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

Groundwater is considered as a main source of providing agricultural, industrial and drinking water requirement in arid and semi-arid regions. The objective of this study was to survey the groundwater depth status and its electrical conductivity during three decades in a part of Torbat Heydariyeh Rokh Plain. In this study, quantitative and electrical conductivity information related to groundwater depth status in 1991-2022 was investigated. Interpolation methods such as ordinary Kriging and invers distance weight were applied for preparing the zonation maps of groundwater depth and its electrical conductivity by using GIS software and ArcMap. The results showed that ordinary Kriging method with the lowest RMSE, MAE and MBE by average amount of 21.82, 4.59 and 4.59 meter respectively, and the highest R2 by amount of 0.99 had the better estimate than IDW method. Through passing time, North West, West and partly East regions of Rokh plain experienced more decrease in water table than Northen and central regions. The average head loss of water table in Northen and central regions of Rokh plain was 11.28 meter (i.e. on average 35 cm/year) and in North west regions of plain was 61.9 meter (i.e. on average 1.93 m/year). Groundwater electrical conductivity in North West regions increased by 1482.22 µmho/cm during 32 years statistical period. According to findings in this research, it is recommended to prevent the head loss occurred in water table in Rokh plain, proficient management of water resources laid on priority of province administrative managers plans.

Soil desalination in drained fields is very important because soil salinity harms on crop yield. Therefore, for the optimal management of water and soil, and the sustainability of agricultural lands, salinity monitoring in soil is essential. In this study, 44 soil samples from the depth of 0-30 and 30-60 cm were prepared from drained lands, during one cropping year. Then, soil salinity and acidity map was produced by GPI, LPL, IDW, Ok, RBF methods. Evaluation of salinity at 0-30 cm showed that stable kriging in the first and third months, exponential kriging in the second month, RBF inverse multi-quadrant model in the fourth and fifth months, were the best models. The results 30-60 cm showed that stable kriging in the first and third month, Gaussian kriging in the second month, Exponential kriging in the fourth month, and RBF inverse multi-quadrant model in the fifth month were selected as the best model. Also, evaluation of pH at the depth of 0-30 cm showed that Spherical kriging in the first month, GPI with the first power in the second and fifth months, IDW with the second power in the third month and Exponential kriging in the fourth month had the lowest RMSE. Evaluation of pH at 30- 60 cm showed that stable kriging method in the first, third, and fourth months and GPI with the first power in the second and fifth months had the lowest RMSE. The problem of salinity and alkalinity was observed in most of the surveyed region, and the level of salinity in the surface layer of the soil was higher than in the deep layer. The comparison of the salinity map in different months shows that the salinity has been decreasing during the 5 months of monitoring and the general trend of pH changes is similar to EC.

The management of water resources, especially groundwater, is of particular importance in arid and semi-arid regions. Improper understanding and unsustainable exploitation in these areas will result in irreparable damage, such as severe and irreversible groundwater level decline, reduction in well and aqueduct discharge, and changes in the pattern of groundwater flow. Therefore, the aim of this research is to investigate the decline in the groundwater levels of Mashhad Plain, which is selected as one of the most important and largest plains in Khorasan Razavi province. In order to conduct this study, the data from 62 observation wells were examined over a period of five years (2011-2016, 2016-2021). Initially, the statistical data was collected and organized using Excel 2017 software, and the hydrograph representing the aquifer of Mashhad Plain was plotted. Subsequently, using ArcMap 10.8 software and the Inverse Distance Weighting (IDW) method, maps of the groundwater level and water table for an 11-year period and two consecutive five-year periods were generated. The results obtained in this study indicate that the groundwater level in this aquifer has, on average, increased by 0.36 meters in the first five years and 0.32 meters in the second five years for the specified time period. The central, southeast, and northwest parts show the highest increase in reaching the groundwater level. Additionally, the hydrograph representing the Mashhad aquifer shows an average annual decrease of 0.33 meters in groundwater level over the 11-year period.

