Wetlands, the transitional zones that occupy an intermediate position between dry land and open water, regulate the flow of water and nutrients, thereby facilitating optimum functioning of the physical and biological cycles of nature. To conserve and manage wetland resources, it is important to invent and monitor wetlands and their adjacent uplands. Wetlands are most productive ecosystems besides being a rich repository of biodiversity and are known to play a significant role in carbon sequestration. Wetlands are halfway world between terrestrial and aquatic ecosystem and share properties of both. Wetlands exhibit enormous diversity according to their genesis, geographical location, water regime, chemistry, dominant plants and soil or sediment characteristic. Wetland vegetation provides a natural barrier to fast moving water and therefore aids in flood speed reduction. Remote sensing offers a cost effective means for identifying and monitoring wetlands over a large area and at different moments of time. The present paper describes the methodology and results of wetland area for the Ranchi city of the Jharkhand state for the year 1996-2004.The signatures of wetlands and associated land features are identified in unsupervised classification approach based on their DN value using Satellite data. There are drastic change in between 1996 and 2004. The spatial distributions of the NDVI values were evaluated to determine the cut-off points for the water bodies, and wetted area.
{"title":"Wetland Assessment and Monitoring Using Image Processing Techniques: A Case Study of Ranchi, India","authors":"M. Rani, Pavan Kumar, M. Yadav, R. S. Hooda","doi":"10.4236/jgis.2011.34032","DOIUrl":"https://doi.org/10.4236/jgis.2011.34032","url":null,"abstract":"Wetlands, the transitional zones that occupy an intermediate position between dry land and open water, regulate the flow of water and nutrients, thereby facilitating optimum functioning of the physical and biological cycles of nature. To conserve and manage wetland resources, it is important to invent and monitor wetlands and their adjacent uplands. Wetlands are most productive ecosystems besides being a rich repository of biodiversity and are known to play a significant role in carbon sequestration. Wetlands are halfway world between terrestrial and aquatic ecosystem and share properties of both. Wetlands exhibit enormous diversity according to their genesis, geographical location, water regime, chemistry, dominant plants and soil or sediment characteristic. Wetland vegetation provides a natural barrier to fast moving water and therefore aids in flood speed reduction. Remote sensing offers a cost effective means for identifying and monitoring wetlands over a large area and at different moments of time. The present paper describes the methodology and results of wetland area for the Ranchi city of the Jharkhand state for the year 1996-2004.The signatures of wetlands and associated land features are identified in unsupervised classification approach based on their DN value using Satellite data. There are drastic change in between 1996 and 2004. The spatial distributions of the NDVI values were evaluated to determine the cut-off points for the water bodies, and wetted area.","PeriodicalId":93313,"journal":{"name":"Journal of geographic information system","volume":"91 1","pages":"345-350"},"PeriodicalIF":0.0,"publicationDate":"2011-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79030614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Fadil, H. Rhinane, A. Kaoukaya, Y. Kharchaf, Omar Alami Bachir
The study of water resources at watershed scale is widely adopted as approach to manage, assess and simulate these important natural resources. The development of remote sensing and GIS techniques has allowed the use of spatially and physically based hydrologic models to simulate as simply and realistically as possible the functioning of watershed systems. Indeed, the major constraint that has hindered the expansion use of these tools was the unavailability or scarcity of data especially in the developing countries. In this context, the objective of this study is to model the hydrology in the Bouregreg basin, located at the north-central of Morocco, using the Soil and Water Assessment Tool (SWAT) in order to understand and determine the different watershed hydrological processes. Thus, it aims to simulate the stream flow, establish the water balance and estimate the monthly volume inflow to SMBA dam situated at the basin outlet. The ArcSWAT interface implemented in the ArcGIS software was used to delineate the basin and its sub-components, combine the data layers and edit the model database. The model parameters were analyzed, ranked and adjusted for hydrologic modeling purposes using daily temporal data series. They were calibrated using an auto-calibration method based on a Shuffled Complex Evolution Algorithm from 1989 to 1997 and validated from 1998 to 2005. Based on statistical indicators, the evaluation indicates that SWAT model had a good performance for both calibration and validation periods in Bouregreg Watershed. In fact, the model showed a good correlation between the observed and simulated monthly average river discharge with R² and Nash coefficient of about 0.8. The water balance components were correctly estimated and the SMBA dam inflow was successfully reproduced with R² of 0.9. These results revealed that if properly calibrated, SWAT model can be used efficiently in semi-arid regions to support water management policies.
