فهرست مطالب

  • Volume:8 Issue: 2, 2020
  • تاریخ انتشار: 1399/02/23
  • تعداد عناوین: 7
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  • F. Adineh, B. Motamedvaziri*, H. Ahmadi, A. Moeini Pages 65-76
    Aims

    In the present study, random forest (RF) and support vector machine (SVM) were used to assess the applicability of ensemble modeling in landslide susceptibility assessment across the Kolijan Rostaq Watershed in Mazandaran Province, Iran.

    Materials & Methods

    Both models were used in two modeling modes: 1) A solitary use (i.e., SVM and RF) and 2) Their ensemble with a bivariate statistical model named the weights of evidence (WofE) which then generated two more models, namely SVM-WofE and RF-WofE. Further, the resulting maps of each stage were dually coupled using the weighted arithmetic mean operation and an intermodal blending of the previous stages.

    Findings

    Accuracy of the models was assessed via the receiver operating characteristic (ROC) curves based on which the goodness-of-fit of the SVM and the SVM-WofE models were 0.817 and 0.841, respectively, while their respective prediction accuracy values were found to be 0.848 and 0.825. The goodness-of-fit of the RF and the RF-WofE models respectively was 0.9 and 0.823, while their respective prediction accuracy values were found to be 0.886 and 0.823. The goodness-of-fit and prediction power of SVM and SVM-WofE ensemble were respectively 0.859 and 0.873. The same increasing pattern was evident for the ensemble of RF and RF-WofE where their goodness-of-fit and prediction power increased, respectively, up to 0.928 and 0.873. Moreover, the goodness-of-fit and prediction power of RF-SVM ensemble were increased up to 0.932 and 0.899, respectively. The results of the averaged Kappa values throughout a 10-fold cross-validation test as an auxiliary accuracy assessment attested to the same results obtained from the ROC curves.

    Conclusion

    Successive intermodal ensembling approach is a simple and self-explanatory method so far as the context of many data mining techniques with a highly complex structure has been simply benefitted from the weighted averaging technique.

    Keywords: Random Forest, Support Vector Machine, Spatial Modeling, Weights of Evidence
  • Z. Chatrsimab, A. Alesheikh*, B. Vosoghi, S. Behzadi, M. Modiri Pages 77-87
    Aims

    Land subsidence is one of the phenomena that has been abundantly observed in Iran's fertile plains in recent decades. If it is not properly managed, it will cause irreparable damages. So, regarding the frequency of subsidence phenomenon, the evaluation of the potential of the country's fertile plains is necessary. Towards this, the present study is formulated to assess the vulnerability of the Tehran-Karaj-Shahriyar Aquifer to land subsidence.

    Materials & Methods

    The vulnerability of Tehran-Karaj-Shahriyar Aquifer was determined using the GARDLIF method in a Geographic Information System (GIS) environment. Seven parameters affecting ground subsidence including groundwater loss, aquifer media, recharge, discharge, land use, aquifer layer thickness, and the fault distance were used to identify areas susceptible to land subsidence. Then, they were ranked and weighted in seven separate layers. In the next step, the subsidence location and rates were obtained using the differential interferometric synthetic aperture radar (DInSAR) method. The weights of the input parameters of the GARDLIF model using the subsidence map obtained from the DInSAR method and the particle optimization algorithm (PSO) were then optimized. Accordingly, the subsidence susceptibility map was generated based on the new weights.

    Findings & Conclusion

    The results showed that by increasing correlation coefficient (r) from 0.55 to 0.67 and the amounts of Coefficient of Determination (R2) from 0.39 to 0.53 between the subsidence index and the obtained subsidence in the aquifer, the optimization of weights applied by the PSO algorithm is more capable for evaluating the land subsidence than the map created by GARDLIF. It was also found that the central parts of the study aquifer had the largest potential for land subsidence.

    Keywords: DInSAR, GARDLIF, PSO, Subsidence, Vulnerability
  • Sh. Rafatpour, A. Shahriyari*, M. Saberi, M. Karvarinasab, F. Tarnian Pages 89-96
    Aims

    The present study aims to shed light on the effects of different treatments of gibberellic, salicylic and ascorbic acid on improving germination parameters of Zygophyllum atriplicoides under in vitro drought stress condition.

    Materials & Methods

    The experiment was conducted in a factorial in a completely randomized design. Five levels of drought stress (0, -0.3, -0.6, -0.9, and -1.2Mpa) with and without priming treatments were used in this experiment. The priming treatments included three levels of salicylic acid (100, 200, and 300mg/L), three levels of gibberellic acid (125, 250, and 500ppm), three levels of ascorbic acid (100, 200, and 300mg/L) and simultaneously distilled water were used as control. Each level of treatments had 4 replications and the total number of replications was 200. The studied traits included germination rate, germination percentage, rootlet length, shoot length, seedling length, and seed vigor index.

    Findings

    According to the results, priming improved germination rate, germination percentage, rootlet length, shoot length, seedling length, and seed vigor index. Among all priming levels, 250ppm gibberellic acid accounted for the highest effect on germination traits of this species under all drought stress conditions.

    Conclusion

    priming with gibberellic acid had significantly more impact on germination parameters under drought stress. Hence, this method serves as a promising step to improve the germination parameters of this plant.

    Keywords: Drought Stress, Germination, Zygophyllum atriplicoides, Chemical Stimuli
  • S. Mirzaei, M. Vafakhah*, B. Pradhan, S.J. Alavi Pages 97-107
    Aims

    Generally, optical satellite images are used to produce a land use map. Due to spectral mixing, these data can affect the accuracy of land use classifications, especially in areas with diverse vegetation.

