جستجوی مقالات مرتبط با کلیدواژه « استان گلستان » در نشریات گروه « آب و خاک »

The purpose of this study was to survey the spatial quantities of 22 crop in seven major agricultural crops in 13 major cities of Golestan province and to study its 9-year mean virtual water flow from 2007 to 2015. The priority of crop cultivation was also ranked based on its virtual water values. The results of this study showed that the virtual water of different crops in the cities of the province is different according to the performance. The results of this study showed that rice with virtual water content of 1740 m3 / ton in Ali Abad and Gorgan up to 2840 m3 / ton in Maraveh-Tapeh area had the highest amount of virtual water. Cereals with an average virtual water of 1500 m3 / ton also have high levels of virtual water and Cucurbits and vegetable products with the average virtual water of 100 and 350 m3 / ton have the lowest amounts of virtual water. The results also showed that exports and imports of agricultural products are currently incorrect and Golestan province, despite having a shortage of water, is an average 396 MM3 of virtual water exporter annually, largely driven by exports of cereal and rice products. Ranking the pattern of crop cultivation from the perspective of virtual water also showed that in this province, cucurbits and vegetable crops in all cities are in the top priority and crops such as cereals and rice are last priority.

In recent years, one of the most significant environmental crises has been the phenomenon of wind erosion and dust emission. Wind erosion is considered one of the effective factors in desertification and land degradation in dry regions. The process of wind erosion, due to the transport of soil nutrients along with fine particles, is recognized as one of the limiting factors for soil fertility in many parts of the world. Evaluating this type of erosion and estimating the soil loss requires the installation of various measuring stations. Establishing and equipping these stations and providing the necessary equipment require large costs and a long time. In addition to direct measurement methods in wind erosion, the use of modeling results, especially in combination with remote sensing techniques, to study and predict environmental effects, trends, and risk assessment has greatly contributed to research in the last two decades. Therefore, this study aims to monitor and investigate the warning zones of wind erosion in northwest Golestan Province using the wind erosion hazard index (WEHI) model.                                 

To assess wind erosion in the western part of Golestan Province, the WEHI model was implemented. This model predicts the sensitivity of the landscape to wind erosion by considering a set of surface and climatic thresholds and using a geographic information system (GIS). In this model, wind erosion severity is determined in three classes: low, moderate, and severe, by multiplying wind speed by the percentage of bare soil and dividing it by the percentage of soil moisture percentage. To monitor wind erosion, the normalized difference moisture index (NDMI) was used to evaluate soil moisture, and the modified bare soil index (MBI) was used to assess bare soil. For validation, these indices were compared to field data and plots in each working unit. Additionally, three statistical parameters, Pearson correlation coefficient, coefficient of determination (R2), and root mean square error (RMSE), were employed to calculate the correlation between these indices and ground data. Furthermore, a Markov chain model was used to examine changes in wind erosion classes. Finally, after monitoring wind erosion and considering a threshold value for this model, the area of warning zones during the statistical period was investigated.

The results obtained from the WEHI model indicate severe wind erosion intensity in the working units of Atark floodplain deposits, saline lands, longitudinal dunes, Barchan dunes, bare lands, and margins area of wetlands. According to the WEHI model, the region was divided into three classes: low (54% frequency), moderate (21% frequency), and severe (25% frequency). The model classified the northern regions into severe and moderate classes, while the southern areas of the region fell into the low wind erosion class. High correlation coefficients between the WEHI model indices based on remote sensing and field data demonstrate the model's ability to monitor wind erosion over time and at different scales. Wind erosion monitoring results showed that the high wind erosion class increased from 59,940.88 ha to 71,698.3 ha, indicating an increase of 11,757.43 ha. Spatial analysis of wind erosion classes indicated that most changes occurred in central areas, with most areas around the Sangartappeh playa and central regions changed to severe wind erosion class, while western, eastern, and central areas changed to the low wind erosion class. Finally, monitoring the warning zones revealed an increase of 41,000 hectares in the areas under warning, in the western, northwestern, and central regions.

In this study, the performance of the WEHI model in assessing wind erosion risk in the western part of Golestan Province was confirmed. Although factors such as roughness, soil structure, and organic matter content are not directly considered in the model, they are indirectly incorporated in scoring the percentage of bare soil. To control wind erosion in these areas, planting salt-tolerant species and implementing soil fertility enhancement strategies, such as soil mulching in heavy-textured areas, are recommended. Finally, mechanical operations and the establishment of windbreak networks are suggested for controlling wind erosion in abandoned land units. This research can serve as a useful approach for planning and managing vulnerable areas to wind erosion in northwest Golestan Province.

