Leila Biabani; Hassan Khosravi; Gholamreza Zehtabian; Esmaeil Heydari Alamdarloo; Behzad Raygani
Abstract
Soil erosion modeling is becoming more significant in the development and implementation of soil management and conservation policies. For a better understanding of the geographical distribution of soil erosion, spatial-based models of soil erosion are required. Wind erosion is a significant cause of ...
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Soil erosion modeling is becoming more significant in the development and implementation of soil management and conservation policies. For a better understanding of the geographical distribution of soil erosion, spatial-based models of soil erosion are required. Wind erosion is a significant cause of land degradation and desertification, negatively impacting the economy, society, and environment, particularly in arid and semi-arid regions. To control and reduce the effects of wind erosion, the first step is to identify sensitive areas. The aim of this research is to identify areas susceptible to wind erosion using the ILSWE model in the watershed regions of the Dar Anjir-Saghand Desert, Namak Lake, and Sefidrud. This model has been calculated by combining five erosion indices, including climate erosivity, soil erodibility, surface crust, vegetation cover, and surface roughness. The model's results indicate that climatic factors, such as precipitation, evaporation, and wind, vary across these regions. These factors play a significant role in determining areas that are susceptible to wind erosion. It is noted that other factors, including differences in vegetation cover, soil characteristics, topographic conditions, and the extent of bare lands, salt marshes, sandy dunes, low-density pastures, and rainfed agricultural lands, have also influenced the results of this. In general, this study presents a new method for identifying wind erosion-sensitive areas in various climates. This method can prioritize regions that require further research and corrective measures.
Gholm Reaza Rahi; A Kaviyan; K Soleimani; H Pourghasemi
Abstract
Creating a gully is a reaction to the geomorphologic conditions, this type of erosion extends over a wide range of environments, and the threshold of topography is related to the slope and drainage level and Controls the position and expansion of gullies in different uses. The slop-area equation as a ...
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Creating a gully is a reaction to the geomorphologic conditions, this type of erosion extends over a wide range of environments, and the threshold of topography is related to the slope and drainage level and Controls the position and expansion of gullies in different uses. The slop-area equation as a relationship between the slope and the upstream area of the watershed in any area will in part help predict gully erosion. The above relationship has been influenced by several factors including environmental conditions (climate, lithology, soil type), the type of land use, and the type of effective mechanisms for the creation and expansion of the gully (surface flow, sub-surface flow, dissolation, and piping), and the type of method used for extraction of slope - area is located. And this is the simplest formula used by two parameters to predict gully erosion. The results show that the value of the relationship between -0.233 and -0.205 was obtained. The equation for agricultural use was equal to Y = 5.7426X-0.205and for the pasture use equal to Y = 10.653X-0.233. In this equation, the power can be close but the coefficient of the equation is different. Gully erosion of the whole hinterland (farmland, agriculture) is expanding. The threshold of topography indicates a negative relationship between land area and slop in different kind of agricultural and rangeland. By reducing the slope, more area is needed for the development and expansion of the gully, and most of the gully is due to surface runoff.
Sayyed Alireza Hosseini; Hassan Khosravi; Hamid Gholami; Yahya Esmaeilpour; Artemi Cerda
Abstract
In this study, land use change trend in coastal areas of south of Iran, including Sistan Baluchestan, Hormozgan, Bushehr were studied during 31 years (1988-2019). Landsat satellite images including TM, ETM +, OLI were used for this purpose. The maximum likelihood method was also used to classify satellite ...