Indiscriminate exploitation of groundwater has caused a decrease in the groundwater level and as a result, has caused land subsidence in many areas. This problem is especially visible in arid and semi-arid regions like Iran, where water supply for agriculture, drinking, and industry is done from groundwater water sources, and in recent years, it has seriously threatened the aquifers of the plains as a serious danger. In this research, due to the importance of the problem, land subsidence in the Damghan Plain aquifer located in Semnan province was studied and investigated.In this research, the amount of subsidence was measured at the field, and then its spatial changes were investigated using conventional methods such as Kriging interpolation, Co-kriging, and inverse distance weighted interpolation (IDW). Also, the artificial neural network model was used to estimate and interpolate the amount of subsidence. Three statistical indices namely the coefficient of correlation (R2), the root mean square error (RMSE), and the mean absolute error (MAE) were used to compare the estimation of subsidence values using an artificial neural network model, kriging interpolation method, cokriging, and IDW. To perform interpolation using kriging, cokriging, and IDW interpolation methods, the variogram of land subsidence data was drawn. Also, in order to increase the accuracy of the mentioned models in predicting the amount of subsidence, the auxiliary variable of water level reduction was used.Using different functions such as circular, spherical, exponential, Gaussian, and linear models for plotting the semivariogram, results show that the Gaussian function with segment-to-threshold ratio (C0/(C0+C)) equal to 0.26 has better performance compared to other models. Also, the artificial neural network has a better performance compared to the kriging method and the inverse weighted distance method and has been able to reduce the RMSE error value in the validation stage by 17.6% and 31.3%, respectively. It has also increased the value of the R2 from 0.502 and 0.421 to 0.721.The use of the auxiliary variable of water level reduction has increased the accuracy of the models used in predicting the amount of subsidence. In this case, the comparison between the estimation of subsidence values using the artificial neural network model compared to the interpolation method of kriging, cokriging, and IDW shows that the artificial neural network model with a coefficient of determination (R2) of 0.860 and 0.751 and 0.015 and 0.017, has a better performance compared to the mentioned methods and reduce the amount of prediction error. Therefore, the artificial neural network model can be used with good accuracy as an alternative method instead of conventional interpolation methods to investigate the spatial changes of land subsidence.In recent years, the phenomenon of land subsidence has occurred in many plains of Iran due to excessive extraction of underground water, including Damghan Plain. In this research, by using the measured data of land subsidence in this plain, its spatial changes were investigated using kriging and cokriging methods (geostatistics method), inverse distance weighted method (IDW), and weighted IDW (deterministic method) in the whole plain. it placed. The research results showed:• Compared to circular, spherical, exponential, and linear functions, the Gaussian function can better estimate the spatial changes of land subsidence.• The results of the kriging method were better than the inverse distance weighted (IDW) method.• The artificial neural network model with Gauss function and two intermediate layers has better performance than other transfer models such as sigmoid, hyperbolic tangent, and hyperbolic Bade secant.• The use of artificial neural network model has increased the accuracy of land subsidence estimation compared to conventional methods such as the kriging method and inverse weighted distance method.

Knowing the spatial and temporal changes in groundwater quality is one of the important issues for optimal management of groundwater resources. In this study, the hydro geochemical properties of groundwater resources in Miandoab plain (West Azerbaijan province of Iran) were investigated.

For this purpose, the data of 51 study wells during the time period (from 2014 to 2018) were used. The qualitative parameters such as the amount of Mg2+, Ca2+, Na+, K+, HCO3-, SO42-, Cl-, CO32- and the indexes such as TH (Total Hardness), TDS (Total Dissolved Solids), EC (Electrical Conductivity), SAR (Sodium Absorption Ratio) and pH were evaluated based on drinking, agriculture and industry water quality standards. Aquifer qualitative zoning maps were extracted by entering the descriptive layers obtained from the qualitative analysis in ArcGIS software and selecting the best interpolation method based on the validation technique.

The groundwater hydro chemical analysis based on the drinking water standards of the Energy Ministry indicated that the groundwater of the plain is in a relatively acceptable condition. This was also obtained from groundwater analysis by the Schoeller method. It was found that the largest areas of this plain had saline groundwater, in terms of agriculture. Industrially, sedimentation in the plain was more pronounced than corrosion.

Results showed that the aquifer quality declined from 2014 to 2017 and improved in 2018. Zoning maps showed that Miandoab aquifer has better quality and condition in the feeding areas in terms of drinking, agriculture and industry. In other words, according to the geography of the plain, the aquifer feeding areas were less vulnerable than the areas located in the evacuation areas.

