Showing 17 results for Pourmanafi
Z. Rahmati, M. Tarkesh Esfahani, S. Pourmanafi, M. R. Vahabi,
Volume 4, Issue 11 (6-2015)
Abstract
Species distribution maps have been widely developed based on ecological niche theory together with statistical and geographical information system in plant ecology. The current study aimed to evaluate Artificial Neural Network (ANN) in mapping potential habitat of Ferula ovina Boiss in Ferydunshar rangelands, Isfahan. This is known as valuable forage and medicinal species. Environmental data (independent variables) and species occurrence data (dependent variable) were required to determine potential habitat of a given species. Some physical and chemical soil properties, climate and physiographic variables were mapped for the entire studied area using krigging and inverse distance weighting methods. F. ovina occurrence data were collected from 278 sites including 137 presence and 141 absence sites. The relationships between the studied environmental variables and F. ovina occurrence data were explored using ANN method. According to the sensitivity analysis, occurrence of F. ovina mostly correlated with silt and sand percentage, elevation slope, and organic matter. Model evaluation based on Kappa coefficient (0.66) and Receiver operating characteristic (ROC=0.9) showed good model fitness in relation to reality on local scales. The ANN technique enables managers to identify appropriate areas for rehabilitation practices such as direct seeding and planting.
Abdolah Salehi Ardali, Mohammad Reza Vahabi, Mostafa Tarkesh Isfahani, Saeid Pourmanafi, Elham Ghehsareh Ardestani, Hamid Reza Farhang,
Volume 6, Issue 3 (12-2017)
Abstract
Vegetation is the most important factor influencing the sustainability of rangeland ecosystems. Therefore, it is important to understand the environmental factors and their effect on vegetation and restoration of rangeland ecosystems. The aim of this study was to identify factors influencing on Gundelia tournefortii L. distribution. Accordingly, the information of Gundelia tournefortii L. was determined in six habitats in Isfahan province. Random- systematic sampling was conducted to calculate canopy and density of the species. In each rangeland place, climate, physiography and soil factors were identified. RDA ordination analysis using CANOCO software was used to investigate the vegetation relationship with environmental factors. In the cluster analysis and RDA ordination analysis, six main habitats of the species were classified into three groups. The first axis of ordination showed a very strong correlation with canopy cover and density and the second axis showed a very strong correlation with soil depth. According to study of the habitats of this species, annual precipitation about 250 to 500 mm, altitude 2300 to 2500 meter, slope about 10 to 40 percent and average of annual temperature about 10 ̊C to 12 ̊C are appropriate for presence of this species.
M. Shafiezadeh, H. Moradi, S. Fakheran, S. Pourmanafi,
Volume 7, Issue 3 (12-2018)
Abstract
Habitat suitability models for the focal species are used to address the concerns related to the limited availability of data for remote habitats by scrutinizing the relationship between the biodiversity distribution patterns and the natural-anthropogenic characteristics. The current study aimed at modeling habitat suitability for seven focal species including Asian black bear, Persian leopard, Persian ibex, Wild sheep, Chinkara, Asian houbara and Mugger in the southeastern Iran, by relying on Generalized Linear Model (GLM), Generalized Boosted Model (GBM), Random Forest (RF), and Maximum Entropy (MaxEnt) models and using 10 physical, anthropogenical and land cover variables. Next, habitat suitability maps were overlaid with sensitive coastal habitats to delineate a final habitat suitability map. Based on our results, more than 34% of the region were identified as sensitive habitats which were mostly located along the coastline. These habitats demonstrated less than 15 percent spatial overlap with the current protected area network of the region. Moreover, a suitable connecting corridor extended in the east-west was identified, but it was neglected due to having lower suitability values in comparison to the central habitats and the focus of conservation objectives on the core habitat.
