نشریه پژوهش های آبخیزداری
پیاپی 82 (بهار 1388)

Present Study was done for distinguishing of relationship between soil characteristics and Plant species densty in Aras Riparian Zone. For this purpose, 20 plots(10×10 m) were selected using randomized systematic sampling and density vegetation and crown cover, diameter and elevetion of native species were recorded. The result of χ2 test showed that different soil textures significantly (p<0.05) have different presence and density of species.Whereas Tamarix ramisissima as compared with other species have the highest presence in bothe soil textures, Loam and Sandy-Loam(%89/7and%74/85). The highest occureance of Eleagnus angustifolia, Salix alba and Populus alba were in Sandy-Loam textures. Correlation cofficients of evaluated parameters showed that study factors of species had different correlation with determined factors of soil. Whereas the soil characteristics significantly (p<0.01) have different correlation with density of Tamarix ramisissima. All the soil characteristics significantly have a positive Correlation with density of Tamarix ramisissima, except pH.

In this study flood harvesting was studied in Herat flood spreading station during 3 years (2005-2007).Changes in soil fertility in flood spreading areas with 3 treatment and 18 replicates were recorded. Strip, kind of land and time (year) are studied factors. Trapezoid methods were used to test soil fertility in different depth (0-90cm) and Strip, kind of land and time (year). Comparing mean of data, using Duncan test showed significant differences in control area(c). Changes N, P, O.C, C.E.C elements in control area and flood spreading area was not significant but K was significant (p<0.01). A change of N, O.C elements in dams was not significant. But P, K, C.E.C elements was significant. A change of C.E.C elements in years was not significant and N, P, O.C elements was significant. A change of N in different depths was not significant but in K, P, O.C, C.E.C elements was significant.

Flood Damage is one of the most important problems in many countries. There are different methods for flood controlling by using indentification of flooding areas. Because most of the watersheds have different flooding seasons, the present study is going to comparison of temporal prioritizing of flooding of Kooshkabad sub-watersheds in Razavi province using HEC-HMS model. In this study we used of SCS hydrologic simulation method at Rainfall-Runoff transformation on sub-watersheds area, and Muskingum routing method on main channels for abtain of watershed outlet flood hydrograph after determination of data for flood hydrograph. Than we calculated prioritization of sub-watersheds to point of flooding conception using HEC-HMS model and we calibrated it on initial adsorption and curve number and lag time parameters in springal and Summer-Autumnal hydrologic priods. Than we prioritized particitation amount of sub-watersheds on peak flood discharge and flood volume in every hydrologic period, using one to one delet of sub-watersheds in flood routing. Paired samples t-test have used for indication of significant difference to point of statistical in temporal prioritizing of sub-watersheds flooding.The results of this research show that participitation amount of sub-watersheds on outlet peak flood discharge and flood volume in different periods is significant.

As average annual precipitation in Iran is less than global, all of the water in hydrological cycle must be used.In this way we must consider all parts of urban and industrial waste water.Lands located in downward of refinery of industrial city of Alborz were subject of this research.As lands are in use for grazing of sheeps and as they are contaminated by waste water, so these lands have more importance than others.Subject of this project is effects of irrigation by industrial waste water on plants and soil of the region.To do this research,enough numbers of soil and plant samples were gathered and be moved to the lab,and then concentration of heavy metals were measured.Results were studied by SPSS soft ware from statistical point of view.Results showed that absorbed heavy metals in plant bodies, soil and water were more than its standard levels.Therefore there are a lot of worries about soil,plants and human health of that region so proper answers must be found for this problem.

Adaptability and productivity are two major factors to be considered when exotic species are going to be introduced. In a split plot design 12 species of medicago genus in Khersanak with 400 mm annual rainfall were examined. Forage and dry matter, leaf to stem ratio and height were the items measured and compared in the first year. Results showed that medicago cody and sativa with 1.7 and 1.34 ton/ha dry matters respectively were most productive, while in second year Medicago cody, was at the top, Medicago ranger, gharah and sativa were also productive and there were no significant differences between them. In third year it was revealed that Medicago sativa, ranger, gharah, local medic and Cody were significantly(p<0.01) most productive species (3.01, 2.78, 2.43, 2.40, and 2.28 ton per hectar respectively). In the first year there were no significant difference (p<0.05) between height. In the second year Medicago ranger, gharah # 1, and cody were higher in comparison to the other (56.45, 55.33, 55.59). In the third year ranger was the highest. In second and third years wild medica showed a higher ratio for leaf to stem.Generally cody and wild medic were well adapted.