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In this study, land use change trend in coastal areas of south of Iran, including Sistan Baluchestan, Hormozgan, Bushehr were studied during 31 years (1988-2019). Landsat satellite images including TM, ETM +, OLI were used for this purpose. The maximum likelihood method was also used to classify satellite images. Vegetation indices (SAVI) and salinity index (SI1) were used to influence land use classes on land degradation and desertification. The results of land use change trend showed that Changes in land use classes of man-made areas and saline lands as the most dynamic land use classes followed an increasing trend of 2.72% and 1.14%, respectively. The results of multivariate regression analysis showed that three vegetation, saline and man-made variables, and four vegetation, saline, man-made and sandy areas explain 22.3% and 37.8% of the dependent variables of vegetation and salinity indices, respectively. Therefore, in more than 60% of changes, other environmental variables are affected. Hence, with respect to the results of land use area and regression analysis and the mean trend of SAVI and SI1 changes, where vegetation and SAVI classes show decreasing trend and saline land and SI1 classes have increasing trend, it can be concluded that land use changes is phenomena that changes ecosystem services with almost irreversible impacts. This will have nothing to do with disturbing the ecosystem balance and intensifying land degradation in coastal areas.
Khosro Shahbazi; Ali Salagegheh; Mohammad Jaafari; Mohammad Khosroshahi
Abstract
Gully erosion affects land degradation, particularly in the semiarid reigns. Topographic thresholds are strongly affected by landuse change and destroy of vegetation. The objective of this study was to evaluate topographic thresholds of gully erosion in different landuse including agriculture (AG), fair ...
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Gully erosion affects land degradation, particularly in the semiarid reigns. Topographic thresholds are strongly affected by landuse change and destroy of vegetation. The objective of this study was to evaluate topographic thresholds of gully erosion in different landuse including agriculture (AG), fair rangeland (FR) and weak rangeland (WR) which carried out in Ghasreshirin, Kermanshah, Iran. The topographical parameters were measured in the field and relationship between gully catchment area and slope was analyzed for each landuse. The results revealed that some main topographic characteristics mainly cross-section, width, depth and gully branches length in the FR was significantly lower than in the AG and WR (p<0.05). Furthermore, analysis of gully threshold based on catchment area-slope showed that the critical area for gully formation in AG, FR and WR was 1300, 1689 and 1233 m2, respectively which was significantly lower in FR reducing by vegetation cover. The respective slope threshed was 1, 3 and 3 percent in AG, FR and WR. However, the affected area by gully erosion in AG, FR and WR was 12.4, 14.1 and 21%, respectively. The gully in the agricultural land was more dipper compared with other land uses. The volume of gully channels in FR was 3.4 and 2.2 times less than AG and WR, respectively. It is concluded that rangeland degradation and thereby removing vegetation attribute to severe gully erosion and consequently environmental problems such as soil carbon dioxide emission.
Meisam Alizadeh; Behrouz Malekpour; Hamid Arya; Samaneh Verdian
Abstract
In near future, earth's temperature fluctuation will be considerable. This phenomenon is the result of concentration of greenhouse gases in the earth's atmosphere. Therefore, it seems necessary to prevent of its happening. The biological methods including plant biomass and phytomass and soil are proposed ...
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In near future, earth's temperature fluctuation will be considerable. This phenomenon is the result of concentration of greenhouse gases in the earth's atmosphere. Therefore, it seems necessary to prevent of its happening. The biological methods including plant biomass and phytomass and soil are proposed as the best and practical ways. Watersheds are the greatest physical and geomorphologic units which are contain two important factors soils and plants. So that the current trend of climate change is a double challenge and threat to the sustainability of watersheds. Soil and plant carbon sequestration are economic feasibility act and adaptable to their environment which they can be provided with land management ways by kind of scientific method. Therefore by scientific method of landuse planning, this research has been carried by aims of study of kind landuse on soil carbon sequestration and determines best of landuse in Vaz watershed of Nour city. Soil sampling was carried at the selected different landuse area at two depths of 0-15 and 15-30 centimeters and after analyzing soil organic matters were calculated. Results showed that forests are rich at both depths. But on the farms and orchards, rangelands and rural areas have had least amounts of organic material. Therefore Vaz watershed has 741666 tons of reserve of carbon.
Sina NabiZadeh; Ataollah Ebrahimi; Masoumeh Aghababaei; Iraj Rahimi
Abstract
The land use of the watersheds is one of the most affected and highly vulnerable due to developmental process which effect on the other variables such as the hydrological function. The purpose of this research is to monitor land use changes in the past and to investigate predictability of its future ...
