TAYYEBEH MESBAHZADEH; ali azareh; Elham Rafiiei sardooi; Fateme FarzanePei
Abstract
Soil moisture, as the soil hydrologic parameters, can be affected by soil temperature and controls various hydrological processes. Given the importance of this issue, in this study, the efficiency of artificial neural network was studied to simulate soil temperature at 5- 100 cm depth. Recorded meteorological ...
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Soil moisture, as the soil hydrologic parameters, can be affected by soil temperature and controls various hydrological processes. Given the importance of this issue, in this study, the efficiency of artificial neural network was studied to simulate soil temperature at 5- 100 cm depth. Recorded meteorological parameters in the Isfahan synoptic station were used to simulate the soil temperature at different depths. The structure of the neural network was formed with an input layer, a hidden layer and an output layer and network training was done by Levenberg–Marquardt algorithm. Also test and error was done to determine a number of suitable neurons in hidden layer. The results showed that error in both neural network and ANFIS model increases with depth increase that can be due to the weak correlation between soil temperature changes in the lower layers and climatic parameters.
Hossein Norouzi; Asghar Asghari Moghaddam
Abstract
the existence of about 6,000 wells in the plain and the extraction of groundwater resources has led to a sharp decrease in the water table and consequently, an increase in the salinity of the aquifer. For this purpose, 27 samples of Malekan water resources were collected and hydrochemical properties ...
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the existence of about 6,000 wells in the plain and the extraction of groundwater resources has led to a sharp decrease in the water table and consequently, an increase in the salinity of the aquifer. For this purpose, 27 samples of Malekan water resources were collected and hydrochemical properties were analyzed. The results of the analysis were compared with the lake water sample with respect to the hydrochemical characteristics of the main elements. Salinity increasing and saltwater intrusion into the aquifer was investigated using geophysical methods, geochemical diagrams, as well as various ion ratios. The results showed that salinity increases in the aquifers around Urmia Lake is related to the low slope at the end of the plains and its ultra-fine grain sediments, which, as a result, when groundwater flow collide with such sediments, their movement slow down and water raised to the surface via capillary action. Finally shallow groundwater cause to intense evaporation and increasing groundwater salinity. Moreover, In addition, the distribution of surface currents in the ends of the plain leads to evaporation and the formation of salt crops, and high exploitation leads to the gradual flow of water to upstream of the aquifer. The presence of the salty sludge from ancient lakes beneath the alluvial and salts formations with high exploitation and decreasing of groundwater levels leads to upconing in the lower layers of clay formations and reaching the saltwater to the wells.
sajad neisi; bizhan khalili moghadam; amin zorati pour
Abstract
Gully erosion is one of the aprogressive forms of soil degradation in ranges and agricultural lands which is a warning sign of land degradation and progressive erosion. Monitoring effective factors of gully length development over time is a necessity for sustainable development in watersheds. In this ...
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Gully erosion is one of the aprogressive forms of soil degradation in ranges and agricultural lands which is a warning sign of land degradation and progressive erosion. Monitoring effective factors of gully length development over time is a necessity for sustainable development in watersheds. In this research, the advancement of 30 headcuts were assessed through digital interpretation of multi-temporal aerial photos, photometric methods, field observations and GIS data analysis over two periods of 1964-1993 and 1993-2013, and its contribution to sediment suspended and bed load, using sediment balance model which was carried out on DarbKhazine basin. Moreover, the stepwise regression analysis procedure was applied to extract the effective factors on gully head advancement (such as topography, physio-chemical soil attributes and morphology of gully). The results indicated that the mean of gully head advancement over the periods of 1964-1993, 1993-2013 were measured 0.37, 0.65, respectively which implies on average, 77percent have increased. Further, regression analysis revealed by 9 main factors and R 95%, as themodel indicated among main factors, the Na, EC and organic matter factors with R2 , 0.83 and R , 0.91 leave the most effect on gully head advancement. The gully sediment balance showed that two-thirds and one-third of sediment discharge are formally suspended load and bed load, respectively. This topic is useful as a suitable criterion to distinguish active gullies in order to prioritize conservation activities.
