سهیلا نوری

The development of residential and urban areas on the banks of rivers and flood plains, regardless of the hydraulic and hydrological conditions govering the upstream basin and the river, increases the risk of flooding. Therefore, the study of floods for the purposes of planning, optimal exploitation and management of this natural phenomenon is one of the important issues in water resources management. The current research aims to investigate the rate of land use change using the HEC-HMS hydrological model and geographic information system (GIS) and Landsat satellite images during the years 1991, 2001 and 2011 in the Rigan watershed of Kerman province with an area of 7091 square kilometers. It was investigated on the increase of flooding of surface runoff in the area. For this purpose, in the first step, satellite images were interpreted and processed, and changes in land use was determined and soil CN values were calculated. Then, with the help of HEC-HMS model, the rainfall-runoff process in this basin was simulated and the peak flood discharge values were obtained in each period, and finally the flood hydrograph of the watershed was estimated. The results showed that with the increase of urban impervious surfaces and destruction of agricultural lands and pastures in the study area, the rate of soil CN from 1991 to 2011 increased from 65.28 to 70.25, following which the peak flood discharge from 29 m3 / sec in 1991 to 29.3 m3 / sec In 2011 and also the volume of runoff has increased from 3.4 to 6 mm during this period. The obtained results can be of great help to the implementation of watershed projects.

Dust storms are natural hazards that cause economic and social damage in the Sistan region. Because the investigation of the impacts of dust storms in all aspects is difficult, in this study a part of the impacts of dust storms was assessed and assessment was limited to extent of damage to roads for the period 2017-2019. The damages cost of dust storms on roads includes damages to the road surface asphalt, signposts, and road maintenance. For estimation of damage cost and obtaining the required information, a series of tables were provided and completed by Road Maintenance and Transportation organizations of Zabol, Zahak, and Hirman. Analyzing dust storms was carried out through recorded wind speed and visibility data at Zabol meteorological station. The results showed that dust storms impacted the signposts and damaged the road surface for which their maintenance and repairmen cost increased. A good agreement was found between the monthly and annual frequency of dust storms and accumulated sediment. The greatest amount of accumulated sediment on the road was observed during the first half of the year, in June and 2018 according to the highest frequency of dust storms. The total damage cost of dust storms on road was obtained about 32.5 milliard Tomans for the period 2017-2019.

Germination is one of the most important stages of plant growth that may be affected by different stresses in ‎natural environments. This study was kind aimed to investigate the effects of substrate and different levels of ‎gibberellic and indole butyric acid on germination characteristics of Salvadora persica seeds in 2019. Two factors ‎was considered consist of substrate (in four types (1- pit moss, 2 - cocopit and 3 - pit moss 50% + sand 50% 4 - ‎Cocopit 50% + 50% sand), and gibberellic acid (in two levels 250 and 500 ppm) and indole butyric acid (in two ‎levels 250 and 500 ppm). Then, the effect of these two factors and distilled water as the control in three ‎replications on seed germination and seedling growth of Salvadora persica was investigated using a completely ‎randomized factorial design. The results showed that the substrate had a significant effect on germination ‎percentage, root length, shoot length, seedling, fresh root weight, shoot fresh weight and seed vigor index ‎‎(p < 0.01). Seed pretreatment with gibberellic and indole butyric acid hormones had a significant effect on all ‎studied characteristics. Interaction of substrate type and pretreatment with hormones had a significant effect on ‎germination percentage, root length, shoot length, seedling and seed vigor index (p < 0.01) and had no significant ‎effect on root and shoot fresh weight. The highest germination percentage was obtained in cocopeat and ‎gibberellic acid 250 ppm (73%).

One of the requirement of sustainable exploitation prerequisite and prevention of the rangeland degradation is identification of the most suitable area of rangelands. In this research, beekeeping potential of the Tamin rangelands was evaluated in order to develop of beekeeping land use through AHP method. To this end, beekeeping suitability model was determined through integrating vegetation criteria , then the beekeeping suitability of different region was determined. Vegetation sampling carried out using randomized - systematic method. Suitability of different vegetation types was assessed using Analytical Hierarchy process. Based on results, weight of vegetation cover factor (0.62) was more than environmental factors (0.37) and water resource availability (0.014). Overall comparison of effective criteria sets showed that Artemisia sieberi - Asteragalus eriastylus (total weight= 0.34) and Astragalus eriastylus - Cousinia stocksi (total weight=0.055) have the highest and lowest priority in terms of beekeeping, respectively. In general, 1820.9 hectares (equivalent to 32.68 %) in the S1' category (high suitability), 2630 hectares (equivalent to 47.2 %) in the S2' category with limited constraints or moderate suitability (770.05 hectares (equivalent to 13.82 %t ) in the S3 category with the high limitation and 351 hectares (equivalent to 6.3%) in the non-suitable (N) was placed for the beekeepers' development land use from the entire of the study area (5572 ha). Result showed that planning to develop of beekeeping land use in Tamin rangelands is necessary and could provide new employment opportunities and improving livelihood of the farmers, which lead to the sustainable utilization of these rangelands.

