نشریه پژوهش های حفاظت آب و خاک
سال بیست و دوم شماره 5 (آذر و دی 1394)

Reduction of surface and ground water resources in country¡ have been caused environmental and ecological hazardsin catchments.Inadequate of water resources affected not only agriculture and natural resources but also society and economic of thecatchments. In such a condition appropriate of water resources management is important and asactual evapotranspiration is the main way ofwasting water in catchments, there for this research¡has focused on evaluation and estimation of actual evapotranspiration in Tuyserkan catchment was investigated.Therefore was used 27 MODIS images¡ 3 LANDSAT images and remote sensing technique was employed to estimated actual evapotranspiration in Tuyserkan catchment. Actual evapotranspiration maps yielded by mountain SEBAL algorithm was comparednational water requirement document. Finally mapsproduced by Modis images wasdownscaled and control using Ladnsat images. Result showed thatmountain SEBALalgorithmis able to estimate actual evapotranspiration with accuracy of 82%.

Today, drought indices as the appropriate tools for management actions and exposure to drought, has been widely used around the world. Application of some indicators, particularly the physical-based indicators such as Palmer drought severity index (PDSI) in a new area may need to be calibrated first. The aim of this study is to calibrate Palmer Drought Severity Index (PDSI) under the climatic conditions of arid and semiarid regions of West and South West of Iran and to compare that with the original version of the Palmer Index. Required input data are values of the monthly mean temperature and monthly total precipitation from nine synoptic stations in West and South-West of Iran were collected for the period 1966-2005. The results showed although does not have much difference between the main coefficients of calibrated Palmer index and the original version of that, but due to the large difference between the monthly weighting factors between the calibrated version of the main series of calibrated version and initial, there are significant differences. In addition, it was found that the equations of severity - duration of drought phenomena and frequency of different classes of drought and non-drought, there are significant difference between the initial version and calibrated versions in the selected stations.

In this study, the relationship between temporal variation of hydrological parameters and climate change was investigated using stationary and trend analysis. For this purpose, the precipitation and temperature (maximum, minimum and average) data of Shahrekord synoptic station and hydrometric data of Armand watershed in the period of 1971-2011 were used. Results showed that the minimum temperature of May, August, June and spring season had a significant decreasing trend. Also, a significant increasing trend was observed in the maximum temperature of September, March and autumn season time series. The average temperature of March has significant increasing trend. In the case of precipitation, the March and winter season experienced a decreasing significant trend. The stream flow time series of Armand River showed a strong decreasing trend and experienced a decline equal to 51.57 (m3/s)in the three past decades. In the hydrological point of view, the main reason is the increasing trend in maximum temperature of the autumn season and reduction of precipitation in winter season (the season with maximum precipitation). In order to evaluate the effect of trend on the stream flow of Armand River that is a reason of existence of climate change in this watershed, three stationary tests including ADF, DFGLS and KPSS were used. The stream flow time series were tested in Normal and standard forms. The results confirmed stationary in stream flow of Armand River at a 95% confidence level that indicating existence of variations in average and variance of stream flow time series.

In the present study, seven temporal rainfall distribution patterns (i.e. SCS, WMO, Huff 1st, Huff 2nd, Huff 3rd, Huff 4th, and regional) were evaluated in order to simulate maximum flood flow using SCS, CLARK, and SNYDER, runoff rainfall models in Atashgah basin of Ardebil Province. The aim of this study is simulation of flood hydrograph using watershed modeling system and selection suitable rainfall pattern of study area. Daily maximum rainfall map was obtained by Kriging and Cokriging interpolation models using circular, globular, exponential, gaussian, and normal fitting models as well as reversed Weighted distance, function-radius-axis, general estimator, and local estimator methods. Universal cokriging model with normal method was selected as the best model. Temporal 6-h rainfall distribution pattern was obtained from 7 rainfall events with durations of 4.5-6.5 hours. The average of curve number was calculated to be 76.5 for the study area. the results obtained from the present study showed that Huff 4th rainfall pattern with the maximum rainfall in the 4th quarter simulat the highest flow. The simulated flow with different patterns indicated that in SCS model, WMO rainfall and in SNYDER and CLARK models, Huff 2nd pattern had the most realistic results compared to observed flow. SCS rainfall-runoff model using WMO rainfall pattern with minimum RE and RMSE equal to 7% and 1.57 m3/s respectively was selected as the best model for Atashgah basin.