Sh. Mohamadi, H.r. Karimzadeh, S. Pourmanafi, M. Alizadeh,
Volume 8, Issue 1 (6-2019)
Abstract
Rainfall erosivity is one of the factors determining the amount of water erosion in the soil. Rainfall erosivity is determined by the total rainstorm energy and the maximum intensity in 30 minutes (I30). Since rainfall erosivity is closely related to the amount and intensity of rainfall, it is expected that the rainfall erosivity would change monthly and seasonally throughout the year. The main objective of this study was the spatial and temporal variation modeling of rainfall erosivity, erosivity density and their impacts on the soil erosion in Menderjan watershed. In this research, by using rainfall data with 1 minute from the rain gauge in the proximity of the basin during the 11-year statistical period (2005-2015), the rainfall erosivity factor (R) was calculated on a monthly average; then it was mapped using geostatistical technologies. Comparison of the monthly, seasonal and annual rainfall erosivity maps showed the highest rainfall erosivity occur in autumn (about 41 percent), while the lowest one was recorded in summer (less than 1%), respectively. According to the results obtained the maximum amount of erosivity was observed in November, which was 65 (MJ.mm.ha-1.h-1.month-1), while the lowest amount was observed in August. This study showed that the highest risk of soil erosion was expected to occur in November, because this month is not only the time of rainfall erosion, but also involves a high erosion density.
O. Ghadirian, M. R. Hemami, A. Soffianian, M. Malekian, S. Pourmanafi, M. Amiri,
Volume 8, Issue 1 (6-2019)
Abstract
Habitat destruction is the most important factor determining species extinction; hence, the management of wildlife populations necessitates the management of habitats. Habitat suitability modeling is one of the best tools used for habitat management. There are several methods for habitat suitability modeling, with each of having some different advantages and disadvantages. In this study, we used 15 modeling methods along with 9 environmental factors including Bio1, Bio2, distance to roads, distance to residential areas, distance to agricultural lands, distance to streams, the percentage of slope, geographic aspect, and NDVI to model the Persian squirrel’s habitat suitability in the forests of Luristan Province. The AUC of each model was computed and the models with an AUC higher than 0.9 were selected. Finally, the output maps resulted from the selected models were multiplied by their AUC and the average of them was considered as a combined model. In this study, Maximum Entropy, Boosted Regression Tree, Generalized Linear Model, and Random Forest were the only models with an AUC higher than 0.9. Based on the combined model, 66% of the forest areas in Luristan Province could be suitable for the Persian squirrel, of which 32.1%, 18.4%, and 15.5% have low, moderate, and high suitability, respectively. Among the 9 environmental factors used in this study, distance to roads, distance to agricultural lands and NDVI showed the highest contribution in the habitat suitability of the Persian squirrel. This study indicated that the combination of high-accuracy models could yield more reliable results, as compared to their separate use.
A. Darahaki, M. Malekian, S. Pourmanafi,
Volume 8, Issue 2 (9-2019)
Abstract
Today’s situation in cities requires that planned parks be set up to create ecological equilibrium. The current study was aimed to identify suitable zones for establishing ecoparks in the central region of Isfahan province; this was done using seven effective criteria including topography, landscape, climate, rock and soil, water resources, environmental sensitivity, and accessibility. The weights of the criteria and the subcriteria were obtained using the analytic hierarchy process (AHP) with expert opinions. All layers were combined using weighted linear combination (WLC) and the land suitability maps for ecoparks were produced. After evaluating and prioritizing suitable zones, finally, the zone with an area of 85.2 hectares, which was located in the Bag Bahadoran district and adjacent to the Zayanderood River, was selected as the most suitable one due to its larger area, more access to the welfare facilities, and higher ecological potentials. Also, the results obtained from overlaying the ecopark’s land suitability map and the map of existing parks in the region suggested that Sararud coastal park, in Mobarakeh, and the coastal park, in Zarrin Shahr, can be suitable places for establishing ecopark in the region.
Z. Asghari Poudeh, O. Ghadirian Baharanchi, Shekoofeh Nematallahi, S. Fakheran, S. Pourmanafi,
Volume 8, Issue 3 (12-2019)
Abstract
Quantifying land use/land cover changes is essential to monitor and assess the ecological consequences of human disturbances. Ecological condition and water quality of wetlands are highly related to the landscape characteristics, including land use/land cover (LULC) types and their fractions in the upland and the surrounding landscape. The changing characteristics of LULC in Shadegan International Wetland, Khouzestan Province, Iran, were detected in this study by using the Landsat Satellite images of the years 2001, 2014, and 2017, which were classified using the Artificial Neural Network algorithm. Then by using Land Change Modeler (LCM) in the TerrSet IDRISI software, the future of LULC changes was simulated using six independent variables and the Markov chain method. The results of this study showed that from 2001 to 2017, about 48200 ha of the wetland water was increased and around 50000 ha of saline soils and vegetation area was decreased. However, since this water increase in the wetland was due to the entry of drainage and wastewater, particularly from sugarcane cultivation around the wetland, this increase could significantly alter the hydrology, the water quality of wetland and also, the plant species composition, as compared to historical conditions; mapping these changes requires further investigations and fine scale monitoring studies.
