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Flood spreading is one of the solutions for water resource management that can have positive effects on groundwater resources. The aim of research is to investigate some qualitative changes of Herat aquifer affected by flood spreading station in the region. Statistics of Ca, HCO3, Mg, Na, Cl, TDS and EC parameters of agricultural wells were extracted. To evaluate effect of water extraction and consequently effect of sediment extraction on efficiency of sites, years of 2003-2011 were selected as the first period and 2012-2021 as the second period. Different interpolation methods were used to investigate spatial changes of qualitative parameters. Map of percentage of spatial changes of each parameter was obtained with using mathematical relationships. The results of examining percentage of spatial changes of parameters indicate an increase of water quality in downstream of flood spreading and outlet of aquifer. The lowest EC with less than 1000 µmho/cm is related to western wells and the highest EC with more than 10000 µmho/cm in is related to eastern wells. This reinforces positive effect of flood spreading. Considering spatial pattern, effect of flood spreading projects in this area has been positive and has been able to control the decline in quality of groundwater.

Background and Objectives Flood spreading has emerged as one of the most important management strategies for soil and water resources in arid and semi-arid areas, gaining attention from researchers worldwide in recent decades. This technique has been implemented in various watersheds globally to address the critical issue of moisture scarcity, which is a significant factor limiting plant growth in these regions. The flood spreading system not only supplies moisture for plants but also helps recharge underground aquifers, making it one of the most innovative methods developed for water management in arid and semi-arid environments. By effectively utilizing floodwaters that would otherwise be lost, flood spreading offers a viable solution for enhancing water resources and supporting sustainable agricultural practices in these challenging landscapes. Methodology In this study, we investigated vegetation density, regeneration, trends, and the condition of rangelands at the Abbarik Bam flood spreading station. To assess the effect of flood spreading on vegetation cover, we identified the site with the most flooding, located away from tree cover, and established four transects, each 100 meters long and spaced 15 meters apart, parallel to the distribution channels. Ten plots were installed along each transect, with a distance of 10 meters between them. At the end of the one-year period, we compared the collected data to accurately assess the changes in the flood spreading environment relative to a control environment, both of which were selected for grazing exclusion. This comparison allowed for an informed evaluation of the effects of flood spreading on vegetation density in the area. The experiment was conducted using a split-plot design in a randomized complete block format with four replications. The main plots included flooded, non-flooded, and control areas, while the subplots encompassed five vegetative forms: perennial grasses, perennial forbs, annual grasses, annual forbs, and density parameters were recorded. Results The results also revealed that the density of forb plants was 2.6 times higher in flood-free plots and 4.2 times higher in flooded plots compared to the control area. In contrast, the density of perennial grasses was 0.1 times lower in flood-free plots and 0.05 times lower in flooded plots than the control area. The density of perennial broadleaf plants was 1.7 times higher in both floodfree and flooded plots compared to the control area. Interestingly, the density of annual grasses was 30.78 times higher in flood-free plots and 6.3 times higher in flooded plots than the control area. Finally, the density of annual broadleaf plants was 2.4 times higher in flood-free plots and 5.1 times higher in flooded plots compared to the control area. Conclusion The results indicated that the highest average vegetation density in flood-free plots was associated with the annual grasses, followed closely by annual broadleaf plants. In the control plots, the highest average vegetation density was found in annual broadleaf plants, followed by perennial grasses. Additionally, the impact of vegetative form on vegetation density was greatest for annual wheat and annual broadleaf plants, while shrub plants exhibited the lowest density. Therefore, the observed differences in vegetation cover between flooded and flood-free areas in the study region may be attributed to factors such as moisture content, nutrient availability, the accumulation of fine-grained sediments, root and bud choking, and reduced soil permeability. [ABSTRACT FROM AUTHOR]