Soil physico-chemical properties and management practices are important to balance different forms of potassium. This study was carried out to compare different land use effects on spatial variability of available and total potassium and to investigate the relationships between available and total potassium with soil characteristics in selected soils of Mazandaran province. A total of 258 composite surface soil samples (0-10 cm) were taken from an area of about 5500 km2 using a systematic sampling scheme. Also 5 profiles located in different land uses were studied. The amounts of available and total potassium in each soil sample were determined. Some soil properties including pH, calcium carbonate equivalent, organic matter, cation exchange capacity and particle size distribution were also measured. The results showed that surface and profile distribution of available potassium is controlled by factors affecting the potassium availability and subsequently, management and land use. Total potassium is affected by inherent factors such as parent materials. The concentration of available potassium was higher in pasture soil samples with high potassium-bearing primary minerals, organic matter and cation exchange capacity. Indicator kriging was used to estimate the potassium deficient areas. Probability map showed that soil available potassium is below the critical limit for rice cropping in an area of about 700 km2, with a probability of more than 60 percent. The low values of available potassium can be attributed to long term intensive rice cropping without K-fertilization.

Aquifer systems are often characterized by non-stationary and nonlinear features. Modelling of these systems and forecasting their future conditions requires identification of these fundamental features. Recently, wavelet analysis have been used widely in hydrological time series forecasting owing to its ability to decode aforementioned features. In this paper, a hybrid model based on coupling wavelet and artificial neural networks (WANN) that use sum of sub-series method, is tested for its ability to yield forecasts of groundwater level. The model results are compared with the results from artificial neural networks (ANN) and multi linear regression (MLR) models. The variables used to develop the models were monthly groundwater level at two piezometers and monthly total precipitation data recorded for 20 years in the Qom plain, Iran. Twelve-month-ahead prediction with the WANN model show that the error of this model is 30 and 23 percent less than ANN model and 37 and 51 percent less than MLR model for piezometers 1 and 2 respectively. The results show that precipitation has no significant effect on groundwater level variations of the two study piezometers; Although for the detail sub-series, use of precipitation improved the results.

Considering limited water resources in arid and semi-arid climate of Iran, deficit irrigation is one of the strategies for efficient use of water, increasing water productivity and water use efficiency in agricultural district. Regulated Deficit Irrigation (RDI) and Partial Root Drying (PRD) are among deficit irrigation methods aiming to limit using of irrigation water. PRD is a new approach for irrigation management due to increasing water use efficiency and non-significant decreasing yield. The objective of this study was to investigate the effect of different levels of irrigation water and nitrogen fertilizer on water productivity and water use efficiency of Sugar beet.
This research was conducted in the agricultural land of Karafs plain on Hamadan province, at latitude 35° 18̍ N, longitude 49° 20̍ E and altitude 1915 m above sea level. This study was conducted in a split block with a randomized complete block design. In the main blocks Irrigation levels included: Conventional irrigation (CI), three levels of partial root drying: 85 (PRD85), 75 (PRD75) and 65 percent (PRD65) and regulated deficit irrigation at three levels: 85 (RDI85), 75 (RDI75) and 65 percent of the crop water requirement (RD 65). Also, in the sub blocks two fertilizer levels were applied: 100 (f100) and 75 percent of fertilizer requirement (f75).
The results showed that the impact of irrigation treatments on water productivity and water use efficiency of all studied traits were significant at one percent level (P The results showed that water productivity and water use efficiency indexes of root and sugar yield of PRD85 irrigation treatment was more than other irrigation treatments. Due to the non- significant differences between the PRD85 with CI treatment in terms of root and sugar yield and also saving 15 percent of water irrigation in PRD85 treatment, under such study conditions, applying PRD85 treatment is recommended. Also, f100 fertilizer treatment was root yield, sugar yield, water productivity and water use efficiency indexes of biomass, root and sugar yield more than f75 treatment. Therefore, PRD85 and f100 were selected as the best treatments.