Ali Yazdanpanahi; Khaled Ahmadaali; Salman Zare; Toraj Shabani Omran
Abstract
This study looked into the effect of different natural and urban waste compost biochar levels (0, 1, 3, and 5%), incorporated in sandy soil (total of 16 soil types), on the saturated hydraulic conductivity coefficient. For this purpose, the hydraulic conductivity of all 16 soil samples was determined ...
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This study looked into the effect of different natural and urban waste compost biochar levels (0, 1, 3, and 5%), incorporated in sandy soil (total of 16 soil types), on the saturated hydraulic conductivity coefficient. For this purpose, the hydraulic conductivity of all 16 soil samples was determined using the constant head method. Then, for all soils, parameters of Van-Genuchten-Mualem (VGM) model for soil moisture characteristic curve (SMC) were determined by RETC and ROSETTA software and inverse modeling based on easily accessible parameters such as soil particle size percentage (sand, silt, and clay), bulk density, field capacity, and permanent wilting point. These parameters were soil residual water content (θr), soil saturated water content (θs), α, m, n and Ks. Results indicated that increasing biochars results in an increase in the Ks for all soils. Soil No. 11 (soil + 5% natural biochar + 1% urban waste compost biochar) and then soil No. 13 with 64 and 61% reduction, respectively, had the highest reduction percentage in Ks. The maximum and minimum value of Ks were 707.9 and 254.8 cmd-1 which were related to soil No. 1 and 11, respectively. All doses of biochars had a significant effect on all VGM parameters (P<0.01) and increasing biochars resulted in an increase in θr, n, and m and decrease in θs and α.
Ali Yazdanpanahi; Khaled Ahmadaali; Salman Zare
Abstract
Biochar, as a soil reclamation material, has received attention by researchers during recent decades. In this study, a greenhouse experiment was conducted in a randomized complete block design (RCBD) in factorial arrangement in order to investigate the effect of natural and municipal waste compost biochars ...
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Biochar, as a soil reclamation material, has received attention by researchers during recent decades. In this study, a greenhouse experiment was conducted in a randomized complete block design (RCBD) in factorial arrangement in order to investigate the effect of natural and municipal waste compost biochars on the chemical properties of sandy soils from Kashan's sand dunes. The experimental treatments consisted of natural and municipal waste compost biochar each with four levels (0, 1, 3 and 5%) with the total of 16 culture media. Chemical analysis was performed for soil, biochar, and for 16 culture media resulting from these combinations in three replications. The results of analysis of variance and comparing means of measured characteristics (EC, pH, Ca, Mg, K, and OM) showed that these characteristics were significantly affected by the different levels of natural biochars. Soil pH decreased in some treatments and treatment No 5 had the most pH reduction. Both biochar treatments increased soil EC, pH, Ca, Mg, and OM by 5.5, 3.9, 2.4, 1.9, and 3.7 times, respectively. In general, treatment No 13 (soil + 5% natural biochar + 5% municipal waste compost biochar) had the highest influence on soil characteristics. As a practical application, the use of studied biochars as sources of Ca, Mg, K, and OM can be considered in soil reclamation projects and fertilizer management.
zahra nikbakht; Mohammad Farzam; Mohammad Khajeh Hosseini; Hamid Ejtehadi
Abstract
The study of soil seed bank provides useful information on management and restoration of natural ecosystems. In the arid environments, some perennial plants may cause accumulation of seed bank under their canopy, thereby protecting them against the livestock herbivory and the other environmental factors. ...
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The study of soil seed bank provides useful information on management and restoration of natural ecosystems. In the arid environments, some perennial plants may cause accumulation of seed bank under their canopy, thereby protecting them against the livestock herbivory and the other environmental factors. This study was conducted with objective to investigate effect of perennial plants on density of soil seeds bank, under different utilization levels in an arid steppe rangeland. Three adjacent rangeland sites were selected, i.e. intense grazing, moderate grazing and no grazing (enclosure), and three line transects were randomly located within each site. Along each transect, soil samples were taken from the depth of 0–5 cm under the canopy of perennial plants or the nearby open space. The seed bank density was determined by the technique for separating seeds from the soil. The density of soil seed bank in the moderate and intensive grazing sites was higher than in the enclosure. In addition, seed bank density under the canopy of perennial plants was significantly higher than in open space, in each of three sites. The highest and lowest seed bank density were observed under the canopy of Rosa persica and Astragalus heratensis, respectively. Generally, the results of this research indicate the key role of perennial range plants in protecting soil seed bank of other plants, under the circumstances of high livestock grazing in the arid steppe rangelands.
hamed nozari; safar marofi; mahnaz edirsh
Abstract
According to the annual damages of flood in Dez river catchment and the lack of information about water quantity which contribute substantially to the flow of the river in the middle sub-basins, the aim of this study was to determine the contribution of sub-basins flow to total basin flood and to identify ...