Introduction and GoalThe rangeland ecosystems of arid and semi-arid regions play the most important role in the distribution and density of vegetation in these areas due to the specific environmental conditions governing the soil, which is the bridge between living and non-living parts of ecosystems. Soil enzymes play important biochemical roles in the decomposition of organic matter at all stages in the soil system. These enzymes play an important role in the stability of the soil structure, the decomposition and formation of organic matter, the cycle of elements and the activity of soil microorganisms. Environmental stresses, such as drought, have negative impact on plant growth and soil microorganism's activity. Therefore, evaluating the effect of flood spreading on soil quality indicators can be a useful step in improving knowledge in this field. Therefore, this research was conducted during 2018 and 2019 to investigate the effect of flood spreading, plant types and characteristics on biological soil in the Kowsar floodplains located in Gareh-Bygone, Fasa.Materials and MethodsSampling of the soil around the roots of Artemisia sieberi Besser, Dendrostellera lessertii (Wikstr) Van Tiegh. and Heliantemum lippii (L) Pers, in two situations: with flood spreading and without flood spreading (control area) in spring and autumn from a depth of 0-20 cm and in three repetitions. After ensuring the normality and homogeneity of the variance of the data by the Shapiro–Wilk and Levene tests, the data were analyzed using the two-way variance method and mean comparison were made using Duncan's test at the 1% and 5% level and using the R software.Results and DiscussionThe results of soil fertility characteristics showed that there was no significant difference in the amount of phosphorus and potassium in the three pasture species studied under flood spreading and the control areas. However, the amount of carbon and nitrogen in all studied species was significantly higher in the flood spreading area (containing 0.3% organic matter) than the control area (with 0.15% organic matter). In addition, the results of this research indicated that the highest activity of acid phosphatase enzyme was observed in the rhizosphere of D. lessertii species and in the spring season, and on the contrary the lowest activity was observed in the rhizosphere of H. lippii species under the flood spreading condition. Alkaline phosphatase activity in all species was significantly higher in spring than in autumn season. The highest activity of this enzyme was observed for A. sieberi in the spring season with an average of 186 (µg p-nitrophenol g-1 soil h-1) in the flood spreading area and the lowest level was observed for H. lippii in the control area with an average of 57 (µg p-nitrophenol g-1 soil h-1) in the autumn season. In general, the level of phosphatase enzyme activity for the A. sieberi species in the spring season was approximately 89% higher in the flood spreading area than in the control area. The dehydrogenase enzyme activity was higher in spring than in autumn. Also, the highest activity of this enzyme was observed in the spring season for the D. lessertii species with an average of 8.5 (µg TPFg-1 soil 24 h-1 ) in the control area, and the lowest level was observed in the autumn season for the A. sieberi species in the flood spreading area with an average amount of triphenol formazan was 1 (µg TPFg-1 soil 24 h-1 ) .In other words, the amount of dehydrogenase enzyme activity in the spring season was approximately 66% higher than that in the fall season in both areas (control and flood spreading). The results of this research showed that the activity of urease enzyme under flood spreading conditions in both seasons (autumn and spring), with an average of 270 and 300 (µg N/g.dm.2h) is more than the control area with an average of 173 and 250 (µg N/g.dm.2h). Also, the soil quality indices in all three studied species in the two (control and flood spreading) areas have a significant difference, so that the flood spreading operation has upgraded the value of these indices for the H. lippii species and the A. sieberi, while which has reduced the soil quality index of D. lessertii.Conclusions and SuggestionsThe results of this research showed that the flood spreading system is a desirable method for improving soil organic carbon, and its efficiency increases with the plant planting. The increase in moisture and the amount of organic matter in the flood spreading area can be a reason for increasing the activity of enzymes in the flood spreading area, so that in both autumn and spring, the activity of soil enzymes is more in the region. Considering the important role of organic matter in improving biological indicators and soil quality and health, the restoration of floodplains with native species can play an important role in providing these conditions. In addition, it is recommended that these tests be repeated with more samples and in different areas and the nitrogen, carbon, sulfur and phosphorus cycles and its relationship with the activity of other soil enzymes related to this cycle should be investigated.

Introduction and ObjectivesBiochemical activities of soil have been proposed as one of the most well-known indicators of soil quality and health, which are considered in evaluating the effect of afforested species on soil characteristics. This research was conducted with the aim of investigating the long-term effect of flood spreading operation and type of vegetation on the activity of acid and alkaline phosphatase, urease and dehydrogenase enzymes and soil microbial activity, including basal respiration and stimulated respiration, in 2019.Materials and MethodsSampling the soil around the roots of Acacia salicina Lindl., Eucalyptus camaldulensis Dehnh., Atriplex lentiformis (Torr.) Wats. (0-20 cm depth) was carried out with 6 treatments in three replications. Statistical analyzes were performed using SPSS software as a factorial test in the form of a randomized complete block design and the means were compared with Tukey test at P

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.