The study of the behavior of river flow is the basic demand in water resources planning. The importance of identifying the river flow process at different temporal scales, by using chaos theory is to predict the river flow and select the proper model framework. River flow has dynamic and nonlinear nature. In dynamical systems, phase space is the space which includes all the possible conditions that are need to describe a system. Because of inaccessibility of exact mathematical equations of system, it is difficult to achieve the phase space. And all the available information is a scalar time series. Therefore, embedding method is used for reconstruction of phase space. In this study the daily, weekly and monthly measured discharges of Nazloochay river from 1990 to 2011 were used for reconstruction of phase space. Time delay was calculated by AMI method and it is 39 for daily, 18 for weekly and 9 for monthly scale. Embedding dimension as a minimum dimension for reconstruction of phase space for description of dynamical system was calculated by using FNN method for daily, weekly and monthly scale and that is 26, 8 and 4 respectively. Chaotic behavior of river flow for daily, weekly and monthly scale was evaluated by using correlation dimension and Hurst exponent methods. Correlation dimension is 2.8 for daily, 3.62 for weekly and 5.52 for monthly scale. Hurst exponent for daily, weekly and monthly scale is obtained 0.84, 0.77 and 0.76 respectively. The results imply that Nazluchay's river flow is chaotic.

Increasing need for water is the result of population growth and urban development, which demands a comprehensive programming for sufficient amount and appropriate quality of water. Modeling is one of the necessary elements of management and planning for water resources and use. Integrated mathematical quality-quantity water models are suitable tool to analysis various water resources management options. MODSIM is a decision support system for the analysis programming of long-term, mid-term and short-term functions that is used in the basin, inter-basin, drinking water and etc The most important urban drinking water supply problems in Gorgan are lack of exploitation of surface and groundwater sources for drinking, groundwater restrictions to supply drinking water of Gorgan, severe drop in groundwater table, increasing trend of drinking water demand, ample water exploitation in agriculture sector in downstream and its effect on declining drinking water and improper recharge aquifers consequently causing disqualification in aquifers and salinity in wells. Offer appropriate solutions is essential for the next horizon, comprehensive study of the sources and the percentage of losses incurred on the desired horizon. The aim of this research is to analysis water resources management of drinking water of Gorgan assessing different managerial scenarios.
Material and In this study drinking water of Gorgan city was evaluated in short-term, mid-term and long-term periods by means of MODSIM model and the city's zoning to provide allowable pressure and prevent the leakage in the network. Model calibration was done for 2012 and 2013 on a daily scale and eventually the model was assessed on the basis of criteria’s such as reliability and vulnerability. Hence by using various scenarios the future management of drinking water was evaluated.
According to results, in all scenarios the 1st pressure zone (the most northern part of Gorgan) and 8-10 zones (the most southern part of Gorgan) have high reliability and low vulnerability indexes. In addition if the water supply conditions remain same as current (the reference scenario) in 2021 with a population increase of 7.2 percent compared to 2012, the reliability index and vulnerability index would be 7.2 percent and 50000 cubic meters per day.
Using MODSIM model has been really successful in simulation and management of drinking water resources hence using this model and linking it to other software’s such as those ones related to groundwater and water quality is suggested. According to the result of model and scenarios, it is possible to inspect future water condition and recommend managerial strategies.