Floristic studies of any regions have high importance, because the florists list is an exploration document to identify the existing species and consequently the potential of the area. The aim of the study was introducing the flora of the transitional zone of Irano-Turanian and Sahara-Sindian phytochoria in Sistan and Baluchestan Province. For a floristic study of the area plant specimens were collected and identified.Field data collections were conducted during the year 2013. The life forms as well as geographical distributions of the species were determined. Flora in this region include 51 families, 233 genera and 327 species. The larger families are Compositae (42 species), Poaceae (39 species), Brassicaceae (28 species), Papilionaceae (27 species) and Chenopodiaceae (25 species) respectivly. The biggest genus was Astragalus with 7 species. Biological types of this area included Therophytes (37.92%) where the dominant life-form followed by hemicryptophytes (22.94%). phanerophytes (18.96%), Chamaephytes (14.37%) and Geophytes (5.81%). Chrological analysis showed 24.77% of the studied plant species belonged to Irano-Turanian / Sahara-Sindian region and 24.16% Sahara-Sindian, 22.33% Irano-Turanian, 3.36% cosmopolitan elements and others are ploriregional. According to the results of this study, it can be concluded that the research area is located in Ecoton region.

The aim of this research was to identify the plant species, introduce the flora, and determine the life forms and geographical distribution of the species in Saravan. The classical method of regional floristic studies was applied to collect plants from the region. The collected samples were identified using the taxonomic methods and the required resources. Afterwards, the family, genera, and the species of each sample were determined. The life form of the plant species was determined by Raunkiers method. The position of the area within Iran’s phytogeography classification was studied according to the geographical distribution data. The results indicated that the region included 150 plant species belonging to 113 genera and 39 families. The most dominant families were Poaceae, Chenopodiaceae, Asteraceae, and Papilionaceae with 17, 16, 16, and 13 plant species, respectively. The life forms of the plant species of region included: Phanerophytes (28%), Therophytes (24.66%), Hemicryptophytes (22.67%), and Geophytes (4%). Considering the chorotypes, the plants mainly belonged to different plant regions. The growth elements of the region were Irano-Turanian (20%), Saharo-Sindian (24.67%), cosmopolitan (4.67%), Pluri-regional (15.99%), Irano-Turanian and Saharo-Sindian (28.67%), Irano-Turanian and Euro-Siberian (2.67%), Irano-Turanian and Mediterranean (2%), and Saharo-Sindian and Mediterranean (1.33%). According to the results of this study, it can be concluded that the research area is located in Ecoton region.

In this research using GIS effect of land management and soil criteria with eight indicators to study the sensitivity to the desert lands of the region of Sistan jazinak creation is evaluated. Vote based on the model parameters wilderness - the latest creation ESAs evaluation method wilderness creation and in most European countries and the Middle East is used, took place. Using the above method each of the indicators studied work unit was evaluated for each index layer was prepared by the information obtained data compiled GIS environment and desired criteria for each layer made of information was. Ultimately determine the geometric mean combining and intelligence layer criteria examined in the study area based on the model (ESAs), the intensity map obtained desert region creation. Based on the results obtained from the map 8/15 percent low fragile Brigade were part of the 20/08 percent Brigade fragile among moderate, 26/80 percent high-intensity part of the fragile type and 39/45 percent of the area Critical moderate intensity is too much Measure of the numerical value of the soil with 1/22 and the least impact with the numerical value of land management measures 1/72 greatest impact in the desert region has creation. Among the indicators two indicators, respectively, slope and soil texture with a numerical value, and 1/03 and the two lowest impact indicator pebbles and operations management, respectively, with the numerical value of 1/91 and 1/84 Desert greatest impact on morbidity region are considered.