Soil properties and land use affect the soil carbon content and reduce the adverse effects of climate change. This study aims to assess the effect of some physical properties of soil and land use on the amount of soil organic carbon content (SOC) and model development to estimate the amount of SOC. This investigation was carried out in 2020 in the areas of flood spreading in of Fasa (Kowsar station). Land uses included acacia (Acacia salicina Lindl.), eucalyptus (Eucalyptus camaldulensis Dehnh.), atriplex (Atriplex lentiformis (Torr.) Wats.) plantation, and natural rangeland, all of which are irrigated by flood spreading. By sampling in three replications of the soil of different land uses from the depth of 0-30 cm (15 composite samples), percentage of sand, silt, clay, silt+clay, percentage of soil saturation moisture (SP), bulk density (BD), particle density (PD), porosity percentage (PS), void ratio (VR) and SOC were determined. Obtained data were statistically analyzed in a complete randomized design and the means were compared with the Duncan test at P

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. [ABSTRACT FROM AUTHOR]

Controlling and managing of seasonal and sudden floods in arid and semi-arid regions, especially in areas where surface water is out of reach is necessary. Flood spreading is one of the best ways to control surface runoff and recharge groundwater resources. In the present study, the appropriate sites for flood spreading project in border area of Taybad county in Khorasan Razavi province is selected using Boolean logic .For prioritization the suitable locations, TOPSIS and VIKOR multi-criteria decision making methods were used. Firstly, using Boolean logic inappropriate areas based were removed on criteria (slopes greater than 8%, urban area, agriculture and covered pediment). Then, 11 zones were selected as the suitable areas of using TOPSIS and VIKOR models based on the criteria of slope, groundwater quality, geology, alluvium thickness, transmission capability, drainage density, surface permeability, groundwater loss, distance from the village, distance from wells and land use.. Results showed that most suitable areas are located in alluvial fans. Based on the TOPSIS model, location J with value of 0.75 was selected as the best site, and using the VIKOR model, location K with a value of 0.96 was selected as the best location for flood spreading projects.

ELECTRE I method was coupled with GIS to develop a model for determining the appropriate location of artificial aquifer recharge (AAR) through the floodwater spreading method (FSM). Khoy Plain, Iran, was selected as the case study. A total of 16 technical criteria (categorized as physical, climatic, hydrological, and hydrogeological criteria) was used to zonate the area into five sectors. Subsequently, six scenarios were proposed for the most appropriate locations. It was found that the marginal areas near the mountains, hillside plains, and plain entries, low-grade zones, areas encompassing high-quality underground water resources and with adequate unsaturated zone thickness, and quaternary alluvial sediment zones with high transmissibility, characterize the most appropriate zones for the AAR through the FSM. Combining the results obtained in the first step into a decision matrix, the scenarios were prioritized using a proposed model based on ELECTRE I; accordingly, Scenario 3 was introduced as the optimal approach. In selecting the optimal scenario, not only the weights of the criteria and the concordance and discordance of different scenarios toward one another, but also the numerical values of the concordance and discordance thresholds played essential roles. Further investigation of the scenarios following optimistic and pessimistic approaches showed that the order of preferences of different scenarios were the same following both normal and optimistic approaches. In contrast, the pessimistic approach led to a completely different set of orders of preference, except for Scenario 3, which was again identified as the most appropriate choice. [ABSTRACT FROM AUTHOR]