Estimating the natural flow regime of a river is crucial for water resource management. Understanding the temporal and spatial distribution of river flow can greatly assist decision-makers in water resource management. This study aims to analyze changes in the Water Year Classification Index (WYCI) at 31 hydrological stations in Ardabil province (1974 to 2018) at different time scales and its spatial changes using GIS. The WYCI index was calculated at all hydrological stations, and the map of the spatial changes of the index was prepared using the inverse distance weighting method. According to the results, the maximum and minimum median flow values were related to the spring season (3.7) and summer (0.3) cms, respectively. The median flow values in the winter and autumn seasons were 2.5 and 1.3 cms respectively. The results showed that the average values of the WYCI index in autumn, winter, spring, and summer are 11.9, 10.7, 13.8, and 15.2, respectively. The status of the index for dry and wet periods was highly irregular (21.6) and moderately irregular (14.3), respectively. Based on the research findings, the snow-fed rivers located in the southern of Sabalan (Lay, Nir, Atashgah, and Yamchi stations) have a regular regime, while rivers in the eastern part of the province become more irregular towards summer with an increase in WYCI values. Overall, the analysis of spatial changes in WYCI indicates the existence of a unique spatial pattern at different time scales, and it is necessary to consider it in water resource management planning in Ardabil province.

The rainfall decrease and limited water resources in arid and semi-arid regions such as the Zahedan region caused the groundwater resources to need more attention in these areas. Moreover, the increase in the population in Zahedan Country and the lack of a suitable system for collecting wastewater in this area have made the pollution of underground water inevitable. So that, the excessive extraction of underground water resources and successive droughts on the other hand have caused a decrease in the underground water level in this region. Therefore, the present study was carried out with the aim of time-spatial monitoring of underground water quality in Zahedan County.

The aim of this study was to monitor the temporal-spatial quality of groundwater quality in Zahedan City in four stages. Determining the geographical coordinates of sampling wells, calculating the water quality index (WQI), and Wilcox index, comparing the interpolation methods in ArcGIS 10.8 software to prepare the spatial map of the WQI and comparing the spatial variations of the WQI. This research was conducted in two time periods 2010-2013 and 2014-2017. To investigate the temporal changes in water quality parameters, annual statistics of 90 wells and aqueducts with continuous statistics were used. Then, WQI and Wilcox’s indices were calculated for drinking and agricultural uses, respectively. One of the most practical methods is WQI, which indicates the degree of its suitability for various uses, including drinking. This index is usually obtained from the values ​​of general water parameters including dissolved oxygen, acidity, hardness, soluble solids, temperature, turbidity, nitrate, nitrite, and some basic ions. This index combines different water quality parameters to provide a numerical value that can be used for spatial comparisons. Besides, Wilcox's classification is one of the most important index in the field of determining the quality of agricultural water, which is calculated based on two parameters of electrical conductivity (EC) and sodium absorption ratio (SAR) as the risk of alkalinity.

The lowest and highest WQI levels were 30.1 and 674.0, respectively in the period 2010-2017. WQI time changes during the study period showed that the WQI is not significantly different between the first (2010-2013) and the second (2014-2017) periods. According to this index, in the first period, 7.9 % of the studied wells were in good condition, 5.6 % in bad condition, 13.5 % in very bad condition, and 73 % undrinkable in terms of drinking water quality. In the second period, 6.7 % of the studied wells were in good condition, 6.3 % in bad condition, 13.3 % in very bad condition, and 73.3 % undrinkable in terms of drinking water quality. In both time periods, the quality of none of the wells in terms of drinking was not in the high class. The results of descriptive statistics showed that the mean parameters of SO42-, Cl-, EC, TH, TDS, and HCO3- were two intervals higher than the standard. According to the results of the Pearson correlation test, there is a negative significant relationship between the pH and other parameters. The pH has the most negative significant relationship with TH. TDS and EC variables have the highest positive and significant relationship. This lack of impact can be attributed to the range of very low pH changes in groundwater samples in the two periods. There is also a significant negative relationship between pH and other parameters. The pH has the most negative and significant relationship with potassium. Moreover, according to the Wilcox index, in the period of 2010-2013, 87 % of the studied stations are in the S4C2, S3C3, S3C4, and S4C4 classes, which are unsuitable for agriculture and 12 % were in the C3S3 class, which by applying the necessary measures can be used for agriculture. Likewise, in the period 2014-2017, 91 % of the sampled stations are located in very salty and unsuitable for agriculture, and 8 % of wells. It is possible that the high extraction of underground water and the drop in the water level in the Zahedan region have caused the EC of water to increase. Also, drought can play a role as an aggravating factor in the change in water quality. The results of the Pearson correlation test showed that there is a significant negative relationship between pH and other parameters. Since in the comparison of various interpolation methods based on RMS and R2 for the WQI, the zoning map was drawn based on the kriging method due to its lowest RMS and highest R2.

