محمد نهتانی

Water resources management is a set of methods, measures and plans compiled for the control, development, and optimal exploitation of water reserves which are adjusted and guided according to all or part of the economic, social, environmental, political aspects. The increasing human needs for ecological goods and services over the past few decades have led to increased attention to wetlands management, and today wetlands ecosystem management is considered one of the land management approaches. The purpose of this research is to investigate the integrated management indicators of Hamon wetland using factor analysis. This research was conducted by document and survey method and using a questionnaire in the villages of Hamon and Nimroz cities, during which, in addition to field visits and observations of the villages, the indigenous people of the region were interviewed. 

Hamon wetland, with an area of nearly 5700 km2 and a depth range of 1 to 5 meters in the desert area of the east of the country, in the region of Sistan is located between 60°39' to 61°35' east longitude and 31°15' to 31°32' north latitude, which is considered as the largest freshwater lake in the entire plateau of Iran. In this study, three economic, social and environmental indicators were selected for Hamon wetland management. The total number of households under study in the two cities is 1987 households from the outskirts of Koh-Khwaje and Talabhamun, and 321 questionnaires were considered to conduct this research. One of the statistical methods for analyzing the information in the data set is factor analysis. This method is used to determine the most influential variables when the number of variables under consideration is large and the relationships between them are unknown.

Considering the importance of Hamon wetland in ecological, economic, social dimensions and direct relationship with people's livelihood and environmental sustainability, it is necessary to change the attitude in the type of management and proper planning to restore Hamon wetland. In this research, the data obtained from the questionnaire was examined and analyzed. Based on the obtained results, it was found that all dimensions and indicators of the research had a significant impact on the integrated management of Hamon wetland. The factor load for the economic dimension is equal to 0.95, the social-participatory dimension is equal to 0.97 and the environmental dimension is equal to 0.85, which shows the social-participatory dimension and its indicators such as the revival of agriculture by the wetland. All kinds of partnerships in this field have had the greatest role and impact in the management of the Hamon wetland. Also, Cronbach's alpha coefficient was obtained for economic, social-participatory and environmental dimensions, which were respectively 0.839, 0.91 and 0.75, showing that the reliability of the questionnaires was good. The integrated management of Hamon wetland requires a kind of systemic approach, which will not be possible without paying attention to local communities and their participatory role in decision-making and planning. The effective factors extracted from the factor analysis of economic indicators showed that employment and income are the main factors in the field of integrated management of Hamon wetland. In this context, by supporting the private sector and increasing investment in the field of creating various businesses in line with the potentials of our wetlands, job security and economic well-being can be provided for the local residents. In this context, considering the interwoven relationship between the natives' income and the vitality of the Hamon wetland, with local management and planning in the field of entrepreneurship, and taking into account the local culture and the prosperity of the handicrafts market, and supporting it, it provided the conditions for economic well-being. Optimal and appropriate training along with the participation of local people is the main factor in the integrated management of Hamon wetland.

For the optimal and integrated management of water resources, a comprehensive look at the economic, social, physical, environmental, cultural and political characteristics is necessary so that the most optimal ones can be developed with a set of methods and strategic plans. Feedback from the proper management of the Hamon wetland is economically very important for the local residents, and it is also considered an important and wonderful resource from the environmental point of view. It is necessary to provide facilities and support platforms in order to increase private sector investment in creating employment and entrepreneurship, as well as supporting handicrafts and the development of small industries, to provide conditions for the economic dependence of local people and excessive exploitation of resources. Managing and protecting the natural potentials of any geographical environment requires comprehensive development and human sustainability in that environment; therefore, it is necessary to provide educational platforms and hold appropriate training courses on the importance of natural resources in the human environment and efforts to protect and optimally exploit it. In this context, it is necessary to take into consideration the local management and use the existing potentials by holding training courses and providing the necessary platforms for the use of local power in the direction of the restoration and reconstruction of the Hamon wetland, which leads to the sustainability of the natural environment in the long run.

In this study, the quantitative zoning is used to identify areas suitable for artificial recharge in the mountainous area of Gohar and Garbayegan plain, Fars province fitting a linear fundamental form to the surface. The structures with grade two for triplex windows and the data from the digital elevation model with a resolution of 10 m was used to determine the best fitable fundamental structure. The sum of square differences of the surface differences is used as an indicator to determine the degree of fitting the fundamental structures. By fitting the interpretable patterns to the Earth's surface it can be determined that the earth was similar to what pattern and formation mechanism. Mountain ranges upstream alluvial cones and plains located downstream of the upstream alluvial cones are not linear levels. Places which are not at the acceptable slope (gradient less than 0.002 and higher than 0.1) allocated to the zero fitting degrees and the fitting degree values are positive in alluvial cones and areas fall in the acceptable range of the slope. The results show that the surfaces located downstream of the alluvial cones and the plains are most suitable areas for floodwater spreading in the Garbayegan watershed.

