جستجوی مقالات مرتبط با کلیدواژه "basin" در نشریات گروه "جغرافیا"

Organization and management of political space through administrative divisions play a crucial role in effectively managing natural territories and their interconnected ecosystems. Failure to align political-administrative boundaries with the natural characteristics of regions, particularly the borders and boundaries of basins, poses a significant threat to ecosystem connectivity. In this study, by employing a descriptive-analytical approach and drawing on library sources, we examined the impacts of political organization of space, specifically national divisions and their changes, on the ecosystem of the Bakhtegan Lake and Tashk Basin. As the second-largest lake in the country, this basin served as a critical case study. The research findings revealed that frequent and arbitrary changes in the country's administrative divisions, particularly the creation of new units and cities in the upstream areas of the basin, had resulted in an increase in political-administrative territories, predominance of a sectoral development approach at the basin level, proliferation of local actors, passage of water currents across multiple political-administrative territories, escalation of hydropolitical tensions, hindrance of integrated basin management, loss of natural homogeneity, and failure to align the basin's natural borders with political-administrative borders. Consequently, this trend had facilitated the unrestrained exploitation of water resources in the upstream territories, disregarding environmental and ecosystem linkages with the lake and ultimately leading to its depletion.

Morphometry can be defined as a quantitative measurement of the shape of landscapes on the ground, which can be used to identify areas with active tectonics. The purpose of this research is to investigate the active tectonics in the Sivand basin using five morphometric indices of Asymmetry factor of the drainage basin (Af), Relative relief (Bh), Form factor (Ff), Hypsometric integral and curve (Hi) and Stream gradient index (SL). By conducting this research, it is possible to understand the active processes in the Sivand basin and prevent damages caused by natural disasters such as floods and earthquakes to some extent.

This is a survey carried out in 2022-2023 in Fars province and it is a practical study in terms of its purpose. The nature of the data and their calculations are quantitative. GIS software and digital elevation map (DEM) with an accuracy of 30 meters, were used to calculate the indices. For each index, a zoning map was prepared in the area, and each of the mentioned indices was classified into five categories very high, high, medium, low and very low geotechnical activity. Finally, by averaging the entire category of indices, a final index of relative active tectonics index (Iat) was obtained and the area was classified into three categories of high, medium and low terraforming activity.

In the sub-basins of Avanjan Fault, Musakhani Fault, Sivand Fault, Sivand river Fault and the faults located in the south of the investigated area, the measured indices showed high and medium values, which is due to the medium to high tectonic activity of the area.

The Sivand basin has medium to high tectonic activity and the northern, northwestern, middle and southern parts of the region are more active than other parts. It is due to the effect of the mentioned faults on the region.

Soil erosion and production of sediment load in the watershed has become one of the important environmental problems today, and therefore, Preventing its occurrence is one of the most important factors for protecting natural resources. Increasing soil loss in watersheds Watershed is a continuous challenge that is caused by the increase in population and the pressure on natural resources and unsustainable cultivation in soils and lands Slope causes a decrease in production in the land (Ahmad Abadi, 2017). One of the most important factors of soil destruction and fertility reduction is soil erosion, which is increasing nowadays and leads to Loss of good agricultural soil.

which is called the RUSLE relationship and is a function of six factors as follows:A=R*K*L*S*C*P (2) A: average soil loss per surface unit (tons per hectare per year) R: rain erosion factor, K: soil erodibility factor, L: slope length, S: slope degree, C: management factor Vegetation, P: Factor of soil protection measures This model is still the best available erosion prediction model that can be easily applied at the local level area to be used. In this method, using the DEM map of the basin in the GIS environment and having the factors RKLSCP factors, raster maps are prepared and finally, with the correlation of these maps, the soil erosion map is obtained. In the GIS environment, rain erosibility index maps (R), soil erodibility index (K), slope length index (L), Slope degree index (S) is prepared. Also, Landsat satellite bands 1 and 7 are used to prepare the NDVI map, Vegetation index (C) is prepared. - Third step: modified PSIAC

