IRANIAN JOURNAL OF NATURAL RESOURCES
Year:2006 | Volume:59 | Issue:1|Papers Count:23

Flood is a complex natural disaster and a destructive phenomenon that causes considerable annual damage. Floodplain and lands alongside river beds are always at the exposure of flood, while most of economic activities are also concentrated in these areas. Therefore, in these regions, flood zoning is indispensable. Flood zoning maps, could be a suitable and well as lawful tool for use in determination of development strategies. In this research, a map of flood zoning with different return periods was prepared. Hydrological data and information were collected and analyzed. Natural unit hydrograph (N.U.H) was derived. In addition, 262 cross sections were surveyed for Broudjerd Seilakhor River and its branches. Some floodplain characteristics, such as situation of bed and river banks as well as vegetation cover were noted. Flood routing was carried out in different branches and reaches employing Muskingum-Cunge method. Finally, by using HEC-RAS model, flood-zoning maps with a scale of 1:50.000, water surface profiles and flow characteristics in different reaches and for different return periods, were derived. Then, the accuracy and precision of maps, by use of historical films and pictures and through regional investigations, were evaluated. The results indicated that by even considering the HEC-RAS limitations, the final flood maps were still accurate enough for the aim followed in this kind of study.

Drought is a meteorological event the adverse effects of which can be observed not only in arid and Semi arid, but in humid regions as well. To reduce these effects, drought should be studied in a scientific manner, and in correct frameworks. As drought can also be considered as a hydrologic event, we can apply hydrologic methods to analyze it. Markov chain is one of the most important and classic stochastic models having many applications in hydrology as well as in meteorology. To prepare a map of drought probability occurrence, the probabilities of different conditions derived from Gibbs and Maher procedure for 22 stations in Isfahan province were considered as Markov chain and the return period for each condition was calculated for each station. Applying ordinary Krigging, the map of drought return period was drawn for Isfahan province.

Drought analysis is of very much importance in evaluation of water resources projects. Based on regional analysis of hydrologic drought, it is possible to develop relations between watershed characteristics and flow indices to estimate drought intensity. In this research, frequency analysis based on normal distribution was performed for 12 watersheds in Tehran province. In addition, Factor analysis on 19 variables including physiographic, climatic and geologic factors resulted in four effective variables of: watershed area, annual average precipitation, weighted mean infiltration and average slope. Cluster analysis was carried out for determination of homogenous regions in which watershed were divided into two homogenous groups. Run theory was used to estimate intensity of hydrologic drought. To find relation between 4month _ 10 yr drought intensity and characteristics of the watershed, multivariate regression technique was used, the best model being proposed. Finally, using data of three control stations, accuracy of the proposed regional model was evaluated. Results show that, in the study area, regression models developed for homogeneous regions are of a higher accuracy as compared with the models developed for the entire region.    

Erosion and sediment Formation is a complex function of different factors, and depending upon regional conditions one or another may be responsible for their intensification. In this research, from among the effective factors on sediment production, land use change was studied in detail. The study area was Taleghan Drainage Basin. Through use of air photos, remote sensing as well as field studies, land use maps of this drainage basin was prepared for years 1970, 1987 and 2000. Then the amount of suspended sediment yield during 1970-1971, 1971-1987 and 1987-2000 were calculated from water discharge-sediment yield data of Taleghan Watershed hydrometric station, located in Galinak. For determination of accuracy of sediment yield data, sediment yield in sub- catchments were calculated using EPM model. Some conclusions are as follows: -Rangelands have been increased by 15% and, dry and agriculture lands decreased by 11.1% and 3.8% respectively. The reasons for these are immigration of young population to nearby cities and climate changes of the basin. -The amount of suspended sediment load has increased during 1970-1987 while being decreased during 1987-2000. The reason for the increase during 1970-1987 is climatic changes such as droughts and wet periods and change in the amount and spread of rainfall. The reasons for the decrease during 1988 to 2000 have been land use as well as climatic changes. The most effective factors in sediment yield of sub-catchments during 1970 to1987 have been water discharge and dry land form of land use. During 1971 to 2000 they have been due to rangeland form of land use and due to precipitation factors.  