Selection and accuracy of appropriate zoning methods and preparation of maps corresponding to variation of groundwater qualitative characteristics depend upon the region's condition and the available statistics and data. The goal of this research is to determine the most appropriate method of interpolation and spatial analysis of qualitative components such as Cl, EC, SO4, SAR, TDS and TH of groundwater in Mashhad Plain. In this research, at first, the data of 177 wells were selected with respect to their dispersion and accuracy for two consecutive years (1392-1393); then controlling and reconstruction of data were performed. Kolmogorov-Smirnov test showed that the data were not normal and to normalize them their logarithm was obtained. Then using GS+software, the best variogram model was fitted to the spatial structure of data. The results show that for qualitative parameters, the exponential, Semi-variogram and linear models are the best semi variogram models. The precision of groundwater qualitative parameters in the three methods of Kriging, Cokriging and Inverse Distance Weighting (IDW) was assessed and the precision rate results showed that Cokriging method has a higher precision and lower error. The spatial structure of studied characteristics follows the exponential, spHerical and linear model with an influence range of 9656 to 71100001m and the threshold range of 0.965 to 5.65, and the spatial dependency class was in the range of 0-0.87. Finally, the zoning maps of water qualitative parameters were prepared using GIS software. Due to population concentration in the southern parts and overuse of wells and recent droughts, the highest values of qualitative components belong to the south of the study area. According to the geological formations and the type of rocks in the northwest and southeast, the concentration of calcium, potassium, sodium, chlorine, as well as the percentage of evaporation and transpiration and temperature are more evident.

In this research, three methods of interpolation, namely, Weighted distance image, Kriging and Co-kriging are used to predict some quality indicators such as Na, TH, EC, SAR, CL, CA, Mg, and SO4 in 2013-2014. Data have been collected from 177 piezometric wells in the Mashhad Plain. In this study, after data normalization, parameters were interpolated using three geostatistical methods (ordinary kriging, co-kriging, and IDW). In order to evaluate the methods of interpolation, the mutual evaluation test was used. Then, based on the best method of mediation and the use of geographic information system, a map of some parameters and plain zoning maps were prepared.

The purpose of this research was to determine the most appropriate interpolation method in order to investigate and spatially analyze the changes in some quality characteristics of underground water in Mashhad plain. After the appropriate model was fitted, according to CO/(CO+C) observations, the strength of the spatial structure in the quality components of the studied water is not very strong. For the zoning of the quality components, the Co-kriging method was introduced as a suitable method, and considering that correlation between different variables is used in this method. It can be said that there is a significant relationship between the components of groundwater (Zahtabian et al., 2019). The results of zoning the quality of the parameters showed two inappropriate ranges in the northwest and east of the region, which about 70% of the exploitation wells are located in these areas. Also, due to the recent droughts, the process of desertification will be accelerated in this region; therefore, more attention should be paid to the proper management of underground water in this region.

 According to the obtained results, the best fitted model for CA and MG parameters is linear model; EC parameters are exponential model and NA parameters are Semi-variogram model. Regarding the spatial structure, parameters MG and TH have strong location continuity (less than 0.25) and parameters MG, NA, EC have weak continuity (more than 0.75). According to the obtained results, was used to estimate TH from anion, CL from TDS, anion from cation, CL from anion and vice versa and estimate CL from SAR.The results show that the concentration of calcium, potassium, sodium, chlorine, SAR, TH, PH is higher in the northwest and southeast, and as a result, the quality of water for various uses is lower, which is one of the possible reasons, in addition to the different formations of the earth. The geology and type of rocks (that is, the presence of gypsum materials and stones in the northwest and southeast parts or smaller amounts of these materials in the north, central and south parts (Owaisi, 2000)) can lead to higher temperature and drier environment which is the result of the higher rate of evaporation and transpiration as well as the type and density of land use (Laleh-Zari, 2019)

In this study, the quantitative zoning is used to identify areas suitable for artificial recharge in the mountainous area of Gohar and Garbayegan plain, Fars province fitting a linear fundamental form to the surface. The structures with grade two for triplex windows and the data from the digital elevation model with a resolution of 10 m was used to determine the best fitable fundamental structure. The sum of square differences of the surface differences is used as an indicator to determine the degree of fitting the fundamental structures. By fitting the interpretable patterns to the Earth's surface it can be determined that the earth was similar to what pattern and formation mechanism. Mountain ranges upstream alluvial cones and plains located downstream of the upstream alluvial cones are not linear levels. Places which are not at the acceptable slope (gradient less than 0.002 and higher than 0.1) allocated to the zero fitting degrees and the fitting degree values are positive in alluvial cones and areas fall in the acceptable range of the slope. The results show that the surfaces located downstream of the alluvial cones and the plains are most suitable areas for floodwater spreading in the Garbayegan watershedIn this study, the quantitative zoning is used to identify areas suitable for artificial recharge in the mountainous area of Gohar and Garbayegan plain, Fars province fitting a linear fundamental form to the surface. The structures with grade two for triplex windows and the data from the digital elevation model with a resolu.

mankind has witnessed various hydrological events such as water shortage, drought, flood, avalanche, etc., and the scope of these events depends on the behavior of hydrological variables and characteristics of watersheds. The lack of statistics and information or the lack of correct and appropriate statistics has caused the investigation and recognition of the behavior of hydrological variables and the characteristics of watersheds with acceptable accuracy. Based on this, hydrological models are a suitable tool for evaluating the current state of water resources and predicting future conditions with knowledge and understanding of the prevailing interactions at the level of watersheds.

In this research, using the SWAT model, the precipitation-runoff simulation of the Lar watershed was carried out, and for this purpose, the daily data of precipitation, temperature and discharge during the common statistical period (1988-2017) were used. The initial simulation of the hydrological model was done in the SWAT plugin, and the SWAT-CUP software and the SUFI-2 method were used as an optimal algorithm for sensitivity analysis, calibration and validation of the model.

