2024-03-28T17:17:55+04:30 http://ecopersia.modares.ac.ir/browse.php?mag_id=60&slc_lang=en&sid=24
60-6782 2024-03-28 10.1002
ECOPERSIA ECOPERSIA 2322-2700 2538-2152 10.22034/ecopersia 2011 0 1 Sustainable Conjunctive Use of Surface and Ground Water: Modelling on the Basin Scale Naveed Alam Theo N. Olsthoorn Farmers in the Indus basin, Pakistan have generally switched to groundwater for additional water supplies due to the irregular supply of irrigation water; currently over 50% of the agricultural land in the basin is at least partially irrigated by tube-wells. These wells pump fresh groundwater, which essentially is the result of massive leakage from irrigation canals into the originally saltwater aquifer since the inception of modern irrigation around 1870. Resalinization of the aquifer now threatens long-term prospects of this new groundwater resource. Since building new dams has become ever more complicated, water resources planning now focuses on sustainable conjunctive use of surface and ground waters. The paper evaluates the raising of the Mangla dam, its effects on long-term groundwater balance and water-logging using an irrigation-economic model. It suggests guidelines to optimize the surface and sub-surface reservoirs by considering the farmers' action in response to government policies. Recently the Government of Pakistan decided to raise the height of the Mangla dam to substantially increase the storage capacity of the basin. This decision was based on basin-wide modelling of conjunctive use by using the General Algebraic Modelling System (GAMS)-based Indus Basin Model Revised (IBMR), which was updated for this purpose in 2000 and supplied with new data in 2002. The results of the analysis reinforced the decision to raise the dam height by 9 m instead of 12 m, which would increase water availability by 68% in the basin. One of the objectives of raising the dam height was to increase the sustainability of beneficial groundwater use in the basin by saving about 2 km3/a of groundwater abstractions. GAMS Groundwater IBMR Indus basin Sustainable conjunctive use 2011 5 01 1 12 http://ecopersia.modares.ac.ir/article-24-6782-en.pdf
60-896 2024-03-28 10.1002
ECOPERSIA ECOPERSIA 2322-2700 2538-2152 10.22034/ecopersia 2011 0 1 Changes in Soil Physical Properties in Response to Metal-Tracked Skidder Traffic Berdimohammad Agherkakli Akbar Najafi Seyed Hamidreza Sadeghi Ground skidding on skid trails affects the physical properties of soil. The objective of this study was to evaluate changes in soil physical properties on skid trails formed due to traffic of metal-tracked skidders with regard to soil bulk density, total porosity, water content and penetration resistance. The studies were implemented on two levels of slope – <20% (SC1) and >20% (SC2) – and three levels of traffic (one, five and nine traffic cycles). The treatment plots with three replications, consequently, were 6 m long and 4 m wide. The measurement of soil penetration resistance was carried out using a cone penetrometer. The samples were taken from 10 cm of top soil at six points in each plot. The results indicated that the skidder traffic did not significantly affect the soil physical properties measured in three levels of traffic at SC1, whereas it was significant between one and five traffic cycles in SC2. Most of the changes in the measured properties in the skid trails occurred after the first loaded skidder traffic. Within all traffic of SC2, differences in the mean values of water content and soil porosity were greater compared with the mean values at the same traffic of SC1, although these differences were not significant. The bulk density and penetration resistance at five and nine traffics of SC2 were significantly different from the same traffic of SC1. Bulk density Skidding operations Soil penetration resistances Total porosity Water content 2011 5 01 13 21 http://ecopersia.modares.ac.ir/article-24-896-en.pdf
60-1493 2024-03-28 10.1002
ECOPERSIA ECOPERSIA 2322-2700 2538-2152 10.22034/ecopersia 2011 0 1 Histopathological and Pathomorphological Effects of Mercuric Chloride on the Gills of Persian Sturgeon, Acipenser persicus, Fry Zahra Khoshnood Saber Khodabandeh Mohsen Shahryari Moghaddam Saeedeh Mosafer Khoorjestan Histopathological and pathomorphological effects of 15 ppb mercuric chloride on Persian sturgeon, Acipenser persicus, were investigated using histological and electron microscopy observations. Light microscopy showed that the gill epithelial hypertrophy, wrinkling and hyperplasia in lamellar epithelia and lamellae fusion occurred after 48 h of exposure. Gill epithelia also showed occasional necrosis, which had almost been completed and blood emerged from the capillaries. However, occasional necrosis in some regions of the filament, both with blood emerging and with no bleeding, was observed by using electron microscopy. These injuries were well observed in inter-lamellar regions of the filament and also wrinkling of the lamellar epithelium. Ultrastructural observations showed some cellular disorders in gill epithelium of the Persian sturgeon, A. persicus, fry. In addition, increase in apical vesicles of the chloride cells and necrosis in apical surfaces of some chloride cells, hypertrophy and necrosis of the chloride cells’ mitochondrion and endoplasmic reticulum also were some of the other cellular disorders observed through transmission electron microscopy. In conclusion, the gills of A. persicus fry were sensitive to low concentrations of inorganic mercury (HgCl2). Acipenser persicus Fish Ggill histopathology Mercuric chloride Pathomorphology 2011 5 01 23 32 http://ecopersia.modares.ac.ir/article-24-1493-en.pdf
60-5583 2024-03-28 10.1002