Sh. Nematollahi, S. Fakheran, A. Jafari, T. Raeisi, S. Pourmanafi5,
Volume 8, Issue 4 (1-2020)
Abstract
One of the primary goals of conservation portfolio selection approaches is to create a functional landscape or network of sites that can support all elements of biodiversity and minimize the environmental risk to critical habitats and species. As human activities, especially roads network development, can be regarded as one of the most important risk elements for the valuable habitats and species of the Chaharmahal & Bakhtiari Province, it is necessary to evaluate the habitat’s condition and ecosystem services for the purpose of conservation planning, as well as minimizing the negative impacts of the roads network on the ecosystem services and habitats. So, for this purpose, first, the habitat quality of Capra aegagrus was modeled using the InVEST module (Integrated Valuation of Environmental Services and Tradeoff). Then, the ecological impacts of roads network were assessed using the spatial landscape index. Finally, the degree of the protected areas was determined and some mitigation measures were introduced. The results of this study revealed that approximately 45 percent of Ch & B Province, including Tang-e-Syyad national park and and the Sabzkouh protected area, could be considered as the suitable habitats for the Wild goat. However, about 28 percent of this province is negatively affected by roads network, thereby highlighting the importance of identifying the priority areas for conservation and mitigation measures.
M. Araghi Shahri, S. Soltani, M. Tarkesh, S. Pourmanafi,
Volume 9, Issue 3 (11-2020)
Abstract
One of the main scientific topics on the effects of global climate change is to assess changes in the carbon cycle in rangelands. Net Primary Production (NPP) is an important component of this cycle, in terms of carbon storage, and a key indicator for assessing the ecosystem function. This research aimed to investigate the correlation between NPP and ocean-atmospheric oscillations, monthly and seasonally, from 2000 to 2016 in the north of Iran’s Alborz Mountains. Net Primary Production of terrestrial vegetation was extracted from MODIS data and used in a model along with ocean-atmospheric oscillations. Multivariate regression analysis was used to investigate the simultaneous and lagged status in different timescales. Mann-Kendal test was used for trend analysis in different seasons over the studied period. Results showed that the highest NPP values were 2.06 and 1.30 g C m-2 d-1 in spring and summer and the lowest were 0.68 and 0.55 g C m-2 d-1 in autumn and winter, respectively. The trend of NPP variations was significantly different in autumn and winter. Overall, it was showed that NPP was affected by climatic variables, especially precipitation, and variables related to ENSO indicator are the main factors affecting precipitation, thereby affecting NPP in the north of Iran.
K. Hajian, O. Beyraghdar Kashkooli, N. Mahboobi Soofiani, S. Pourmanafi,
Volume 10, Issue 1 (5-2021)
Abstract
Nowadays, the risk of degradation of wetlands is one of the main environmental challenges in the world, so continuous and long-term monitoring of ecological changes in wetlands can play a key role in their protection and proper management. In the present study, the trend of monthly changes in some of the most important ecological indicators of the aquatic environment of Shadegan wetland including WST, NDVI, MVWR, VWR, LSWI, MNDWI and Chlorophyll-a concentration (during 2003-2017) was evaluated using MODIS satellite imagery. The Mann-Kendall and Sen’s slope tests were used to analyze the trend and its magnitude, respectively. Results showed a significant increasing trend in the volume of water in Shadegan wetland, while the vegetation of the wetland had a significant decreasing trend during the study period (p <0.05). Also, the change in the monthly trend of NDVI, MVWR, MNDWI and LSWI time series was observed around October 2012, which approximately coincided with the development of aquacultural facilities in the northern part of this wetland. In addition, a strong inverse correlation (about -0.86) was observed between vegetation and water indices. Results further provided evidence of an inverse sequence and critical conditions in Shadegan wetland. Integrating remote sensing techniques and statistical methods in this study (to provide continuous time series of ecological indicators) can help to better understand the dynamics of wetland ecosystems (at different temporal and spatial scales). This approach is also applicable in evaluation, modeling and prediction of ecological changes in Shadegan wetland.