Based on the SWAT model, the study area was divided into 37 sub-basins and 308 hydrological response units. In addition, by analyzing the sensitivity of 24 parameters affecting the simulation of the monthly runoff of the Lar watershed, it was determined that 7 parameters based on the values of the t-state and p-value indicators were selected as the parameters with the greatest effect, and out of these 7 parameters, Three parameters curve number for medium humidity conditions, base flow return factor to the main waterway and average usable water were identified as the most sensitive parameters in runoff simulation. Then 18 years of the statistical period (1988-2005) were selected for recalibration and 12 years (2006-2017) for validation. Also, the effectiveness and efficiency of the model was evaluated using NS, R2, p-factor and r-factor coefficients. Model efficiency was evaluated using NS, R2, p-factor and r-factor coefficients. The values of these coefficients were estimated as 0.80, 0.82, 0.80 and 0.33 during the calibration period and 0.90, 0.90, 0.39 and 0.43 during the validation period. In addition, the temporal compatibility of the high and low points of the simulated and measured discharge hydrographs also confirmed the high accuracy of the model in the simulation.

The obtained results show that despite the seasonal flow and no base flow, as well as the frequency of days with zero flow, the SWAT model has a high ability to simulate the monthly discharge of watersheds in dry areas.

Detecting the potential of groundwater resources is one of the most important methods of water exploitation management to deal with water shortage, which is inevitable due to the growing need for water in the country. The first step in managing groundwater resources is to recognize the potential of groundwater. Fuzzy-Analytic Hierarchy Process (AHP) is also recognized as an important tool in decision-making about natural resources management, especially water resources. Bam-Narmashir plain, in Kerman province, is one of the most important plains of the country. This plain plays a very important role in the region in terms of supplying the water resources needed by agriculture, industry and drinking parts.

In this study, AHP-fuzzy model and GIS were used to identify suitable areas for potential groundwater resources in Bam-Narmashir plain. Criteria such as rainfall, temperature, geographical direction, slope, land use, vegetation cover, distance from the road, distance from the river, distance from the fault, distance from the city and village, distance from wells and springs, soil texture and the permeability of the formation were selected for decision making and the weight of each of them was calculated and prioritized using AHP model. Then, the desired layers were fuzzy and indicator maps were prepared using Arc GIS software. Then, the groundwater potential map was prepared. Finally, the ROC curve was used to validate the groundwater potential map in the region.

The result of ROC curve indicated the high accuracy of Fuzzy-AHP method in preparing the groundwater potential map in the study area. The results were consistent with the results of researchers such as Rezaei Moghadam et al. (2017) and Faraji Sabokbar et al. (2011). Also, the results showed that the regions with geological sub-criteria have the highest weight of 0.614 and the climatic sub-criteria have the lowest weight of 0.117. The value of inconsistency ratio was 0.07, which is smaller than 0.1, and it indicates consistency in the opinions and judgments of research decision-makers. Finally, the results showed that about 7.77% of the total area of the plain, equivalent to 755.54 square kilometers, is suitable for the implementation of underground water resources potential detection systems. Also, 1.57, 31.71, 58.98 and 7% of plain lands have very weak, weak, medium, and high potential for finding the potential of underground water resources, respectively.The results showed a sparse distribution of suitable areas for groundwater potential in Bam-Narmashir plain, which is compatible with the results of Sekar and Randir (2007), who stated that the groundwater recharge potential at the scale of the watershed has non-uniform spatial distribution. The results showed that in the northern and western part of the plain, where the soil is mostly low capacity for groundwater potential and infiltration, which is in line with the results of Akbarpour et al. (2015), who stated in west and north-west of Birjand basin, the soil has a low capacity for groundwater penetration due to the low depth of the soil and high slope.

In recent years, the use of geographic information system (GIS) and its combination with multi-criteria and decision-making methods to obtain more accurate results have increased and played a key role in studies of the finding potential of groundwater resources. Even though it is very difficult and complicated to accurately identify suitable places for the potential of underground water resources, this study showed that the use of GIS makes it possible to identify these suitable places with minimal facilities, which is consistent with the findings of Khairkhah et al. (2013). Overall, according to the results of this study, about 7% of the region has high groundwater potential. Therefore, it is necessary to adopt scenarios to reduce the over-exploitation of groundwater and to apply the measures to improve the irrigation systems, the methods to reduce evaporation and improve the cultivation system.

Drought is one of the most destructive weather events that cause great damage to human societies every year. Therefore, drought indices can indicate the natural limits of droughts. In this way, they make it possible for us to evaluate at different time and place scales. In this regard, in the present study, zoning and monitoring of meteorological drought in arid desert areas using indices (SPI, SIAP and PN) in Zahedan plain were studied.

In this study, daily rainfall data sets of operating stations in the study area were collected. Due to the low density of stations and severe limitations of data access in arid areas, five stations (refinery, FBI, Khinjak train, Pudeh Chah and meteorological department of Zahedan) were evaluated as suitable during a 30-year joint statistical period (1987-2016). The selected stations had complete time series and no statistical deficiencies during the selected statistical period. After ensuring the quality of the data by using homogeneity, random and discrete tests, the annual SPI, SIAP and PN indices of the annual time scale were extracted using DIP software and also in order to zoning the evaluated indices by distance photo interpolation method in the environment. Arc GIS was used.