This study aimed to select favorable site using analytic hierarchy process (AHP) for practices including seeding and seed broadcasting, hoeing and seeding, contour furrowing, pitting and flood spreading to restore degraded rangelands Ghayen Plain, Iran. First, major effective criteria in selecting favorable sites for range restoration measures were adopted from the reputable literatures. Then, 80 questionnaires in the form of pair matrix were designed for each restoration measure with regard to the selected criteria. Questionnaires were distributed among lecturers, experts and authorities in local universities and offices. Final score and relative importance of criteria were calculated on the basis of geometric mean of questionnaires. Hierarchical tree structure with appropriate adaptability was generated in Expert Choice software. Results showed that rainfall and slope played an important roles in selecting favorable site for pitting. Soil infiltration rate and runoff volume had the highest relative importance in selecting suitable site for flood spreading project. Furthermore, for seeding and seed broadcasting practices climate and slope showed high relative importance. Rainfall expressed high relative importance in selecting favorable site for hoeing and seeding projects. Finally, slope and runoff volume were the major criteria in selecting site for contour furrowing project. Based on the generated location maps, 628 ha were suitable for flood spreading. In addition, the suitable area for the contour-furrowing and pitting operations was estimated to be 103 and 199 ha, respectively. The area of suitable sites for direct seeding and hoeing and seeding operations was calculated to be 3623 and 2750 ha, respectively.

This study aims to determine the effect of a flood-spreading system on the morphometric characteristics of alluvial fans (AFs) in Gribayegan Fasa, Iran, and its relationship with erosion, age, texture, and type of formations. After determining the AFs using the semiautomatic method and determining their recharged watersheds, 25 morphometric characteristics were investigated. The most important morphometric characteristics were identified using principal component analysis (PCA). The group method of data handling (GMDH) neural network is used to predict erosion, soil texture, age, and formation material based on the morphometric characteristics of the fan. The results demonstrate that the semiautomatic method can effectively extract AF from the landscape. The results of AF morphometry before and after flood spreading show that the fan area, drainage basin circularity (Cirb), fan perimeter, relief ratio of the fan, fan length, minimum fan height, and maximum fan height were higher before flood spreading, and basin shape, St (soil texture), upper fan slope, fan volume, and sweep angle had higher values after the flood. In addition, the results of PCA show that fan area, fan perimeter, fan length, fan radius, fan volume, basin area, basin perimeter, main channel length, basin length, and drainage density are important factors. The results of the GMDH algorithm reveal that this method can accurately predict the formation, age, soil texture, and erosion rate using morphometric characteristics. Therefore, the R2 is 0.92 for the formation age and R2 is 0.86 for the erosion rates, formation types, and soil texture, respectively. Therefore, the most important morphometric parameters can be determined using PCA, and the conditions and processes in the basin, such as formation material, age, soil texture, and erosion rate, can be predicted with high accuracy using the GMDH algorithm. [ABSTRACT FROM AUTHOR]

Carbon sequestration (CS) in soils is a phenomenon consistent with the principles of sustainable development. Further, it is a vital solution for reducing the atmospheric CO2 and other GHGs. To identify the role of spate irrigation (SI) of afforested plots and rangeland in CS, 36 soil samples were collected from the 0–30 cm top soil in different spate-irrigated and control treatments in November 2017. Organic carbon (OC) was measured by the standard laboratory procedures, and then converted to the sequestered soil carbon (SOC). The data were analyzed using the randomized complete block design benefitting from the SAS software. The means were compared with the Duncan test at P2; this amounts to 4.6 tons of CO2 per year on average.The total income from the carbon rent of the dense Eucalyptus camaldulensis Dehnh. aforested plots at the Kowsar Station is $32381.00 per hectare with an annual mean of $925.17 per hectare.