In this research for evaluating the natural and artificial recharge of Moosian aquifer (located in Ilam provience, Iran) and for predicting its water table flactuations in the future years, a three dimensional groundwater numerical model (MODFLOW) were used. Based on the measured water level in 1989, the water table in 8 piezometric wells was assumed to represent a stable state of the aquifer and the model was calibrated on the basis of this information as the stable condition. In the next stage of the calibration, based on the output of the first stage, the unsteady state of the calibration was carried out for 7.5 years in 15 periods (1989-1997). To investigate the effects of flood spreading on the water table in the next 48 priods(24 years), the forecasting outputs of a stochastic-deterministic rainfall-runoff model was used as input to the numerical model, and the response of the aquifer in the unsteady state was predicted. The results showed that in spite of recharging the aquifers, because of high rate of exploitation, the aquifer will not come to a steady state and the water table in many piezometric wells continue to fall. Sensitivity analysis of the model showed that recharge is the most sensitive factor on the fluctuation of water table.

Different methods are employed in application of probability distribution in hydrology. The most common among these methods is the Central Moment Method. Maximum Likelihood Method is applied where computers are available and employed. In this study it has been tried to make a comparison between L-moment applicability and applicability of the other methods. To determine the probability distribution parameters and suitable distribution for annual discharge series, with an application of L-moment Method, 20 hydrometric stations were chosen for minimum, mean and maximum annual discharges. A number of 17 stations were picked up for maximum peak (flood) discharges. Results obtained for the study area in the central plateau watershed indicate the most fitting way of evaluation for different annual discharges as follows: Minimum discharges: P3 (third kind Pearson distribution), and L moment method. Medium annual discharges: P3 & LP3 (Log Pearson of third kind), and L moment method. Maximum annual discharges: P3 distribution & L moment method, and also LP3 distribution and two parameter LN (LN2) & normal moment method. Maximum annual momentous discharges: LP3 distribution & normal moment method, as well as the three: P3, three parameter LN (LN3) and two parameter LN (LN2) distributions.

In order to investigate on the spatial structure and estimation of forest growing stock in the Caspian region using geostatistical approach, this study was carried out in the Educational and Research Forest Station of Tehran University, Kheyroodkenar- Noshahr. Field sampling was performed, based on a 150m by 200m systematic rectangular grids. Since geostatistical techniques basically, rely on good estimates of spatial auto-correlation, particularly at short distances, four sample plots were taken 50m away, from central sample plots in the W-E and N-S directions. Each sample plot contained two concentric circles with areas of 300m2 and 700m2. Overall, 721 sample plots were inventoried in total area of 502 hectares. Then experimental variogram was calculated and plotted using the geo- referenced inventoried sample plots. The variogram revealed more than 80% Nugget effect, implying weak spatial auto- correlation between samples, even in 50m distances. Estimation was performed by ordinary block (100×100 m) Kriging using spherical model. Cross- validation results indicated that all the estimations are biased because of the large Nugget effect in the experimental variogram. Therefore, Kriging couldn’t make a precise estimation due to large variability in short distances and the weak spatial structure of forest growing stock in this heterogeneous and uneven-aged forest.