Identification of rangeland species is an essential step in range management. This study aimed to study the flora, and investigate on the relationships of species distribution with climatic factors in Iranshahr region rangelands. Taxonomic studies were conducted to provide the plant floristic list. Plants life forms were determined using Raunkiaer categories. Twenty seven climate variables were collected from 12 synoptic stations close to the study area. Principal component analysis was used to identify the most effective climatic variables on the plant species distribution. According to the results, 175 plant species from 136 genera and 44 families were identified in the study area. Gramineae, Compositae, Papilionaceae and Chenopodiaceae contained the most plant species in the flora respectively. Results indicated that 25.72% of the plant species were Therophytes, 25.14% Hemicryptophytes, 24.57% Phanerophytes, 20.57% Chamaephytes and 4% Geophytes. According to the chrological analysis, 28.57% of the studied plant species belonged to Sahara-Sindian region, 24% Irano-Turanian /Sahara-Sindian, 20% Irano-Turanian, and 4% cosmopolitan elements. Results showed that the study area is located in Sahara-Sindian region. PCA results also indicated that the average of maximum relative humidity, number of days with thunderstorm, number of days with precipitation and maximum daily precipitation had significant effects on the plant species distribution.

Detailed studies of vegetation in desert areas are almost difficult due to the limitations and conditions of the areas. Remote sensing technology with numerous capabilities can be used as an efficient method in the areas. This study was aimed to determine an appropriate vegetation index to assess vegetation changes in the desert area of West Karkheh over a period of 18 years using satellite images of TM (1991) and ASTER (2008). After measuring the canopy cover, geometric and atmospheric corrections, different methods of detection and classification were applied on the images with maximum likelihood method. Results showed that PVI2 index was the best indicator to produce vegetation changes map during the study. So based on this index, final map of desertification was produced in the three classes with no changes and rehabilitation. The results showed that canopy cover increased up to 17.5% of the total area during the study period due to the implementation of desertification projects in some parts of the region and combined cultivation. These changes were classified in two classes of rehabilitation (69.8%) and desertification (30.2%).

In this research، desertification intensity of sistan plain was evaluated using IMDPA the newest method of Assessment of Desertification Potential in arid and semi arid regions of Iran. For this purpose 4 criteria selected including vegetation cover، soil، climate and wind erosion. Each criterion was assessed based on the selected indices which result in qualitative mapping of each criterion cased on geometric average of the indices. Then، sensitive map of region was extracted using geometric average of all criteria. Thematic databases، with a 1:50000 scale resolution، were integrated and elaborated in a GIS based on arc/info8، arc view3. 2 and especially ILWIS. By laminate of thematic databases layers and using this formula DM= (SI×WEI× VI×CLI) 1/4 to Calculate the geometric mean Criteria. Then Desertification intensity map was obtained with analysis IMDPA Model. The result showed that 51. 09% of study area was found to be in medium and about 45. 09% in high class of desertification. And while 3. 82% of the region in clouding Residential and Water tanks (CHAH NIME) there aren’t in any classification. Analysis of desertification criteria in Sistan region showed that among study criteria، wind erosion criteria is a major problem with a geometric average of 1. 67 which shows high class while soil with a weighted average of 1. 34 has lowest effect in desertification. Also vegetation cover and climate criteria with a geometric average of 1. 51 and 1. 57 show middle class desertification.

Drought stress is one of the most important factors controlling plant growth in arid and semi arid regions. Super absorbent polymers has introduced for absorbing seasonal rain to decrease moisture stress. As a result of over population and industrialization, water shortage is pronounced in dry or semi arid areas; hence use of waste water for some crops is being important. This study aimed to evaluate the multiple effects of municipal wastewater and super absorbent polymer on Nitraria schoberi growth under greenhouse conditions. In this study factorial complete randomized design with four replications was used. The treatments used included: two types of soils (clay and sandy), three level of super absorbent (0, 4, and 8), irrigation at two levels (wastewater and Tap water) and two irrigation regimes (5 and 15 days). The results indicated that the number of established seedlings, plant height and root length, plant dry weight were affected by different quantities of super absorbent and wastewater. According to results, application of polymers significantly increased water holding capacity especially in sandy soils. Therefore using polymer can increase the success chance of seedling establishment in rehabilitation projects.

Water crisis is an important issue in arid and semi-arid regions like Iran. Due to drought events, the situation has become more acute in recent years. Therefore, where good quality water is not available, the use of unconventional water has increased considerably. One of these resources is municipal wastewater that can also provide some of the nutrients needed for plant nutrition. Therefore, in this research, the combined effects of treated municipal wastewater and soil texture on growth and yield of Nitraria schoberi under greenhouse conditions, was investigated. The experiment was a factorial completely randomized design with four replications. The treatments included: two types of irrigation water (wastewater and water), two soil textures (clay and sandy) and two irrigation frequencies (5 and 15 days). Analysis of the wastewater showed that concentrations of the elements were in the standard limits. The results also showed that the use of wastewater has positive effect on stem length and dry and fresh weight of the plants. Therefore, due to the problem of water supply to plant species in the arid regions, this method can have a significant role in the stability of plants, reducing costs of irrigation and fertilizers, and biological restoration.