Introduction: Carbon sequestration (CS) by forests, pastures, afforested stands and soils is the most appropriate way to reduce atmospheric carbon. A combination of all these activities can help balance the global warming process by reducing the concentration of atmospheric CO2. The amount of CS and quality of carbon storage in the soil depends on the interaction between climate, soil, tree species, litter chemical composition and their management. The results of Dinakaran and Krishnayya (2008) research showed that the type of vegetation cover has a significant effect on soil carbon storage. So that the amount of carbon storage in the soil depends on the amount of carbon entering the soil through plant debris and carbon loss through decomposition. To increase carbon in the soil, management activities such as increasing the amount of carbon entering the soil by adding litter and crop residues as well as reducing the rate of decomposition of soil organic matter should be done. Decomposition rate of soil organic matter is affected by soil condition (humidity, temperature and access to oxygen), sequestration of organic matter, placement of organic matter in the soil profile and the degree of physical protection by aggregates. Evaluating the role of aquifer management in reducing via storing the atmospheric CO2, to organic carbon (O.C) is the aim of this study. Materials and Methods: The studied land uses were as follows: 1-Rangeland-without flood spreading-with grazing (control), 2- Range without grazing-without flood spreading, 3- Six rangelands stripes-with grazing-with flood spreading, 4- Rangeland-Atriplex plantation-with spreading of flood, 5- Eucalyptus control forest-without flood spreading, 6- Eucalyptus forest-first strip-with flood spreading-BisheZard 4 (BZ4), 7- Eucalyptus forestsecond strip-with flood spreading-(BZ4), 8- Eucalyptus forest-third strip-with flood spreading-(BZ4), 9- Acacia forest-with flood spreading-(BZ4). Soil and plant were sampled from each land use type. Then, the amount of O.C was measured in the laboratory and CS was calculated. The economic-environmental value of carbon stored in the soil is based on Rivers' proposal, which declares a carbon tax rate of $200 per tonne of CO2. The dollar is equal to 42,000 Iranian rials. Data were analyzed using randomized complete block design and Duncan test (at P<0.05) was used to compare mean values using the SAS software. Results and Discussion: The analysis of variance showed that the effect of different land uses on the bulk density (BD), %O.C and the CS in the soil was significant at the level of 1%. Comparison of the mean of BD in various land uses showed that the eucalyptus forest (third strip) had the lowest BD compared to others, and the difference between this land use and other land uses was statistically significant. The first strip of Eucalyptus forest had the highest %O.C and the highest amount of CS in the soil, and the statistical difference between these two indices in this land use with other land uses was significant. Among the studied land uses, the lowest amounts of CS were related to the control range and range without grazing-without flood spreading. The interaction of plant to plant species on plant dry weight and plant carbon storage showed that the rangeland species of Heliantemum lippii and Dendrostellera lessertii in the range with flood spreading have the highest dry-weight and the species of Helianthomus has the highest amount of carbon storage. This indicates that the impacts of flood spreading on plant biomass production and carbon storage have been greater than the impact of no grazing on these indicators. In all uses, Artemisia sieberi showed the lowest dry weight and carbon storage. Planting of Eucalyptus camaldulensis irrigated with flood water spreading increased the soil O.C from 0.51% in the control to 1.68% in the first strip of eucalyptus forest (3.29 times). By calculating the mean of the three strips in which the eucalyptus was planted, it was found that the highest carbon content of 121.84 ton/ha was stored in the plant, litter and soil of this land use. Given that, each tonne of carbon is equivalent to 3.67 tons of CO2 gas, it can be concluded that 447.15 tonnes of CO2 gas from the air is stored as organic matter. The economicenvironmental value of this CS is 3.76 billion rials ($89523.81) per hectare. Conclusion: The studied land that was irrigated with flood spreading, especially the eucalyptus forested area at Kowsar station, captured significant amounts of CO2 from the air and stored it as organic matter in the root and shoot of plants and in the soil. Also, this may lead to the release of a large amount of oxygen gas to the environment which play an important role in reducing air pollution. Considering the economic-environmental value of the carbon stored in the eucalyptus plantation forest areas, the development of this method in flood prone areas is quite economically justifiable. Due to the high potential of tree species in improving soil carbon storage, it seems that increasing the percentage of woody species and their physiological diversity have increased the carbon storage capacity of these species. Therefore, in order to improve the carbon storage capacity of flood distribution systems, it is suggested that the planting of native and perennial compatible species in these systems should be considered. [ABSTRACT FROM AUTHOR]

The present study aimed to locate the areas prone to flood spreading in order to manage surface water resources. Therefore, the information layers of slope, land capability, quaternary units, alluvium thickness and land-use were applied in GIS environment. In this regard, the layers were rated in proportion to their effect on feeding of aquifer. Then, according to the Multi Class Maps model, the weighted layers were combined and the map of areas prone to flood spreading in with four very suitable, suitable, somewhat suitable and unsuitable classes was prepared. The results showed that using this method, large areas can be studied using GIS and remote sensing. The total area of the region studied is 1 280 762 hectares of which 58 524 ha are in a very suitable class, 132 673 ha in suitable class, 245 584 ha in somewhat suitable class and 843 978 ha in unsuitable class. The factors of slope, alluvium thickness, quaternary units and land capability are the most important factors, respectively. [ABSTRACT FROM AUTHOR]

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.

