فهرست مطالب زهره خورسندی کوهانستانی

Conservation and utilization of water resources are principles of sustainable development of each country. Surface waters or rivers are one of the most important water resources which have important role in supplying water demands in different sectors such as agriculture, industry, drinking water and energy. Shavoor River which is one of the effective rivers in Shoosh City is important due to its quality in water urban and agricultural usages. Land use and its changes have important effects on river water quality. In this research, the effect of land use change is investigated in water quality of Shavoor River in 1985-2015. For this reason, land use maps of 1985 and 2015 were prepared by satellite imageries and land use changes were investigated. Results showed an increase in residential and agricultural lands and a reduction in rangelands and forests. Also, the changing trend of water quality factors in Shavoor River was studied with Mann-Kendall test and graphs. Results demonstrated that the changes overall trend of Hco3, Cl, TDS, EC, Ca, Mg and So4 were increasing in the period. According to meaningful changes of parameters, it can be concluded that the increase in residential and agricultural lands and reduction in rangelands and forests cause the water quality of Shavoor River in the study period.

Flood is one of the most dangerous and destructive phenomena which endangers people’s lives and properties all around the world. According to statistics of a 30-year period (1974-2003), about 2162 major floods have occurred which constitute 34% of the world's disasters (Tajbakhsh and Khodashenas, 2012). Floods are frequent and ruinous in Iran due to severe weather condition. Several factors intensify the risk of flood in urban areas including urbanization, land use changes, inappropriate drainage systems, and impermeable area development (Sabeti, 2011). Likak has faced numerous floods due to high rain density, high rate of urban development, unsafe and unproductive urban development, ignoring safety criteria in developing urban areas, road watering issues, inefficient drainage systems, and inefficacious water channels. Water channels and drainage issues have never been evaluated in this town. Applying an effective runoff management plan is the ultimate solution for the problem of flood in Likak. Storm Water Management Model (SWMM) is one of the most reliable and prevailing models for evaluating and managing the urban runoff issue. SWMM is a dynamic rainfall-runoff simulator which can be used for simulating the quantity and quality of the run-off for a single raining event or continuous long-term rains (Gironas et al, 2010). Yu et al. (2014) adapted and calibrated SWMM to Jinan, a typical piedmont city in China. Fourteen storms were used for model calibration and validation, finally verifying large-scale applicability of the model to piedmont cities. Results of this study verified that SWMM is applicable to  large-scale cities.

  Human beings have always attempted to meet their requirements by using agriculture lands for many years. This is changed in such a way that today with present population with diversity of human needs and overuse of land, they created many adverse effects. Wide areas of natural resources disregarding ecological principles to meet their needs have been turned into the degraded lands, while many of these lands have not been cultivated with a high erosion potential. Having knowledge of land use and its changes and reviewing possible causes are important in planning and policy-making in the country. The ratio of land use changes can help to anticipate upcoming changes and perform appropriate actions. Remote sensing techniques can be helpful to detect changes in land-use patterns as great resources for management and planning. The aim of this study was to investigate changes in land use and land cover based on the data derived from satellite images, since these changes along with environmental effects have different impacts on the economy and living conditions of beneficiaries. In addition, the assessment of the following direct economic impacts on land use change considered living and livelihoods of all residents of the area.
Materials and methods
Behbehan city is located in the southeastern areas of Khuzestan and limited to the cities of Kohgiluyeh and Boyer Ahmad provinces. The job activity of the majority of the villagers is agriculture and animal husbandry. There are three types of vegetation, bushes and grass cover in Behbehan. In this study, we used Landsat satellite images, Landsat TM data in 1991 and the Landsat OLI satellite images of in 2016, general aerial photographs of 1: 20000, numerical topographic map of 1: 25000, and GPS data (Etrex Model). In the first step, the satellite images were processed and geometric and atmospheric corrections are made to prepare the raw image data. Then, we have used maximum likelihood method for supervised classification. After selecting training samples of the images from 1991 to 2016, we used maximum likelihood classification in ENVI to classify the images. Using the clasification method, we divided the images into 6 classes of woods, grassland, agricultural areas, abandoned land, residential areas and water groups. The classification accuracy for image was assessed by using the kappa index. The communities affected by changes in land use were identified in order to evaluate the effects of changes on economic dimension of beneficiaries. At the end, we have analyzed the changes in economic situation of people due to landuse changes.
Results and discussion
After classifying maximum likelihood classification in ENVI, land use maps were obtained from 1991 and 2016. The maps are related to the two time periods (1991-2016) evaluated by overlaying the two maps in GIS environment to obtain change map. The results indicate that the forest area in 1991 was 9348.93 hectares and with 4.57 percent decrease reached to 8812.53 hectares in 2016. The area of pasture is also decreased by 36.63 percent and it has decreased from 86596.92 hectares in 1991 to 82297.71 hectares in 2016. The agriculture land-use has increased 11.72% from191.61 hectares in 1991 to 1567.26 hectares in 2016. The area of abandoned lands has also increased from 15137.19 hectares in 1991 to 18413.91 hectares until now. Residential areas have also increased from 1044.27 hectares in 1991 to 2337.39 hectares in 2016. Water level is faced with a reduction in 2016 and it was more than 1399.05 hectares in 1991 and reached to 444.69 hectares in 2016, a decrease of 8.13 percent. The reduction of 536.4 acre in the use of forest and palm groves caused £ 25064958204decrease. A decrease in 4299.21 acre of pasture caused £2923462800 of devaluation. Increase in the agricultural use of lands caused increased income, equivalent to £ 825390000000. Increase in abandoned lands caused decrease in income and consequently devaluation of £ 318168655183.
Conclusion
Given that in this study period, residential areas has increased due to increased urban population and immigration, the need of people for housing has, consequently, increased. The pasture area has been reduced in this period since they are changed these lands over time in recent years. Because of increase in the use of agricultural lands and unprincipled irrigation using traditional methods, water resource and droughts are, consequently, declined in recent years. With increasing population and development of residential areas, it is needed to fix the problem and this reduces natural resources (pasture, water and forest). Although land use change and decrease in the level of natural resources during this period had not so negative complications, but continuation of this process and non-normative change of land use can have more negative consequences in the long run. Therefore, we have to determine uses which are compatible with the environmental potential and capacity of lands