ECOPERSIA ECOPERSIA 2322-2700 2538-2152 10.22034/ecopersia 2011 0 1 Appraisal of the Trend of Soil Infiltration Rate Changes in Flood Spreading Stations of Iran Mohammad Hosein Mahdian Reza Sokouti Oskoee Kourosh Kamali Flood spreading stations were constructed in Iran with different objectives such as groundwater recharge and vegetation recovery. Accumulation of sediment can be a major problem in flood spreading stations. According to generally accepted theories, floods and salt pollution can reduce gradually the infiltration rate. In order to investigate this issue, 13 flood spreading stations were selected across the country and infiltration rate changes were monitored over five years in the flood spreading areas. Non-parametric tests were used to analyze the abnormally distributed data. Based on the soil properties of the spreading stations, stations were first classified into three groups separately by cluster analysis; next, studies were conducted in three separate groups. Results in stations group 1 showed that, in the first year, the infiltration rate among spreading lines was not significantly different, but data for the second year showed a significant difference at α = 0.05. For stations group 2, in the third year, the difference in the infiltration rate was significant at α = 0.05. In addition, changes in the infiltration rate were significant at α = 0.05 in stations groups 1 and 2 in the second spreading line. For stations group 3, significant changes among lines have been detected. Results also showed that changes in the infiltration rate in different years were somewhat different among the three groups of stations. Although infiltration rate changes were low, there was a general decreasing trend. Floodwater Infiltration rate Iran Sediment 2011 5 01 33 43 http://ecopersia.modares.ac.ir/article-24-5583-en.pdf
60-6299 2024-03-28 10.1002
ECOPERSIA ECOPERSIA 2322-2700 2538-2152 10.22034/ecopersia 2011 0 1 Effect of Some Environmental Factors on Plant Species Diversity in the Mountainous Grasslands (Case Study: Hamedan - Iran) Bakhtiar Fattahi Ali Reza Ildoromi Species diversity is an index for sustainability of rangeland ecosystems. We studied the effect of environmental factors (soil properties and aspects) on plant species diversity in Zagros mountainous rangelands (vegetation type: Festuca ovina-Astragalus parrowianus) in the west of Hamadan in March–July 2009. For this purpose, four aspects were defined in the study area. Vegetation types were studied by physiognomic-floristic method in the field. The factors of vegetation were measured by transects using a systematic-randomized method. Five transects (100 m) and five plots along each transect were used. One soil sample (composition, 0–40 cm) in each plot was collected by a randomized method and assessed the following factors: pH, OM, N, EC, P, K and texture in the laboratory. The multiple regression method was used to investigate the relationship between species diversity (dependent variables) and soil and topographical factors (independent variables). Results showed that soil characteristics and aspects had significant effects on diversity in which north, east and west aspects as well OM, N, EC and clay were the most prominent factors influencing diversity. Iran Grassland Mountainous rangeland Plant Diversity Zagros 2011 5 01 45 52 http://ecopersia.modares.ac.ir/article-24-6299-en.pdf
60-6157 2024-03-28 10.1002
ECOPERSIA ECOPERSIA 2322-2700 2538-2152 10.22034/ecopersia 2011 0 1 Kinetic Energy Model of Two-Phase Debris Flow Zhoayin Wang Guangqian Wang Onyx Wai Yong Chen Chun Zhen Wang A numerical model for two-phase debris flows is developed in this paper, on the basis of understanding of the physical characteristics of debris flows from field investigations and experiments. Employing a moving coordinate, the kinetic energy equation of gravel particles in unit volume in debris flow is developed by considering the potential energy of the particles, energy from the liquid phase, energy consumption due to inner friction-collision between the particles, energy dispersion through collisions between particles, energy for inertia force, energy consumption due to the friction with the rough bed and energy consumption at the debris front. The model is compared with measured results of two-phase debris flow experiments and the calculated velocity profiles agree well with the measured profiles. The gravel’s velocity at the debris flow head is much smaller than that of particles in the following part and the velocity profile at the front of the debris flow wave is almost linear, but the profile in the main flow shows an inverse ‘s’ shape. This is because the gravel particles in the main flow accelerate as they receive energy from the gravitational energy and flowing liquid and decelerate as they transmit the energy to the debris flow head and consume energy due to collision with the channel bed. Energy Consumption Kinetic energy model Two-phase debris flow Velocity profile Collision 2011 5 01 53 63 http://ecopersia.modares.ac.ir/article-24-6157-en.pdf
60-10438 2024-03-28 10.1002
ECOPERSIA ECOPERSIA 2322-2700 2538-2152 10.22034/ecopersia 2011 0 1 Application of Methodology for Mapping Environmentally Sensitive Areas (ESAs) to Desertification in Dry Bed of Hamoun Wetland (Iran) Seyed Hedayat Parvari Ahmad Pahlavanravi Ali Reza Moghaddam Nia AbdolHamid Dehvari Davood Parvari Several models have been developed to estimate land degradation rate and evaluate desertification severity. This study attempts to apply the MEDALUS (Mediterranean Desertification and Land Use) model by considering existing conditions in the Hamoun wetland, located in south-eastern Iran. At first identification of the main factors affecting the desertification phenomenon was attempted, based on field survey. These factors include climate, soil, vegetation and management practices. Results showed that land management and extreme climate are the most important factors affecting the desertification process. In addition, in some land uses, lack of vegetation accelerates the prevalent wind intensity in the study area (known as “the 120Rozeh” (means 120 days and refers to the wind, with high speeds that blow from the North to the South during summer time) – the most famous Iranian winds) which continues its path without any barrier, and erodes the land surface. Results also indicated that the study area is mostly located in the critical desertification class. Based on the results, it is known that 14% of whole region (12,273 ha) is in the low-critical class, 48.2% (42,251 ha) in the medium-critical class, and 37.8% (33,134 ha) in the high-critical class. Desertification MEDALUS model Sistan region Wind erosion 2011 5 01 65 80 http://ecopersia.modares.ac.ir/article-24-10438-en.pdf