Floods control, artificial recharge of ground water aquifers, and attempt to optimize the efficiency of water and soil resources are the most important benefits that have been achieved as a result the construction of flood spreading stations in the country. The aim of this research is assessment and determination of economic effects of flood spreading project on water resources and agriculture by monitoring and recording relevant data steadily and continuously. For this purpose, profitability and economic justification of the project were studied using proper criteria of economical evaluation of investment projects. The results showed that water cultivation area of downstream villages of project have been 3.5 folds more compared to the year 2013. Moreover, the added value of the injected flood based on measuring the volume of controlled flood was estimated to be 14.6 Million Rials. The added value of grassland production project became 1354 Million Rials. Whereas, the added values of wood production and agriculture section were estimated to be 13.4 and 657 Million Rials respectively. Economic evaluation indicators of project (NPV, ROR, and B/C) were estimated to be 1399 Million Rials, 0.38, and 2.87 respectively showing economic justification of project.

Loamy sand soils cannot hold considerable amounts of water and nutrients. A flood-spreading project generates fine particles, often stored in sediment. In addition, established plants have interactive effects on beneath-canopy. This research investigated the effects of flood spreading and Prosopis juliflora on soil characteristics. Fourteen years after the flood-spreading project was initiated, quality of soil was compared between FS and control sites, and the accumulation of nutrients in soil beneath the P. juliflora was compared to soil from between trees with t test. For soils, we analyzed texture, water infiltration, organic carbon, pH, total nitrogen, available phosphorus, available potassium, cation exchange capacity, calcium carbonate equilibrium, and soil microbial respiration, and for plants, we measured the below-ground root. Few variations were found in the soil characteristics as a result of flood-spreading establishment. The results indicated that fine fractions of soil in FS site were greater than that in control (p < 0.05). It was obvious that flood spreading and P. juliflora could alter soil infiltration rate. The soil infiltration rate of the under P. juliflora had the highest value (3.05 ± 0.22 cm h−1), and in flood-spreading site without P. juliflora had the lowest value (2.48 ± 0.20 cm h−1). FS had a significant improvement in soil nutrient concentration and soil microbial respiration. This research suggests that flood spreading in coarse texture soils provided a beneficial approach to remediation of sandy soil characteristics. In addition, P. juliflora had a significant effect on developing soil fertility under plant canopy. [ABSTRACT FROM AUTHOR]

The selection of suitable location for implementing of flood spreading project and artificial recharge of aquifers is an important step. To assess this purpose, the Geographic Information System (GIS) conceptual models and decision making systems were used. Regarding different mentioned criteria, it is not possible to use GIS without appropriate Multi-Criteria Decision Making (MCDM) technique. The main aim for this research is to access the suitable location for flood spreading by using the most efficient criteria and classify them into several groups. Consequently, major factors such as slope, geology, geomorphology, hydrology, infiltration rate, cover and environmental impacts of the projects should be considered in the process of selecting appropriate site for artificial recharge through flood spreading. Also evaluating accuracy and application of conceptual models such as Logic Boolean, Multi classmaps, Binary Evidence, the Analytic Hierarchy Process (AHP) have been noticed. In this research, nine physical and environmental efficient variables essential for locating of flood spreading are used. The results indicate GIS-based data combination for ranking suitablelocation of flood spreading by itself, though it is not reliable enough. Also evaluating accuracy of models shows that accuracy of Binary Evidence model for identifying and ranking suitable location of flood spreading is more than that of Boolan model and the Multi class maps model can give better insights to create more realistic output scenarios The most important step in flood spreading process is to define optimal site. The Analytic Hierarchy Process (AHP) is an approach that is suitable for dealing with complex systems related to making a choice from among several alternatives and which provides a comparison of the considered options. In the present research relationship between GIS and Multi-Criteria Decision Making analysis has been investigated in order to find optimal site for flood spreading. The research emphasized the capability of resultant map to be used in site selection for flood spreading.