Land-use and land-cover are considered as determining factors in studies of water resources, erosion, and sediment yield watershed (32). Computerized simulation of land-use change effects on the watershed processes have been studied in the last decade (2,13,16,24,25). Modeling the effects of land-use change on flood has been numerously investigated in the last decades (2). Bahremand (2006) has conducted a research on the effect of afforestation on the flood hydrograph features in one of the watersheds in Slovakia. The results revealed that 51 percent increase in jungles led to 12 percent reduction of Debi peak and also causes nine-hour increase up to the hydrograph peak using WetSpa distribution model (2). Banasik and Fam (2010) have investigated the effects of land-use change on flood hydrograph in a watershed in Netherlands using Curve Number method and Nash model. The results indicated that land-use change in 2007-2009 increased Debi peak from 1.1 cubic meters to 8.92 cubic meters (3). Therefore, regarding the significance and the role of land-use change and also considering the fact that flood hydrograph is the hydrological respond of the watershed to land-use change, in this study, land-use change effects have been studied on flood hydrograph in Jafarabad watershed in Golestan province using GFHM (21) distribution model.
In this study, land-use change effects have been studied on flood hydrograph in Ja’farabad watershed using GFHM (21) distribution model. GFHM (21) model is a hydrological temporal and place distribution model. DEM maps, land-use, soil type, and also precipitation data of the watershed are the main data required by this model. In order to calculate surplus precipitation amount, this model applies Kinematic- wave method using curve number method of Natural resources reservation organization (NRCS) and the kinematic-wave method for routing. Based on the conditions of the watershed, four management scenarios were developed with an approach of the effects of destruction and land-use reclamation on flood hydrograph.
The results indicated that 4.2 percent jungle growth (scenario 4), reduces flood Debi peak to 0.55 percent and decreases the flood volume to 2.6 percent. Changing 3.9 percent jungle lands to arid lands (scenario 2) increases flood Debi peak to 0.85 percent and also adds 1.83 percent to flood volume. Also changing 17.8 percent semi-dense lands to water-fed lands (scenario1) can raise flood Debi peak to 7.8 percent and increase flood volume to6.08 percent. The results also depicted that land-use change affects cloudbursts with low Debi, and has more effects on peak Debi and flood volume.
The results revealed that flood Debi and volume can be reduced through non-structural land management in order to lower and manage the floods. Hence, land-use reform plan of watersheds with a jungle reclamation pattern and also changing agricultural land-use into agro-forestry lands especially olive orchards (most similar areas are conducted in Golestan Province) significantly increase early casualties and land capture.

Climate which is defined as the average weather, has been changed in recent years due to increased greenhouse gasses emission and imbalance of radiation in atmosphere.Climate change is one of the major challenges with affect different aspects of human life on the earth.For recognition of climates a set of rules are employed which are called climatic classification.For performing classification the observed at-stationdata should be interpolated using different methods.Golestan province located in northeast of Iran with diverse climates is chosen for current study. As it is animportantagricultural production region, its climatic classification is ofmainconcern. The aim of this study is to investigate the effects of climate change on climatic zones .
The study area is located in southeastern part of Caspian Sea, between 36˚ 24' to 38˚ N and 53˚ 51' to 56˚ 14' E. The required data of temperature and rainfall for baseline period 1982-2011 were generated using LARS-WG model these generated data along with historical observed dataset were used for calculation of DeMartone classification index. Besides, the index was workedout using the data for baseline and outputs of HADCM3 climate model for three future periods of 2011-2030, 2046-2065 and 2080-2100 under three emission scenario of A2, A1B and B1. The rainfall and temperature data were interpolated using Kriging and Geographically Weighted Regression methods, respectively. The climatic zones were compared based on their coverage percentage in province.
The outputs of LARS weather generator indicated the increase of mean air temperature in Golestan province for about 4.3°C by 2100. Among different emission scenarios, the A2 scenario at the period of 2070 to 2100 shows the maximum increase in temperature . The average monthly rainfall showed decreasing trend in some months and increasing trend in some others but in general, the total annual rainfall will increase. The evaluation of different interpolation methods revealed that the Kriging method is performing more accurately than IDW and Spline methods atinterpolation of rainfall data.
The outputs of LARS weather generator showed an increasing trend in both temperature and rainfall, but the increase would be more significant in case of temperature which in turn, would shift the climatic zones of province. In overall, the province would experience more arid conditions in future periods as a result of climate change. In this manner, the A2 scenario projects morearid conditions for Golestan provinceby the end of this century.