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According to the annual damages of flood in Dez river catchment and the lack of information about water quantity which contribute substantially to the flow of the river in the middle sub-basins, the aim of this study was to determine the contribution of sub-basins flow to total basin flood and to identify areas of flooding potential. So, the standard precipitation index was calculated to identify the wettest period in the region. Then, the whole basin was divided into 11 sub-basins and subsequently a rainfall-runoff simulation was carried out by using WMS software. Finally, the contribution of each sub-basin to the outlet flood peak was quantified by successively eliminating sub-basins from the simulation process. The result showed that the Dokouheh sub-basin by decreasing the peak flow (40 percent) is the most effective region in flooding. Then, Hamidabaad with 35 percent and Dez dam with 15 percent are the sub-basins with more flood potential, respectively. In addition, to eliminate the effect of sub-basin area, prioritization was done corresponding to the contribution at the outlet per unit area of sub-basins. Dokouheh with 29 percent, Hamidabaad with 25 percent and Dezful with 15 percent were given first, second, and third rank, respectively
Shahram Yousefi khanghah; Damoon Razmjuee; Somayyie Dehdari; Nasim Arman
Abstract
To better managing of rangeland the vegetation map is one of major factors, because plant communities is planning units of rangeland management and vegetation map shows the current status of plant communities. This research was conducted to produce vegetation type's map using Landsat 8 image classification ...
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To better managing of rangeland the vegetation map is one of major factors, because plant communities is planning units of rangeland management and vegetation map shows the current status of plant communities. This research was conducted to produce vegetation type's map using Landsat 8 image classification in Behbahan, Khuzestan province. Rangelands of the study region is warm semi steppe and winter grazing. Geometric correction of satellite image was performed by ground control points with an error of less than one pixel. Atmospheric correction of existing data using the dark object subtraction was done. Field visits for vegetation type's border controlling and sampling training area was conducted. Eight supervised classification algorithms included Parallelepiped (PP), Minimum Distance to mean (MD), Mahalanobis distance (MAH), Maximum Likelihood (ML), Neural Net (NN) and Support Vector Machine (SVM) was performed. The results showed that ML algorithm has the highest overall accuracy (87.5 percent) and kappa (0.867) and PP algorithm has the lowest overall accuracy (67.1 percent) and kappa (0.571). It is suggested that, along with digital methods of classification of satellite images, visual interpretation should be used to clarify the boundary of the obtained vegetation types map.
roya vazirian; Ali Akbar Karimian; Alireza Afshani; Mohammad-Taghi Dastorani
Abstract
In Collaborative management of arid regions, it is necessary to analyze the social relationships between farmers. The purpose of this study was to evaluate and analyze the social network of farmers in trust links and to participate in irrigation, marketing and cultivation activities in three villages ...
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In Collaborative management of arid regions, it is necessary to analyze the social relationships between farmers. The purpose of this study was to evaluate and analyze the social network of farmers in trust links and to participate in irrigation, marketing and cultivation activities in three villages of Aryan, Hareth Abad and Robat Sarpush in Sabzevar. For this purpose,in the firstusing with qualitative studies of survey approach,direct observation method and target population interview were identified. Then, the quantitative network analysis method, four important indices consist of "density", "reciprocity", "transitivity" and "average geodesic distance" in the links of trust and participation in agricultural activities of the farmers' network were evaluated. According to the results, the density of the four transplants was higher in Aryan village than the other villages, which is indicating more social cohesion in this village. The results of reciprocity and transitivity indexed in the studied links show more balance, equilibrium and stability of the network in Aryan village than the other villages, thus there is more social capital in this village. The average geodetic distance results also indicate the most favorable geodetic distance among the farmers in Aryan village. Increasing the cohesion and solidarity of these villages will speed up the flow of information and exchange, as well as increase social capital in them, and will help people to coordinate and access each other with less cost and time. Therefore, reinforcing trust and social participation is essential for increasing social capital as a necessity for participatory management
fatemeh maghsoud; Arash Malekian; Mohsen Mohseni Saravi; Omolbanin Bazrafshan
pooya hoshyar; Hossein Khademi; Shamsollah Ayoubi; Mehdi Norouzi
Abstract
Parent material and vegetation are two important and influential factors in the formation of soil. Type of elements in the soil and their availability to plants depends deeply on soil parent material. However, type and density of vegetation change with amount of organic matter and mechanism of element ...
