that the "implementation" and "conflict resolution" with the highest and "planning" and "coordination" with the lowest were at the highest and lowest levels of governance index, respectively. On the other hand, according to the average obtained in the participatory governance index (3.58), the tendency of governance is toward community-oriented management. There was a positive and significant relationship between the variables of livestock history, number of livestock, age, annual income and the tendency to rule in the rangeland. According to the obtained results and also the importance of rangeland governance, the involvement of beneficiaries in the preparation of rangeland plans and projects and the use of their rich native knowledge, holding classes in line with the cooperative activities of beneficiaries with the Department of Natural Resources and Watershed Management as a representative of the government are the most important suggestions of this research.
ِAli Tavili; S. Motahareh Hosseini; Mohammad Jafari; Ali Golkarian
Abstract
MAXENT model was used to evaluate the probability of Dorema ammoniacum development in rangelands of Southern Khorassan. Presence data of D. ammoniacum was recorded based on field survey and GPS application. Nine environmental information layers were used to model potential habitat of the understudy species. ...
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MAXENT model was used to evaluate the probability of Dorema ammoniacum development in rangelands of Southern Khorassan. Presence data of D. ammoniacum was recorded based on field survey and GPS application. Nine environmental information layers were used to model potential habitat of the understudy species. Relationship between species presence and environmental parameters was determined using maximum entropy. Map of species distribution was achieved. Results showed that the probability of D. ammoniacum is higher in regions with the following environmental characteristics; elevation of 1017-1933 m, average temperature of 13.96 to 15.17 ºC, average precipitation of 112- 131 mm, slope of 0-14% and LST range between -4 to 10 ºC. An AUC of 92 demonstrated that MAXENT is a suitable model for prediction of D. ammoniacum distribution and potential habitat.
Bahman Kavari; Yahya Esmaeilpour; Ali Akbar Mousavi; Ommolbanin Bazrafshan; Arashk Holisaz
Abstract
The main source of water in the Arsanjan plain is underground water, which has been exploited in the past with Aqueduct and now with numerous wells. For knowing about the quality conditions of these sources; multivariate statistical analysis and interpolation methods were used in three years with different ...
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The main source of water in the Arsanjan plain is underground water, which has been exploited in the past with Aqueduct and now with numerous wells. For knowing about the quality conditions of these sources; multivariate statistical analysis and interpolation methods were used in three years with different rainfall. Factor analysis determined the key indicators of underground water quality and mapping was done with interpolation methods. The maps were classified using the Jenks optimization method of classification and the area of each class in each year calculated. Based on the results of factor analysis, EC, TH and Sodium concentration were selected with factor loadings of 0.843, 0.889 and 0.991, respectively. The RBF interpolation method for the sodium parameter was suitable in all three years of the study. For parameters of EC and TH, RBF-MQ method and LIP method had the least error in 2014 and 2015. Mapping spatial changes of the three mentioned parameters showed that in 2015, when the rainfall was lower than the average, the area of the regions with low values decreased. Due to the quantity and quality of its changes, sodium concentration parameter has a good potential to be used as an indicator of changes of the quality of underground water in response to climatic or management factors. In general, it is suggested that in assessment of the groundwater quality of Arsanjan Plain, the proximity factor to Bakhtegan Salt Lake, in addition to factors related to climate and watershed, should be considered.
Morteza Shahnori; Maryam Azarakhshi; Mehdi Bashiri; Hasan Rezaee Moghadam
Abstract
Evapotranspiration as an important component of the hydrological cycle plays a major role in the study of water balance in watersheds. The purpose of present research was to investigate the response of Atriplex canescens to different levels of water salinity and the effect of irrigation water salinity ...