Desalination by solar radiation is one of the efficient ways to filter sea water and regarding the renewable solar radiation energy application as a way to provide sweet water is regarded in line with sustainable development and adaptable to environment. Condensation irrigation system is a developed modern idea which takes into consideration environmental issues together with application of sea water. This system is being used for providing drinking water and plantation. The major part of this system that is responsible for providing sweet water is solar still. Solar stills utilize solar radiation for sea water desalination. In the present research, the effect of atmospheric factors and solar still base surface parameter on the evaporation potentiality in solar stills has been investigated in a one-year statistic period that purpose of this study, is trying to determine and recommend using stills with high evaporation potential. Results of this study indicate high dependency degree of stills evaporation potential to atmospheric factors that the intensity dependency of this parameter is including: positive relationship of ambient air temperature (R=0.95), the positive relationship of the number of sunshine hours per day (R=0.73) and negatively relationship relative humidity (R=-0.72). These observations also showed that by reducing the solar stills surface, evaporation potentiality in solar stills will increase and Investigate the effect of solar still base surface by ANOVA results indicated significant differences at the one percent level between evaporation from Solar Stills.

One of the most important environmental pollutants is petroleum compounds that contaminate aquatic ecosystems. Petroleum pollutants affect the aquatic and terrestrial ecosystems and caused the adverse change in them. Petroleum pollutants contain heavy metals and hazard compounds and will have harmful effects on the ecosystems and organisms. Aromatic polycyclic hydrocarbons (PAHs) from the oil derivatives, which are generally caused by human activity and high stability, and have multiple side effects (carcinogenic and mutagenic). Anthracene, a combination of tricycles aromatic hydrocarbon and exist in contaminated areas. Anthracene is one among the 100 most toxic aromatic compounds and therefore reducing of Anthracene is important. Some of environmental bacteria are used from PAHs as a source of carbon and energy and convert it to the other compounds and final products of degradation are carbon dioxide and water. Anthracene due to low solubility in water less direct effect of land and microbial degradation of the biotic and abiotic conditions must be optimized for analysis to microbial degradation have the greatest efficiency. Bacillus is belonging to spore forming bacteria and able to grow in improper environmental conditions and different species of Bacillus are extensively used in biotechnology research, including the production of biological products and reduce environmental pollutants. In other hand, bacillus species are capable to grow in simple environments with minimal nutrient and therefore to reduce environmental pollutants.
Sampling was done from river estuary sediment and had cultured in Minimal Salt Medium (MSM). Bacillus Spp. was one of the isolated bacteria from river sediment that identified by molecular technique. In next step, influence of pH, temperature and concentration of anthracene were surveyed on anthracene biodegradation by Bacillus spp during zero, 24 and 48 hours.
The results showed that the optimized condition for biodegradation included pH= 7.5, 35◦C and 150 ppm of anthracene. Bacterial degradation of anthracene was increased with prolong of incubation time. Efficiency of bacillus sp for decomposition of anthracene was 42% during 48 hours.
As regards to high potential of bacillus and also its survival in improper condition (spore – forming bacterium) can be used as biological tools for degradation of anthracene in oil contaminated regions. This method is an eco friendly way for removal of petroleum based pollutants and used the biological factors so it doesn’t have a negative effect on the environment. This method is recommended to remediation of petroleum polluted environment.