In order to determine the effects of Sorbus torminalis seed origin altitude on the germination of seed,  200 seeds of  40 individual wild service trees from two origins, namely Ashak ( 2100-2200m a.s.l) and Sangdeh (1700-1800m a.s.l), were planted in plastic flower- vases, in a nursery at 1500 m a.s.l. Germination of seed, survival and height growth of seedlings were recorded during the first year. Analyse is of data showed that, the effect of seed sourse altitude on seed germination was significant (p<0.05). The effect of seed sourse altitude on seedling survival (p<0.05) and the height growth of seedlings (p<0.01) was significant too. Germination rate of seeds collected from higher altitudes alttitute(Ashak) was higher than the germination of seed from lower altitude (Sangdeh). Despite that, the survival and height growth in seedlings of seeds from lower altitude was more than those in seeds collected from higher altitudes. It is therefore suggested to collect seeds from the nearest origin to the nursery.

In order to evaluate the quantitative and qualitative characteristics of Alnus subcordata in areas of different altitudes, three sites were selected and studied in Asalem. The areas of the first, secound, and third sites were 1.8 , 5.1 and 4.9 hectares respectively. In these sites, the following parameters were studied: kind of tree species, DBH, tree height, trunk quality analysis, extent of the branchless part of the trunk, number of branches from tree trunk, form and symmetry of crown, and tree regeneration. 100% inventory was taken as a means for sampling method. Height above sea level, slope in percent and aspect were also among factors determined for the sites. There was no significant difference obseved among curves relating tree diameter with site elevation at a probability level of 0.01, but at a probability level of 0.05 a difference was observed between sites of the 2nd and 3rd elevations. The 1st and 2nd sites are in a more vavorable condition than site 3 as far as branchless section of the tree trunk and intensity of branches on the trunk are concerned. Regeneration was in a better state in site / than thant in the other two. It is finally concluded that in addition to elevation, other factors such as slope, soil moisture and pH and above all the stie situation are all effective in quantitative and qualitative characeristics of mountanous Alnus subcordata.

To study the quantitive and qualitive  characteristics of Picea excelsa and Pinus nigra plantations in Ardabil, Fandoghloo forest reserve was selected. Seventeen square sampling  plots (10×10 m) were selected using randomized systematic sampling. Quantitive characteristics included survival rate, total and height, collar diameter while vitolity was taken as the qualitive characteristic. A comperative study between Picea excelsa and Pinus nigra on indentical aspect and slope ( southern, 20%) indicated a higher growth of diameter and height for Picea excelsa. (Picea excelsa 1.12 Cm and 0.26 m , Pinus nigra 0.64 Cm and 0.15 m). Results showed that from survival point view, there was no significant difference between the species. From vitality point of view, Picea excelsa was superior.

This research was conducted to study the structure of testis and reproductive cycles of male Bulatmai barbel (Barbus capito). The samples were collected from captured fish during May till June 2001 in the Sefidrood and Polrood Rivers and then transferred to an earth pond. During one-year, from October 2001 till September 2002, the testis samples of adult specimens were collected. The testis samples were fixed using Boain and tissues were prepared for histological observation using parraffinization sectioning and haematoxylin-eosin staining. The testis of Bulatmai barbel was found lobular. Spermatogenesis starts with either releasing or the degeneration of sperm and continues up to the middle of autumn. Spermatogenesis then goes to a dormant period which lasts up to next spring. At the late of March along with water-temperature arising, spermatogenesis develops rapidly, with result of the appearance of sperm in lobules. This process continues up to July. So, the maximum of GSI indicate the maximum growth of testis which varies from 1.34±0.5 to 1.75±0.09 during the reproduction season.

