Year:2003 | Volume:16 | Issue:1 (58 IN NATURAL RESOURCES)|Papers Count:18

Some relations for flood design estimating in sub-catchments in east and west part of north basin (Khazer basin).are established using multiple regression and index flood method.There are 31 sub-catchments in east part and 22 in west part of this area as gauged catchments.Factor analysis approach has realized that amongst several factors affecting on instantneous peak discharge, area of watershed, length of main channel, mean slope of watershed, mean annual precipitation, drainage density and compactness coefficient harv the largest effects, thus they are used in regional flood estimation analysis. Four homogenous groups of catchments are classified for each part of whole area and also entire area as one group using cluster analysis, Anderw curves and discrimination test. Some relations have been established for each of these groups and also for entire area of both part of Khazer basin using flood index method as well as multiple regression analysis. The results are successful in comparison with previous works have been done by others in this area.

Nepeta pogonosperma is which are growing wild in north of Iran (Qazvin province and Ramsar in Mazandaran). In this study sample collected from Khashchal in Alamut in July 1999 an altitute of 3000 m and cultivated in the Research station of Medicinal plant an altitute of 1450 m.The essentail oil obtained by hydrodistillation method. The percentage of oil on wild catnip 1.7% on cultivation irrigation condition (first harvest) 1.59%, second harvest 1.8% and non - irrigation condition 1.32 calculated on the dry weight, essential oil composition analized by Gc and Gc/Ms. The majore constituents were 1.8 cineol, Nepeta Lactone, and b-Pinene that in wild catnip 26.4%,57.6, and 4.93%, 47.82%, 27.27% and 4.93% (First harvest), 52%, 16.7% and 6.7% (second harvest) Irrigation condition and 43.5%, 34.96% and 3.59% in non condition in respectively.

Stepped gabion weirs are composed of termed gabion, and stone have many applications especially in full water rivers and steady slope as well as applying for elevation of water level, decreasing of water erosion severity of high steady rivers in mountainous area and as weirs crest and over part stairs will cause losing a large quantity of water potential energy. This study was cunducted on the basis of some research conclusions on physical model of stepped gabion weirs more attention were paid to application of gabion buill and some given results were also presented in this in stance with the aim of dimensions analysis and applying of physical model froud number with general slope of down slope 1:1, 2:1 and 3:1 (horizontal: vertical) in two general state of permeable and impermeable gabion body were made, and set up under passage of various flow with calculation of specific energy of water flow in downstream and upstream of models, the loss energy percentage on weirs was calculated and them with the help of some available softwares, various conditions of flow parameters were examined and compared with each other. One the basis of this investigation we concluded that minimum velocity speed flow in minimum debi (flow) is related to weir with down slope of 1:1and fit to impermeable model and the maximum debi (flow) is related to weir with some slope fit to permeable model. There fore the necessity of establishing the energy dispersion structures with long length for, erosion cotrol in ceased in such cases.

The study was located in playa marginal area (35 Km South-West of Sabzevar city, Khorasan-Iran).Influences of two methods of irrigation (Basin Irrigation Method as control plot with 36 m3/ha of fresh water and flood - water irrigation method with over 800m3/ha of saline flood-water) on plants vegetative characteristics (cover, yields, density, stablishment), were investigated. Results showed that, in basin irrigation method the plant cover percent was %3.9, stablishment percent was %3, density was 18 (shrub/ha), yields was 70 (kg/hg) and biomass was 78 (Kg/ha).But in flood water irrigation method, this plant factors increased about: %15, %70, 564 (shrub/ha), 533 (kg/ha) and 1064 (kgr/ha) in respectively. Thus for saline - sodic soil reclamation and rehabilitation in arid and semi arid climate, basin irrigation method because of less amount of water is not efficient but flood - warter irrigation method because of much amount of water is suitable for soil leaching and breter reclamation.

Effect of gap size on survival, growth and vitality of beech (Fagus orientalis Lipsky) potted- seedlings was investigated in a beech forest of Sangdeh (1400 m a. s.1.), situated in the north of Iran. Three gaps with areas of 50, 200, 600 m2 and one gap in open were selected whereas in each gap, potted-seedlings were established at four replications of 49 units. The results show that after one growing season, mean survival rate of seedlings in either gaps of 50 m2and 200 m2 is about 75% and in 600 m2 as well as in open about 10%. Total height is, in the order, 60 mm and 90 mm in gaps of 50 m2and 200 m2 and 40 mm and 30 mm in gaps of 600 m2 and open. Vitality is of better quality in gap of 50 m2 compared to that in 200 m2,but in gaps of 600 m2 and open it is presented to be desiccated more and pale less, respectively. Generally, it can be deduced that at first growing period, the condition of beech potted-seedlings is more favorable in smaller gaps than in bigger gaps. Whereas their natural regeneration training in gaps created by marking (shelterwood system or selection system), as well as their seedling production, in areas greater than 200 m2 would be caused to decrease their qualitative and quantitative status. For encouragement of seedlings growth in smaller gaps, regarding to their status and site, removal of few tree or shrub individuals around gaps in following years is advised.