In 1968, the American Water Management Committee presented the Psiak method qualitatively. This model is based on the sum of 9 factors (X1-9) Effective on erosion, it gives the sedimentation of the basin, according to which the erosion class of the basin can be determined. In the year 1982 Johnson and Wegbhart took these factors numerically (Y1-9) so that the model takes on a quantitative state and its accuracy to increase Factors affecting erosion in this model include: lithology, soil, climate, runoff, topography, vegetation, Land use, the current state of erosion and erosion of Khanhai River. - Fourth step: preparing the necessary invoices:As stated, the revised global equation of soil erosion is an empirical model of soil erosion estimation based on the global equation. Soil erosion is designed. This model, in addition to being able to use data such as the physical characteristics of the basin and Meteorological stations can estimate the amount of soil erosion, it also enables the spatial distribution of soil erosion.

In this regard, in order to calculate the average loss of soil per surface unit (tons per hectare per year), the following factors were examined and calculated and prepared:- Slope degree: S=L* H/A S =541781.94*20/144538670=0.074 S=0.074*100=7.4 - Slope length:Basin slope length 16.03 square kilometers were calculated. Then, the erosive factors of precipitation, soil erodibility, slope length, slope degree, vegetation cover and protective measures were calculated and put in relation to the global equation as follows:R=8.86*0.376*0.72*7.17*1 R=17.197 Also, 3 factors involved in the modified Psiak model were calculated as follows and placed in the relevant section as follows:Q = 0253e^(0/036R) Q = 0.253*〖2.718〗^2.641 0.253×14.02=3.54

In this research, by preparing different layers of information, the state of sediment erosion and the amount of sediment production were determined. According Based on the amount of sediment production calculated and comparing this number with the sediment determination table, it can be said that the basin In terms of sedimentation and erosion, Kal Ismail Dara is in Class I and among the areas with very low intensity of sedimentation. The studied basin has a maximum height of 2000 meters and a minimum height of 1320 meters and in terms of topography (82.38) percent of the region includes, as well as the mountainous region with an area of 25.43 square kilometers, 17.61 percent of the basin includes In this research, using the Revised Universal Equation of Soil Erosion (RUSLE) (sediment erosion rate in the basin) 17.197 tons per hectare per year was obtained in Kal Ismail Valley, and other researchers used the same model for basins.They have calculated different figures. So that Artman et al. (2011) in Navroud, the rate of sediment erosionSediment erosion is 0-100 tons per hectare per year, Mousavi (2015) (in Shahroud-Miami, Mohammadi et al.) (2016) Taaler, Mahmoudi and Naqshbandi (2019) (in Gavshan dam, Arman et al.(2015) in TengSarkh dam, Mozbani et al.( 2021) In Sikan, the amount of sediment erosion was calculated as 2.31-68.185, 0-92.01, 35.2 and 62.17 tons per hectare respectively.Other researchers have also provided different figures for different basins using the PSIAC method. Rostaminia and Safarlaki (2017) In the Cham Gardalan basin, Eylamra 9.6, Alipour et al. (2016) in the Iver basin, 2.95 and Divasalari et al. (2013) in Solqan Qom, Nasiri et al. (2021) in Bakhtar, Qochan and Ghafari et al. (2015) in Cannes, the amount of sediment erosion They calculated 19.85, 4.5-84.2, 4.6-4.17 and 72.78 tons per hectare respectively. The basin of Kal Ismail Dara has an elongated shape

Wetlands are mainly adjacent to settlements and there is a two-way relationship between wetlands and the stability of marginal rural settlements. As much as the stability of rural communities depends on the sustainability of wetlands. Anzali Wetland is also one of the important tourist attractions of Gilan and the livelihood of the inhabitants of the wetland in terms of agriculture, fishing and supply of raw materials for handicrafts depends on its life. The catchment area of the wetland has an area of about 374 thousand hectares and the study area in this study is 15 villages on the edge of the wetland. Also, Anzali Wetland is one of the important centers of tourist attraction in Gilan. Economic stability analysis in rural communities around the wetland is based on the model of the village ecosystem and the purpose of this study. The village has been examined. The analysis of economic stability in rural communities on the edge of the wetland is based on the model of the village ecosystem and the purpose of this study. The present study is applied in terms of purpose and based on a descriptive-analytical method. Indicators were developed to determine the degree of sustainability of the villages. Finally, the data were analyzed analytically and comparatively. Based on field studies conducted in the villages, it was found that the majority of the active population of these villages are engaged in agricultural activities affected by agricultural lands. Considering that most of the rice cultivation