By calculating the coefficient of variation from year to year during the census period (1987-2016), the minimum coefficient of variation was 88.7 and the maximum value was 208.8, it was found that Zahedan plain has irregular rainfall and high variability, which indicates the Occurrence of drought in the region. Then, by examining the three indices of SPI, SIAP and PN, it was found that the conditions of Zahedan plain based on SPI indices were 24 normal years, SIAP 25 normal years and PN 25 years of drought were weak. Also, according to all three indices, the most severe meteorological drought that occurred in Zahedan plain during 2003 was related to 2003. The values ​​of each of these indicators for 2003 are -1.49, -1.16 and 25.32, respectively. According to SPI index, during 24 years of normal statistical period, SIAP index has 25 years of normal conditions and according to PN index of Zahedan plain with 6 wet years, 12 normal years and 5 years of weak drought. The annual drought threshold for the three indices is SPI 1-, SIAP -0.25 and PN 80. In addition, monitoring of spatial variations of three indices, SPI, SIAP and PN, showed that during the statistical period, the northern half of Zahedan plain was more affected by drought. Based on the meteorological zoning maps of Zahedan plain, it was determined that based on the SPI index in the years 1999-2005 of the northeastern region, the SIAP index during the years (1987-1989, 1998-2006) of the northern and northeastern parts and based on the PN index during In the years 2003-2006, the southern and western parts of Zahedan plain had more potential in terms of continuity, frequency and severity of meteorological drought.Overall

Considering that the spatial zoning maps of drought indicate the spatial expansion and more intensity of critical zones during the 30-year statistical period studied in the present study, the identification of these vulnerable and endangered areas and The extent of this phenomenon is also necessary for the implementation of management as well as development, economic, social, environmental and agricultural planning by the government of men and policy makers.

Climatic changes and the occurrence of long-term drought have greatly affected the vegetation pattern of watersheds, which results in the change of runoff coefficient and flood potential. The phenomenon of flooding in Iran is more than caused by the occurrence of heavy rains, it is the effect of disturbing the natural balance and geographical conditions of the region so that the occurrence of ordinary rains also causes floods.

In order to investigate the flood changes and prioritize the sub-basins of the Dehak watershed in South Khorasan province based on flood potential under the influence of drought periods, 30 years of annual rainfall statistics were used and the SPI drought index was determined. Digital elevation model maps, soil hydrological groups, and Landsat 5 and 7 satellite images for the years 1990, 2000, and 2009 were prepared and the Normalized Difference Vegetation Index (NDVI) was calculated with the help of ENVI 4.8 software and maps of vegetation and land use status were prepared. With Arc GIS 9.3 software, curve number maps from the integration of soil hydrological group maps, land use, and vegetation status, based on the Soil Conservation Service method, and with the SCS method, the participation rate of each of the sub-basins in the output flood of the entire area is determined, and by repeating the individual removal of each of the sub-areas, the sub-areas were prioritized based on flood potential.

The results of classifying Landsat images using the maximum likelihood method showed that the overall accuracy and the Kappa coefficient obtained from the estimation of accuracy in the NDVI map in 1990, obtained from Landsat images were equal to 73.2 and 0.68%, respectively, in the map obtained in 2000 equal to 75.2 and 0.71% and in the map obtained in 2009 it is 79.8 and 0.84 respectively. The results of the correlation of the percentage of the area of the NDVI for the three years 1990, 2000, and 2009 using SPSS software And the analysis of variance test (One-Way ANOVA) and Duncan's subset and also a significant level of 95% showed that between the three NDVI indices for the three years 1990, 2000 and 2009, the normalized difference index of vegetation cover had a high correlation (0.91) at the level There was a significant value of 0.05. Based on the standardized precipitation index, from 1998 to 2010, with the exception of 4 years, the rest were determined as drought periods in the region. The kappa coefficient obtained from the estimation of the accuracy of the NDVI map was 0.84, which was the most accurate in monitoring vegetation changes. The set of the slope, soil, and geological factors has led to placing 86.6% of the area in hydrological group C, which by definition has a high ability to produce runoff. The weighted average curve number (CN) of the Dehak watershed has changed from 62.35 in the wet year of 1990 to 65.04 and 63.50 in 2000 and 2009, which were dry years. Examining the significance of the simulated values of runoff height and flood peak flow using the analysis of variance test showed that there is a high correlation (0.71) at a significant level of 0.5 between the values of the runoff height corresponding to the three years 1990, 2000 and 2009 and there was a high correlation (0.68) between the values of the peak flow of the flood corresponding to the three years, the studied index. The peak flood discharge with a 5-year return period increased from 7.89 m3/s in 1990 to 13.67 m3/s in 2000, which was affected by drought, which is equivalent to 74.87%. This increase for the peak discharge of 200 years was equal to 21.64% so its amount increased from 93.68 m3/s in 1990 to 112.42 m3/s in 2000. The investigation of the runoff curve number of the Dehak watershed in 1990, i.e. before the drought period, showed that it was 62.35 in 1990 and 65.04 in 2000, and 63.50 in 2009, so it can be concluded that the period of Drought caused an increase in the number of runoff curves in Dehek watershed. The investigation of the height of the flood runoff of the Dehak watershed in 1990, that is, before the drought period, was determined to be 1.8 mm, and this ratio changed from 3.23 mm in 2000 to 2.8 mm in 2009, so it can be concluded that the occurrence of the period Drought has caused an increase in the height of the runoff in the Dehak watershed. Vegetation has less effect in the relative reduction of terrible floods with a high return period. In the study of the effect of changes in vegetation cover on the peak discharge and flood volume, it is also observed that the peak discharge of the flood is more sensitive to land use changes. The results of the flood discharge in the land use scenario (continuing the process of vegetation destruction) also showed that in case of further destruction of forests and pastures in the area and development of agricultural lands, the peak flood discharge will increase by 35 and 24% with a return period of 5 and 100 years, respectively. Found. This means that vegetation alone plays a limited role in controlling large floods with high return periods. The high weighted average of the curve number in the whole area in different years indicates the high risk of flooding in the Dehak watershed.