For compare of diversity and species abundance flora plants in natural hardwood and softwood selected two stands in two areas. This areas located in lajim of Mazandaran in 35km souths of Sari. This stands have 8 hectar areas which of stands plantes Norway spruce (Picea abies) in 1963 and other stand is including natural hardwood with species such as Anus subcordata, parrotia persica, Fagus orientalis. The height of sea surface 850-950m, slope is 10-40% with south and westsouth aspect. The texture of soil is heavy and semi – heavy (Clay, loam, Clay-Loam) with median and hith deep. Mean annual rainfall average 1300 mm and climate is cool-humid, For compare of diversity in two area were used to shannon index diversity. In these areas were used 1~.quadrat 10* 10m with random sampling for diversity assesment and In each quadrats species number of species and individuals species determinated. The results shwed that shanon index diversity were - 1.922 in natural hardwood forest and 1-3697 in plantation of Norway spruce. Floor diversity in hardwood is higher in compare with plantation Norway. By using of. Test distinguished which difference of diversity between plantation Norway spruce and natural hardwood were significant. Species abundance was higher in plantation Norway spruce.Equatability index wer 0.835 in natural hardwood and 0.705 in plantation Norway spruce.

Tripleurospermum disciforme which belongs to the asteraceae family, can be found in many region or Iran.Primary studies on this plant indicate the flavonoids and essential oil are the main secondary metabolites of flower parts of this plant. Flavonoids of the plant were separated by using a preparative thin layer chromatography method and then identified by means of US-VIS spectra and shift reagent. The result of this part of our research indicates that the main flavonoids of T. disciforme belong to flavones. The essential oil the plant was isolated by hydro distillation method and then analyzedby GC/MS and TLC. The main components of the oil are: Trans - beta - Farnesene (14.2%).Farnesene of the essential oil separated by using a column chromatography method and then identified by means of UV-VIS spectra and IR. Conformity of these spectra approved the presence of farnesene in the essential oil of this plant. We can not use this plant instead of Marticaria recutita, because the main componests are different.

Submerged rectangular orifice is among discharge measuring device which is suitable in small canal especially when the amount of fallis not adequat for application of weir, during the past decade many study have been conducted for evaluation of discharge coefficient of orifice. For free the case of submerged orifice only an average value of 0.61 has been mentiond in the literature. Since this coefficient depends to the flow characteristics and the orifice dimensions, an equation for determination of discharge coefficient is needed. The development of such formula is the main goal of this study. To do so an experimental program was conducted and applying the dimensional analysis and data obtained from these tests, one relation was developed. This relation can be used where an accurate value of the discharge coefficient and consequently the flow discharge is needed.

In order to investigate the effects influence of press time and temperature on development of particleboard strength and reach the minimum energy consumption and press time, two press temperatures of 165G and 185G and three press times of 3, 4 and 5 minutes were selected. Heat transfer from the mat surface to core was determined by placing thermocouple at different locations in board thickness. Mechanical properties of boards were determined and the relation between board properties and heat transfer measurement especially time to reach the temperature of 100G at the core was analyzed. The results indicate that press time and temperature did not significantly but the influence of these variables on MOE was significant, and increasing press temperature reduced MOE. The influence of both variables on IB was significant, increasing these variables increased IB. The results of heat transfer measurement indicate that increasing press temperature reduced the time to reach 100G at the core, which caused an increase in IB. This indicates that at higher temperature and press time sufficient time is available for resin to develop bond strength.

In this investigation a karyological study ofl Salsola abarghuensis from north of Abarkuh playa is presented. The work deals with number, size and chromosome morphology.The results showed that the chromosome number in this species is 2n=18. From 9 pairs of chromosomes, 5 pairs are metacentric, 3 pairs are submetacentric and 1 pair is subacrocentric, the average of chromosome length is 0.97 micron, the longest 1.17 micron and the shortest 0.64 micron.

Ulmus glabra, is the most endangered species of northern forests of Iran. due to the Dutch elm disease; older trees with high diameters is quite rare in northern forests today. These experiments were carried out as a step toward clonal propagation of superior genotypes. The effects of various hormone concentrations were investigated on the buds or three genotypes of Ulmus glabra. One of the chosen trees was juvenile and the two other were adult trees. Axillary and apical buds were collected in winter and cultured on DKW medium supplemented with different concentrations of BA. (0.02, 0.51, 2 mg/lit) and IBA (0.2, 0.1 mg/lit). Immersing buds in 70% (DKW. ethanol for five minutes and subsequently application of 3%. DKW. Hypochloride forests minutes.Was the best way to remove surface contamination. Complete removed bud scales was necessary. There was always some callus formation at the base of the microshoots. Higher concentrations of BA. caused more callus formation. The best IB medium for shoot proliferation was DKW Y. supplemented with 1mg/I IBA and 0.01 mg/I IBA. Shoots of different genotype rooted very easily. The juvenile genotype showed the highest rate of shoot proliferation and lowest amount of callus formation. Different genotypes showed different rates of rooting. All of the transferred plantlers established well in the field.