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Parent material and vegetation are two important and influential factors in the formation of soil. Type of elements in the soil and their availability to plants depends deeply on soil parent material. However, type and density of vegetation change with amount of organic matter and mechanism of element cycle overshadowed the availability of element in rangeland ecosystem. This study were conducted to investigate profile distribution of nutritional elements affected by rangeland species and different parent material as a factorial trial and completely randomized design with three replications in rangelands around Kuhrang city. Therefore, in the study area, three different parent matter such as fossiliferous marl limestone, fossiliferous dolomitic limestone and red conglomerate and sandstone were selected. In each parent material, three places under Astragalus spp and Daphne and the bare part as a control profile to depth of 100 cm were dug. Then the soil physical and chemical properties and concentrations of nutritional elements in profiles were measured. The results of this study showed that type of parent material have significant effect on amount of soil element while the vegetation in some cases could not make a significant difference in concentration of elements. Red conglomerate parent material because of coarser texture, release fewer element compared to marl and dolomite limestone in soil. Soils in study area except soils derived from red conglomerate parent material, there is no shortage of potassium and phosphorous. Furthermore, concentration of elements in different depths of the profiles obeyed a similar pattern
Reza Yari; Esfandiar Jahantab; Gholam Ali Heshmati
Abstract
Given the importance of having data on vegetation and soil in different geographical aspect, the aim of this study is the assessment the geographical aspect's impact on Functional Potential and soil surface indicators in Chhar-Bagh Summer Rangeland, Golestan province. For the study used the method Landscape ...
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Given the importance of having data on vegetation and soil in different geographical aspect, the aim of this study is the assessment the geographical aspect's impact on Functional Potential and soil surface indicators in Chhar-Bagh Summer Rangeland, Golestan province. For the study used the method Landscape Function Analysis (LFA) and main Geographical aspect. For this purpose, in the four main geographical aspect, three transects 100,m were established and along the transects type, length and width patches and interpatches were measured. To calculate the Functional Potential (Soil Stability, Infiltration and Nutrient Cycling and and Vegetation Organization Index). To investigate the functional significance potential of SAS Software and ANOVA, for mean potential functional classification of Duncan Test used. To investigate the soil surface along each transect, 5 plots and 11 indicators way quality and using the scoring tables and to check the normality of the data, the Kolmogorov-Smirnov test was used. To investigate the significance Kruskal-Wallis nonparametric test and classification of soil surface indicators grouped Duncan test was used. The results showed a significant difference between the functional potential in different geographical aspects (P> 0.05), So that the highest percentage of functional potential to the north and lowest in the East was estimated. Vegetation organization index for geographical aspects North, South, East and west were respectively 0.53, 0.43, 0.38 and 0.51. The results showed that except cryptogam cover and Micro-topography indexes, all indicators were significant in different geographical aspects (P> 0.05).
Setareh Bagheri; Reza Tamartash; Mohammad Jafari; Mohammad Reza Tatian; Arash Malekian
Abstract
Plain ecosystem is highly vulnerable to environmental changes, and drought is the most famous ecosystem change driver that is difficult to identify after its occurrence. In this research, to study the slope of vegetation changes against drought, the NDVI index of MODIS images and the SPI index from 2001 ...