During the last years, following an increase in damages due to occurrence of landslides, human has decided to reduce such losses. Therefore, identifying regions susceptible to landslide and classifying them can partly help man to prevent from happening above phenomena. The current study aims to demonstrate factors contributing to occurrence of landslide in Candrigh Chay basin and then, flattening the basin regarding risks related to landslide event using one methods, Network Analysis Process. In this direction, as respects to basin morphology and also, findings of past researches , ten factors involved in occurring landslides in Candrigh Chay Basin were recognized and used : lithology , land use , rainfall , slope , slope aspect , road slide , sluice power index (SPI), sediment transfer index (STI).Network Analysis Process(ANP) Method was implemented to score and classify factors and  scales. Was carried out in order to measure classes of each parameter. The final map showed that the basin has 4 classes considering landslide. Findings reveal flats with low risk and flats with high risk have the least area in Candrigh Chay basin. On the other hand, flats with medium risk and high risk allocate the most area of basin for themself. Comparing slid surfaces with flats facing risks indicates regions located at high and average risk class possess most areas of slide surfaces so that a flat involving very high risk  and a flat with high risk devote 35 percent (79km²) and 32/6 (72km²) of landslides for themselves, respectively. In other words, more than 77 percent of landslides conform to flats covering very high and average risk. Moreover, petrology, slope, and, sluice slide were identified as the most effective agents in occurring land_slides. One models, Network Analysis Process (ANP) were utilized through this project

In Iran, which is a water-scarce country, planning is centralized and large-scale based on political-contractual boundaries. This has led to the degradation of the functional levels of the land and has caused numerous problems. Therefore, finding the optimal geographical context and efficient planning unit for the lower levels has always been the focus of planning scholars including geographers. The purpose of this study is to propose a basis for the political division of space for spatial planning and transition from centralized national-sectoral planning. This research is theoretical and in terms of nature and method, it is a deep descriptive-analytical case study. The present study, with a combined approach (analogy and deduction), firstly, by analogy and logical analysis, evaluates the status quo using documentary study. Then, it studies inductively the Karkheh catchment as a spatial domain of research in order to explain an alternative pattern. Analyzes were performed using Arc GIS software. New theories of development, especially the theory of bio-regionalism, emphasize ecological factors in the designation of biological areas. The ecological implications of these theories have been specifically introduced through catchments and their relationship to communities. The findings of the study identified the catchment as a bioregional boundary and considered the Karkheh catchment to be compatible with the Lak spoken area. The results show that Karkheh catchment can be a suitable spatial planning unit for the study area. The relative homogeneity in the structure of natural-ecological, social, cultural, economic, and spatial convergence within the territory as well as the adaptation of rural and urban settle

In recent years downscaling models are increasingly used in predicting climate variables. One of the application of the downscaling general circulation model (GCM) is used to predict the hydrological watershed. In this study, using rainfall data during the observed period (1961-1990), in the first step using SDSM model and data HadCM3 scenario A2, were simulated runoff in Khansar watershed located in southern Yazd previence. Then anticipated rainfall-runoff Khansar basin in 30-year period (2011-2040). After downscaling and forecast rainfall Meshkan station, the nearest meteorological stations in Band-paein basin, implemented rainfall and runoff forecasting Band-paein Station at the same period. The results show that, despite the fact that rainfall in the forecast period is 6% higher than the normal period, the rate of runoff from 19.3 million cubic meters during the 30 year period (normal climate) of 1971-2000 to 17.4 million cubic meters The period will be from 2011 to 2040, which is about 9% lower. The effects of changes in the distribution of rainfall means an important issue in the future, climate change is one of consequences. Therefore, it need to planning and management of water resources, particularly for the study in arid areas.