By prioritizing flood potential, it was found that among the 7 sub-areas, F3 sub-area (CN) has the highest value with 66.89 and is the most flood-prone sub-area, which is due to the existence of phyllite formations, Marne and also the abundance of sloping surfaces are in it, and sub-areas F4 and F5 are placed in the next level of flooding, which should be considered in management and executive planning. The priority map of the sub-basins in terms of flood potential shows that in the southeast margin overlooking the heights of the basin, there are factors such as high slope and rocky outcrops without vegetation cover next to the land use, the risk of flooding is very high and therefore the priority of any watershed engineering operation. In this area, it is more priority than other points.

In the management of desert areas, studies related to water, soil and vegetation are carried out at the watershed or regional scale. Geomorphological zoning is one of the basic studies.. Considering the increase in population and decrease in rainfall, it seems necessary to use surface waters.  Therefore, identification of geomorphological Features of the earth's surface is important for the construction of water structures and their site selection Identifying geomorphological types and land units of Earth's surface is necessary for Landuse planning and land use for different uses. So far, Identification of geomorphological features has been done qualitatively and based on expert opinion In this study, the quantitative zoning is used to identify suitable areas for artificial recharge in the mountainous area of Gohar and Garbayegan plain, in Fars province fitting a circular fundamental form to the surface. In this research, with digital elevation model and ArcGIS 9.3, Matlab 7.1 and ENVI 4.8 softwares, and using quantitative relationships for the Kuhghar area in the Garbaigan plain of Fasa, site selection of the floodwater spreading was investigated. The structures with grade two for triplex windows and the data from the digital elevation model with a resolution of 10m was used to determine the best fitable fundamental structure. The sum of square differences of the surface differences is used as an indicator to determine the degree of fitting the fundamental structures. Using the degree of fitting, the degree of suitability of the surface for artificial recharge has been determined only by surface morphology view. By fitting the interpretable patterns to the Earth's surface it can be determined that the earth was similar to what pattern and formation mechanism. The results show that the surfaces located downstream of the alluvial cones and the plains are most suitable areas for floodwater spreading in the Garbayegan watershed. One of the uses of quantitative zoning in the field of erosion and sedimentation is that by accurately fitting the areas exposed to erosion, it is possible to accurately calculate the ratio of height changes in the margins of basins and erosion areas, as well as the height increase in low-lying areas as a result of sedimentation.

The basis of land management is the geomorphological zoning of the land surface, which is determined based on the same geomorphological characteristics of the zoning. Ground zoning detect land features by basic surface features such as height, slope, and slope direction. In this study, quantitative zoning of the land surface with small coefficients to the surface has been used to identify suitable areas for artificial feeding in the mountainous region of Gohar and Dasht-e Gorbayegan in Fars province. Quantitative zoning of the land surface has been performed by Evans-Shri coefficients due to the accurate determination and separation of types, faces, and surface features of the land has an important role in determining the exact land use. In this research basic models included linear, circular, and divergent models. These basic models with the dimensions of the final windows are ranked second in the MATLAB software to the level the ground is fitted to determine the fit of these models, the parameter of total squared difference has been used. In addition, the suitability of the study area for flood distribution in five different classes was determined using fuzzy logic. The most suitable areas for feeding downstream of the cones had five parameters with a maximum score of 20. The inappropriate class related to the lower plains of alluvial fans have a minimum score of five input classes in fuzzy logic, which is equal to zero.

Wind erosion is one of the most important natural processes in arid and semi-arid regions. Sistan plain has a hyper-arid climate and is one of the windy regions of the country. Due to the soil characteristics of the Sistan plain, wind erosion is very intense in this region. In this study, the relationships between some soil's physical and chemical properties and wind erosion were investigated in different land cover in a part of the central region of Sistan in 2018. A map of land cover in five classes was prepared using the results of field studies and the classification of satellite images. Fifty soil samples at a depth of 10 cm were collected to investigate the physical and chemical soil properties and the wind erosion threshold was determined at each location using a portable wind tunnel device. Also, the relationship between physical and chemical soil properties including soil texture, soil moisture, specific apparent weight, EC, SAR, ESP, Na+, k+, with the speed of wind erosion threshold was investigated. According to the results, the highest and the lowest threshold speed were 8.2 and 3.8 m s-1 and occurred in agricultural lands and hilly lands, respectively. The results of this study indicated that the velocity of wind erosion threshold in different lands adjacent to sandy areas is less than the average of that cover. Also, the soil texture, EC, and SAR have the most significant effect on soil wind erodibility at P <0.05 in the study area.