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. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate the success rate of planting project. Also reviews combating desertification in this region by the Project. First, plant characteristics including canopy cover and vegetation density were measured by transect of 100m and plots of 225m2 (15×15), respectively. Also physical (soil texture) and chemical properties of soil samples including salinity and acidity at three depths of 0-30, 30-60 and 60-90cm (roots development zone) were measured. A region as a flood spreading area including three phases, two phases of Atriplex and one phase of Haloxylon was selected. Also, another region was considered as the control area. The results were compared by Duncan's test according to Completely Randomized Block design. The results of physical and chemical properties of the soil samples showed that the electrical conductivity and pH have decreased in the most samples. These changes were significant at the 5% level. Soil texture and sand increased but clay has decreased in the depth of 0-30cm, therefore soil structure has improved. The results of plant characteristics showed that water spreading has positive effects on establishment and natural regeneration of the planted spices (15.75 percent increase) and these changes are significant at the 5% level. Based on canopy cover and vegetation density results, there are no significant differences between Atriplex and Haloxylon; but the establishment of endemic species has been more successful in Haloxylon phase.

Flood spreading is one of the suitable strategies to control and benefit from floods which in turn improve the groundwater recharge, makes soil more fertile, and increases nutrients in soil. It is also a method for reusing sediment, which is usually wasted. Thus, selection of suitable areas for flood spreading and directing the flood water into permeable formations are amongst the most effective strategies in flood spreading projects. Having combined analytic hierarchy process (AHP) of multi-criteria decision analysis and genetic algorithm (GA) of artificial intelligence approaches, this paper addresses the problem of finding the most suitable area location for flood spreading operation in the Gareh Bygone Plain of Iran. To this end, the nine effective geodata layers including slope, alluvium thickness, geology, morphology, electrical conductivity, land use, drainage density, aquifer transmissivity, and elevation were prepared in geographic information system environment. This stage was followed by elimination of the exclusionary areas for flood spreading while determining the potentially suitable ones. Having closely examined the potentially suitable areas using the proposed methodology, the land suitability map for flood spreading was produced. The AHP and GA were used for ranking all the alternatives and weighting the criteria involved, respectively. The results of the study showed that most suitable areas for the artificial groundwater recharge are located in Quaternary Q ft and Q sf geologic units and in morphological units of pediment and Alluvial fans with slopes not exceeding 2 %. Finally, further evidence for the acceptable efficiency of the integrated AHP-GA method in locating most suitable flood spreading areas have been provided by such significant spatial coincidence between the produced map and the control areas located near Kowsar research station, where the earlier flood spreading projects were successfully performed. [ABSTRACT FROM AUTHOR]

Flood spreading is a suitable strategy for controlling and benefiting from floods. Selecting suitable areas for flood spreading and directing the floodwater into permeable formations are amongst the most effective strategies in flood spreading projects. Having combined geographic information systems (GIS) and multi-criteria decision analysis approaches, the present study sought to locate the most suitable areas for flood spreading operation in the Garabaygan Basin of Iran. To this end, the data layers relating to the eight effective factors were prepared in GIS environment. This stage was followed by elimination of the exclusionary areas for flood spreading while determining the potentially suitable ones. Having closely examined the potentially suitable areas using the Preference Ranking Organization Method for Enrichment Evaluations (PROMETHEE) II and analytic hierarchy process (AHP) methods, the land suitability map for flood spreading was produced. The PROMETHEE II and AHP were used for ranking all the alternatives and weighting the criteria involved, respectively. The results of the study showed that most suitable areas for the artificial groundwater recharge are located in Quaternary Q and Q geologic units and in geomorphological units of pediment and Alluvial fans with slopes not exceeding 3 %. Furthermore, significant correspondence between the produced map and the control areas, where the flood spreading projects were successfully performed, provided further evidence for the acceptable efficiency of the integrated PROMETHEE II-AHP method in locating suitable flood spreading areas. [ABSTRACT FROM AUTHOR]