A comparative study on the effect of insulin-like growth factor-I (IGF-I) with DHP, hCG and acetone dried pituitary in Persian sturgeon (adsP) on in vitro germinal vesicle breakdown (GVBD) was examined in oocytes of Persian sturgeon. Moreover, the effect of DHP and hCG in pretreated oocyte with IGF-I was also examined. The study was carried out on two maturational stages of oocytes according to polarization index (PI<0.07 and PI>0.1). The oocytes, used on two germinal vesicle positions, underwent GVBD in response to IGF-I (10, 100, 1000 ng/ml). The rate of GVBD varied on each dose. In oocytes with PI<0.07, IGF-I (10, 100 ng/ml) it was more potent than DHP (10 ng/ml) while in oocytes with PI>0.1, IGF-I (100, 1000 ng/ml) more potent than DHP (10, 100ng/ml) on GVBD induction. IGF-I (10 ng/ml) in PI<0.07 and (100, 1000 ng/ml) in PI>0.1 induced more GVBD than hCG (10, 100, 1000 IU/ml).In two PI,s , adsP was more potent than IGF-I. Pretreatment of oocytes (PI<0.07 and PI>0.1) with IGF-I (100, 1000 ng/ml) and then treatment with DHP (100 ng/ml) could increase GVBD as compared to oocytes that were not pretreated. Oocytes pretreated with IGF-I (1000 ng/ml) and then treatd with hCG (100, 1000 IU/ml) underwent GVBD only in PI>0.1 (P<0.05). These results suggest, for the first time in chondrostean fish, that IGF-I is involved in the induction of GVBD of oocytes. IGF-I appears to act directly on oocyte as well as in conjunction with DHP or hCG, to induce GVBD.

A simple recirculating tilapia and lettuce culture system containig aerobic and anaerobic bacterial compartments was designed. The efficiency of the system for fish and lettuce production as well as improvement of water quality parameters were investigated. Seventy five juveniles of red tilapia with a mean individual weight of 5.62±1.75 g (Mean±SD) were  introduced in each rearing fish tank. Fsh tank was a rectangular fiberglass one with the capacity of holding 840 liters of water. At the initiation of the experiment was the tank filled with 640 liters of fresh water. The system benefitted from a good efficiency in the reduction of N-compounds (total ammonia –N, nitrite and nitrate) at the defined standard levels after five weeks. The concentration of total ammonia-N increased and reached a level of 8 mg/l after 5 weeks. Concentration of total ammonia-N was 0.73 mg/l at the end of experimental period. Concentration of nitrite increased and got to less than 1.52 mg/l after 9 weeks. Concentration of nitrate averaged 0.73±0.61 mg/l at the end of the experimental period. The fish attained a mean individual weight of 188±19g at the end of 15-week experimental period. Mean fish was 9.14 ± 1.55 kg per unit of production system or about 13 kg/m3 of water at the end of experiment. Three harvests biomass of lettuce yielded wet weights of 1437 ± 339, 2112 ±297 and 1173  ±202g respectively during the experimental period. Results indicated that with use of available facilities, construction of a simple recirculating aquaponic system for combined production of fish and vegetable with a minimum use of water and space would be practically possible.  

This study was conducted to determine a proper formulation for Kilka soup powder preperation, and to find its nutritive value, as well as its shelflife. Newly caught fish were dried in the oven after having been prepared and cooked, then converted into powder in a mortar. The resultant powder was processed with different additives to make Kilka soup powder in three formulae. The best formula was chosen using Hedonic’s method. In order to determine the shelflife, tests of TVN, peroxide, total microbial count and organoleptic tests were made at predetermined time intervals for a duration of 120 days. The results indicate that TVN changes from 5.56 to 21.5 mg/100g., peroxide from 1.39 to 4.28 meq/kg. and total microbial count from 9´ 104 to 2.2 ´ 102/g. Percentage protein and fat in the samples decreased from 52.05 and 5.8 to 46.3 and 4.9, respectively. TVN and peroxide changes are shown to be in a linear relationship with temperature and shelflife. These results as well as the results of organoleptic tests suggest that the samples remain in good conditions for a period of about 60 days, before being deteriorated. Also statistical tests indicated that at a level of p<0.05 the results were significant. Thus the shelflife of the product was finally determined to be about 60 days.