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Evapotranspiration as an important component of the hydrological cycle plays a major role in the study of water balance in watersheds. The purpose of present research was to investigate the response of Atriplex canescens to different levels of water salinity and the effect of irrigation water salinity levels on actual evapotranspiration under lysimetric conditions. For this purpose, four treatments inclusive 0, 25%, 50%, and 75% of maximum salinity tolerance of Atriplex canescens with 3 replications were considered which equal as zero, 19.6, 39.2, and 58.8 ds/m of Sodium Chloride. The lysimeters were placed in greenhouse and two Atriplex canescen shrubs were cultivated in per lysimeter. 5 liters of water with mentioned salinities were added to each lysimeter every two weeks. During the vegetative period of the plant, from 6th March to 15th of August of 2019, the measurement of evapotranspiration was done by weighing the lysimeters at intervals of one week. After the end of the experiments, the weights of shoots and roots of each treatment were measured in wet and dry situation. The results showed that evapotranspiration decreased from 3.94 to 2.84 liters with increasing salinity of irrigation water from zero to 58.8 ds/m, and there was a significant difference between control and 58.8 ds/m salinity treatments at 5% level. By increasing salinity from 0 to 19.6, 39.2 and 58.8 ds/m, the dry weight of shoots increased compared to control treatment 20.13%, 41.87% and 11.55% respectively. Therefore, with the conditions of the present researchو Atriplex Canescens was produced the highest amount of dry shoot in 39.2 ds/m salinity.
Moselm Rostampour
Abstract
This study compared of univariate outlier detection methods among vegetation data in a study of the effect of grazing intensity in the rangelands of arid regions. For this purpose, after measuring the vegetation cover in the rangeland and before the statistical analysis, the presence of outlier data ...
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This study compared of univariate outlier detection methods among vegetation data in a study of the effect of grazing intensity in the rangelands of arid regions. For this purpose, after measuring the vegetation cover in the rangeland and before the statistical analysis, the presence of outlier data was examined as the assumption of parametric comparison tests. In this study, eight methods including the boxplot and IQR (Tukey method), standard deviation of the mean (three-sigma rule), median absolute deviation (Hampel method), trimmed mean, 1st percentile and 99th percentile, The Chi Square test (χ²), the Grubbs Test (ESD) and the Rosner test (generalized ESD) were used. The results showed that the vegetation cover of rangelands with light and moderate grazing intensity was not normally distributed (Shapiro-Wilk test: p≤0.05). Even deletion of outliers did not lead to a normal distribution, but it resulted in the homogeneity of variances (Levene's test: p≥0.05). The modified Z-score and the Grubbs and Rosner tests (p≥0.05) did not identify outliers from the vegetation cover data. Among the methods evaluated, the boxplot and MAD method, which are not dependent on the mean, are more suitable for the vegetation cover. Therefore, before performing any comparison test, a combination of visual and statistical methods is recommended to evaluate the presence of outliers.
Fariba Esmaeili; Mehdi Vatakhah; Vahid Moosavi
Abstract
The current study evaluates the effectiveness of Clark's Instantaneous Unit Hydrograph (IUH) model from the accuracy of different Digital Elevation Models (DEMs) including TOPO, ALOS PALSAR, ASTER, SRTM and GTOPO in the Amameh watershed. For this purpose, at first, 34 rainfall-runoff events were selected. ...
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The current study evaluates the effectiveness of Clark's Instantaneous Unit Hydrograph (IUH) model from the accuracy of different Digital Elevation Models (DEMs) including TOPO, ALOS PALSAR, ASTER, SRTM and GTOPO in the Amameh watershed. For this purpose, at first, 34 rainfall-runoff events were selected. Also, the drainage network, the length and slope of the main river in each of the five DEMs were calculated using Arc GIS software. Then, the 30-minute isochrone map of the watershed was extracted using the spatial distribution of travel time method. Finally, the dimensions of Clark's IUH were estimated for each rainfall-runoff event and DEM. The results showed that with the decrease in the length of the main river following the decrease in DEM spatial resolution, the number of isochrone has been decreased, so that TOPO DEM has estimated the largest number of isochrone with the largest estimate of the length of the main river. The average percentage of the Relative Error (RE) of the runoff volume was estimated as 22.92, 26.68, 27.7, 32.15 and 35.66% respectively for the aforementioned DEMs. Regarding peak flow estimation, there is a significant difference between the average RE values in different DEMs. So that the lowest average value of the RE is related to TOPO DEM with a value of 31.7%. On the other hand, the Root Mean Square Error (RMSE) values also show that TOPO DEM has the lowest RMSE value (3.39 m3) compared to other DEMs. In general, it can be said that the use of TOPO DEM in Clark's IUH model will provide acceptable results.
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