F. Khazaee Fadafan, A. R. Soffianian, S. Pourmanafi, M. Morgan,
Volume 11, Issue 3 (12-2022)
Abstract
The importance of the economic aspect of tourism usually overshadow many natural tourism destinations. Fereydounshahr county in Isfahan province, with pristine mountainous landscapes and diverse natural features, has high potential to attract many tourists. However, pristineness over much of its area suggests limiting the public access based on the degree of naturalness. Hence, the aim of this research was to classify Fereydounshahr county based on naturalness. Accordingly, nine effective indicators were weighted, using Analytical Hierarchy Process (AHP). Idrisi software was then employed to overlay the digital layers of criteria and produce a naturalness map, that consisted of five classes (from very natural to developed), based on Ordered Weighted Averaging (OWA) approach under six different scenarios. Results showed that developed areas under the AND scenario and the natural areas under the OR scenario have the largest range. The extent of desirable areas, including natural and relatively natural, increased when moving from risk aversion to risk taking scenarios. Based on the results, most of the natural areas were concentrated in western parts of the region, due to the long distances from the main roads, high presence of wildlife, and the presence of steep slopes.
M. Tarkesh, N. Monsef, M. R. Vahabi, S. Pourmanafi, M. Amiri,
Volume 11, Issue 4 (1-2023)
Abstract
In the present study, the relationship between the distribution of Astragalus verus, climate, soil and topography in Isfahan province was investigated using the CART (Classification and Regression Trees) non-parametric regression. According to the vegetation types dominated by Astragalus verus, 287 sites were selected using stratified-random sampling and 106 presence points were recorded. Non-normally distributed soil variables were normalized according to the skewness type by data transformation. For variables that were not normalized by the data transformation, the inverse distance weighted and for normally distributed variables, kriging methods were used for mapping. To investigate the spatial continuity of these variables, the best variogram was selected. Using the principle component analysis (PCA) and correlation matrix, the most effective factors on distribution were clay percentage, mean temperature of the coldest (Bio11), and driest (Bio9) quarter, minimum temperature of the coldest month (Bio6), annual mean temperature (Bio1), saturated moisture and organic carbon, respectively. Model evaluation using replacement method and using independent data indicated high accuracy of the model. According to the optimum threshold of 0.41 and fuzzy-based habitat suitability map, the suitable habitat for the species was 34.5 % of the area. The results are used in sustainable rangeland management, conservation and their restoration.
M. Karimian, O. Beyraghdar Kashkooli, R. Modares, S. Pourmanafi,
Volume 11, Issue 4 (1-2023)
Abstract
Chlorophyll-a concentration is among the most important parameters used to investigate the primary production in marine ecosystems. Chlorophyll-a concentration is influenced by climatic/environmental factors, including Sea Surface Temperature (SST). Satellite sensors are able to provide reliable products of chlorophyll-a concentration and SST data with an adequate spatiotemporal resolution. In this study, level 3 (resolution 4 km) MODIS monthly products of chlorophyll-a concentration and SST from year 2003 to 2018 of the Persian Gulf and the Oman Sea were used. The data were transformed into a raster format and the values of each pixel were extracted. Several gaps were observed in MODIS products of chlorophyll-a concentration. The Data INterpolating Empirical Orthogonal Functions (DINEOF) algorithm was used to reconstruct these gaps. Pearson correlation procedure was applied to analyze the correlation between chlorophyll-a concentration and SST. Results showed that during the study period, the correlation between the two parameters was negative (-0.44 to -0.67) and significant in the most part of the study area. The correlation coefficients in December were negative (-0.67 to -0.05) and significant in the Oman Sea and the most areas of the Persian Gulf, while in July those relationships were mostly positive (0.13 to 0.64) and significant.