    Materials & Methods

    In the present study, in order to achieve the correct land use classification in a mountainous-forested basin, four Landsat 8 thermal images were used with a few additional information (Normalized Difference Vegetation Index (NDVI), Digital Elevation Model (DEM), slope angle and slope aspect) along with optical data and data of multi-temporal images.

    Findings

    Results showed that thermal data, slope angle and DEM have a significant role in increasing the accuracy of land use classification, so that they increase the overall accuracy by about 3-10% from late spring to the beginning of autumn. Among the data used, slope angle and elevation data have a significant role in increasing the accuracy of agricultural classes. The total accuracy and Kappa coefficient in land use maps obtained from monotemporal images in the wet season (late spring; 83.93 and 0.82) and early summer (83.79 and 0.81)) are more than the dry season (late summer; 81.25 and 0.79) and early autumn).

    Conclusion

    Generally, the highest total accuracy among monotemporal images generated from optical data is about 83.95%, while the application of thermal and additional data along with optical data and the combination of monotemporal images of the wet season, the accuracy of the information multitemporal increased to 91.60% of the land use map.

    Keywords: Land Use Classification, Remote Sensing, Landsat 8, Forested Area
  • M. Elahi, M. Aliabadian*, S.M. Ghasempouri, H. Winkler Pages 109-115
    Aims

    Integrating ecological niche models (ENMs) into phylogeographic studies, enables identifying the evolutionary processes and can be used to confirm species delimitation, particularly in species complex. The current study examined the divergence of two lineages of Eurasian green woodpecker complex (Picus viridis and P. innominatus), which were recently genetically proposed to the species level, using ecological niche modeling (ENM).

    Materials & Methods

    The ENMs were built using 1346 occurrence points, and environmental layers including 19 bioclimatic variables as well as elevation and land cover for past and present timescales. Niche identity, background tests and principal component analyses (PCA) were then performed to compare their ecological niches and explain ecological differentiation.

    Findings

    Results of identity and background tests and PCA revealed the lineages occupy unique and distinctive niches, and supported recently proposed genetically distinct species. Regarding the environmental variables, PCA results revealed that precipitation has a more important role in the separation of P. viridis and P. innominatus.

    Conclusion

    This study, in addition to provide an ecological support for recent molecular classifications, revealed niche conservatism had a more important role in the evolution of the two lineages of Eurasian green woodpecker complex.

    Keywords: Ecological Niche Modeling, Niche Conservatism, Divergent Lineages, Eurasian Green Woodpecker Complex
  • A. Tongo, H. Jalilvand*, M. Hosseininasr, H. Naji Pages 117-124
    Aims

    The present study aimed to investigate the anatomical properties of wood and xylem functioning of Persian oak affected by crown dieback.

    Materials & Methods

    Affected Persian oak trees were categorized into four different classes based on the severity of crown dieback (healthy, slight, moderate, and severe trees) with three replicates. The target trees were randomly selected from three forest stands. Branch samples at the age of 4-6 years were randomly taken from the trees’ crowns and the anatomical traits such as tree ring width (TRW), vessel density (VD), average vessel size (AVS), and relative specific conductivity (RSC) were determined. One-way ANOVA and LSD comparison of means were used to analyze the data and their mean comparison.

    Findings

    The results showed that oak trees are using different hydraulic strategies in different habitat conditions. The effect of severity of canopy dieback on xylem anatomical traits was significant. The narrowest ring width as 257.67, 365.56, and 159.17µm was observed in trees with a severe degree of dieback (with more than 66% canopy dieback). The RSC was decreased in response to reduction in the vessel size (2905.7µm2) and density (26.09mm-2) for declining oak trees from the last site. The AVS was increased in moderate and severe degree of canopy dieback from two sites, resulting in enhanced conducting efficiency. Whoever, their resistance decreases because of the risk of cavitation.

    Conclusion

    Healthy oak trees showed the highest values of RSC and VD. However, the AVS was not increased. The results suggest that larger and more abundant vessels would allow for more efficient water transport. However, these larger vessels may also promote a greater risk of cavitation during a drought that illustrates the tree's incompatibility with water deficit stress.

    Keywords: Oak Forest, Crown Dieback, Ring Width, Xylem, Ilam
  • M. Ghalambor, Z. Eslamifar, Z. Khoshnood* Pages 125-131
    Aim

    The aim of the present study was to investigate the biochemical characterizations of the lysozyme enzyme for evaluation of its importance in the immune system of the common carp, Cyprinus carpio.

    Materials & Methods

    In the present study, lysozyme was extracted from the spleen of common carp, Cyprinus carpio. Then, partially purified by ammonium sulfate and some properties such as optimum pH and temperature as well as the effects of different salt concentrations of NaCl, MgCl2, KCl, and urea on enzyme activity were evaluated. The enzyme activity was assayed using a suspension of Micrococcus lysodeikticus as a substrate.

    Findings

    The optimum pH and temperature were found 4 and 50°C, respectively. Furthermore, lysozyme activity was found to be dependent on salt concentration.

    Conclusion

    Based on the results, it's been concluded that lysozyme extracted from the spleen of the C. carpio has its optimum activity at high temperature and low pH condition and its activity could be continued with the presence of different salt compounds which all these are related to the environmental conditions of natural habitats of the C. carpio and showed that lysozyme could be one of the key factors of the immune system in this species.

    Keywords: Common Carp, Lysozyme, Enzymology, Immune System