Due to the high salinity of water, the study wells are not used for drinking and agriculture purposes but they can be used in ordinary applications such as washing. Besides, considering the quality characteristics of groundwater in the Zahedan region, it can be acknowledged that proper water management in this region is very important.

In recent years, the accumulation of heavy metals in the environment mostly due to its adverse impact on human health and wildlife has become a main concern (Al-Yemni et al., 2011). Meanwhile, sediments are the main storing heavy metals accumulations and serve as tools for assessing the status of river pollution (Taghinia Hejabi et al., 2010). At the same time, to using geographic information systems and Geostatistic methods is desirable. Many studies have been conducted by researchers such as Mortazavi and Saberi nasab (2017) in Meiqan, and Islam et al. (2015) in the water and sediments of the Korotoa River in Bangladesh. The purpose of this study was to investigate the concentration of lead, zinc, copper and chrome metals in surface sediments of GharehSo River and zoning of sediments of the region with Potential Ecological Risk Index and Muller's Geo-accumulation Index.

Groundwater is always considered one of the important water resources, especially in arid and semi-arid regions of the world, such as Iran. In recent decades, it has decreased drastically due to excessive use. The objective of this study was to determine the best interpolation method and evaluation of the spatiotemporal variations for the groundwater level in the Sahneh-Biston plain of Kermanshah province during three decades from 1991 to 2020. At first, four Gaussian, linear, spherical, and power semi-variograms were obtained for observations. Then, the best semi-variogram and interpolation methods were selected among the evaluated methods for zoning the groundwater level in the region. The lowest value of the sum of RMSE, MBE, and MAE error criteria and the highest coefficient of determination (R2) between observations and estimates in all three decades and the average of the entire period were calculated and considered to evaluate the most appropriate semi-variogram and interpolation methods for spatial distribution. The results showed that the ordinary kriging method with Gaussian semi-variogram is the best method to estimate the groundwater level in the Sahneh-Biston plain. The average difference between the minimum and maximum groundwater levels based on the observation wells of the study area and the zonation method is from 1279 to 1372 meters and 1289 to 1409 meters during the studied period time, respectively. The groundwater level is placed in more depth with the proximity to the central and southern regions. The maximum decrease and increase of groundwater level variations have been 12 and 19 meters during three decades, respectively. Also, the underground water level variations during these three decades showed that both the second and third decades compared to the first decade and the third decade compared to the second decade have increased in more than 50% of the region. This increase can be caused by the optimum management and water use in these years. Therefore, groundwater level monitoring provides effective help for experts and users in planning and optimal management of groundwater for the sustainable development of water resources.

Assessment of groundwater quality and quantity variation in drought and semi-drought region are of most interest especially in Iran. This research is going to analysis salinity reasons by ground water quality mapping in the Khafr plain.

To do this the principal components of water quality extracted in spring and autumn seasons. Then Spline, IDW and Kriging interpolation techniques were fitted and evaluated for mapping. Finally, the best model was determined and ground water quality mapped using principle components.

Kriging recognized as the best model for autumn. The first component with high coefficients on TH, K, Mg, Ca, SO4, TDS, EC showed maximum values in the center and eastern south of the region. For the second component (SAR, Cl, Na) maximum values observed at the eastern south as well. The third component (PH) increased from center to the north and western north and decreased from center to the south and eastern south, and for the Forth (HCO3) maximum observed at the north and minimum in the eastern south. Spline method recognized as the best model in spring season. The first component (SAR, Cl, Na) showed maximum values in the eastern south of the region. The second (Th, Mg, Ca) maximum values observed at the center and the third component (PH) maximums in the west. Forth component (HCO3) maximum valued observed in the center and western north. Finally, the reasons of spatial and temporal variation of the components analyzed.

