فهرست مطالب

ECOPERSIA - Volume:2 Issue:2, 2014
  • Volume:2 Issue:2, 2014
  • تاریخ انتشار: 1393/03/25
  • تعداد عناوین: 7
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  • Soheila Aghabeigi Amin, Hamid Reza Moradi, Bakhtiar Fattahi Pages 525-538
    Soil erosion is an abstruse phenomenon which contains segregation and transmission of soil particles and runoff from rainfall and infiltration. Runoff and sediment generation was compared using rainfall simulator in grassland (St. parviflora-Br. tomentellus) and shrubland (As. parrowianus-As. gossipinus). For this purpose, vegetation map was supplied for two vegetation types four main aspects and two slope classes (12%-20% and 20%-40%) and corresponding work units were accordingly determined Three points were selected in each unit and rainfall simulator set inside them through a randomized pattern. The intensity of rainfall simulation was 1.6 mm min-1 with 10 minute duration and then runoff and sediment were measured. One soil sample (depth of 0–40 cm) was collected and assessed for pH, OM, EC, P, K, Ca, Mg and texture in the laboratory at the vicinity of the study area. The results of Duncan test and multiple regressions showed that grassland had more runoff and sediment than shrubland, but initial time of runoff in grassland was less than shrubland. Also aspects, slopes and soil characteristics (EC, Ca, Clay, P) had significant effects on runoff, sediment and initial time and they had linear correlation with runoff and sediment.
    Keywords: Rainfall Simulation, Rangeland, Runoff, Vegetation Types
  • Farhad Nourmohammadi, Majid Soufi, Seyed Hamidreza Sadeghi, Shahram Mirrezaie, Vahid Kazemi, Hamidreza Karimzadeh, Mohammadreza Ekhtesasi, Mohsen Sheklabadi, Hamidreza Azimzadeh Pages 539-556
    Different types of soil erosion including gully erosion occur in many parts of Iran. The west of Iran is further threatened by gully erosion due to its specific physical and climatic conditions. However, few studies have been carried out to study the sediment production of gully erosion in Iran. This research was therefore conducted to measure storm-wise sediment production of gully erosion in the west of Iran. To achieve the study objectives, 48 gullies located in three small watersheds viz. Darreh-Shahr, Abbas-Abad and Hollowsh in Ilam and Lorestan Provinces were monitored. The volumes of gullies were measured before and after 5 rainstorms for Darreh-Shahr and Abbas Abad watersheds and 6 rainstorms for Hollowsh watershed from 2005 to 2007. Sediment production was calculated on storm basis for each gully. The results revealed that the minimum and maximum volumes of gully erosion were 0.002 and 1.010 m3, respectively, for one millimeter of rainfall. The results indicated that soil moisture, percentage of silt and clay, amount and intensity of rainfall and drainage area were the most important factors on formation and sediment production of gully erosion.
    Keywords: Gully erosion, Ilam, Lorestan, Rainfall event, Sediment production, West of Iran
  • Ghorbanali Rassam, Alireza Dadkhah, Armin Mashayekhan Pages 557-569
    This research conducted in order to prioritize the effective criteria on development of medicinal plants cultivation in North Khorasan Province using Analytical Hierarchy Process (AHP) and Delphi methods. For this purpose, a list of effective factors offered to delphi group. Analysis of delphi process showed that among 23 offered factors 19 factors, had greater impact on development of medicinal plants cultivation. Hierarchy tree was drawn through grouping of 19 factors into four criteria including economic, promotional-educational services, cultural-social and supportive policies factors. The pair wise comparison questionnaires were then distributed among relevant researchers and experts of the province to get their opinions about the priority of criteria and sub- criteria. The questionnaires were analyzed using Expert Choice software. The result revealed that economic criterion with respective weight of 0.406 had the most impact among four criteria affecting the development of medicinal plants cultivation. The supportive policies (respective weight of 0.275), educational-extension services (respective weight of 0.193) and cultural-social factors (respective weight of 0.125) received the maximum towards the minimum priorities, respectively. The results of synthesis process showed that among the 19 factors, the guaranteed purchase and establishing of pilot fields of medicinal plants, farmers'' awareness of comparative advantage of medicinal plants, and the development of processing industries had the maximum towards minimum impacts on development of medicinal plants cultivation.