In order to determine viability of unfertilized eggs of rainbow trout (Oncorhynchus mykiss) out of body cavity, eggs obtained from three females were stored in three different treatment media for three time periods of 0 , 24, 48 hours at 10-11°C. In the first treatment medium, 15ml of unfertilized eggs from each female were stored separately on plates. For the second treatment medium, 5ml of eggs from each female were obtained, mixed together, and stored on plates. In the final treatment medium, eggs were obtained like in the first treatment but (100Iu/mL) penicilin and (0.1mg/mL) streptomycin sulfate were added to each plate. Maximum eyeing was observed in treatment medium containing antibiotics and at all time periods of storage. In all treatment media, at storage time periods of 24 and 48hrs, percent eyings was more than that in freshly fertilized control eggs. Although, there wasn’t any significant difference observed between eyeing percent in control as to separate and mixed eggs, but in times periods of 24, 48 hrs, percent eyeing in mixed stored eggs was significantly more than that in separately stored eggs. According to results obtained in this experiment, unfertilized eggs of rainbow trout can be held in coelomic fluid out of body cavity for at least 48 hrs without need for any special technology.

Export of commodities is very important for the economy in every country, because of its resulting revenue. Most developed countries gain part of their financial resources through export. Considering the above mentioned policy, the trend of importing paper in to the country can be reversed. Paper pulp and its related industries can be imported and expanded to produce the final export and non-export products. The related export revenue can be used to improve and expand the said industries. In recent years the products of our industrial paper units in Iran have increased from 329736 M.T. in 1377 (1980) to 426953 M.T. in 1381 (2002) to meet over 65% of domestic needs. Accordingly importing and exporting of paper products has had an upward trend in the same period.  The annual import of all kinds of paper products in 1377 (1998) has increased by 27% in comparison with 1372 (1995) while the export volume of all kinds of paper products in 1377 (1998) showed an increas of 95% in comparison the year 1372 (1993) approximately 685% increase in 1381 (2002) as compared with 1377 (1998). As the upward trend and increase in paper and paperboard consumption can be considered a normal phenomenon, so the ratio of about 50% increase during a five year period (1993-98) and a similar increase during 1998-2002 seem to be completely normal. Certain restrictions and limitations limit the competing abilities of our paper industries and thus he market share. Limitations in domestic sources of wood supplies, raw materials and paper pulp making units together with the low quality and high price of local paper products in comparison with foreign products can be considered as the main factors in this respect. Boosting investment in paper industries, installation of new factories, improving management to reduce the price of final products are the firm protective steps in overcoming the problems and to develop the paper industry in Iran.

Tehran as one of the most polluted cities in the world is a good candidate for an evaluation of pollution (from vehicles) effect on radial growth of ash (Fraxinus excelsior) trees. Since ash trees in Azadi square (most polluted site) and Sorkhehesar as well as Chitgar Parks (control or unpolluted sites) were not of the same age, a comparison of ring widths was made only after cross dating and standardization. Concentrations of Pb, Mn, Ba, Cu, and Zn in tree rings determined through ICP (Inductive Couple Plasma Spectroscopy) indicated no significant difference among tree rings (grouped in 5- year intervals) and no significant differences among sites (blocks). There was no significant difference observea among indices in ash trees at the three sites, indicating that pollution did not have any noticeable effect on the radial growth in ash trees.

Improving effect of paulownia in manufacture of particleboard from Eucalyptus cameldulensis was investigated. In order to find out the effect of eucalyptus extractives on adhesion phenomenon, The amount of extractives, PH after particle drying, end buffering capacity were measured. Laboratory boards were manufactured from a mixture of eucalyptus and paulownia particles. Percentage of eucalyptus and paulownia in mixture, press time, amount of resin, and the amount of hardner were considered as variables with other parameters begin kept constant. Test specimens were cut from manufactured boards. Modulus of rupture (MOR) was obtained for specimens. Results indicated that adding paulownia to eucalyptus p to 40 percent increases MOR in boards. Increase in compressability of mixed particles was the reason for this improvement due to lower density of paulownia. Press time, and the amount of resin content play a significant role in reducing the negative aspects of eucalyptus. Increasing press time up to 10 minutes and the amount of resin content up to 11 percent increased MOR. Results indicated that boards made by employing one percent hardner benefited from a higher MOR than boards made while using two percent hardner. It seems that eucalyptus is of an acidic nature which helps curing of the resin. Ingeneral boards manufactured from 40 percent paulownia, 60 percent eucalyptus while using 11 percent urea form aldehyde resin of one percent hardner content, and pressed for ten minutes yield particleboards of the highest MOR.