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Plain ecosystem is highly vulnerable to environmental changes, and drought is the most famous ecosystem change driver that is difficult to identify after its occurrence. In this research, to study the slope of vegetation changes against drought, the NDVI index of MODIS images and the SPI index from 2001 to 2016 were used and the map of vegetation changes against drought with five drought stress classes included very low classes, Low, moderate, high and very high, so that a suitable assessment of the drought can be made at specified time scales. The results of slope pattern of spatial change of vegetation against drought showed that across the plain vegetation changes have declined, and from east to west of Qazvin plain, the slope of vegetation changes and land susceptibility to drought have been reduced. So that the most percentage of area in a one-month drought related to the drought class is very low, but in droughts of 3, 6, 9, 12, 24 and 48 months, the highest percent of the area belonged to moderate and high drought classes. The results of this study, the determination of the level of vegetation changes in against drought in the past years and prediction of these changes in the future years, can be used in the planning and optimal use of resources, control changes in the future.
Esmatullah Ghaljaee; Shahram Khalighi-Sigaroodi; Alireza Moghaddam Nia; Arash Malekian
Abstract
Reliable estimation of precipitation is one of the most essential needs in water resources management. However, in many parts of the world, especially in Iran, the lack of time and place of rainfall data is very noticeable. Therefore, the use of satellite information is one of the ways to compensate ...
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Reliable estimation of precipitation is one of the most essential needs in water resources management. However, in many parts of the world, especially in Iran, the lack of time and place of rainfall data is very noticeable. Therefore, the use of satellite information is one of the ways to compensate for the lack of information. The purpose of this research is to compare the accuracy of rainfall information of TRMM-3B42 and PERSIANN-CDR products on a daily scale. The products of these two satellites are available daily for free in the pixel size of 0.25 degrees. The daily rainfall of 12 stations in the southern slopes of Alborz in a statistical period of 2000-2014 was used. The results show that these two satellite products are not the same in different statistical parameters, so that CDR and 3B42 have estimated 100% and 25% more rainfall events than the stations, respectively. Also, PERSIANN satellite is significantly superior to 3B42 in terms of RMSE, POD and CSI parameters, but on the other hand, it is weaker in terms of Bias and FAR parameters. Therefore, the selection of the desired satellite product should be based on the proper parameters.
Saeid Khosrobeigi Bozchelui; Arash Malekian; Alireza Moghaddam Nia; Shahra,m Khalighi
Abstract
Flood is one of the most devastating natural disasters, causing financial and human losses each year. At the same time, many rivers in Iran's watersheds lack complete and accurate statistics and information. On the other hand, estimating the flow of floods is one of the most important factors for the ...
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Flood is one of the most devastating natural disasters, causing financial and human losses each year. At the same time, many rivers in Iran's watersheds lack complete and accurate statistics and information. On the other hand, estimating the flow of floods is one of the most important factors for the design and implementation of water structures. In such cases, one of the appropriate solutions to estimate the maximum flow rate with different return periods is flood analysis. In order to conduct the present study, 55 hydrometric stations with a common statistical period of 20 years were considered to perform the work after the statistical deficiencies were eliminated. Then, based on the distribution of the third type of Pearson logo with the lowest error rate and the highest number of first rank as the most suitable fit function, the amount of discharge in different return periods was estimated. The following information was collected on the types of physiography, land use, climate and geology variables. After collecting information about all independent variables using Gamma test, the most important variables affecting the maximum instantaneous flow, including area, drainage density, maximum 24-hour rainfall and watershed environment, were selected and modeled using methods. Random forest modeling and support vector modeling were performed and their efficiency was determined based on statistical indicators With an efficiency coefficient of 74 to 83%, the error of 3.05 to 32.11 m3 and the coefficient of explanation of 76 to 91 are more accurate than the random forest model.
Reza Erfanzadeh; Mohammad Jafari; Misagh Ghasempour
Abstract
This study aimed to investigate the effect of Juniperus sabina (evergreen) and Berberis integerrima (deciduous) and herbaceous patches on some soil properties (pH, EC, aggregate stability, microbial respiration, organic carbon and nitrogen) in their habitats. In June, when maximum growth of the dominant ...