There are many ways for flow hydrograph separation. .Base flow as a component of river flow, which reacts to precipitation, includes interflow and ground water flow. The spatially distributed hydrological WetSpa model calculates discharges and hydrograph at any point of the basin and gives 3 components of flow separately i.e. surface runoff, interflow and groundwater. In this study, the WetSpa model has been applied for flow simulation and hydrograph separation in the Ziarat river basin. In order to apply the model, hourly hydrometeorological data for a period of four years (2007-2010) including rainfall, evapotranspiration, temperature and discharge are used as inputs. Additionally, three main maps of the digital elevation model, soil map (texture), and landuse are also applied and converted to digital formats. The result of the simulation shows a good agreement between the simulated hydrograph and the observed one. The water balance components for the entire simulation period is given as well as for a flood event. In this mountainous forested watershed, the basflow forms the major part of the flow. As for the studied flood, it has formed 97% of the flood volume. . Forest and vegetation affect each of these components differently.

Due to the time consuming manual calibration data, especially in low and high parameters automatic calibration methods based on the use of systematic search methods in multi-dimensional space using an objective function is very useful. In this study, the simulation model HEC-HMS and collective intelligence algorithms, PSO as an optimization model act. The integrated model proposed dam basin has been studied Kardh. Model calibration was performed using the objective function NASH and RMSE resulting parameters were used to those achieve. To evaluate the ability of the PSO algorithm to achieve the optimal solution, a single calibration approach results occurred with semi-automatic calibration results based on Nelder & Mead search algorithm in HEC-HMS PBIAS and RMSE were compared by functions that PSO algorithm represents the connection to a hydrological model. The results show that both the objective function values obtained in the semi-automatic model is considerably higher than the model introduced. Also simulated hydrographs obtained from PSO-HMS model is much better. Finally, those parameters were determined from single approach occurred in the event verification. The results showed that the method according to the solution of the calibration problem of Ghyrmnfrd an inverse problem can be effective in limiting the number of candidate solutions.

Limitation of suitable water resources is a major problem of agriculture in Iran. Increase in irrigation interval caused cracks in the intermittent irrigation in paddy fields. To evaluate the effect of shallow water table on humidity conditions and physical properties of paddy soils, soil texture factors at three regions (Moasese (Rasht), Shanderman and Astaneh) and a factor shallow water table at three levels (zero, 7.5 and 15cm) and in three replicates as the factorial based on complete randomized blocks design in Rice Research Institute. The amount of moisture, crack width, soil’s resistance to penetrometer, soil column height, yield and yield components of rice were measured Results showed that the effect of shallow water table levels on soil column height, cracks width, moisture content and resistance to pentrometer penetration has been significant at one percent statistical level. All three soil texture, moisture content in the water table level 15 cm below field capacity moisture content. Resistance to pentrometer penetration at water table 15 cm for the Moasese and Shanderman, respectively reached to 52.29 and 11.44 kPa. The maximum width of the crack in the water table 15cm is between 1.2- 1.5 cm. At water table 7.5cm only been seen capillary crack. Also effect of water table on yield and yield components of rice was not significant. Can be expressed in the shallow water table management in the scale of pot can be effective in preventing leaks and cracks.

Drip irrigation is one of the efficient method, that, in recent years, it is widely used in Iran agriculture. But the use of low quality waters caused problems in this system. Physical clogging of emitters is the most important of these problems. Emitters clogging reduce Irrigation efficiency and drip irrigation system lifetime. Entry of Suspended and physical particles into the emitter is the most important factor of emitters clogging and reducing the discharge rate of there. On the other hand, various factors such as water temperature affect the discharge rate and clogging of emitters. The objective of this study was to investigate the effect of temperature on the anti-clogging performance of the long path emitters. For this purpose by constructing an Experimental physical model and the use of sand grain with different sizes and concentrations, the anti-clogging performance of seamed and seamless irrigation tapes and Emitting pipe was studied at temperatures of 13, 23, 33, and 43 °C. The results show that raising the temperature has a positive effect on reducing of the clogging emitters. The results also showed that the Emitting pipe and seamed irrigation tape have the minimum and maximum clogging rate , respectively. Also, the uniformity coefficient of emitting pipe and seamless irrigation tape was greater than 90 percent in all circumstances. . Statistical analysis showed that the effect of temperature on the clogging rate of emitters is significant at one percent level.