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The land use of the watersheds is one of the most affected and highly vulnerable due to developmental process which effect on the other variables such as the hydrological function. The purpose of this research is to monitor land use changes in the past and to investigate predictability of its future using Land Change Modeler (LCM) in the watershed of Farsan County of Chaharmahal-va-Bakhtiari province. For this purpose, the Landsat-5 TM images of 1986 and 2009 as well as the Landsat-8 OLI images of 2017 were analyzed. Land covers including residential areas, agricultural land, dryland farming, rangelands, rocks, water bodies, bare-land and snow were classified for the three periods. The prediction of land cover of 2017 was done using the LCM model based on Artificial Neural Network and Markov chain analysis after assessing model’s accuracy based on Kappa index. The land cover of 2027 was also predicted using a change probability table extracted from occurred changes from 1986-2017. The results show that the rangeland decreased by 4379-ha in the years 1986 to 2017, but the agricultural land increased by 1922-ha. This study proved that the LCM could accurately forecast future changes (85% overall accuracy). An increase of 149-ha of residential area and 100-ha decrease of rangelands in the study area was predicted for 2027. Therefore, while emphasizing the conservation of rangelands, it is necessary to study and use this technique to predict changes, its causes, as well as the consequences of land use changes at the broader scales.
Azam Tayebi; Mohammad Faraji; Shahram Yousefi khanghah
Abstract
This study with purpose analysis the effect of Maroun՚ dam construction on land use changes using Landsat satellite images taken. For this study two The Landsat satellite image of in 16-year period (1999-2014) and maps Topography was used by applying geometric and atmospheric correction. Then using ...
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This study with purpose analysis the effect of Maroun՚ dam construction on land use changes using Landsat satellite images taken. For this study two The Landsat satellite image of in 16-year period (1999-2014) and maps Topography was used by applying geometric and atmospheric correction. Then using the software ENVI maximum likelihood supervised classification land use map to 7 ClassesRiver, Rangeland , Agriculture, Woodlands and gardens, villages, Palms and Bayer, respectively, with an Kappa coffecient of 75% and 86% were classified . Results classified maps years (1999- 2014) showed that during this period due to dam construction, Agricultural lands, Woodlands and gardens, Village, Palms, Rangeland , increased area and River and Bayer levels was reduced. So by comparing the studing periods of use map, the map changes, represents the maximum land use changes, Agricultural conversion to Rangeland is the equivalent 2875/270 hectares, the lowest changed into Bayer to the village with an area of 0/19 hectares. Overall findings showed that the establishment of Maroon Dam improves the user in the region. Therefore, investigation account the cost of building the dam, construction of the dam has been a lot of positive effects, and in the long run lead to positive economic growth in the region . Changes in cross-river bed also shows that in 1999 the average width bed, 106/10 meters but in 2014 115/89meters and an average of about 7/79 Kilometers been reached. These changes represent a reduction of width and curvature of the river was in 2014.
sedigheh mohamadi
Abstract
This research was done to investigate the effects of change in land use on chemical soil properties in Jamalabad region of Baft county of Kerman province. The experiment was conducted in six sites with the same ecological condition as non grazed site (NG) for 10 years, a moderately grazed site ...