{"title":"Hydrologic Modeling of the Bouregreg Watershed (Morocco) Using GIS and SWAT Model","authors":"A. Fadil, H. Rhinane, A. Kaoukaya, Y. Kharchaf, Omar Alami Bachir","doi":"10.4236/jgis.2011.34024","DOIUrl":"https://doi.org/10.4236/jgis.2011.34024","url":null,"abstract":"The study of water resources at watershed scale is widely adopted as approach to manage, assess and simulate these important natural resources. The development of remote sensing and GIS techniques has allowed the use of spatially and physically based hydrologic models to simulate as simply and realistically as possible the functioning of watershed systems. Indeed, the major constraint that has hindered the expansion use of these tools was the unavailability or scarcity of data especially in the developing countries. In this context, the objective of this study is to model the hydrology in the Bouregreg basin, located at the north-central of Morocco, using the Soil and Water Assessment Tool (SWAT) in order to understand and determine the different watershed hydrological processes. Thus, it aims to simulate the stream flow, establish the water balance and estimate the monthly volume inflow to SMBA dam situated at the basin outlet. The ArcSWAT interface implemented in the ArcGIS software was used to delineate the basin and its sub-components, combine the data layers and edit the model database. The model parameters were analyzed, ranked and adjusted for hydrologic modeling purposes using daily temporal data series. They were calibrated using an auto-calibration method based on a Shuffled Complex Evolution Algorithm from 1989 to 1997 and validated from 1998 to 2005. Based on statistical indicators, the evaluation indicates that SWAT model had a good performance for both calibration and validation periods in Bouregreg Watershed. In fact, the model showed a good correlation between the observed and simulated monthly average river discharge with R² and Nash coefficient of about 0.8. The water balance components were correctly estimated and the SMBA dam inflow was successfully reproduced with R² of 0.9. These results revealed that if properly calibrated, SWAT model can be used efficiently in semi-arid regions to support water management policies.","PeriodicalId":93313,"journal":{"name":"Journal of geographic information system","volume":"3 1","pages":"279-289"},"PeriodicalIF":0.0,"publicationDate":"2011-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73897462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Agricultural land has a strategic function as the primary food provider for the people of Indonesia. Various methods of agricultural production estimation, particularly food crops, provide different information. It can be a source of error in decision making. Satellite data, provides information periodically, wide coverage area, can be used as a source of information on the condition of agricultural lands and even remote areas. The advantages of SAR data that does not depend on sunlight and can penetrate of clouds and fog can fill the lack of optical data. ALOS PALSAR data has been used for analysis and ALOS AVNIR-2 is for checking of land cover visually, with acquisition date on 10 May 2007. Sampling of each rice crop growth period used several of rice field conditions in each period, on one scene data. Results showed a possibility to use soil moisture conditions derived from ALOS PALSAR for estimating rice planting area. On a scatter diagram between backscatter of ALOS PALSAR and near infrared of ALOS AVNIR-2 showed a specific pattern for each growing period of paddy. The results of the analysis produce distribution maps of the rice planting area Subang area, West Java Province. However, validation of the method used remains to be done. Remote sensing results of this study are expected to provide better information and can contribute in the planning of higher quality agricultural land.