In arid and semiarid areas, bimodal and high rainfall leads to infrequent flood that can be extremely damaging. To reduce the impacts of persistent intra-seasonal drought and also to reduce flood damaging in arid and semiarid areas, rainwater storage is a prerequisite that keeps water far from evapotranspiration, increases groundwater level and decreases flood hazards modification to exchange between surface water and groundwater through flood spreading, dams, etc. The purpose of this paper is to delineate and explain variations in groundwater recharge and groundwater quality along an ephemeral stream that has been modified by flood spreading. Groundwater samples were collected from 14 deep wells located at different distances from flood spreading projection area (FSPA) in 1 month interval during September 2005 to September 2008. Groundwater quality was followed via Na, K, Ca, Mg, Cl, Hco SO, Electrical Conductivity (EC) and pH measurements for two time periods between 2005 and 2008. The results show significant impact of flood spreading in groundwater table and groundwater salinity variation. Groundwater table decreased in all study wells, but groundwater drawdown increased by increasing the distance to FSPA (during 4 years study, 11.02 m in the well located at 20 m of FSPA versus 38.88 in the well located at 1,825 m). Also ion concentration increased in all of the wells during the study period, but the increasing ion concentration was significantly less important in FSPA closeness. [ABSTRACT FROM AUTHOR]

Flood spreading (FS) is one of the suitable methods for flood management and water harvesting that increases the groundwater recharge, makes soil more fertile and increases nutrients in soil. It is also a method for reusing sediment, which is usually wasted. The purpose of this paper is to investigate the impact of flood spreading on physical and chemical soil properties (soil texture, infiltration rate, pH, EC, Na, P, K, Ca, Mg, Cl, HCO3, and SO4). It is examined that the soil properties change in the flood spreading projection area (FSP). The physico-chemical properties of soil and infiltration rate were measured in different soil depths at both flood spreading and control area. For the 20 cm of top soil, the amount of clay increased after the flood spreading implementation especially in the first and second dikes. Increasing clay was accompanied by decreasing soil infiltration and sand percentage. The mean differences of the clay, sand and infiltration rate between FSP and the control area were statistically significant ( P < 0.01). A significant difference was not observed in 20–30 cm of the depth. Soil pH, Mg, HCO3, Cl and SO4 in different soil layers did not show any significant difference between the control and FSP. Soil EC in 0–20 cm depth of FSP and control area was showed a significant difference ( P < 0.05) but no significant differences were found in deeper layers ( P < 0.05). K, Na and Ca were remarkably different between 0 and 10 cm depths ( P < 0.05) whereas no significant differences were found in deeper layers ( P < 0.05). Comparison of the physico-chemical properties and infiltration rates between the dikes in the FSP shows that there are the significant differences between the medians of dike 1 with dikes 2, 3, 4 and 5, but the differences were not observed between dikes 3, 4 and 5. Our results show that the flood spreading operation can be influenced by the area that is under this operation. This study allowed us to investigate the mechanisms that regulate the infiltration rate and chemical soil properties throughout a seasonally flooded area. [ABSTRACT FROM AUTHOR]

Flood spreading is an inexpensive method for flood mitigation and artificial recharge of aquifers that results in a large budget return for relatively small investment.It is necessary to study some regional characteristics in order to determine the appropriate areas for artificial groundwater recharge by flood spreading in Meimeh Basin, Isfahan Province, Iran. Necessary regional characteristics to be studied are: slope, infiltration rate, sediment thickness, transmissivity, and water quality. In this research to identify suitable areas for artificial recharge several thematic layers were prepared, assigning each layer to one of the mentioned characteristics. The thematic layers were classified to several classes based on the existing criteria. All of the classes of the thematic layers were integrated and analyzed using a decision support system (DSS) in a geographical information system (GIS) environment. Finally suitability of the integrated classes for artificial recharge was identified in which the following classes were separated:(i) Very suitable, (ii) suitable, (iii) moderate suitability, and (iv) unsuitable.The validity of the generated model was verified by applying the model to a number of successful floodwater spreading stations throughout Iran. The verified model showed satisfactory results for all of the stations. The results for Meimeh Basin showed that about 70% of the Quaternary sediments in the studied area are suitable and moderately suitable for artificial recharge by flood spreading. [ABSTRACT FROM AUTHOR]