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This research was done to investigate the effects of change in land use on chemical soil properties in Jamalabad region of Baft county of Kerman province. The experiment was conducted in six sites with the same ecological condition as non grazed site (NG) for 10 years, a moderately grazed site (MG) and a heavily grazed site (HG), a dry farming site of barley and wheat (D), a long time fallow site for 5 years (F) and a plowed Glycyrrhiza glabra site (Gl T). Soil samples were collected from two soil horizons (0-15 and 15-30 centimeters) based on a randomized complete blocked design with six replications from each horizon in 2013. Samples were sent to laboratory for soil chemical properties as organic carbon, total nitrogen, available phosphorus, available potassium, PH and electrical conductivity. The results indicated that Land use change significantly decreased organic carbon, potassium content, available phosphorous and nitrogen content as 58.2, 21, 23.5 and 71 percent in dry farming site and 58, 17.3, 19 and 60 percent in plowed Glycyrrhiza glabra site compared to non grazed site. A decreasing trend of organic carbon was seen in moderately and heavily grazed sites in comparison to non grazed site as 42 and 56 percent, respectively. Available potassium of moderately and non grazed sites were maximum. Total nitrogen of soil in moderately and heavily grazed sites was decreased in comparison to non grazed site as 0.035 and 0.04 percent. PH of soil was significantly changed only between non grazed and plowed Glycyrrhiza glabra site (Gl T). Electrical conductivity of soil was increased in dry farming site (165 percent) and heavily grazed site (140 percent) in comparison to non grazed site. According to negative effects of land use change on soil quality and remaining this harmful effect after release of dry farming lands, our recommendation to natural resources offices are programs preventing rangeland occupying, minimizing giving off rangelands, rehabilitation of released dry farming by pioneer plants and improvement of soil qualities in root collection designs of Glycyrrhiza glabra.
jalil farzadmehr; payam Ebrahimi; mehdi Eslah
Abstract
Predicting the hydraulic behavior of the river and flood zone determination to reduce probable damages, are among measures which in recent years has been the attention of many researchers. Mazandaran province, especially the city of Neka, each year is affected by the floods with different return periods; ...
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Predicting the hydraulic behavior of the river and flood zone determination to reduce probable damages, are among measures which in recent years has been the attention of many researchers. Mazandaran province, especially the city of Neka, each year is affected by the floods with different return periods; therefore, land use changes and the role of these changes were evaluated in flood zones. In this study, with integration of river system analysis, GIS and Remote Sensing, images of the years 2000 and 2011 were processed and Neka river hydrological response was determined in specified return periods. The results showed Pearson type 3 distribution, roughness coefficient determined by Cowan’s method and IRS image in comparison with ETM+ image, have good accuracy. With determining land use changes in the years 2000 and 2011, the area of each land use class was specified in GIS, and then attached to the HEC-GeoRAS. By determining two flood maps with return periods of 2 to 200 years, the difference of each layer was determined. Many studies determined land use only; but according to the results of this study and impact of the 14.60-percent increase in flood area, the role of changes is noticeable. This study suggests that in the flood zone determination, addition to land use designation, we should pay special attention to its changes and hydrological response of the total area to these changes, and its role in the flood zones. The simulation of river bed and flood zone in forest areas depends on land use, and deforestation in this river is one of the most important factors.
Saeide Heydari; Ali Akbar Mehrabi; Mohsen Mohseni Saravi; Sakine Saedi
Abstract
The concept of land use transition highlights that land use change is non-linear and is associated with other societal and biophysical system changes. Changes in human systems has resulted in changes in the natural system such as changes in land use. Land use change causes not only environmental factors ...
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The concept of land use transition highlights that land use change is non-linear and is associated with other societal and biophysical system changes. Changes in human systems has resulted in changes in the natural system such as changes in land use. Land use change causes not only environmental factors like geography and topography are important, but social factors examined such as population growth or decline as well as changes in land use is a mix of economic, social and physical problems. Human societies and their environment, such as feedback, change, uncertainty and adaptation of interaction is social and biophysical changes associated with land use change is non-linear. Changes in human systems with natural systems, such as changes in land use will change. Landuse change causes not only environmental factors like geography and topography should not be involved in social factors such as population growth or decline as well as changes in land use is a mix of economic, social and physical problems. Migration impacts on economic activity seriously and may be initiate land use changes. this study was conducted To analyze the effects of Taleghan dam construction on developments in a human population and land use change analysis in a natural system,In general it can be suggested that in the years before the Taleghan dam, the area's population has been decreasing And pasture lands in the lower level of the population is in decline, but after the dam construction the lands become values in the area and seasonal population increases.
Mehdi Vatakhah; Mohsen Mohsenisaravi; Hasan Ahmadi
Abstract
Land use optimization is one of the suitable methods for soil conservation. The present research with objective of land use optimization for soil erosion minimization and pure income maximization was conducted in the part of Taleghan Watershed which comprises 80427.23 ha in area. To achieve this propose, ...