Planting the proper cultivar in the most optimal sowing date is very decisive in the management of environmental resources, including water resources, and leads to maximum water productivity of and energy efficiency for increasing performance. Therefore, this research was conducted with the aim of determining the most appropriate sowing date and water productivity for commercial cultivar of bread wheat under supplemental irrigation and water deficit conditions in the climatic conditions of Gorgan, Iran.

This experiment was carried out as split-split plots based on randomized complete block design (RCBD) with four replications, during the 2021-2022 cropping season. In this experiment, two moisture conditions (supplemental irrigation and water deficit conditions) were placed in main plots, seven sowing dates (from 1 November to 31 December, 10-day intervals) were placed in subplots and four bread wheat genotypes (including Arman, Araz, Taktaz and N-93-9) were placed as sub-subplots.

The analysis of variance for grain yield and water productivity showed that the effect of moisture conditions was significant at the 0.05 level and the effects of sowing date and cultivar were significant at the 0.01 level. The results of mean comparisons showed that the grain yield in water deficit conditions (5288 kg ha-1) was significantly lower than the supplemental irrigation conditions (5715 kg ha-1). Water deficit conditions caused a significant increase in water productivity (17.3 kg ha-1 mm-1) compared to supplemental irrigation conditions (16.1 kg ha-1 mm-1). The highest grain yield was obtained on the second (11 November, 6340 kg ha-1) and third (21 November, 6165 kg ha-1) sowing dates. Also. the highest water productivity was related to the second and third sowing dates (18.6 kg ha-1 mm-1). The results of mean comparisons for cultivars showed that in Taktaz (as an early-maturing cultivar) grain yield (5872 kg ha-1) and water productivity (17.8 kg ha-1 mm-1) were significantly greater than other genotypes.

The results of this research showed that water deficit conditions caused a significant decrease in grain yield and a significant increase in water productivity. The highest grain yield and water productivity were obtained on the second and third planting dates. Also, grain yield and water productivity in Taktaz cultivar were significantly greater than other genotypes. In general, it can be said that the planting of Taktaz cutlivar in the second and third sowing dates (11 and 21 November) has resulted in achieving the maximum performance and water productivity in both supplemental irrigation and water deficit conditions.

The current study is aimed to zoning flood probability map in the Saliantapeh catchment is located in the Golestan Province. To this aim, two well-known data mining models namely Random Forest (RF) and Support Vector Machine (SVM) were applied due to their robust computational algorithm. Flood inventories were gathered through several field surveys using, local information and available organizational resources and corresponding map was created in the geographic information system. Reviewing several worldwide studies, 13 predisposing variables including proximity to stream, soil texture, lithological units, land use/cover, slope percent, elevation/DEM, slope aspect, plan curvature, profile curvature, stream power index and topographic wetness index were chosen and the corresponding maps were generated in the geographic information system. In this study, after preparing the predictor maps, SPSS software was used to analyze this data and testing Multi-collinearity. In order to evaluate models’ results the area under the receiver operating were used. Three different sample data sets (s1, s2, s3) including 70% for training and 30% for validation were randomly gathered to evaluate the robustness of the applied models. Results showed that the RF model with the area under curve value of 0.96 and robustness of 0,001 in validation step had better performance on flood probability zonation over the study area.

Nowadays, participatory water management receives much attention as one of the key elements of sustainable water resources management. The feasibility of good governance in the process of participation of stakeholders in water exploitation can meet the interests of all users in a fair way. The purpose of this research was to investigate the feasibility of good governance in the process of participatory water management. The study was conducted in Payvand Production Cooperative (PPC), Aqqala County. Research method was survey and questionnaire tool was used for collecting the required data. Target population included 400 farmers who were members of PPC and received services related to participatory water management. The data was collected from 196 farmers from 7 targeted villages. Reliability of research questionnaire was approved based on opinion of experts, and its validity was confirmed by Cronbach`s Alpha coefficient in two parts: importance and feasibility of good governance components. Results of evaluating the feasibly of good governance components showed that the majority of respondents believed that the components of good governance in the process of participatory water management in the study area had been considered at an acceptable level. Also, the results of one sample t-test showed that the process of participatory water management in the study area was successful in terms of attention to all five components of good governance, namely, public participation and collective agreement, responsibility and law enforcement, accountability and transparency, fairness and efficiency and effectiveness. Results of independent sample t-test indicated that respondents whose main job was farming (compared to those whose main job was not agriculture) and respondents who received water share in a group manner (compared to those who received water individually) evaluated the feasibility of good governance components at high level.