Geomorphological zoning of the earthchr('39')s surface is the basis of land use planning. The first step of land use planning is to determine homogeneous zones of the earthchr('39')s surface in terms of geomorphological characteristics. Geomorphologically homogeneous areas can be managed in one approach. Ground zoning is the detection of land features by basic surface features such as height, slope, and slope direction. In this research, the appearance of the earth from the quantitative point of view and geomorphological zoning of the earthchr('39')s surface are studied. The quantitative zoning is conducted using automated and predefined based on zoning criteria. Quantitative zoning does not involve the expertchr('39')s taste and skill level, and the zones will be obtained using specific quantitative strategies. The specified zones are determined by coefficients, which changes of these coefficients in different regions can be used to compare zones. In this study, quantitative zoning was performed by a digital elevation model, Arc GIS 9.3, Matlab 7.1, and Envi 4.8, and applying relationships for the mountainous region in the Gerbaigan plain of Fasa. For this research, digital elevation data with an accuracy of 10 meters from the surveying organization has been used. Using the level fitting tool in MATLAB software, the relationship related to each form to limited parts, or limited windows, has been fitted from the surface. These windows are selected in such a way that they have a square shape and their dimensions are, for example, 3*3, or 9*9. By applying for the given programs, each of the quantitative coefficients is presented as zones. To determine the degree of fit, the RMSE has been used. Evans-Shary quantitative parameters have the highest and lowest values for the valleys and peaks, respectively.

Recent droughts have caused a decline in the level of groundwater aquifers, which has affected water quality and usability. The aim of this study was to investigate the effect of drought on groundwater quality in Iranshahr plain aquifer. In this study, drought rates were studied using the statistics of Iranshahr synoptic station during the 30-year statistical period (1987-2017) based on SPI index in DIP software, for 6 to 24 months’ time series. Water quality was studied for 16 piezometer wells and 6 aqueducts during 2005-2017. Also, the top four models of semi-spherical, exponential, linear and Gaussin were evaluated using GS + 5.1 software. Then zoning maps of groundwater quality parameters were prepared using the models detected in ArcGIS 10.4.1. The results showed that during the period 1987-2016, normal drought has been dominated in the plain. Drinking water quality is divided into 4 classes in wet hydrological years (2005-2006) and 5 classes in drought (2016-2017). Good quality in terms of drinking decreased from 7.53 percent to 3.92 percent. Water quality has decreased from east to west of the region and the percentage of suitable and usable classes has decreased.

Introduction:

 Spatial variations of soil properties is a natural event, which recognizing these changes is inevitable in order to planning and right management of both agricultural and natural resources. Soil organic carbon (SOC) is the most important factor in soil fertility and quality, climate change and reduction of greenhouse gas emissions. Furthermore, evaluating the rates and spatial distribution of the soil properties, land improvement and restoration can be traced from the carbon sequestration index. According to the above, providing quantitative and qualitative conservation of soil properties such as SOC can be considered an effective way to achieve sustainable development of natural and environmental resources. Digital soil mapping (DSM) can determine the spatial variations of soil organic carbon by exploring the relationship between soil properties and effective environmental variables. Different statistical models such as regression trees and random forest are used in order to communicate between soil characteristics and its spatial distribution. The present study was carried out to investigate the spatial distribution of SOC, as well as, to determine the most important variables affecting their prediction in Ravang watershed in Minab County.

Materials and Methods:

Ravang watershed with an area of 13821.6 hectares is located in Hormozgan province, Minab city. The maximum and minimum elevations are 357 and 33 meters, respectively. Digital Elevation Model of Ravang watershed was used to extract 17 environmental covariates (such as elevation, aspect, slope, valley depth,…) by SAGA software (http://www.gdem.aster.ersdac.or). Moreover, two environmental covariates related to remote sensing including Normalized Difference Salinity Index (NDSI) and Normalized Difference Vegetation Index (NDVI) were determined in the study area. In addition, the maps of land use, sand, silt, clay and pH were used as covariates in modeling. In order to determining the location of sampling points, the conditioned hyper-cube technique was used. After determining of soil sample location, field sampling was carried out at a depth of 0-30 cm. then, 100 soil samples were taken and the amount of SOC was measured. Random forest model was applied to the relationship between SOC and covariates. The model includes two user-defined parameters, including the number of variables used in the construction of each tree, which expresses the power of each independent tree and the number of trees in each forest. Considering the strength of independent trees, the predictive accuracy of the model increases, conversely, the correlation between them will decrease. The accuracy of the soil organic carbon distribution was also evaluated using root mean square error (RMSE), mean error (ME) and correlation coefficient (R2), which were determined.

Results and Discussion:

 Based on the present study results, elevation, soil silt and sand maps, channel network base level, slope and NDVI are the most important factors on predicting the of SOC variations. The results indicated that RMSE, ME and R2 were 0.36, 0.26 and 0.38, respectively .Results also showed that affecting erosion and sediment, as well as, human effect, have the most impact on the SOC soil spatial distribution in the Ravang watershed. Moreover, result show SOC deficiency in the soil of Ravang watershed due to high salinity, low percent of vegetation cover and land use changes. In addition, drought intensifying and decrease in precipitation have reduced SOC content, which itself causes changes in the texture and chemical properties of the soil and, as a consequence, makes them more susceptible to erosion.

Conclusion :

The variability of SOC is very high in the study area because of intensive water erosion and land use change. Overall, the results of the present study indicated that the critical condition of soil organic carbon in the Ravang watershed, which requires a comprehensive management of the region's water and soil resources to improve soil conditions and increase the reserves of this important and influential variable in the soil structure. On the other hand, despite of the acceptable performance of the random forest model in estimating of soil properties, due to high variability of some soil properties, model prediction performance may be decreased.