M. R. Abolmaali, M. Tarkesh, A. Mousavi, H. R. Karimzadeh, S. Pourmanafi, S. Fakheran,
Volume 12, Issue 1 (5-2023)
Abstract
In order to make decisions for regional planning and achieve sustainable development, it is necessary to quantify land use and land cover changes. In this study, the land use and land cover maps of the Zayandehrood Dam watershed were prepared for the period of 1991 to 2021, using Landsat satellite images, and the changes that occurred in this period were revealed. Using the land change modeler (LCM), land use and land cover and their future changes for 2051 were modeled and predicted. The results showed that in the period between 1991 and 2021, the coverage of poor rangelands with 51,871 hectares of change had the largest decreasing trend, and the agricultural class had the largest increasing trend with 71,478 hectares of change. The largest decline in the period from 2021 to 2051 is related in the coverage of the fair rangelands class with 66192 hectares, and the agricultural class potentially has the largest increasing trend with 70328 hectares of change. The findings of this research will be useful for policymakers and planners. They can use the findings of this study for spatial planning in the region, managing the process of land use and land cover changes for sustainable development.
M. Abdolahabadi, Dr M. Malekian, S. Pourmanafi,
Volume 12, Issue 4 (2-2024)
Abstract
Wetlands are one of the most unique ecosystems on earth, and their destruction is a result of direct and indirect human interactions. This study examines the abundance and diversity of birds in the Bandalikhan wetland and their relationship with water fluctuations and drought over a 10-year period (2012-2022). Bird census data was collected, and species richness and diversity indices were calculated. The changes in the water level were determined using the normalized water difference index (NDWI) and Landsat images. Rainfall, temperature, and drought index were extracted from meteorological records, and their correlation was analyzed. Results showed that common teal (Anas crecca) and mallard (Anas platyrhynchos) were the most abundant birds, and the highest values of species diversity and richness indices were obtained for the wettest year (2019). Linear regression revealed a positive and significant relationship between NDWI and the number of bird species (R2 = 0.72) and abundance (R2 = 0.74) of birds. A significant relationship was found between the drought index and the number of species (R2 = 0.62). To conserve the diversity and abundance of wetland birds, it is necessary to prevent large fluctuations in the water level, as this reduces the habitat suitability for birds.
R. Peykanpour Fard, A.r. Soffianian, M. Ahmadi, S. Pourmanafi,
Volume 13, Issue 1 (11-2024)
Abstract
Zoning of protected areas is an effective solution for reducing conflicts between various objectives, such as prioritizing conservation while also addressing secondary goals like rehabilitation, tourism, and multiple-use zones. Achieving these objectives is not feasible without zoning. This study aimed to allocate areas for conservation, rehabilitation, tourism, and multiple-use zones within the Abbasabad Wildlife Sanctuary, considering the interactions among different zones to optimize the arrangement of incompatible areas through multi-criteria evaluation method. Fuzzy models were used to standardize criteria, and Best-worst Weighting Model (BWM) was used to determine their weights. Suitability maps for each land use were prepared separately using the Ordered Weighted Average (OWA) method, while the zoning map for optimal land allocation was created using the multi objective land allocation (MOLA). The results indicated that the final suitability of the designated zones ranged from zero (the lowest suitability) to one (the highest suitability). The suitability scores for conservation, rehabilitation, tourism, and multiple zones were 0.82, 0.98, 0.82, and 0.84, respectively. The findings of this research can be used as a model for planning and prioritizing land use in protected areas.
Z. Niknaddaf, Z. Mazloumi, Sh. Nemat Allahy, S. Pourmanafi, S. Fakheran,
Volume 13, Issue 1 (11-2024)
Abstract
Globally, bird populations are experiencing a significant decline due to disruptions caused by human activities. The Chahakhoor International Wetland, as one of the important bird areas, is located in Chaharmahal and Bakhtiari Province. In this study, we evaluated the habitat quality of Chahakhoor over an 11-year period using the InVEST model. Land use and land cover maps for 2013, obtained from the Forests and Ranges Organization, and for 2024 were prepared using Landsat 9 image classification, employing a supervised method and the random forest algorithm. The results showed that habitat quality for waterbirds in this wetland declined by approximately 20% from 2013 to 2024. Additionally, changes in land use and land cover indicated reductions in water resources, dense vegetation, and average pasture land, while areas allocated for villages, cities, roads, and agriculture increased. Overall, our findings suggest that the decline in the abundance of many surveyed waterbird species in Chahakhoor Wetland is likely associated with the decline in the habitat quality over the 11-year period. This highlights the urgent need for conservation initiatives aimed at restoring and protecting this wetland, which supports bird populations.