Evaluation of a system needs a combination of indicators that can show their current situation and future. Multilayer aquifers are more complicated due to different recharge and discharge processes of each layer. This paper aims to evaluate sustainability of phreatic and confined layers of an alluvial aquifer in Golestan province. The relevant data includes monthly precipitation of 19 rain gauges, groundwater level of the phreatic layer in 19 observational wells and piezometric level of 19 wells in the confined layer. In this paper combination of eleven indices that selected according to available data in the region, is used to assess sustainability. Results show in spite of detecting no significant trend in the precipitation data, there is descending trend in the water table of phreatic layer and piezometric level of confined one. Aquifer sustainability index of phreatic and confined layers are 0.89 and 1.01, respectively, that means unsustainability of both layers and worse condition of confined layer. Of course unsustainability of the confined layer has been covered by existed non-renewable groundwater resources. According to groundwater abstraction development index equal to 0.26, implementation of water resources development plans is allowed with considering limitations in terms of water quantity and quality. Also 2.82 as the aquifer recovery potential index revealed if driver factors change toward providing sustainable conditions, both layers can be recovered soon. It can be concluded that the region is facing water scarcity that is a limitation to economic development and human health and well-being.

Groundwater is of valuable resources that its conservation needs quality and quantity monitoring. Different indices such as WQI (water quality index) are used in order to monitor the groundwater quality. The objective of this study is to assess spatial-temporal changes in WQI in groundwater aquifer of Golestan province including Ghare-Sou, Grgan-Roud and Gorgan gulf basins. The Golestan province was selected as the study area. WQI was calculated based on the quality parameters data of 114 deep wells in the study area, collected during a 21-years period. After zoning WQI in GIS, the spatial-temporal changes of this index were investigated considering the range of changes, the observed minimum and maximum values during the study period. The empirical Bayesian kriging method presented better results in comparison to other methods for WQI zoning in GIS environment. The quality zoning of WQI in the studied area showed that the aquifer is in a good and very good condition and it is only bad in a small part of aquifer located in the eastern shores of the Caspian Sea and the northern part of the study area. In addition, no considerable differences were found between the WQI averages of the two events data sampling during the year. Also, the investigations show a decrease in water quality as closing to the sea shore and to the northern part of the study area. According to the fact that WQI follow the general slope of the region, there was a good spatial structure in the region which caused a better result for empirical Bayesian kriging interpolation method.

Precipitation-based drought indices including the SPI generally neglect the effect of other variables such as temperature and evapotranspiration on drought intensity. However, some studies have confirmed the systematic errors involved. Therefore, alternate indices like Standardized Precipitation Evapotranspiration Index (SPEI) have been proposed. The current comparative study was aimed to evaluate the SPI and SPEI indices’ skill for drought monitoring in different climatic regions of Golestan province. The results were analyzed in different seasons based on the correlation between SPI and SPEI indices classes in a 12-month window. The results showed that in more humid regions, the correlation between the two indices is higher. Similarly, in smaller time scales, the correlation was higher. The SPEI detects greater number of wet and dry spells comparing to SPI. Significant correlation between the two indices was observed at Ramyan station using Pearson's parametric test at 95% confidence level for 3 and 6 months time series. Seasonal frequency analysis of drought classes showed that both indices have more inter-classes variations in summer. Maximum number of severe and extreme drought events was observed at Ghaffar Haji station during summer using both indices. Also the comparison of SPI and SPEI time series showed that SPEI index detects longer wet and dry periods, but SPI index revealed bigger extreme values.