Several factors affect the rate of annual sediment basin. Components of the basin and drainage network have a very important role in river sedimentation rate. This study calculated morphometric parameters of basin such as: area (A), the perimeter (P), the ratio of a circle (Re), elongation ratio (Rf), mean height (H), mean slope (S), drainage density (Dd), drainage frequency (Df) along the channels (BL), fault density (DF), the percentage of Quaternary formations (PQ), bifurcation ratio (Rb), the number of hierarchical anomaly (Ha), hierarchical anomaly index (Δ a), density hierarchical anomaly (ga) in the 17 Basins in the North east of Iran. Then, the annual sedimentation rate of the basins (t / y per square kilometer) and the annual sediment suspended (ss) of each station were determined by multivariate statistical methods and using discharge and sediment data Khorasan Razavi regional water authority. Then the annual sedimentation rate of the basins (tons per year per square kilometer) was calculated. Finally, linear regression and correlation coefficients were evaluated among the components of the basin and the rate of annual sediment. The results of the research show that the highest annual sedimentation rates are in the Torghabeh and Radekan basins, respectively, with 1533.1, 1437.1 tons / km2. The lowest annual sedimentation rate is in Yangaje and Bar watersheds with 224.1, 462.3tons / km2 per year. According to the calculations of P, Ga, A, L, Ha, Δa, and Re indexes, with the values of 0.301, 0.249 0.232 and 0.230, respectively, have the most correlation with the annual sedimentation rate. In addition, there is a relatively weak correlation between PQ, S, Dd, Rb and annual sedimentation rates. In the case of other parameters, there is no correlation with the annual rate of sedimentation of the basins. The analysis indicated that annual precipitation rates are not entirely affected by morphometric factors in research basins. Factors such as intensity and duration of precipitation, soil type, land use and vegetation in estimating the annual sedimentation rate of the basins should be considered to achieve more accurate results.