Maximum sprinkler flow rate, maximum irrigation interval, and leaching requirement are the primary factors in designing sprinkler irrigation systems, which are determined based on the physical and chemical properties of water and soil. This study aimed to prepare the spatial maps of the mentioned parameters in the plains of Islamabad-Gharb district, Kermanshah province. In previous studies, kriging and IDW methods have been found to be suitable for zoning the physical and chemical properties of groundwater and soil. Asadzadeh et al. (2019) investigated the spatial changes of groundwater quality indicators in Ardabil plain by kriging method to investigate the water situation in this area for irrigation systems. Yonesi et al. (2020) also zoned some critical water quality parameters (such as nitrate) of the Najafabad aquifer using the kriging method. Kumar and Sangeetha (2020) used the IDW method to classify groundwater quality in the study area and classify it according to drinking and agricultural uses. Karami and Basirat (2015) evaluated the spatial variations of some surface soil characteristics of Arsanjan plain by kriging and IDW methods. on the other hand, a specific method can not be considered the best method for intermediation and zoning of these parameters. In this study, both methods were used for mediation.

Due to the lack of facilities and commitment in climate stations establishment in large scale interpolation has become an important technique in spatial mapping studies. In this study, the Kriging interpolation technique as a prevalent technique has been explained and 17 Kriging models were evaluated, in order to select the most suitable one, using a case study. Because of increasing trend of drought in Iran and management necessity of water resources, meteorological drought of Fars province has been investigated in this study. For this purpose the calculated SPI-3 months of the Fars province synoptic stations were calculated. SPI-3 months is widely applied in agricultural drought studies. The empirical semi-variogram of the SPI-3 of the stations was calculated and graphed, fitting 17 Kriging models to select the best one using the cross-validation technique. Results showed that the Linear, Power, Square root, Logarithmic and Gaussian models were the best interpolation techniques for SPI-3 spatial mapping. Geostatistic methods could be used to determine the adequacy of the rainfall gauge stations, especially in the western mountainous region of the province. A complete-length of data could modify the results. The Gaussian model as one of the best-fitted models defines good spatial continuous of precipitation in the region. The semivariograms were fitted to data with the hypothesis of no precipitation trend. Considering the linear and non-linear trends of data, and analyzing error maps may result in better models.

Due to the spatial variations of evapotranspiration, and lack of adequate point estimations using interpolation methods for spatial analysis is necessary. The aim of this study was to estimate the regional values of reference evapotranspiration (ETo) in Kermanshah province, west of Iran and comparison with Iran National Water Document. For this purpose, daily weather data of 38 meteorological stations of Kermanshah and neighboring provinces were obtained from the Iran Meteorological Organization. Three methods were used for calculation and zoning of ETo, based on Penman and Penman-Monteith equations. In the first and second methods, the meteorological data were interpolated and then ETo was calculated using the interpolated data, while in the third method the point estimation of ETo (weather stations) were interpolated. For the purpose of interpolation, the CGMS software was used in a gridded network of 366 cells with 10 × 10 km size. The results showed that there exist a significant spatial variations ETo across the province. In general, in the western regions of the province, with higher temperature and lower altitude, higher values of ETo was observed. The ETo estimations based on Penman-Monteith method were higher than Penman method. Although the ETo values presented in the Iran National Water Document are calculated by the Penman-Monteith equation, but obtained amount for plain regions of the province are more consistent with Penman- equation estimations.