{"title":"Identification of Paddy Planted Area Using ALOS PALSAR Data","authors":"R. Shofiyati, Ishak Hanafiah Ismullah, D. Hakim","doi":"10.4236/jgis.2011.34033","DOIUrl":"https://doi.org/10.4236/jgis.2011.34033","url":null,"abstract":"Agricultural land has a strategic function as the primary food provider for the people of Indonesia. Various methods of agricultural production estimation, particularly food crops, provide different information. It can be a source of error in decision making. Satellite data, provides information periodically, wide coverage area, can be used as a source of information on the condition of agricultural lands and even remote areas. The advantages of SAR data that does not depend on sunlight and can penetrate of clouds and fog can fill the lack of optical data. ALOS PALSAR data has been used for analysis and ALOS AVNIR-2 is for checking of land cover visually, with acquisition date on 10 May 2007. Sampling of each rice crop growth period used several of rice field conditions in each period, on one scene data. Results showed a possibility to use soil moisture conditions derived from ALOS PALSAR for estimating rice planting area. On a scatter diagram between backscatter of ALOS PALSAR and near infrared of ALOS AVNIR-2 showed a specific pattern for each growing period of paddy. The results of the analysis produce distribution maps of the rice planting area Subang area, West Java Province. However, validation of the method used remains to be done. Remote sensing results of this study are expected to provide better information and can contribute in the planning of higher quality agricultural land.","PeriodicalId":93313,"journal":{"name":"Journal of geographic information system","volume":"8 1","pages":"351-356"},"PeriodicalIF":0.0,"publicationDate":"2011-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89365718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
One of the most important factors affecting the precision of the performance of a GPS receiver is the relative positioning of satellites to each other. Therefore, it is essential to choose appropriate accessible satellites utilized in the calculation of GPS positions. Optimal subsets of satellites are determined using the least value of their Geometric Dilution of Precision (GDOP). The most correct method of calculating GPS GDOP uses inverse matrix for all combinations and selecting the lowest ones. However, the inverse matrix method, especially when there are so many satellites, imposes a huge calculation load on the processor of the GPS navigator. In this paper, the rapid and precise calculation of GPS GDOP based on Recurrent Wavelet Neural Network (RWNN) has been introduced for selecting an optimal subset of satellites. The method of NNs provides a realistic calculation approach to determine GPS GDOP without any need to calculate inverse matrix.
{"title":"Performance Improvement of GPS GDOP Approximation Using Recurrent Wavelet Neural Network","authors":"S. Tafazoli, M. Mosavi","doi":"10.4236/jgis.2011.34029","DOIUrl":"https://doi.org/10.4236/jgis.2011.34029","url":null,"abstract":"One of the most important factors affecting the precision of the performance of a GPS receiver is the relative positioning of satellites to each other. Therefore, it is essential to choose appropriate accessible satellites utilized in the calculation of GPS positions. Optimal subsets of satellites are determined using the least value of their Geometric Dilution of Precision (GDOP). The most correct method of calculating GPS GDOP uses inverse matrix for all combinations and selecting the lowest ones. However, the inverse matrix method, especially when there are so many satellites, imposes a huge calculation load on the processor of the GPS navigator. In this paper, the rapid and precise calculation of GPS GDOP based on Recurrent Wavelet Neural Network (RWNN) has been introduced for selecting an optimal subset of satellites. The method of NNs provides a realistic calculation approach to determine GPS GDOP without any need to calculate inverse matrix.","PeriodicalId":93313,"journal":{"name":"Journal of geographic information system","volume":"42 1 1","pages":"318-322"},"PeriodicalIF":0.0,"publicationDate":"2011-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85017674","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. S. Guettouche, Amar Derias, Makhlouf Boutiba, Mohand Ouabdallah Bounif, M. Guendouz, A. Boudella
The management of the forest fire risk starts with it assessment. This assessment made the object of several works of research and many models of fire risk have been related. The model that interests us here is that established for Mediterranean forests. This last is conceived according to a sum weighted model integral three factors, where each is affected by a weight, function of his influence on the propagation of the fire. However, this model remains critically and deserves a development and an improvement. For it, and seen the importance and the influence of climatic condition in the departure and in the propagation of fire, we propose, in this paper, to improve this formula by the addition of another climatic factor (marked ICL), and to present it under a product shape while respecting the same definition of the risk. The application of the proposed model, suggested uses the technical geomatics to mapping the degree of the fire risk. In this setting, a SIG has been established and applied on a forest of Bouzareah clump in Algiers. Originality as it will allow the understanding of fire hazard and vulnerability of the environment for a better control of risk.