Sustainable Sustainability assessment using IUCN is a technical tool to understand and measure sustainable development. This technique allows comparing the existing conditions of the region with its ideal state, namely, full human development and a healthy and productive ecosystem. This approach simultaneously examines ecosystem sustainability and human sustainability. In this study, Dorook basin sustainability was assessed using IUCN method by 7 criteria and 17 indicators in the human section and 8 criteria and 18 indicators in the ecosystem section. In this study, Dorook basin was divided into two sub-basin called Aghcheshmeh and Ghaleghafeh. The measurements were done in each sub-basin separately. The results of analysis indicated that relation to sustainable human criterion and indicators, land use changes is the lowest score criterion. The criterion is moderate in education, skill and poverty in both sub-basins. By increasing youth employment, it can reduce dependency and improve the standard of poverty. The food security and nutrition standards are acceptable in both sub-basin. The criterion of justice and equality is poor and acceptable conditions in sub-basins of Aghcheshmeh and Ghaleghafeh, respectively. The final score of the Ghaleghafeh sub-basin is equal to 44 and the final score of the Aghcheshmeh sub-basin is 61. Generally the scores of both sub-basins indicate that sub-basins are in the medium range in terms of sustainability. The final score of the Dorook basin is 52, which is within the medium range. Investigating the indices showed that the area in terms of land use and erosion in comparison with other indicators is in a very bad situation and this index has the most negative effect in basin.
Extended Abstract
1- According to FAO studies, about twenty million hectares of forest have been planted from 1995 to 1980 in developed countries, while two hundred million hectares of forest has been reduced in developing countries during this period.
In contrast to other approaches, the IUCN method of Sustainability Assessment gives equal treatment to people and the ecosystem. It involves stakeholders in determining for themselves what sustainability means in their context. It uses, as its framework, a hierarchy of elements and objectives to translate the concept of sustainable development into concrete targets and measurable indicators. Thus making clear to all those involved what features everyone agrees contribute to measuring sustainability. The elements are designed to be tailored to local conditions and needs. The IUCN Sustainability Assessment Method is a user-focused process and thus can be used at international, regional, national, district or local scales. The IUCN Sustainability Assessment Method, in its full version, describes a process with seven stages. It is presented as a cycle because the assessment process is designed to allow updates that can show changes over time.
According to the IUCN method widely used in different countries, in this study a set of measurements was determined according to the IUCN sustainability assessment method and organized based on issues and concerns related to forests.
2- Dorook Catchment is the political section of Golestan province, Minoodasht city, and central section. There are 13 Villages in the basin. This catchment is the most important in Golestan province because of deforestation and loss of forest.
A full Sustainability Assessment follows all seven stages in the assessment cycle. The general purpose of such assessment is to engage in reflection about sustainability, collect data for indicators, combine indicators and undertake analysis based on the indicators and use the data and process to assess priorities for action.
Many indicator models use the Pressure-State-(Impact)-Response model to identify and organize indicators. Pressure three key types of indicators one covering the element's state, one showing pressures and one showing the way society is responding to the problem. Sustainability assessment primarily uses 'state' indicators, because in most cases, they are the most reliable measure of an element. Pressure indicators are useful in instances where measuring the pressure that one area is having on another is preferable – particularly cross border pollution, long-range transport of air or water pollutants and impacts on the global atmosphere. The use of response indicators is not encouraged in sustainability assessments, as it is often hard to link the state of an element with the responses society is undertaking to alleviate the problem.
Three main components of ecosystems have been used including forests; water environment and climate were a total of 18 indicators and eight criteria. 7 criteria and 17 indicators were measured in human wellbeing.
3- The results of analysis indicated that the relation to sustainable human criterion and indicators, land use changes is the lowest score criterion. The scores of Ghaleghafi and Aghcheshme are 30 and 0 respectively, indicating that the rate of land degradation is high. Changing of forest to agricultural land is the most important role in reducing stability in Dorook watershed.
Education and skills criterion is medium in two sub-basin. Poverty criterion is medium in both sub-basin. In order to improve the conditions situation in the farms provide area youth by increasing employment rates, reducing dependency ratio. Food supply and food safety is in acceptable condition in both sub-basin. Justice and equality Criteria is in poor condition and acceptable in Aqcheshme and Ghaleghafi respectively.
Score of soil conservation criteria in Aghcheshme sub-basin is 0 and in Ghaleghafi sub-basin is 28 that seems reasonable according to land use changes made in the following basins. Water status map shows that both sub-basin in good condition and is acceptable and In general, water ecosystem are in a much better situation than forest and human ecosystems.
Weather and climate criteria in Aghcheshme sub-basins is in acceptable condition and in Ghaleghafi sub-basins is in the middle.
4- Sustainable development indicators are expressing such interaction model between society and the environment. In general, Dorook basin ecosystems in Ghaleghafi sub-basins socio-economic performance and water criteria is in stable condition and in Aghcheshme sub-basins conservation and soil conservation are in unstable condition. The entire watershed is in the middle range and change conditions to improve sustainability need to promote appropriate policies.

Areas of the earth, which are covered by limestone formations and dissolved by water flows, are called karst areas. Due to the fact that karst forms play an important role in water resources, tourism and development activities, their study is considered a necessity. Darparchin basin is one of the sub-basins of the Bidvaz River in northeastern of Iran, that due to the calcareous formations , various forms of karstic has formed in it. In this article, it is tried to study and identify the factors affecting on karst production in this basin, in order to control these factors in development activities and basin planning. In order to achieve this goal, after specifying the boundary of this basin, by using the library method , field studies, topographic maps, geological maps and satellite images , the karsts of this basin were identified and studied. Early studies have suggested that in the formation of karsts in this basin, factors such as lithology, hydrology, tectonic activity, and climate have played a greater role. After studying these factors, lithology was found to be effective in shaping the basin through dissolution, porosity, fracture and type of rocks coating. In terms of hydrology, the high water dissolution capacity of this basin and the lack of conformity of its sub branches with the geological structure played a role in this field. Also, the ranking of this basin revealed that the largest and most diverse forms of karst in the basin formed in its high ranks. In terms of tectonics, the three sides of the basin are surrounded by faults, the fault of Hame Ghaji in the north and Ardaghan fault in the south of the basin has facilitated the process of forming the groove and hammer carneys in this basin. Also, the force exerted by faults has damaged the rocks and provided the situation to dissolve them by water penetration and created karstic forms. Regarding the effects of climate, it has been found that among the climate parameters, the temperature and precipitation had a more important role. Temperature through different forms of weathering and precipitation through its influence on the formation of honeydew carneys, rainfall carneys and vegetation cover has played their role in this respect