Rainfall data are required for planning, designing, developing and managing water resources projects as well as hydrological studies. Some previous studies have suggested increasing the density of the rain gauge network to reduce the estimation error. However, more operational stations require more installation costs and monitoring. Some common techniques including statistical methods, spatial interpolation, information-based theory and combination are used to evaluate and design the network. Chaharmahal va Bakhtiari province is a mountainous region; hence, a denser rainfall network is expected in this mountainous environment. The aim of this study was to evaluate the condition of rain gauge stations in Chaharmahal va Bakhtiari province using two approaches, i.e. geostatistical methods and entropy theory.
The main required data set for this study is a time series of rainfall data. These data were collected on a daily scale from the Regional Water Company of Chaharmahal va Bakhtiari. After performing statistical tests, the annual data series was prepared for 46 rain gauge stations. A statistical period of 2000 to 2016 was used. The homogeneity of data was investigated by double mass test and histogram drawing methods using Excel and SPSS software, and the existence of trend in the time series of data was investigated by applying a Spearman test. Then, the adequacy of rain gauges in the gauging network was investigated. Annual rainfall interpolation maps and their standard error maps were prepared using the kriging method. Contribution of each station in reducing or increasing the error in the rain gauge network was investigated by removing each station in a cross validation procedure. The efficiency of the rain gauge network was evaluated using the concept of discrete entropy and the values of entropy indices. The value of keeping the rain gauge stations was determined using the net exchange information index.
There was no homogeneity problem and significant trend in the data series. Considering the permissible error percentage of 5%, there is a need to add 15 new rain gauge stations to the network. To apply the geostatistical method, we applied it once without deleting any station; then, the kriging interpolation error was calculated for the precipitation data. Then, only one station was removed at each stage, and both the error and the contribution of each station in increasing or decreasing the error compared to the case without Station deletion were obtained. The results indicated that Ab-Turki, Shahrekord, Borujen and Barez stations were more important than other stations. Two stations namely Chaman-Goli and Ben stations can also be considered as the influential stations in error due to the density of stations in the region and error maps. Similarly, the results of the entropy theory method were found effective in evaluating the design of the rain gauge network. The highest value of H(x) was observed in the data of Armand station (3.26) and the lowest value was observed in Abbasabad station (2.28). Since H(x) shows the uncertainty of measuring data, the maximum and minimum uncertainty were found for Armand and Abbasabad sites, respectively. Based on the Net Exchange Information Index, Bardeh, Bareh Mardeh and Dezkabad stations were ranked 1 to 3, respectively, indicating that they transmit and receive more information than other stations. On the other hand, a number of stations including Dorak anari, Abtorki and Chelo stations had the lowest values.
Due to the vast extent of the area and also considering the permissible error percentage of 5%, the number of the stations in this area was found to be insufficient. Thus, although calculating the kriging error maps showed that some stations do not have a significant share in increasing the error, removing the stations is not recommendable. Regarding the new stations, new 15 rain gauge stations are needed to check out the error maps. According to the field observations, the higher priority should be given to the northwestern area (which had the largest interpolation error) in the first place. For the regions with lower error, such as northeast, east, southeast, west and southwest that do not have rain gauge stations, additional rain gauge stations should be constructed.

Groundwater resources are one of the most valuable national resources, and the protection of its quality is vital. One of the best ways to prevent groundwater pollution is to study the spatial changes in their quality and manage the utilization of water resources and land use. In terms of accuracy and effect of interpolation and origin, this study analyzes a comparison between OK, RBF and IDW interpolation methods for Pb, Zn and Cd . Also, the difference between the accuracy and uncertainty of interpolation and the source of pollution was analyzed and the results show that based on the spatial distribution of elements in the most polluted area in the southeast of the area around the coal and marble mine in the conservation area. Has been blacked out. Pollution has decreased from the south to the north of the region and the lowest amount of pollution is in the north of the region and near Bojagh National Park and Caspian Sea. According to WHO standards, it can be seen that for Zn, the whole area is within the WHO allowable range, the standard limit is 15 mg / L and the maximum Zn in the area is 1.64 mg / L. For Pb only small areas in the north of the area are within the allowable range. For Cd, the permissible limit of the global standard is 0.003 mg / L, which due to its spatial distribution, the whole area is contaminated with this element. Higher uncertainty of the elements is primarily distributed around the mines, which is related to the spatial diversity of toxic elements caused by human intervention. In addition to mining activities, the entry of industrial and municipal wastewater and effluents into groundwater resources can be considered as the cause of water pollution in the study area.

Simulation in groundwater flow is important for agricultural use and access to high quality groundwater.In many arid countries of the world, especially Iran, the main source of water supply is groundwater reserves.This study, using geostatistical analyzes, has investigated the environmental effects of heavy elements of Gol Gohar Goljan iron ore mine in Sirjan.For this purpose, heavy metal elements (iron, copper, chromium, cadmium, antimony, arsenic) were sampled from 115 groundwater samples.Then, by drawing a histogram, preliminary statistics and exploratory-spatial information obtained from the data of the study area were examined.The experimental half-change of each parameter was calculated using isatis software and fitted with Gaussian, spherical, linear and exponential models.After variography, Gaussian simulation in a block model prepared in the study area was performed 100 times and the map obtained from Gaussian simulation of each of the mentioned variables was prepared. In addition to examining the spatial coherence of the variables, the probability and uncertainty map was prepared according to the EPA drinking water standard and the points where the concentration of heavy metals was within the allowable drinking water limit or above the threshold were determined. The validation results were finally compared with the simulation results and the original values. The results of the studies showed that the highest risk of contamination of heavy metals iron, copper, arsenic and chromium, according to the EPA drinking water standard, is related to Gol Gohar iron ore mineral areas and long wells in Kefahnamak, Khairabad and Qatarbaneh area. Also, the results of studies on the element antimony showed that most of the groundwater resources in the study area are contaminated with this element and are not drinkable according to the EPA limit. Groundwater at points KH1, KH2, KH3 and CHD20 had the highest concentration of cadmium, and probability maps of each element were prepared.