Wood furniture production industry in the world is growing. According to estimates around 180 billions $ US furniture produce in the world each year (2000) (12). Iran, similar to other countries, has been trying to promote its export in this field, to gain more financial resources. In this study Iran’s export and import of furniture during the years 1991 to 2001 was investigated, in which a considerable degree of fluctuation is observed. Iran’s export of wood furniture in 1991 was just 0.05 million US dollars, but in 1996 reached its peak in a whole period of 11 years to about 24.8 million US dollars. Then, it declined year by year and in 2001 it stopped at 10.6 million US dollars. The level of import (with only an exception) is not noticeable during these years, for example in 1991 (according to Iran Import Statistical Yearbook) it is merely 0.008 million US dollars, but during the following year (1992), with an unbelievable increase, it climbed to 475 million US dollars, then dramatically went down to zero in 1994-95 and then again an increase in 2001 to about 0.221 million US dollars. As the whole picture shows, during an 11-years period, wood furniture export decreased, while on the other hand its imports increased. This indicates that there are some serious problems in production, marketing and/or export of wood furniture in Iran. The majority of Iran furniture export destinations are Asia Minor countries especially Azerbaijan and Armenia. Apart from overseas markets, due to booming residential constructions and newly emerging young married couples Iran will have a fast growing domestic market demand for furniture in the near future. Main reference in this study was library search (foreign and domestic) as well as data collection from Iran foreign business statistical yearbooks. Some gaps have tried to be filled by arranging interviews and through distribution of questionnaires among some known furniture producers.

Variation in forage quality at different phenological stages was investigated for twenty forage plant species. Samples at two phenological stages were collected from Taleghan summer rangelands. Nitrogen and acid detergent fiber (ADF) were measured through chemical analysis. Crude protein, ADF, dry matter digestibility and metabolizable energy were assessed as indicators of forage quality. Forage quality significantly differed at different phenological stages. It was higher at vegetative stage, while lower at maturity. Forage quality also differed significantly for different species (p< 0.01). Among species the highest forage quality was related to Lotus goeblia while the lowest related to Cynodon dactylon.

Asafoetida (Ferula assa-foetida L.) belongs to cryptogam's phylum, angiosperm sub-phylum, dicotyledons class, dialypetals order and Apiaceae family. It is a herbaceous, perennial and monocarpic plant. The flowers appear only once during the life cycle of the plant. In the root is accumulated the resin. The resin which is through incision secreted of the root has medicinal properties. It is used as vermicide as well as medication in treatment of insomnia. This study was carried out in the rangelands of asafoetida (Ferula assa-foetida L.) in Khomrout located in Zarand, Kerman province. The main aim was to find out the correlation between root diameter and resin yield and also the effect of number of root incision on resin yield the statistical design was a complete randomized one with five replications. The results indicated that root diameter significantly affected resin yield Incision methods also affected resin yield significantly. By increase in root diameter resin increased. Mean resin yield per plant was 43.34, 48.62, 55.26, 62.54, 72.38 and 85.90 g from roots of 4-5, 5-6, 6-7, 7-8, 8-9 and 9-10 cm diameter respectively. Incision time also significantly affected the resin yield. There was an increase of resin observed during the first 9 incision operations and then declining up to the 14th. Incision of larger diameter roots (6 to 10 cm) and incision for the beginning nine times is more feasible and therefore recommended.