Landslide is one of the most destructive natural events in steep areas. Due to its geographical position, climatic and geomorphological conditions, population increase, pressure on natural resources and land use change, Iran is exposed to natural hazards. Therefore, preparation of landslide hazards mapping is very important. So according to landslide events reports of Oghan watershed basin in Golestan province, The aim for this research is landslide hazards mapping using Analytic Network Process model.
For landslide hazard mapping in Oghan watershed basin, At first step, maps of effective factors were prepared by using of information sources, 1:50000 topographic and 1:100000 geological maps, rain statistics, aerial photos and satellite images. Then, these information were completed by field surveying in mentioned region that its geographical position is between37° 9´ to 37° 15´ northern latitude and 55° 5´ to 55° 43´eastern longitude with area and average altitude of 40352 ha. After that, maps of the effective factors were organized, such as: slope, aspect, elevation, rain, distance from streams, roads and fault, land use, lithology and landslide dispersion layer at ArcGIS. In the second step, the weight of effective factors was calculated by ANP model and applied to the information layers in the GIS environment. By overlapping them, a map of zonation of landslide occurrence was prepared. In the third step, the accuracy of the map of zonation was evaluated using the degree of proportionality and index Density ratio.
Result of identification of 88 landslide zones with area of 181ha and investigation of their relationship with effective factors showed that most of landslides are located in lithological units of shale, marl, bedded limestone, sandstone and quaternary deposits (Table1). Furthermore, results of elevation and slope layers assessment show that most landslides were happened in slope of 15-30% . In rain classes assessment, landslide occurrence has direct relationship with rain increase and classes of 500-700 and more than 700mm of annual rain have considerable percent of landslide. Results of distance from road and stream showed that most of occurred landslides are in distance less than 100m from these features and it demonstrates the role of mass taking from downhill via human or natural factors. Finally, assessment of distance from fault showed that most of landslides are located in distance classes of more than 400m (Table1).
The results of zonation with the ANP model in the Oghan watershed basin showed that 29 percent of the basin in the four classes is in high and very high hazard areas. Among the eight information layers, the slop factor (0.215), lithology (0.182) and distance from the road with score weighted (0.173) had the highest weight and gradient direction with the score weight (0.018), the lowest Points in the zonation. Evaluation of different classes of effective factors also showed that the class is 100 m distance from the distance from streams with score weight (0.08), slope class of 15-15% with a rate weight (0,788) and a class of 100-0 (m) distance from the road With a score weight of 0.068, they earned the highest rating weighted. The results of this model finally showed that the convergence of factors such as slope, lithology, distance from the river as natural factors along with the human factor, such as road construction, has a great influence on the hazard of landslide. Finally, by studying the density rate of 88 landslide occurrence in the basin and its upward curve and the adaptation of the sliding zones with the application of the degree of proportionality of 69.7% on the high and very high classes in the final map.

At present, the development of new irrigation systems is one of the most effective strategies for efficient use of water resources. In recent years, the area covered by pressurized irrigation systems has been a growing trend. If the quality of the implementation of these systems (technical, administrative, operation, management and equipment) are not given sufficient importance, motivating farmers to use these systems gradually decreased and thus their area covered will be reduced. The present study was conducted to evaluate some sprinkler irrigation systems (on 21 farms) in Golestan province in the years 2012 and 2013.
In this study, infiltration rate, hydraulic characteristics of the systems (pressure and flow rate of sprinklers, efficiencies, and uniformity), irrigation scheduling and wind and evaporation losses were considered.
The results showed that 38% of sprinkler irrigation systems in terms of distribution of uniformity (DU) and application efficiency of low quarter (AELQ) and 48% of systems in term of coefficient of uniformity (CU) were below the acceptable values. In 50 percent of the systems that were evaluated, their Application efficiency (Ea) was more than 65% and they were acceptable, but in 40 percent of the systems, the Ea was less than 40% and they was unacceptable. The results showed that 39% of the projects, the amount of water loss due to evaporation and wind were more than 20%, which is unacceptable for a sprinkler system. In most systems, it has been observed that the designer suggested an irrigation scheduling, type of sprinkler or sprinkler and lateral spacing, but operator and also farmer operates other program. Comparison of the measured soil infiltration rate and application rate of sprinklers indicated that there is not an appropriate match between the estimated values by the designer and measured in the field. Some of the design parameters such as cropping patterns, sprinkler type, sprinkler and lateral spacing and the pump were changed while the running. Normally, a change in any of the mentioned parameters influence on all the basics including the irrigation scheduling.
The most important problems in terms of management and operation of sprinkler irrigation systems were inadequate awareness of users of the system and irrigation scheduling. Teaching and principles of irrigation scheduling is required to good management and proper operation of sprinkler irrigation system, resulting in such cases authorities must take effective steps. In general, farmers tend to perform pressurized irrigation systems especially when they receive financial facilities. But to achieve objectives such as efficient use of water resources that can be realized with the implementation of sprinkler irrigation systems is still faced with serious challenges.