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This study aimed to investigate the effect of Juniperus sabina (evergreen) and Berberis integerrima (deciduous) and herbaceous patches on some soil properties (pH, EC, aggregate stability, microbial respiration, organic carbon and nitrogen) in their habitats. In June, when maximum growth of the dominant plant species in rangelands of central Alborz was occurred, of each plant patch, 10 patches were randomly selected and soil were collected beneath of the canopy species in each from two depths: 10-0 and 20-10 cm (in total 60 soil samples). Then, soil physico-chemical characteristics were measured in the laboratory. In order to examine the differences between each soil characteristics associated with patches and depths, two-way ANOVA using GLM was applied. In addition, one-way ANOVA and post-hoc tests were used to compare soil characteristics between patches, in each depth separately. The results showed different effect of different patches on the soil characteristics. In upper soil layer, the highest contents of organic matter (4.62%) and aggregate stability (36.08) were observed under J. sabina, while the highest total nitrogen was found under B. integerrima. In deeper soil layer, the highest content of organic matter (5.19%) was found under J. sabina. The highest microbial respiration contents in both depths were observed under herbaceous patch. The variation of other soil characteristics were less pronounced by type of patches. In general, the results of this study cleared that different woody plant species have different effects on soil characteristics, should be mentioned in the rangeland development and improvement projects.
Sajad Amiri; Hossein Azarnivand; Mehdi Ghorbani; Mohammad Jafari; Sajad Barkhordari; Hossein Azadi
Abstract
Awareness of human about the existence of environmental pollution crisis and its effects on his own destiny can have a positive effect on changing the course of these crises. Sangan mines release dust particles and pollutants into the soil and air, which will have huge consequences for environmental ...
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Awareness of human about the existence of environmental pollution crisis and its effects on his own destiny can have a positive effect on changing the course of these crises. Sangan mines release dust particles and pollutants into the soil and air, which will have huge consequences for environmental pollution and even endanger human Health, including the spread of skin and respiratory diseases. Environmental assessment is considered as one of the most efficient methods to evaluate and predict plans and projects on environmental components, so the present study aims to Environmental impact assessment of Mine Utilization Using Iranian Leopold Matrix (Study area: Sangan Khaf Mines). The main tool for collecting research data for the study area is a library and a field survey based on a questionnaire that was completed among the community of experts. The statistical sample population is 30 experts who were familiar with environmental issues. The results showed that the number of negative algebraic mean effects in the column is equal to 10 and the number of negative algebraic mean consequences in the row is equal to 14, among which the number of negative consequences less than -3.1 in the column is only related to the effects of dust diffusion. The most important negative effects among the environmental components are related to dust diffusion activity with an average classification of -3.1 with an algebraic sum of -50.
Zakiye Dastoori; Mohammad Farzam
Abstract
Ferula foetida is one of the important medicinal plants in the steppe rangelands of Iran. Applying effective methods for its establishment can be useful for reviving the ecosystems of arid areas and the economy of its indigenous people. Due to the fact that drought stress is one of the main limitations ...
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Ferula foetida is one of the important medicinal plants in the steppe rangelands of Iran. Applying effective methods for its establishment can be useful for reviving the ecosystems of arid areas and the economy of its indigenous people. Due to the fact that drought stress is one of the main limitations in the establishment of plants in arid and semi-arid regions, in this study the effects of various treatments were studied on seed germination and establishment of Ferula foetida seedlings, in the Kakhk Twin Watersheds, located in the south of Khorasan Razavi province, Gonabad city. Experiment included some soil moisture conservation treatments (stone shelter, superabsorbent, superabsorbent + stone shelter or control) and seed treatments (prechilling or control), with 30 replicates for each treatment. Superabsorbent + sand shelters and sand shelters alone, reduced temperature and increased soil moisture. Moisture conservation treatments led to higher number of seedling emergence and survival and higher seedling height than those of control. Among the moisture conservation treatments, superabsorbent + stone shelter performed better, especially for the prechilled seedlings. According to the our results, superabsorbents and stone shelters can improve the production and productivity of Ferula foetida, especially during the drought times. We also suggest prechilling treatments to overcome the dormancy of Ferula foetida seeds.
Hannaneh Sadat Sadat Mousavi; Afshin Danehkar; Ali Jahani; Vahid Etemad; Farnoush Attar Sahragard
Abstract
Different forms of land use development and human activities in protected areas are considered to be the main drivers of change, which have many effects on habitats, habitats, diversity and richness of species. The purpose of this research is to model the effect of human activities on the diversity of ...