Improper quality water use causes problems such as soil salinity and reduced soil permeability. In this study, groundwater quality in Sirjan city has been investigated using common diagrams and parameters in water quality classification for agricultural and industrial uses. Archmap and mini-tab software has been used to graphically display changes in quality parameters in the region and statistical classification of data. The results of the study showed that well (W2) located in the northeast of the aquifer has a higher quality than other sample wells, which is in the range of good to acceptable according to Schuler diagram and in good range according to Wilcox diagram. The amount of magnesium, calcium, sulfate, chlorine and sodium in the well was less than the World Health Organization standard. Also according to the obtained results of well (W12), (W13), (W15), (W17), (W3), (W9) (W10 (W14), (W3) which are located in the northwest, west, south and southwest of the aquifer, both in terms of drinking and agricultural use, of poorer quality than other wells. Enjoys. According to the classified maps, for effective parameters in the Schuler method, the parts of spatial continuity of the data were examined and after preparing the map, locations with different qualities were identified. Also, according to the results obtained from the classification map of the EC parameter by Wilcox method, a large part of the aquifer is in the inappropriate class and only parts of the northeast, east and middle parts of the aquifer are in the middle class.

This paper tries to forecast and determine the desertification warning threshold using groundwater resources quantitative and qualitative parameters modeling. The data from 62 piezometric wells and 55 quantitative wells were selected from Iranian Water Resources Management Company and Khorasan Razavi Regional Water Authority. Handling missing data, and statistical analyzes such as the Mann-Kendall test and Pearson correlation were performed. The desertification intensity and early waring maps was provided based on the Iranian Model of Desertification Potential Assessment (IMDPA) Model. The maps of quantitative and qualitative indices of groundwater were classified according to the desertification severity and threshold of each index for a 20-years period (1996-2016). Desertification intensity and warning threshold maps of each groundwater quantitative and qualitative index were classified according to the IMDPA Model. The ground water parameters were predicted by MATLAB 2015 software and artificial intelligence fore 2022. The results showed that among the quantitative and qualitative indices the highest decertification warning area was related to drop index. The electrical conductivity index was in second-order warning. Sodium sorption index is located in low desertification class and only southern part of Mashhad aquifer will be in warning condition in 2020. In terms of chlorine content, the aquifer of Mashhad plain has not been under warning condition. But considering the trend of changes in the index in the future may be on the verge of warning.

Wind erosion is one of the environmental problems worldwide, particularly in arid and semi-arid areas of Iran. Different methods and models have been proposed to measure and monitor wind erosion in the recent years. One of the accurate models for measuring f wind erosion is the USEPA model. The purpose of this study was to evaluate the quantification of wind erosion with the USEPA model and the comparison of different interpolation methods for drowsing high-precision soil erosion mapping. For this purpose, 50 samples from 0-30 depth were taken from the study area. Based on the analysis of the physical properties of the soil, including the distribution of the primary and secondary particle sizes, climatic parameters such as evaporation and transpiration, rainfall, wind speed and also, the vegetation and topography characteristics of the area, the erosion rates of Q, Q30 and Q50 were measured. Interpolation methods including general kriging, IDW, LPI and RBF were compared. The results showed that the highest erosion emission rate of Q50 was 39 ton ha-1. The highest and lowest erosion rates for the Q30 index were 0.060 and 2.694 ton ha-1, respectively; for the Q index, the highest and lowest erosion rates were 0.009 and 0.055 ton ha-1, respectively. The results also showed that the IDW method for the Q50 index with the minimum error rate (RMSE) values of 3.94 and the mean absolute error (MAE) with the valueof 1.89 had the best performance among the studied models. The LPI model Q had the best performance with the lowest error (0.0086) and absolute absolute error (0.0021).