Aquifer overexploitation can cause problems such as salt water intrusion and land subsidence. This condition drives the necessity for the optimal management of aquifers which requires an understanding of aquifer hydrodynamics. In this regard radioisotope dating is one of the useful methods. This paper presents a practical method to determine the age of groundwater using tritium radioisotope. The tritium dating of groundwater includes sampling, initial distillation, enrichment, secondary distillation, measurement of tritium radioactivity, calculation of device parameters, and age of the samples. The electrolytic enrichment method and radioactivity measurement using LSC, which is introduced in this paper, make it possible to measure tritium below 1 TU that means dating water up to 50 years and can overcome the problem of tritium concentration decline in the atmosphere to some extent. The results of a study performed using this method during spring 2012, with interior facilities of the country, showed that the age of the samples were divided into two groups of 5 to 10 years and the mixture of modern recharge and recharged before 1952. Therefore the young parts of aquifer are influenced more readily by qualitative and quantitative climatic and factors. On the contrary, territories with older water reserves are less affected by these changes and have a higher degree of reliability. In the allocation of such resources only the renewable volume should be considered. To achieve this objective imposition of restrictive policies of exploitation seem to be necessary in aquifer management plans.

In the present study, dealing with water deficit challenges for Gorgan River Basin has been considered. Golestan province's economy is dependent on agriculture but the occurrence of drought periods reduced the agricultural production and consequently the region's economy is in crisis. Therefore, performing studies for programming and management of the water resources of the province and the water allocation in the margin of Voshmgir dam in Gorganrood basin has a great deal of importance. The issue of the allocation of water resources is proposed in order to maximize the expected profit of the water system. According to the regional water organization policy, one of the main goals of Voshmgir dam water management is the allocation of water between the competing consumers. If the amount of promised water is released in the future, the expected net profit of the system will be realized and if it is not released, the system will experience losses.
In this studyWater supply is considered stochasticand objective function of the model is to maximize the system (Agriculture, Aquaculture and Environment) profit and optimal allocation of water during the programming period using a two-stage stochastic model as follows: Constraint of the available land: Constraint of the available water in each of the main canals: Constraint of the available water: Constraint of the amount of inflow water
Reservoir capacity constraint
Constraint on the maximum and minimum water demand for environmental sector
Constraint on the maximum and minimum water demand for crops
Constraint on the maximum and minimum water demand for warm-water fish
Constraint on non-negativity of the decision variables in the model
The length of the right main canal of this network is about 17.76 km and the length of the left main canal is about 21.338 km. In this study, is considered for the right main canal and is considered for left main canal. Lands under irrigation network are considered in three regions. Right bank regions and sample farm are covered by the network in the right part of the network and the left bank regions are covered by the network on the left. Thus, there is one region in the left side of the network and there are two regions on the right. The major crops cultivated in the agricultural lands of the network include wheat, barley, canola, cotton, alfalfa, sunflower, rice, cotton-melon, and maize. Due to the random nature of the river flow to the dam, fixed and determined data cannot be used to calculate the volume of water entering the irrigation system, for this reason, using simulation techniques, we can predict the future behavior of the system for each reservoir. The results of the study showed that only agriculturalsector suffers from water deficit and target water demand of the other sectors is supplied and there is no deficit of water for these sectors and target water demand, lack of water and the final allocation of water in the agricultural sector are declined under different efficiencies of irrigation. If other sectors are remained unchanged and irrigation efficiency did not affect them, it is because irrigation efficiency has a direct impact on the water use in agriculture and decreases by increasing the efficiency of the allocated water to this sector and the amount of water stored in the reservoir for the coming year is added. By increasing the efficiency of irrigation which has a direct impact on water use in agriculture sector, the amount of water deficit reduced as a result of the increased system profit.
The results showed that there is no water deficit for aquaculture and environmental sectors in the scenarios of dry, wet and normal years and the target water demand of these sectors is supplied. However, the amount of water deficit in agricultural sector in dry year with the probability of 18% and under the efficiencies of 37, 45 and 51 percent would be 40.98, 23.67 and 14.07, respectively. With the increase in efficiency, water demand in agriculture, water deficit and ultimate allocation of water to this sector are decreased and system profit under different efficiencies is increased. Based on the obtained results, highlighting the irrigation efficiency and allocating the minimum water demand of the sectors is recommended.