Phenology of four range species including Elymus transhircanus, Elytrigia libanotica Stipa bromoides and Stipa capillata were studied in Homand Absard Research Station, 70 km far from east Tehran, for five years (2003-2007). 20 plants were selected for each species and four important phenological stages including early and vegetative growth, flowering, seed milk stage, seed maturity and autumn regrowth were recorded. Data recording was done once each week and once 15 days in growing and inactive seasons respectively. Phenological data were recorded during five years and interpreted using climatic data (temperature and precipitation) to calculate Growth Degree Days in each stage. The purpose of this study was to identify and introduce important phenological stages with a view to livestock grazing and farm management based upon phenology and Growth Degree Days. The results showed that onset and end of growth varied in different years and these changes occurred based upon temperature. Phenological period of all studied species in cool years was longer than that of warm years. But required Growth Degree Days for all mentioned species were almost similar. For example, Elytrigia libanotica required 833.3, 830.8, 834, 832 and 846.3 GDD for vegetative stage in 2003, 2004, 2005, 2006 and 2007 respectively. For flowering stage, 1342.1, 1342.8, 1355, 1344.8 and 1346.3 GDD were calculated from 2003 to 2007. In other words, Elytrigia libanotica species needs the mentioned GDD so that it can start seed milk stage. Start of growth varied in different years according to plant type and climatic condition and it was usually from mid to early March. Active growth continued to early July and then stopped. All studied species had an autumn regrowth in wet season.

Determination of forage quality is one of the fundamental factors for sound management of rangeland. There are spatial and temporal variations in the nutritive quality of range species. In this study, forage quality of two salt tolerant grasses Aeluropus littoralis and A. lagopoides were measured at two phenological stages: vegetative and seed ripening. Study area was located close to Hamoon lake, Iran-Afghanistan border. Plant samples were collected at two growing stages and were chemically analyzed in laboratory. Data were analyzed by using ANOVA and Duncan’s test. The results showed that the forage quality of both species were higher in vegetative growth in comparison with the seed ripening stage. In both phenological stages, for all factors; A. lagopoides had higher forage quality than A. littoralis (p<0.05).

Accessibility to a major portion of information about vegetation cover function of ecosystem is provided by the way of autecological study of plant species. Autecological study of Desmostachya bipinnata carried out in Sistan plain. This species is a perennial plant from Poaceae. For autecological study of D. bipinnata,at first vegetation habit of this species in Sistan plain was determined. Then, ecological characteristics such as climatic and edaphic characters of habitats, root system, phenology, reproduction, preference value and chemical compounds were assessed. The results showed that this species grows intensively in north eastern parts of study area. Based on the collected data in several years, annual rainfall of the study area is 60.8 mm and mean annual temperature is 22 0C. This species appears on soil with loam and sandy loam texture, pH of 8.03 – 8.31 and salinity of 10 – 60 ds.m-1. The plant has a adventitious root system and rhizome that penetrates in the soil about 2 meters. Root has a lot of subsidiary branches in soil surface. At different habitats, canopy cover of this species was about 14 – 28 %. Vegetation growth stage of Desmostachya bipinnata usually starts in late February and flowering complete at May and seed ripening start at July. Above ground materials of Desmostachya bipinnata contains 7.56 and 6.71% crude protein in their leaf and stem, respectively. Preference value of this plant is 25% for sheep and goats. This species has a high level of resistance against grazing and relatively harsh natural conditions. With above mentioned characteristics, this plant is a suitable species to be used in management and amendment programs for Sistan plain.

In order to determine suitable indices for vegetation cover and production assessment based on remote sensing data, simultaneous digital data with field data of summer rangeland in south of Mazandaran province were analyzed. During 3 years monitoring vegetation cover including annuals, grasses, forbs and shrubs and total production data of sixty plots in each site (1 square meters) were collected. The Global Positioning System (GPS), geometric correction, histogram equalization and images digital numbers were converted to reflectance numbers. In the next stage, intrinsic indices, soil-line related indices and atmospheric corrected indices were generated. For determining suitable indices, linear regression model was used. The results showed that there are significant relationships between satellite data and vegetative characteristics. Among indeces, VI10 with annual covers, VI6, VI10, MIRV1 with grasses cover, PD312, VI9, MIRV1, GVI indices with forbs cover, MIRV2, VI6, VI10 with shrubs cover, VI12, MIRV2, VI5, fuse2 and total cover and MIRV1, MIRV2, VI5, Tgr with total production, showed significant relationships. Generally introduced indices presented accurate quantitative estimation of the parameters. Therefore, it is possible to estimate vegtation cover and range production as important factors for range monitoring using landsat ETM+ data.