Land management leading to sustainable development requires reliable and update data on land cover/use and mapping its changes at various spatial and temporal scales. In this aspect, water resources management also needs to assess land use and its changes across the basin to maintain water quality for a variety of uses. Thus, the primary goal of this study is to evaluate the effectiveness of various spectral-based supervised classification methods of Operational Land Imager (OLI) data for mapping land use across the Kan and Karaj Rivers basin. At the Anderson Level 1 and 2, the basin’s land use was mapped in five and nine classes, respectively using a broad range of different supervised classification methods, including Parallelepiped, Minimum Distance, Mahalanobis Distance, Maximum Likelihood, Spectral Angle, Binary Encoding, Spectral Information Divergence, Neural Net and Support Vector Machine. All classification methods were verified using the Google Earth images and accurate ground control points, in which the Maximum Likelihood method of both levels with Kappa coefficient of 0.77 and 0.76 and overall accuracy of 84.94 and 80.70 percent, identified as the optimum method to map the land use at the local and regional scales respectively. In addition, following the named method, the Neural Net, Support Vector Machine and the Mahalanobis Distance methods also showed acceptable accuracy indicating that like the choice of classification method, precision in procedures and accuracy assessment of land use classification map is very important and could affect the results.

The aim of this research is to investigate the correlation of greenhouse gases-carbon dioxide and methane - as elements of global warming on the Kashkan River’s discharge values. The data used in this study consist of seasonal and annual data of greenhouse gases and Kashkan River’s debby between 1984 to 2010, using Pearson correlation coefficient, linear regression and Man-Kendal graphic method. The results show a strong negative correlation between the rate of global warming and the Kashkan River. This process has been intensified over the last 15 years, and from 1995 onwards the Kashkan River’s discharge has faced a sharp decline. Study of the changes in the annual runoff discharge strongly indicates an inverse relationship between global warming and Kashkan River flow; so that 2/55 of the annual discharge decrease in Kashkan River’s basin is the result of the global warming. Global warming has also affected the seasonal scale of Kashkan River’s discharge. The results show a reduction of discharge by 7/47 in summer, 6/45 in autumn, 38 percent in spring and 1/33 percent in winter. Finally, the use of exponential regression model predicted that if the global warming continues with the same scale, the average annual flow of the river will be below 10 cubic meters per second in the next 30 years, i.e. is till 2040.