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Land use optimization is one of the suitable methods for soil conservation. The present research with objective of land use optimization for soil erosion minimization and pure income maximization was conducted in the part of Taleghan Watershed which comprises 80427.23 ha in area. To achieve this propose, area, erosion rate and net income value of each land uses according to requiring standards of each land uses area was extracted. Then, limitations and two objective functions were determined and optimization problem was solved by using ADBASE software. The results revealed that the optimization decrease 6.99 percent of erosion rate(6.28 ton/ha/year to 5.84 ton/ha/year) and 4.65 percent of pure income(118174.38 to 112681.02 million Rials). Also, the results proposed that drylands farming are changed to garden and orchard and rangelands.
Aliakbar Nazari Samani; Hesam Heravi; Mehdi Panahi; Masoud Jafari Shalamzari
Abstract
Natural landscape alternation is a problem that has been under debate for a long time. Landutilization techniques like agriculture, forest and rangelands, residential and urban are amonginfluential criteria affecting erosion severity and sediment yield in a given region. In this respect,land management ...
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Natural landscape alternation is a problem that has been under debate for a long time. Landutilization techniques like agriculture, forest and rangelands, residential and urban are amonginfluential criteria affecting erosion severity and sediment yield in a given region. In this respect,land management is a promising option to mitigate it. Thus, acquaintance with quantitative soilerosion owing to land-use changes is of great importance for estimating disadvantages andlatent and intangible symptoms of erosion. Strategic planning for sustainable developmentcould be benefited from such knowledge. The current research considered a statistical periodfrom 1970 to 2004. This period was sub-divided into two separate periods from 1970 to 1987and from 1987 to 2004. During these periods, statistics relating to sedimentation, climatology(precipitation) and hydrology were analyzed. Results revealed that the sediment reduction inthese two periods under similar rainfall would be as a result of an increase in abandoned areas.
Fazel Amiri; Hassan Yeganeh
Abstract
فرآیند ارزیابی پوشش گیاهی به وسیلة تصاویر ماهوارهای نیازمند استفاده از شاخصهای گیاهی است. شاخص گیاهی بطور گستردهای برای ارزیابی و پایش تغییرهای بو شناختی (اکولوژیک) ...
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فرآیند ارزیابی پوشش گیاهی به وسیلة تصاویر ماهوارهای نیازمند استفاده از شاخصهای گیاهی است. شاخص گیاهی بطور گستردهای برای ارزیابی و پایش تغییرهای بو شناختی (اکولوژیک) مانند پوشش گیاهی، بیوماس پوشش سطح خاک و شاخص سطح برگ استفاده میشود. اهداف این مطالعه شامل بررسی قابلیت دادههای ASTER به منظور برآورد پوشش گیاهی در حوزه آبخیز قره آقاچ و همچنین انتخاب شاخصهای گیاهی مناسب در تهیه نقشه پوشش گیاهی منطقه، میباشد. پیشپردازشهای مختلف شامل تصحیح هندسی با استفاده از تصاویر موجود مربوط اردیبهشت 1387 با RMSE حدود 5/0 پیکسل انجام شد و تصحیحات اتمسفری و توپوگرافی به ترتیب به کمک روش تفریق عارضه تاریک و مدل لامبرت انجام شد. از شاخصهای گیاهی و طبقهبندی نظارت شده برای تهیه نقشه پوشش گیاهی استفاده شد. عملیات برداشت زمینی در اردیبهشت ماه 1387 در سطحی معادل 25/8962 هکتار آغاز شد. تیپهای مختلف گیاهی به روش نمونهبرداری سیستماتیک- تصادفی، سطحی که اختلاف مهمی در ترکیب فلورستیک- فیزیونومیک نداشت، به عنوان تیپ گیاهی مستقل و یکنواخت در نظر گرفته شد. در کل منطقه حدود 60 نقطه تصادفی انتخاب و اندازهگیری پوشش گیاهی به روش