In arid areas, water resources management and utilization is of great importance in minimizing the damage caused by water shortages in these areas while maximizing water resources efficiency. The present research aims to assess water resources management in Sistan with an approach to cope with dust storms and desertification phenomena using lexicographic goal programming method. Lexicographic goal programming is one of the most important multi-objective optimization problem solving methods. GAMS programming was considered to design research model. The results showed that according to the experts, in order to coping with dusts phenomenon, followed by meeting domestic demands in Sistan, water transfer priorities are related to critical control point of Hamoon Wetland and plantation areas in wind sedimentation. For this, once research model was run and under optimal water resources management, in addition to meeting all domestic consumption demands, the amount of water transmitted to Hamoon Lake to supply its minimum water requirement was 61.4 million cubic meters. Hence, the water needed for the stabilization of the critical control point of Hamoon Wetland was fully supplied. In addition, under optimal management conditions, water transportation to plantation farms of northern Mohammad Shahkarm and Jazinak cities was increased by 13.22 and 7.76 million cubic meters, respectively, i.e. up to twice a current value. As a result, all of water demands in these sectors have been met completely. According to the results, under optimal water management conditions in addition to meeting basic needs, water transferring to critical control point of fine grain sediment origins to stabilize them.

Human interventions on natural trend and overexploitation of natural resources, altogether have interrupted nature reclamation and accelerated its degradation. The present research aims to determine anthropogenic factors on wind erosion intensification in Hamun area, Sistan. The study populations included two groups, first all experts in the natural resources sector in city of Zabol (36 experts) which were  surveyed and second group included all households in Hamoon area of Sistan which their number was 4121 households and according to Cochran formula, the sample size was obtained 221 households. The results of the questionnaires responded by experts showed that off-season cultivation of melon Hamoon lake bed, Excavation of water storing pits and manipulation of stabilized Lake bed and overgrazing vegetation in Hamoon bed are found to be the most important factors in exacerbation of wind erosion in this area. Pearson correlation coefficient was used to determine anthropogenic factors affecting the above three factors. Data analysis showed that experience of stakeholders and number of stockholders family members both have positive significant role in increasing our off-season cultivation of melons on the lake bed, Excavation of water storing pits and grazing on lake bed in 99% confidence level. On the other hand those stakeholders owning greater farmlands, high education level and income have fewer tendencies to overexploitation and degrade area.

In the present study, the impact of watershed management practices on flood hydrograph characteristics was investigated using HEC-HMS model. In order to design, calibrate, and validate the model, data from a representative paired watershed (Kakhk Watershed, Khorasan Razavi Province, Iran) was collected and field surveys were performed to have the dataset further completed. Results of paired sample t-test, relative error statistics, Nash–Sutcliffe relative error and coefficient of determination for both real data and simulated results utilizing the HEC-HMS simulation software confirmed efficiency of the model in simulating flood hydrographs of the control and sample watersheds. Based on the results, watershed management practices could attenuate hydrologic response of the watershed and flood hydrograph characteristics such as flood coefficient (p-value: 0.001), peak discharge (p-value: 0.027), and flood volume (p-value: 0.026). Moreover, a comparison between structural practices and biological practices showed that, the biological practices could further attenuate the peak discharge and flood volume by 8.8 and 12.64%, respectively.

The purpose of this research is to study the changes in some features of the topsoil and vegetation in the land affected by flood and comparing its results with the control area in koh khajeh flood spreading station in hamoon area of Sistan. For this purpose, four sites were considered as flood spreading area and two sites were selected as control area. Samples were taken in six sites using the random-systematic method. To this aim, 3 transects of 100 meters was established in each field and each one had 10 plots of 1 square meters regarding the dispersion of vegetation. Canopy cover percentage and density were calculated through use of plots and clipping and weighing was used to measure current year's growth as production. Also, to measure soil properties, sampling along each transect and in six points (3 points in shrubs understory and three points in bare soil), and factors as EC, pH, nitrogen percentage of the soil, and organic matter percentage were calculated. In order to compare the results regarding soil features, we used 2*2 factorial tests and for the factors regarding vegetation we used non-paired t test in spss. Data normality was assessed using Kolmogorov test. The results indicated that flood water spreading has a significant effect on canopy cover percentage and plant production respectively in probability level of 5 and 1 percent, but there is not significant difference between vegetation density in flooded and control area. Results showed that flood has led to significant increases in soil nitrogen percent and organic matter as well as low acidity and EC in probability level of 5 %.at the same time, organic matter, nitrogen and acidity are low compared to shrub understory soil in both treatments. However, EC in soil under shrub is higher than bare soil in both treatments.

One of the most important processes of erosion and sediment transport in streams is the river most complex engineering issues.this process special effects on water quality indices, action suburbs floor and destroyed much damage to the river and also into the development plans Lack of continuity sediment sampling and measurement of many existing stations. due to the low number of hydrometric stations in Iran and the lack of continuity of sediment sampling and measuring in many existing stations, on one hand the exact amount of sediment load in many rivers in the country is not available and because of differences in climatic, hydrological and topographical conditions in the country, on the other hand, the preparation and calibration of sediment Erosion Models different regions, is unavoidableCalibration models of erosion and sedimentation in different locations is difficult and requires financial capital andthe time . the But evolutionary optimization algorithm able to resolve this problems of mathematical and experimental methods in this paper, a new optimization algorithm spiders can be made to education And the evolutionary pattern for input (discharge and precipitation) and rain-gauge gauging stations and Watershed Kardeh designated evolutionary algorithms and artificial network performance for 24 year 24-year dam catchment Kardeh for the period studied. In conclusion, the results proved that social spiders optimization algorithm t better resultspredic to for sediment in watershed Kardeh