Climate change has various effects on the quantity of rainfall and warming also is lead to increases in frequency and intensity of droughts by accelerating earth drying up and consequently. It is effective on the curves of severity- duration- frequency of drought (SDF). The purpose of this study is to evaluate the effects of climate change on SDF curves in the future in Qareh su basin located in the Golestan province. First, precipitation and temperature variables were generated using basin-areal average time series from years 1983-2012 and “CanESM2” model outputs as a general circulation model under the RCP 2.6, RCP 4.5 and RCP 8.5 scenarios and “SDSM” model as a statistical downscaling model over the period 2019-2048. Then SDF curves were derived from 3-month Reconnaissance Drought Index (RDI) and Copula approach and conditional return period in the base and future time periods. The results showed that monthly precipitation and temperature for the future time period under different scenarios are generally decreased and increased, respectively and the return period of a drought event with severity equal to 10 with respect to 6-month duration or less, is 5 years in the base period. The return periods of the same event under RCP 2.6, RCP 4.5 and RCP 8.5 are 21, 17 and 4 years, respectively.

Agh Emam(2) Watershed is one of the watersheds in the Golestan Province with an area of 2595 hectares and has considerable problems with soil erosion, particularly gully erosion. In order to carry out this study, at first, the total number of linear gullies in the study area (eleven gullies) was determined. Then, different physical soil properties (sand, clay, silt, and moisture saturation percentage) and chemical soil properties (electrical conductivity, bio- carbon, lime, cation exchange capacity, sodium adsorption ratio, and exchangeable sodium percentage) were investigated by soil sampling (eleven samples) inside the gullies and in the watershed upstream of the gullies at two depths (0-20 centimeters and 20-50 cm). Non- soil effective factors in development of linear gullies including slope classes, altitude classes, land use, and lithology were also evaluated. The results showed that, among soil characteristics, clay percentage (surface), silt percentage (surface), saturated moisture percentage (sub- surface), electrical conductivity (sub- surface), bio- carbon (surface and subsurface), lime (surface and sub- surface) and also lithology from non- soil factors had significant role in development of linear gully erosion in the study area.