Modeling of the rainfall-runoff process is important. The Results of the rainfall-runoff models have been used directly on issues such as water resource management, flood control and design of hydraulic structures. According to variety of accessible rainfall runoff models, selecting an appropriate model for a basin is important in terms of productivity and water resources management. In this study the performance of two rainfall–runoff models, IHACRES and GR2M in simulation of monthly flow were evaluated in Darhe Tkaht basin between 2000 and 2013 time. The models in the study region were calibrated and validated. The error between observed and simulated flow values was estimated based on the criteria Nash, root mean square error and the total flow volume error. Simulations is indicative satisfactory performance of two models in monthly flow simulation. In addition, the results show that the HACRES model simulate monthly flow with The Nash coefficient 0.7 and RMSE 0.56, better than the GR2M model.

Providing and water holding, especially in prototypical stages of growth and seedling establishment and their resistance against environmental tensions is a key factor to achieving the goals of managers. One of the new methods to conserve water and reducing irrigation costs is the use of super absorbents. Zeolites are porous materials with crystalline structures acting molecular sieve and due to open channels in their network, allowing some ions to pass and block crossing path of some other ions. In this experiment after preparing the soil, some species of Cymbopogon Olivieri, Medicago sativa, Medicago scutellata in three zeolite (2 g, 4 g and zero in a kilogram) with 15 repetitions was considered. After ensuring the germination of plants, 7-day irrigation tension was used on them. The results showed that the first effect of zeolite application in improving viability and mitigation of drought tension will be appeared and it is observed that the treatments of 20% and 40% of Zeolite, the percentages of viability and germination of plants are much more in comparing with control group. The average number of remaining saplings using tensions were decreased in control treatments. The use of zeolites in the number of base remained has a positive impact on whole plant length, fresh stem length, fresh weight, dry weight, root fresh weight, root fresh weight and increases their performance .

Run off simulation is one of the most important topics in hydrology And its study is based on rainfall- run off models. Several rain fall and run off models have been developed and the most appropriate model should be selected for each catchment. By applying the appropriate model the water consumption will be optimized. The model should be selected for each catchment based on the model abilities and limits. In this study, the performance of two rain fall and runoff models, GR2M and GR4J were compared in Darehtakht Basin in Lorestan Province during 1379 to 1392. The Nash coefficient was used as a decision criteria for comparing two model performances. Nash coefficient for GR4J and GR2M were 42.7 and 65.5, respectively. Results showed that both models can predict the performance of the catchment accurately, but, based on Nash coefficient the GR2M is more accurate than the GR4M.

Allelopathy is one of the main factors limiting the plants growth. The present study investigated the effect of aqueous extract of leaves and fruit of Artemisia sieberi that is an important species for rangeland rehabilitation on seed germination and seedling growth of three alfalfa species (Medicago sativa cv. Nikshahri, Medicago polymorpha and Medicago scutellata cv. Robinson) in laboratory and glasshouse. Treatments were five concentrations of 0, 25, 50, 75 100% Artemisia extract. Treatments were evaluated using a completely randomized factorial experiment in four replications in germinator and pots separately (2014). Data were collected and analyzed for the germination percent, germination rate, seedling length, seedling weight and seed vigor index. Means comparisons were made using Duncan test. The results showed significant differences between extract concentrations of Artemisia on all of traits in both growth conditions (P

Quantification of urban hydrologic response of catchments to rain fall is one of the most important issues in urban hydrology. Despite its importance, there is scant information by means of which required data can be obtained for quantifying hydrologic response. In this study, urban database was developed for a part of Baharestan City in Isfahan Province and using the information, the urban unit hydrograph was determined through URBS-UH model for two catchments of Baharestan. Peak of hydrograph of the first and second catchment was estimated 0.0727m3/s and 0.096, respectively. Flood hydrograph of some rain occurred previously in Baharestan was determined through the unit hydrograph. Peak discharge of flood was also measured and the efficiency of the developed model was examined based on the peak information. Nash–Sutcliffe coefficient of the first and the second catchment were estimated 0.89 and 0.79, respectively. The developed model showed good to very good performance in the pilot area.

A runoff can have devastating casualties and destructionsin a densely populated city. In a more plausible situation, the cost of runoff collection and disposal riseup as the maximum flow rate of runoff increases.Urban areas are combinations of permeable and impermeable lands. The runoff and maximum flow rate are increased by impermeable areas in cities. Recently, the runoff control techniques become more popular because of their low cost and high efficiency. One of the control techniques is to manipulate the distribution of landscapes in order to reduce the runoff maximum flow rate. In this research, the effect of different landscape distributions on runoff maximum flow rate is studied. The runoff is modelled for different landscape distributions based on URBS-UH models. The study results show that the distribution of landscapes can affect the maximum runoff flow rate up to 23%.