Seasonal rivers have high capacity of Sediment transport Sediment to the downstream areas. The sedimentation of high quality suspended particles on the alluvial zones caused that the fertility of lands increased. . So that importance of sedimentation in flood spreading projects and temporal refilling is much more than the water itself. The purpose of this study is to examine Temporal refilling effects on physical and chemical properties of Sediments in Hamoon Wetland of Hirmand. In this regard, physical and chemical properties of Sediments were measured in 40 points as refilling non-refilling areas Moreover, in order to determine of physical and chemical properties of the soil, samples were taken from the surface and depth of 0 to 20 using ordered grid method, and then the samples was Examined in laboratory for determination of physical and chemical properties. Then, the physical properties such as clay, Sylt and sand percentage, and chemical properties such as organic matter, total nitrogen, total phosphorus, cationic exchange capacity, calcium and magnesium, absorbable sodium, sodium absorption ratio, lime, absorbable potassium, acidity, and electrical conductivity were determined. The results of the data analysis by T-tests and Mann Whitney U tests in Mini tab Software indicated that there was a significant increase in organic matter total phosphorus, calcium and magnesium %1 (p

The basis of land use planning is geomorphological zoning of Earth's surface. The quantitative zoning is conducted using automated and predefined based on zoning criteria. In this study, the quantitative zoning is used to identify areas suitable for artificial recharge in the mountainous area of Gohar and Garbayegan plain, Fars province by fitting a linear fundamental form to the surface. The structures with grade two for triplex windows and the data from the digital elevation model with a resolution of 10 m was used to determine the best fundamental structure fit. The sum of square differences of the surface differences is used as an indicator to determine the degree of fitting the fundamental structures. By fitting the interpretable patterns to the Earth's surface, it can be determined that the earth was similar to which pattern and formation mechanism. Mountain ranges upstream alluvial cones and plains located downstream of the upstream alluvial cones are not linear surfaces. Places which are not at the acceptable slope (gradient less than 0.002 and higher than 0.1) allocated to the zero fitting degrees and the fitting degree values are positive in alluvial cones and areas fall in the acceptable range of the slope. The results show that the surfaces located downstream of the alluvial cones and the plains are most suitable areas for floodwater spreading in the Garbayegan watershed.

The basis of spatial planning is the geomorphological zoning of ground surface, in which the first phase is determining the homogeneous zones of the ground surface in terms of geomorphological characteristics. The current study aimed at determining the proper zones for artificial feeding in Gahar mountainous region and Garebayegan plains in Fars province by the use of zoning the ground by Evans-Chezy quantitative coefficients. The quantitative zoning of ground surface plays a vital role in more accurate determination of the land capabilities due to precise determination and division of the types, facies, and surface terrains. For this study, the elevation numeral data with 10m resolution obtained from the National Cartographic Center was used. By the use of surface fitting tools in MATLAB software, the equation for each form was fitted to limited fragments of the surface and the program was applied. Then, each of the quantitative coefficients was illustrated as some zones. For determination of fitting degree, the total squared difference between the rate parameter was used and by the use of fitness degree, the propriety degree of the surface for optimal positioning of flood spreading with surface morphological view was determined. The results indicate that the surface downstream the alluvial fans and plains located on the southern region of the studied land is the most appropriate zone for the Flood Spreading. This area constitutes a surface of 10% of the total area of the region.

This study aims at comparing the performance of logistic regression, maximum entropy, and multilayer perceptron techniques in preparing the predictive habitat distribution map of Amygdalus scoparia in rangelands of Qom province. For this purpose, vegetation sampling was done using random systematic methods after identifying pure habitats of this species. For soil sampling, eight profiles were excavated and two samples were taken from 0-30 and 30-80 cm depth. After analyzing the soil characteristics in the laboratory and generating the layers of physiographic characteristics (slope, aspect, and elevation), geology and physical and chemical characteristic of soil, predictive habitat distribution modeling was performed. Then the accuracy of generated map was evaluated by kappa. Based on the calculated kappa coefficient, logistic regression model was able to predict the habitat distribution of studied species at the excellent level (kappa= 0.91). Meanwhile, predictive maps derived from maximum entropy and multi-layer perceptron had very good aggrement with actual map (kappa 0.85 and 0.8, respectively). These results indicate that the logistic regression model is more accurate than other methods for predicting the distribution of this species due to specific circumstances. Based on logistic regression model, geological formation (Igneous formations) and soil gravel amount are the most influential factors effecting the the presence of this species in this habitat. These results indicate that in order to select the optimal modeling approach, it should be given special attention to the ecological niche of the species studied in addition to the capabilities of each method.

One of the most important problems in the management and planning of water resources is to forecast long-term precipitation particularly in arid and semi-arid regions. Climate Change affects local hydrology of different regions, through changes in the pattern of precipitation. In this study, the impact of climate change on the precipitation of Chatrood and Saadatabad Sirjan stations using HadCM3 model outputs under A2 and B2 scenarios and SDSM downscaling model was predicted for three periods of (2010-2039), (2040-2069) and (2070-2099).Then, according to statistical measures of model performance such as Mean Absolute Error (MAE), Root Mean Squared Error (RMSE), Nash-Sutcliffe efficiency (NS) the results of model were evaluated. The results indicated that the SDSM model had high performances in two stations. Moreover, amount of annual precipitation under A2 and B2 scenarios will be decreased by 10.02 and 8.87 mm at the Chatrood station and 16.51 and 14.09 mm at the Saadatabad station, relative to reference period, respectively until 2099.