Modeling and predicting Urmia Lake level have the importance in investigating facilities and related structures risk, lake water storage changes, costal constructions and environmental impacts. The main object of the present research is to model and predict Urmia Lake level using time series model. In the present research, Urmia lake level data from 1964 to 2006 were used and the prediction carried out to 2016. In order to model, time series different components such as trend, periodicity and stochastic component of lake level were separated and then these components were modeled. The results showed that the used model had a high ability to model Urmia Lake water level. Monthly periods and 3, 4, 20, 35 and 47 years periods are considerable periods and considering these periods, Urmia Lake water level is modeled. Because by removing these periods, obtained series do not have periodicity property. The results showed that Urmia Lake water level decrease from 1270 (m) in 2009 until 1270 (m) in 2016. The results of the present research emphasize to select the basic decisions for protecting Urmia Lake.

Thermal properties of soils are very important in different areas of agriculture, engineering and soil science. Nevertheless their direct measurements are difficult, costly and time-consuming. Thus, in this study thermal conductivity of the soil was estimated using pedotransfer functions. In this regard, 156 data of Great Plains of South America were used to create pedotransfer functions in 12 steps by regression method for the estimation of thermal conductivity. At the first step, only the soil texture fractions were used as input variables. Later in other steps hydraulic and other physical properties were applied to estimate thermal conductivity. The model 2 using clay, silt/sand and bulk density as inputs and model 12 using the residual and saturated moisture contents, n and alpha parameters of van Genuchten model as inputs were the most accurate models. The model 2 showed RMSE and R2 values of 0.186 and 0.628, respectively, and the model 12 showed RMSE and R2 values of 0.235 and 0.319, respectively, in the evaluation step. The results showed that thermal conductivity was satisfactorily estimated using hydraulic and other physical properties as predictors.

Evapotranspiration is one of the parameters that have special importance in various areas of agriculture and water resources management also for definition of future policies estimating of it, is required. In this study for studying evapotranspiration behaviors, Genetic programming is applied. Four synoptic stations in Zahedan, Zabol, Iranshahr and Chabahar for determining structure of models is used. Inputs are the time series of evapotranspiration that calculated from penman- mantis and regulated in 16 individually dilatory patterns. Reason of this research is to determine mathematical models for estimating evapotranspiration and studying assessment of Genetic programming at estimating evapotranspiration. 80% of data are used in train section to develop models and 20% are used for testing and validating models and calculating the accuracy of them. Results showed that Genetic programming is suitable approach for modeling evapotranspiration. Also the best model with 1.03 RMSE and 0.96 R2 in test section is obtained to Zabol station.

In this paper, compared applicability stepwise and logistic multivariate regression, two hazard statistical analysis methods in order to determine suitable model for gully erosion hazard management of Naghan inter basin. First, Gullies was mapped through field observation, using native and agency watershed management information’s and using GPS set. Through reviewing literature and studying conditions of Naghan inter basin, 15 factors elevation, slope, aspect, lithology, temperature, distance from road, land use, precipitation amount and soil forming factor include soil texture, soil depth, organic carbon, Caco3, EC, pH and hydrological group were chosen as effective factors on gully erosion and relative hazard map was prepared via 2 models. Qs and ROC indexes was used for evaluation of models accuracy. Stepwise multivariate regression model is selected as suitable model for Naghan inter basin with ROC equal to 0.876. Results show that about 31% of the watershed area was located in high and very high hazard classes.