برآورد انجام گرفت. اطلاعات رقومی و شاخصها به عنوان متغیر مستقل و اطلاعات زمینی به عنوان متغیر وابسته معرفی شدند. معادلات مختلف با استفاده از شاخصها بر روی تصاویر اعمال و سپس تصاویر به 5 کلاس پوشش طبقه بندی شد. در نهایت نقشه پوشش و نقاط نمونهبرداری برای بررسی صحت نتایج، کنترل گردید. نقشه پوشش منطقه با اعمال پردازشهای گوناگون بر روی تصویر تهیه گردید. با بهره گیری از سامانه اطلاعات جغرافیایی تمام لایههای اطلاعاتی با یکدیگر ترکیب و نقشه پوشش اراضی منطقه تهیه شد. نتایج این پژوهش نشان داد که، شاخص NDVI همبستگی بالایی با درصد پوشش گیاهی داشت (01/0P?). صحت کلی و ضریب کاپا برای نقشه پوشش با شاخص NDVI به ترتیب برابر 5/68 % و 4/72 % بدست آمد. نتایج این مطالعه نشان داد که پوشش گیاهی با درصد تاج پوشش 40-20 درصد، وسیعترین طبقه تراکمی پوشش این منطقه میباشد. نتایج این پژوهش همچنان نشان داد که تصاویر سنجنده ASTER و شاخصهای گیاهی ابزار قدرت مناسبی برای تهیه نقشه پوشش گیاهی میباشد. بنابراین، می توان از نقشه پوشش تهیه شده از دادههای ASTER برای برآورد پوشش و تولید و ارزیابی مراتع استفاده کرد.
D Talebpoor Asl; S Khezry
Volume 63, Issue 3 , December 2010, , Pages 341-358
Abstract
The Mahabad River Watershed has been exposed to severe erosion as a result of landuse change. The aim of this study is to quantify the amount of sediment yield and the relationship between land use change and slope. Different sources such as geologic and topographic maps, satellite images, hydrometric ...
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The Mahabad River Watershed has been exposed to severe erosion as a result of landuse change. The aim of this study is to quantify the amount of sediment yield and the relationship between land use change and slope. Different sources such as geologic and topographic maps, satellite images, hydrometric as well as meteorological data were used to extract and gather the information needed for this research. Six factors including altitude, slope, precipitation, rock erodibility, time of concentration and land use were specified as the most effective factors. The overlapping of the six factors maps resulted in the preparation of sediment delivery potential map. The distribution maps prepared on each of these parameters and their overlaps have shown that areas with more severe slopes are categorized as highly susceptible to erosion. However, in areas with resistant rocks, change of land use has been the determining factor. Comparison of water and sediment discharge data of 1996-97 with 2001-02(similar annual water volume) showed that the sediment yield has increased. Studying land use map prepared using satellite imagery of 1987 and 1998 showed that land use of the area has severely changed from pasture to dryland farming. This factor has also caused the intensification of mass movement recently occurred in the area. Landuse is the only parameter modified by human, and it is the only one which can be quickly and effectively changed. Hence, it seems that the upstream areas in the south and southwest of the basin with low concentration time, steep slope, high erodibility, high amount of precipitation, and the landuse of forest and pasture mixture as well as alluvial terraces with fine and granular sediments are the most sensitive areas which need protecting and control measures.
H. Saidian; H. R. Moradi; F. Tarnian
Volume 63, Issue 1 , June 2010, , Pages 1-12
Abstract
Using of different systems of soil plough after changing unconsciously and non-scientific of land use, other soil physical and chemical characteristics affected. This fact, especially in marginal lands and mountainous regions is more visible. This research compared with the purpose of studying land use ...