Soil moisture regime refers to the presence or absence either of ground water or of water held at a tension of less than 1500 kPa in the soil or in specific horizons during periods of the year. It is the most important factor in soil formation, soil evolution and fertility affecting on crop production and management. Also, it widely is practical in soil classification and soil mapping. The soil moisture regime depends on the soil properties, climatic and weather conditions, characteristics of natural plant formations and, in cultivated soils, is affected by the characteristics of crops grown, as well as the cultivation practices. Determination of soil moisture regime within a landscape scale requires high information and data about moisture balance of soil profile during some years according to Soil Survey Manual (2010). This approach is very expensive, labor, time and cost consuming. Therefore, achievement to an alternative approach is seems essential to overcome these problems. The main hypothesis of this study was to use capability of magnetic susceptibility as a cheap and rapid technique could determine the soil moisture regimes. Magnetic properties of soils reflect the impacts of soil mineral composition, particularly the quantity of ferrimagnetic minerals such as maghemite and magnetite. Magnetic susceptibility measurements can serve a variety of applications including the changes in soil forming processes and ecological services, understanding of lithological effects, insight of sedimentation processes and soil drainage.
This study was conducted in an area located between 36°46ó 10˝ and 37° 2’ 28˝ N latitudes, and 54° 29’ 31˝ and 55° 12’ 47˝ E longitudes in Golestan province, northern Iran. In the study region mean annual temperature varies from 12.4 to 19.4 °C. The average annual rainfall and evapotranspiration varies from 230 mm and 2335 mm in Inchebrun district (Aridic regime), to 732 mm and 846 mm in Touskstan uplands (Udic regime), respectively. this study was conducted in four soil moisture regimes (Aridic, Xeric, Udic and Aquic), for exploring the relationships between soil properties and magnetic measures. In each regimes, 25 soil profiles were drug, described and soil samples were collected from each of soil horizons. Soil samples were air-dried and sieved using a 2 mm sieve. The dithionite-citrate bicarbonate (DCB) method was used to measure Fed and acid ammonium oxalate for Feo. In this study, a set of environmental magnetic parameters including magnetic susceptibility at low frequency (χlf), saturation isothermal remnant magnetization (SIRM), isothermal remnant magnetization (IRM100 mT) were measured. Magnetic susceptibility (χ) was measured at low frequency (0.47 kHz; χlf) and high frequency (4.7 kHz; χhf) using a Bartington MS2 dual frequency sensor using approximately 20 g of soil held in a four-dram clear plastic vial (2.3 cm diameter). Frequency dependent susceptibility (χfd) was determined by the difference between the high and low frequency measurements as a percentage of χ at low frequency. IRM was measured at the field of 100 mT generated in a Molspin pulse magnetizer (IRM100mT) and at the back field of 100mT (IRM−100mT). The IRM acquired in the maximum field of 1000 mT was measured and defined as the saturation isothermal remnant magnetization (SIRM) of the soil sample.
The results showed that moisture regime induced significant differences for soil physical and chemical properties. Diversities in genetic soil horizons and soil development degree have been increased from Aridic to Udic soil moisture regime. The results also indicated that selected properties including magnetic measures and physical and chemical properties were significantly different in four soil moisture regimes. With increasing rainfall and reducing temperature from aridic to udic soil moisture regime, soil organic matter was increased. Otherwise, in arid environment Gypsic, Calcic and Salic horizons were observed in the near of soil surface. Fed and Fed-Feo were the highest in udic and the lowest in udic soil moisture regime, respectively. Moreover, higher soil development because of climate effect leaded to higher amount of pedogenic ferromagnetic minerals, as well as the highest were observed in the Udic regime. Otherwise, in Aquic moisture regime, the lowest value of magnetic susceptibility was obtained because of dissolution of ferromagnetic minerals (magnetite and maghemite) under supersaturating condition. In overall, close relationships were observed between soil physical and chemical properties and magnetic measures in various soil moisture regimes.

Climate condition is one of the most important factors which affect agricultural production. Amongst climate parameters, rainfall variability is one of the most crucial factors which has important role on agricultural productions because of its effect on available water for plants. The amount of water available to plants strongly depends on the rainy seasons onset, length and rainfall temporal distribution, hence can determine a success or failure of a growth season. One of the most important areas for crops production in Golestan province is the Aq-Qalla township. Most of the areas are used for rainfed farming, such as wheat and barely. In general, agriculture in Aq-Qalla township is dependent on rainfall. Determination of the precipitation spatial variability in these agricultural lands is particularly very importance. Therefore, the objectives of this research were the investigation of different interpolation methods for estimation and zoning of precipitation variables in agricultural lands of Aq Qalla township for rainfed cropping of autumn cereals. Also, this research provides information at local level that could be used by farmers to increase of yield in rainfed condition.
In this research, the spatial distribution of precipitation on agricultural lands of Aq-Qalla township evaluated using 18 method-models from deterministic and geostatistic interpolation such as, Inverse Distance Weighted (IDW), Universal Kriging (UK), Ordinary Kriging (OK), Radial Basis Function (RBF) and Local Polynomial Interpolation (LPI). The performance criteria for evaluation were Root Mean Square Error (RMSE) and General Standard Deviation (GSD) with the Cross Validation methods.
The results showed that Local Polynomial Interpolation (1 and 2 degree) was the best method to estimate precipitation parameters except spring and June precipitation. Because, it had the highest accuracy and the lowest error for estimating of these parameters. Semivariograms analysis indicated that annual and June precipitation were best fitted to Exponential model, also, autumn, spring and May precipitation by Spherical model. Results of final maps showed that amount of annual, autumn and June rainfall were lower in north than south regions. Moreover, the results of this research showed that about 65.62 percentage of agricultural lands of Aq-Qalla had suitable level of annual rainfall (300-400 mm). Also, in this area amount autumn rainfall was 101.11 to 166.08 mm.
The results indicated that same as temperature requirements, the annual and autumn rainfall requirements of current crops such as wheat and barley are provided in this township. But, amount of spring and June rainfall are non-suitable in this area. Wide area in Aq-Qalla township were under 10 mm rainfall in June. This amount is not enough for grain filling.