    Keywords: Analytical Hierarchy Process, Iran, Medicinal plants, North Khorasan Province
  • Afsaneh Tongo, Ali Mahdavi, Ehsan Sayad Pages 571-583
    To investigate the effect of droughtstress on chlorophyll content, enzymatic responses and some growth characteristics of Acacia victoriae seedlings and the effect of super-absorbent polymers (SAP) in reducing drought stress, a split plot experiment based on the completely randomized design was conducted. The treatments included four levels of drought stress (15, 30, 60 and 100% of field capacity) and four levels of SAP (0, 0.2, 0.4 and 0.6% weight percentages). The results of ANOVA showed a significant effect of drought stress on all growth characters, chlorophyll content and catalase and peroxidase enzymes activity, while the SAP didn''t show any significant effect on the weight and areas of the leaves. The interaction effect between drought stress and SAP on the weight, number of leaves, proportion of root dry weight to aerial organs, chlorophyll and peroxidase enzyme activity was also significant. The effect of drought stress on reducing the number of the leaves, leaf area, length, volume and surface of roots and also increasing the root dry weight to aerial organs dry weight ratio, amount of chlorophyll and activity of antioxidant enzymes was significant. The different levels of SAP could absorb and hold water and consequently reduce the effect of drought stress and improve the growth characteristics and reduce the activity of catalase and peroxidase enzymes.
    Keywords: Acacia victoriae, Catalase, Drought tolerance, Hydrogel, Peroxidase
  • Climate Change Induced Water Conflict in the Himalayas: A Case study from Mustang, Nepal
    Jagat Bhusal, Bhim Subedi Pages 585-595
    The water remains at the centre of livelihood from the beginning of human civilization. Civilization enriched mostly on the fertile plains and river valleys. With times, people began migrating to highland slopes where there was easy access to water to use. Two villages in Mustang region of Nepal were considered for research to drill the causes of conflicts on water sources right and water shares. People’s perception, traditional practices and field evidences from those two villages were collected and analyzed. There were no any conflicts over water rights between two villages over long period in the past (until 200 to 300 years before). When the natural hydrological process derailed, people felt effects in decreasing in agro products and pasture due to scarce waters. Worsening livelihoods reflected to conflicts over water in the area. Communities were not only demanding greater portion of water share but also were claiming exclusive right over sources. The inherent cause of conflict were climate change which appeared through dyeing springs and changing nature of hydrological cycles.
    Keywords: Global Warming, Water Manegment, Mustang, Water Conflict, Water Share
  • Mohamad Sakizadeh Pages 597-612
    The objective of this study was to classify the Shoosh Aquifer to several zones with different water quality in Khuzestan Province, Iran. In this regard, the performance of classification methods (Discriminant function and Cluster analysis) for the classification of groundwater based on the level of pollution with an emphasis on the problem of over-fitting in training data were considered. An over-fitted model will generally have poor predictiveperformance, as it can exaggerate minor fluctuations in the data. Cluster Analysis(CA) was adopted to spatially explain the similarity of sampling stations with respect to measured parameters. Three methods for variable selection were used including regularized discriminant analysis, principal component analysis and Wilks''s lambda method. The best algorithm for variable selection was Wilks''lambda which resulted in reducing the generalization error of the test sample to 0.1 for leave-one-out and 4-fold cross-validation. The second best performed algorithm was regularized discriminant function with 0.167 and 0.133 misclassification error for the two above-mentioned methods, respectively. Principal component analysis did not proved to be a promising algorithm for variable selection in the classification methods.
    Keywords: Cluster analysis, Discriminant function, Groundwater quality, Over, fitting, Variable selection