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Different forms of land use development and human activities in protected areas are considered to be the main drivers of change, which have many effects on habitats, habitats, diversity and richness of species. The purpose of this research is to model the effect of human activities on the diversity of vegetation using the artificial neural network method and determine the impact of ecological and human variables on them. This research was done in the Central Alborz protected area under the management of Alborz Province. To achieve the mentioned purpose, firstly, 101 plots and 101 soil samples were collected and, soil and vegetation analysis were performed on the samples. Finally, using the multilayer perceptron neural network method and using 18 input variables including physical and chemical variables of the soil, physiographic variables, and human factors variables , the effect of human activities on the diversity of vegetation in the study area modeled. According to the results, the vegetation diversity model with the structure of 1-5-18 according to the highest value of the coefficients of determination in the three categories of training, validation, and test data is equal to 0.82. 0.81 and 0.68 show the best structure optimization performance, distance from roads, electrical conductivity, and percentage of organic matter in the soil show the greatest effect on the diversity of vegetation in the study area. The model presented in this research is used as a decision support system in evaluating the effects of human activities on the diversity of vegetation in protected areas and provides the possibility of predicting the extent of these effects on the diversity of vegetation in these areas.
Amir Hossein Parsamehr; Ali Salajegheh; Shahram Khalighi; Khaled Ahmadaali
Abstract
Aim: The aim of this study is to propose an approach for modeling spatiotemporal changes in rainfall that can be used as input for rainfall-runoff models.Research Method: To achieve this, rainfall data from four rain gauge stations in the Paskouhak catchment were used. Five parameters, including elevation, ...
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Aim: The aim of this study is to propose an approach for modeling spatiotemporal changes in rainfall that can be used as input for rainfall-runoff models.Research Method: To achieve this, rainfall data from four rain gauge stations in the Paskouhak catchment were used. Five parameters, including elevation, slope, aspect, longitude, and latitude, were identified. The different combinations of these five parameters were prioritized using the gamma test in WinGammaTM software. After the use of different regression models, the best model was selected based on evaluation criteria such as R2, RMSE, and the Taylor diagram. A raster map of a selected rainfall event was drawn in the Arc GIS environment. Finally, using the proposed approach of relative equations, the spatiotemporal changes in rainfall were modeled.Results: The results showed that using a second-degree nonlinear model and parameters of elevation and latitude, it is possible to accurately obtain the spatial distribution of rainfall in the form of a regular pixel grid (100 square meters) with high precision (R2=0.917 and RMSE=0.2277).Conclusion: In different rainfall events in small catchment areas, the variation in rainfall in each pixel is almost constant relative to other pixels, including the rain gauge station, the proposed approach in this study can model the spatiotemporal changes of each rainfall event as a three-dimensional matrix in the study area. The approach can be valuable in predicting potential flood events and in water resource management and planning. However, further research is required to validate the results and test the approach in other areas.
Raziyeh Dehghani; Mohammad Jafari; Mohammad Ali Zare Chahouki; Salman Zare; ِAli Tavili; Babak Moteshrezadeh
Abstract
The use of biochar as a soil amendment is one of the new methods to improve soil properties and increase plant yield. In this study, in order to evaluate the effect of adding natural biochar on soil properties and yield of Pamirian winterfat (Eurotia ceratoides) plant, an experiment in a completely randomized ...
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The use of biochar as a soil amendment is one of the new methods to improve soil properties and increase plant yield. In this study, in order to evaluate the effect of adding natural biochar on soil properties and yield of Pamirian winterfat (Eurotia ceratoides) plant, an experiment in a completely randomized design were performed with 11 treatments by different levels of biochar (0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10% by weight) and three replications in greenhouse conditions. After the end of the growing season, some physical and chemical properties of the soil (pH, EC, organic matter (%), lime, bulk deisty, particle density, and porosity percentage), germination percentage, and yield of E. ceratoides were measured. In all the studied traits of the soil (except for the particle density), and the characteristics of the E. ceratoides plant, the statistical difference between the various levels of biochar was significant (a = 0.01). Adding different levels of biochar increased pH, ECy, soil porosity percentage, soil organic matter, whereas decrased bulk density, lime percentage, clay percentage, sand, and silt.