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Using of different systems of soil plough after changing unconsciously and non-scientific of land use, other soil physical and chemical characteristics affected. This fact, especially in marginal lands and mountainous regions is more visible. This research compared with the purpose of studying land use changing on some soil physical and chemical characters like very tiny sand percent, pH, Ec, clay percent, sand percent, silt percent, soil moisture, calcium carbonate in Gachsaran and Aaghajari formation. So that in aghajari formation 7 points and with 3 replicates and in gachsaran formation 6 points and with replicates in three land uses range, residential and agricultural land uses sampling of soil was done. Sampling of the depth 0-20 cm soil was done. After tests implement are concerned, the results were investigated. According to the results, range land in two Aghajari and Gachsaran formations in terms of clay percent, sand, EC, pH, moisture and Calcium Carbonate a meaningful difference have, and in other cases was not seen any disagreement. between agriculture land use in two Aghajari and Gachsaran formations in terms of very tiny sand percent, sand, clay, moisture and calcium carbonate meaningful difference have, and in other cases was not seen any disagreement. In residential land use in two Gachsaran and Aghajari formations only in clay percent and EC, there are a meaningful difference, and in other cases was not seen any disagreement. In each formation also land uses had effective role in soil physical and chemical characteristics.
M Ghorbani; A.A Mehrabi; M Servati; A.A Nazari Samani
Volume 63, Issue 1 , June 2010, , Pages 75-88
Abstract
Nowadays, population growth and on the other hand resources limitations astonish authorities. Population changes cause variation in economic activities and land use changes. As a whole, overusing, improper land use and human disturbances over natural resources make environmental imbalances worse. In ...
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Nowadays, population growth and on the other hand resources limitations astonish authorities. Population changes cause variation in economic activities and land use changes. As a whole, overusing, improper land use and human disturbances over natural resources make environmental imbalances worse. In recent decades, we have seen land use changes in Taleghan basin. Land use changes were produced by many factors, e.g. in abandoned lands, some parts of the region have been converted to residential areas and constructions. Since one century before, because of vicinity to population centers like Tehran and upland condition, this region has been a suitable place for recreation of travelers. Also one of the most important factors has been changed in population which has occurred in Taleghan. So that the statistical information shows substantial decrease in villages population in Taleghan. Similar to the, other regions in Iran, landuse changes especially in rangelands, is an important subject in Taleghan too. This paper tries to illustrate the relationship between population and land use changes in the given region of study and to detect the land use changes in a 15-year period. For determining the landuse, we used geographic information system and statistical methods, remote sensing also landSat images for 1987 and 2001 together. Population size were gained and analyzed for computing the population growth rate. According to what we concluded, in abandoned lands in given region of study the growth rate was positive and in other word, it increased and for other land uses this rate was negative together with negative increasing in all villages, therefore the population decreased. The villages of this region according to their magnitude of reduction in population growth and abandoned lands are: Gateh deh, Narian, Noviz oliya, Dizan, Jovestan, garab, Orazan, Nesa Bala, Mehran, Khachireh, Drapy. Thus, great number of settlers during these years migrated and the population decreased and following this trend, great area of rangelands (37.88%) which has already converted to rain-fed lands, has emerged in the form of abandoned lands in this region. In Gateh deh village, the area of rangelands had the maximum reduction and on the contrary, abandoned lands had the maximum amount of growth. Finally, it could be inferred that, there is a logical relationship between population growth and the area of abandoned lands.
M Jafari; M Tahmoures; M. Naghiloo
Volume 62, Issue 1 , June 2009
Abstract
The use of GIS tools is one of the newest methods for performance of different land evaluation and planning projects. This research with the purpose of determination of appropriate landuse to natural land potential and improvement of land management of catchments was executed using GIS-tools in Taleghan ...
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The use of GIS tools is one of the newest methods for performance of different land evaluation and planning projects. This research with the purpose of determination of appropriate landuse to natural land potential and improvement of land management of catchments was executed using GIS-tools in Taleghan area. At first ecological and socio-economic resources determined, mapped and entered to GIS environment. Then by analysis of more than 15 information layers, homogeneous and ecological units determined. By the use of watershed management and combined land planning model and in accordance with natural and socio-economic characteristics of the watershed, suitable landuses were proposed. At last optimum landuse map and the existing state of landuse map were adapted in GIS space. The results showed that 17 percent of the watershed area has suitable landuses while 83 percent of the watershed area needs landuse change.