Saturated hydraulic conductivity is an important factor in the related issues to water and soil. The aim of this study was to estimate the saturated hydraulic conductivity (Ks) for 280,000 hectares of land in the Northern Rivers Gharasoo - Gorganroud. For this purpose was used data from 188 soil profiles. Available soil information includes some of the physical properties of soil (till the depth 6 m), some of the chemical properties of the soil (till the depth 1.5 m) and some chemical properties of the water in the wells. The aim of the present study was evaluating the effects of combined physical and chemical available parameters from different depths on the accuracy of the models were fitted. To this end, three models were proposed with different inputs. The first model was created by using the chemical properties of water and soil, the second model was developed by using soil physical parameters and third model were created by combining parameters of the two previous models. The results showed that the third model is more accurate and the value of R2, R2adj and RMSE, respectively was, 0.61, 0.56 and 0.34 also ME values for the three models respectively was 0.05, 0.02 and 0.06. Verification test results showed that the average predicted values and the measured Ks in all models, with no significant difference.

Erosion and sediment transport is a complex process that is influenced by soil texture, topography, regional climate, land use, human activities such as farming systems and soil conservation measures. This study examines the effects of changes in land use and residential development on erosion and sedimentation in Ziarat watershed in Iran.. In this study, the basic WetSpa model inputs were the maps of a digital elevation model (DEM), land use and soil type in GIS raster format, and hydrometeorological data including hourly precipitation, evapotranspiration and temperature for 4 years (2007-2010). Hourly discharge and suspended sediment at the watershed outlet were used for the model calibration and validation. The accuracy of flow simulations based on the Nash - Sutcliffe model efficiency was 67.02% respectively. The evaluation of suspended sediment simulations for the calibration period based on the Nash – Sutcliffe criteria was 63.08% and 72.22 % for the suspended sediment concentration and sediment yield, respectively. Then, the residential development and land use change scenarios were developed in GIS environment and were used as input maps for the calibrated model. Comparison of the components of erosion and sediment transport results showed that by increasing the residential areas, suspended sediment concentration changed from 0.23 g/l for current situation (zero scenario) to 2.27 g/l in Scenario IV(100% increase in residential areas). Also the amount of suspended sediment yield increased from 253 g/s in current situation to 1143 g/s.

Underground water resources is One of the most important parts that supplies the human need, particularly in arid and semi-arid. At present, a considerable part of the drinking water is supplied from underground water sources, which are mostly free aquifer. Therefore,the Quality protection of this sources is important. Decontamination of groundwater is costly and lengthy process and is often diagnosed when the aquifer decontamination is impossible. Identify vulnerable areas of aquifers and land use management is one of the best ways to prevent contamination of groundwater. So in this study, the qualitative protection zone of tow drinking water wells located in the Alluvial area and plain of golestan province, using WHEAM2000 software and use the method of equations in groundwater flow in uniform flow conditions and constant radius, To compare the performance of two methods to calculate protection zone in these areas, was calculated. The results showed that in the presence of hydrological-reliable parameters for the establishment of wells area, the above software can be used as a useful tool for the determining protection zone of wells. Since in the plain area the hydraulic gradient (i) and hydraulic conductivity (k) is lower, so the protection zone calculated by method of equations in groundwater flow in uniform flow conditions and constant radius overlap more than the Alluvial area.

Precipitation is a highly variable Meteorological and hydrologicalmeteora. Investigate variation of spatio-temporal of precipitation for water resources planning and management in different parts of the catchment is essential. Autocorrelation of this kind of data however makes their analysis complex، but increases their analysis accuracy. The goal of this study is، modeling Spatio-temporal variationand interpolation of monthly precipitation in Golestan province. So، 30-yr monthly precipitation variations for 30 meteorology and rain gauge stations was studied. To analyse spatio-temporal precipitation،variance hemogenity and space/time stationarity was assessed. By examining different models of the Spatio-temporal variogram، SumMetric model with RMSE of 0. 14 mm was selected as the most suitable spatio-temporal variogram model. Then، with this model، by different neighbors، interpolation was done. therefore، 360 monthly precipitation distribution maps was produced. Kriging interpolation with 20 neighborhoods minimum estimation error is revealed. The mean of kriging estimation error is close to zero. Based on the results، pattern of variation in precipitation in this maps with observed maps، haveSimilarity that show the suitability of the modeling approach. Results of this study can be used in determining precipitation in zones with no station in every time (under the influence of spatio-temporal autocorrelation).