1- Introduction To investigate climate change impact on different sources in the future periods, at first climatic parameters should be simulated under climate change effect. Various methods simulate the parameters, but the most valid method is application of AOGCM (Atmosphere-Ocean General Circulation Model). A general circulation model is a three-dimension mathematical model of the general circulation of a planetary atmosphere or ocean and based on the Navier–Stokes equations on a rotating sphere with thermodynamic terms for various energy sources (radiation, latent heat). These equations are the basis for complex computer programs commonly used for simulating the atmosphere or ocean of the Earth. Atmospheric and oceanic GCMs (AGCM and OGCM) are key components of global climate models along with sea ice and land-surface components. AOGCMs are widely applied for weather forecasting, understanding the climate, and projecting climate change. Estimates of global warming are generally based on the application of general circulation models, which attempt to predict the impact of increased atmospheric CO2 concentrations on the weather variables. In this study, it is tried to investigate the effect of climate change on five climatic parameters including maximum, minimum, and average temperatures, rainfall and the relative humidity in Tehran-Karaj sub-basin using HadCM3 model under A2 emission scenario for three future periods containing 2010-2039, 2040-2069 and 2070-2099 as near, middle and far future periods, respectively. The years 1976-2005 is considered as the base period. 2- Theoretical framework Atmospheric carbon dioxide levels have been recorded continual increases since the 1950s, a phenomenon that may significantly alter the global and local climate characteristics, such as temperature and available water resources. IPCC (Intergovernmental Panel on Climate Change) predicted that the world mean temperature will be increased up to 1°C by the year 2050 and up to 3°C by the end of the next century. AOGCMs are the most suitable tools for studying the climate change phenomenon,; however, regarding large-scale spatial resolution of these models, regional scale is not possible. In other words, the models simulate climatic parameters in large scale. Whereas comparing the output for historical periods with observed data shows differences. Therefore, various methods of downscaling are created. 3- Methodology In this paper, IDW method is presented with eight grids and climate change scenarios are achieved using change factor method. Making time series of climate scenario for the future periods, the change range and its averages in different periods were calculated. In the first step, the monthly mentioned climatic parameters for the base and future periods for main box and the surrounding eight boxes were extracted from IPCC website. Then spatial and time downscaling processes were carried out using IDW and change factor methods, respectively. 4- Discussion It is predicted that the minimum temperature will increase up to 0.17-1.65, 1.38-3.61 and 2.28-6.4 degrees Celsius for the three periods, respectively. These values for maximum temperature are 0.43-2.23, 1.79-4.16 and 3.23-7.59 and they are 0.63-2, 1.74-3.92 and 2.93-7.02 for average temperature. Taking rainfall into consideration, all months except November and January have decreasing rainfall percentage which is more significant in warm months. Relative humidity has also decreased in all periods and months however, it is more severe in warm months than cold months. Most changes are related to 2070-2099 period. Rainfall moving average has a decreasing trend when approaching the future period indicating increasing dry spells compared to the base period. 5- Conclusion and Suggestions In all periods, the three parameters relating to temperature will increase with the far future period showing maximum differences. The reverse of this situation will happen for relative humidity parameter; especially it will have high severity in warm months. The changes for rainfall are not significant but a decreasing trend is predictable. Finally, the impact of climate change on dry and wet spells is assessed using a 5-year moving average manner. The results verify more effects approaching the far future period. The results also indicate increasing temperature parameters and decreasing relative humidity in the future periods in comparison to the base. For example it is predicted that the average temperature parameter will have increased between 2.9 to 7 degrees Celsius up to the end of future period. Moreover, a gradual decrease in rainfall approaching the far future period increases dry spells. The estimation of long period changes in climatic and hydrological variables requires a more careful management of water resources, taking into consideration the consequences of climate change, especially for the regions having arid and semi-arid climate like the studied region.

Water resources and their appropriate exploitation are among important and critical issues in deserts and semi-desert areas. Qom has always faced water shortage and Panzdah-e Khordad Dam was built between Qom and Delijan to resolve the problem. This dam faces lots of sedimentation. This inevitably results in dam filling and shortening of its useful life. Therefore, studying erodibility potential in upstream basin is essential. The present study primarily seeks to divide the basin into different zones based on formations sensitivity to erosion and their role in the creation of new sediments. To reach this goal, boundaries of Panzdah-e Khordad Dam basin were identified using 1:50000 topographic maps. Then, it was carefully implemented on 1:50000 geological map of Qom-Delijan. After producing geological maps, channels, precipitation, geomorphology, slope and soil permeability were digitalized. Then, erodibility intensity in Panzdah-e Khordad Dam basin was produced using GIS, layer scoring and integrating techniques (Overlay index). Results indicate that sensitive units with severe erosion cover a vast area of central basin and a large volume of soil in this semi-desert area is sedimenting in Panzdah-e Khordad Dam reservoir. Finally, the article proposes some logical solutions to control and reduce erodibility of soil.

Ahvaz Karoon River, 18 meters above sea level, and is spread on both sides. The flat land of the river city in the rainy season, at the time of flooding of residential areas causes enormous human and financial losses. In this paper, formulas, coefficients basin and topographic maps as well as aerial photographs and geological materials and set tables and charts related to the area of quantitative methods were used. The result showed that the correlation coefficient between the two variables catchment basin area and elevation, of the type that was partially reversed by increasing the relative area decreases with increasing height reduction variable and it is the cumulative relative area. Due to the gentle slope of the Karoon River in Ahvaz aging process is caused by deposition of material and forming islands.