In order to assess the satellite data in soil investigation, digital data of LISS_III, field study and laboratory results of Kashan soil, were analyzed. Upon merging all the morphological and physico chemical characteristics, the soils were classified. The geometric correction on the satellite images was performed by the method of map to image and the error was less than 0.5 pixels. Atmospheric correction was done by minimum histogram method. The train samples were chosen upon directing homogenous units on the color composite, using field study and other information. The images were classified by using supervised method and maximum likelihood algorithm, than were compared with the ground truth map and information. The results showed that for choosing a suitable band combination while different phenomena have the same_spectral behavior like Torriorthents and Aquisalids.The good index is not only efficient and other information such as DEM in the spectral combination, causes increase in accuracy of classification and Kappa coefficient. The results indicated that, LISS_III can not discriminate Typic Haplosalids from Typic Aquisalids. Gypsic Aquisalids Have the least reflection, so that this soil have spectral interference with Typic Torriorthents. The surface of Gypsic Aquisalids are full of salt and gypsum, while soil surface of typic Aquisalids are with sponge like and polygons seals, which are moist at the deep layers. Na and Mg salts are the most predominant in the two soils, it seems that moisture and roughens of the soil surface is the main reason for reduction in spectral reflection in Typic Aquisalid.We may conclude that LISS_III data can not differentiate saline soils with different surface moisture condition.

Cymbopogon olivieri is one of the major rangeland plants of Hormozgan province with 2921547 ha. This investigation was carried for knowing some ecological charasteristics of Cymbopogon olivieri from 2003 for three years. Climatic, geologic characteristics, land types, habitate types and distribution map were provided for all of habitates and in Bashagard, Bastak and Sarze kharu were done vegetative parameters measurment and soil analysis. This species was located from 20 m. Alt. in Bandar Khamir till 2900 m. Alt. in Bokhon mount in Haji Abad, from mountainous different regions thll pedimente and river bed.This species is in 31 vegetative types as major species and in 90 vegetative types as Campanion plants. It is seen in five different climates that hot and dried desert is the most and extra dry temperated is the least. Also it is seen in different geological units that quaternary formations is the most and shaly sandstone is the least. This plant grows in sandy-loam with pH=7.42-8.28 and EC=0.29-2.38 mm /cm.

The ruination of agricultural and rangelands and gotten them out of production areas has been mad by over population and irregular use of natural resource to obviate.In many part of the world human are thinking to take a right advantage of soil and water resource in order to provide more food and compensate the ruination of flood that is arising from disproporationate function.Such as thing in Iran also has been thought about water spreading on poor rangeland to revive vegetation cover and store the aquifer.The main object of this study is investigation of water spreading influences on quantitative and qualitative variation of vegetation cover in the Sarchahan station in north of Hormozgan province since 2000-2005. For this purpose two areas were chosen. One of the water spreading net as a treatment and similar area in terms of vegetation cover and soil that it just not flood as a control.60 quadrats for water spreading area and 12 quadrat for control by 22 m and the items was recorded. This area is with a poor range condition and negative trend. In this study percentage of vegetation cover, density and forage production of rangeland plants were measured at water spreading and control area. ANOVA test showed there is no significant differences between percentage cover and productivity during 2000 –2003 years (p<0.05). But there is a significant difference between those factors at water spreading and control area in 2004 and 2005 years.Water spreding project to be succeeded to revival the rangeland depends up on the same spread of water flood over the lands and enough time flood during the year. More study during next years cause in better results.

In order to increasing productivity and achieving to reclamation objectives, it is necessary to recognize relationship between soil and plant. Selection of adaptable and resistant plant with arid conditions depends on distinguish of ecological needs of them. Plants have special effects on there habitat and study of these effects can be useful in planning projects.In this research, we try to identify Atriplex canescens effects on physico-chemical properties of soil in different layers in Qom. Split plot plan was used for sampling and analyzing. Cultivated and natural lands were considered as between factors and different depths [(0-10),(10-30),(30-60) cm] as within factors. Soil properties including texture, EC, acidity, nitrogen, phosphorous, potassium, organic matter, sodium, calcium, magnesium, chloride, carbonate, decarbonate were measured. Results show that Atriplex canescens increased phosphorous, potassium, acidity in surface layer more than other layers in cultivated area.