Taleghan area due to existence of fracture zones, active faults, seismicity, and geological features is potentially an unstable region. Study of lineaments due to their significance in conducting surface water and also as a landslide controlling factor is very important in such area. In this research landslide inventory map was produced based on aerial photo interpretation and field investigation in a geographical information system (GIS).Image processing of TM data was performed by applying gradient filters in four directions. (NW-SE, NE-SW, E-W and N-S), and lineament layers were extracted. Relation between landslide frequency and distance from lineaments, and also landslide frequency and lineament frequency were obtained.On the other hand, the relation between lineament directions and the main geological structures such as faults and folds were studied. The results indicated that: 1- In general, lineament directions follow geological structural feature in the study area. 2- The result indicates good agreement among landsliding and lineament density as well as distance from lineaments. 3- Lineaments with NW-SE direction are well correlated with predominant of fault directions and fold axis. 4- Landslides in the area are closely related with NE-SE lineaments. The research indicates the capability of remotely sensed data and GIS for recognition and analyses of lineaments which play important role in recognition of new geological structures responsible for landsliding in Taleghan area.

Parts of artificial forest with 10 hectars area were selected in northern forests of Iran. This forest were estabilished in two forms (pure and mixed stands) with Populus delta ides in 1987.20 plots were selected for consideration (10 plots in each stand). The diameter at breast height and height of trees, length and diameter of crown, healthy, vitality, volume and growth of trees and soil in all plots were considered. 12 trees (6 trees in each stand) were cut for wood physical and chemical analysing. The results are following:Thickness of liffer layer was more in pure populus stand. The situations of soil in two stands were similar. The growth of trees was more in pure populus stand. The quality of trees in pure stand was better than mixed stand. The fiber lumen was more in wood of pure stand, therefore, the burst and tensil resistence and breaking length in this stand was more than mixed stand. The wood density in mixed stand greater than pure stand. As the percent of lignin and extraction material in pure stand is less and its cellulos is more than mixed stand, therefore pure stand is more suitable for pulpwood. As a whole, because the mixed stand having variety production resistence against pestes and fungi and more uses of soil and space better than pure stand, but the base of different conditions of climate, site and uses of wood the selection of pure or mixed stands is different. In this area the pure stands of populus in some objects especial for pulpwood more better than mixed stands.

Three elevation levels (300, 850, and 1200 meters above sea level) of Nowshahr forests were chosen to investigate regeneration and qualities characteristics of oak (Q. castaneifolia) stands. At each elevation level 10 macroplots (1000 m2) were allocated randomly and systematically. At each macro plot 12 microplots (1m2) were allocated along two diameters of the circle macroplots (nothern - southern and eastern - western) by three meters intervals. The growth parameters which were studied at each macroplots were diameter of oak trees and other species; total height of oak trees and crown height of oak trees and oak trees quality (stem twist, stem crokedness, stem smoothness, crown harmony and branching). Cover percent of herbal accompanied plants in each micro and macro plots were determined. The results showed that the best stands of oak species in view of dominant height and regeneration was found at the medium level of elevation(850 m) where as the best in view of quality was found at the lowest level of elevation (300m) . It means that by increasing the elevation, the qualities of Oak stands were decreased. The soil type at 300 m and 1200 m elevation levels was brown autroph where as at 850 elevations level was classic brown. The soil depth at each soil type was considerable.

Ziziphora clinopodioides Lam. Which belongs to the Labiatae family grows wild in many parts of Iran. The plant is used as stomachic, antifever, anti inflammatory, sedative and flavoring agent in Iranian folk medicine. The chemical composition of the essential oil of Z. clinopodioides growing wild in Iran was examined by GC and GC-MS. Twenty-two components were identified in which pule gone (53.2%), p-mentha-1-en-1-01 (21.4%), 1,8-cineole (10.3%), p-mentha -3, 8-diene (3.7%),  b-pinene (1.6%), cis-isopulegone (1.5%) and bornyl acetate (1.2%) were the main components. The results of this investigation indicate that the oil of aerial parts of Z. clinopodioides characterized by high contents of monoterpenes (98.5%) and only trace amounts of sesquiterpenes (0.4%) and aliphatic hydrocarbones (0.2%).