{"title":"A Fire Risk Modelling and Spatialization by GIS","authors":"M. S. Guettouche, Amar Derias, Makhlouf Boutiba, Mohand Ouabdallah Bounif, M. Guendouz, A. Boudella","doi":"10.4236/jgis.2011.33022","DOIUrl":"https://doi.org/10.4236/jgis.2011.33022","url":null,"abstract":"The management of the forest fire risk starts with it assessment. This assessment made the object of several works of research and many models of fire risk have been related. The model that interests us here is that established for Mediterranean forests. This last is conceived according to a sum weighted model integral three factors, where each is affected by a weight, function of his influence on the propagation of the fire. However, this model remains critically and deserves a development and an improvement. For it, and seen the importance and the influence of climatic condition in the departure and in the propagation of fire, we propose, in this paper, to improve this formula by the addition of another climatic factor (marked ICL), and to present it under a product shape while respecting the same definition of the risk. The application of the proposed model, suggested uses the technical geomatics to mapping the degree of the fire risk. In this setting, a SIG has been established and applied on a forest of Bouzareah clump in Algiers. Originality as it will allow the understanding of fire hazard and vulnerability of the environment for a better control of risk.","PeriodicalId":93313,"journal":{"name":"Journal of geographic information system","volume":"36 1","pages":"254-265"},"PeriodicalIF":0.0,"publicationDate":"2011-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85870901","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Glacier variation is one of the best indicators of climate change in mountainous environment. In French Alps, many temporal data are acquired by glaciologists at glaciers scale: geometrical parameters (surface area, thickness, length and front altitude) are surveyed since the end of the 19th century. Those parameters are necessary to estimate the mass-balance of glaciers and, then, an accurate temporal signal of glacier variation. However, the time-response of the glaciers can be highly variable because of the topoclimate, and more generally the local settings of the glaciers. Moreover, climatologists and hydrologists are requiring estimation of glacier variations at regional scale and not only at local scale. In this paper, we highlight that the Equilibrium Line Altitude (ELA) is a parameter prone to spatio-temporal reconstructions at regional scale. ELA can indeed be interpolated at a region scale from local data: for instance, many geographers have reconstructed spatial trends during 1980s. Here, we try to interpolate ELA from multi-dimensionnal regression analysis: ELA is explained by many local parameters (Incoming solar radiation, topographic indexes, snow-redistribution by wind, etc.). Regression model was adjusted from a spatio-temporal database of 50 glaciers, located in the Massif des Ecrins. ELA was estimated for each glacier thanks to the Accumulation Area Ratio (ratio = 0.65) at two stages: LIA maximum and at present. Results first show that the multiple regression analysis is efficient to interpolate ELA through space: the adjusted r2 is about 0.49 for the reconstruction during the LIA, and 0.47 at present. Moreover, the RMSE error is about 50 meters for the LIA period, 55 meters at present. Finally, a high spatial variability (standard deviation of about 150 meters) is highlighted: incoming solar radiation and snow redistribution by wind mostly explain the observed differences. We can also assess a rise of the ELA of about 250 meters during the 20th century.
{"title":"Mapping Glacier Variations at Regional Scale through Equilibrium Line Altitude Interpolation: GIS and Statistical Application in Massif des Écrins (French Alps)","authors":"É. Cossart","doi":"10.4236/jgis.2011.33020","DOIUrl":"https://doi.org/10.4236/jgis.2011.33020","url":null,"abstract":"Glacier variation is one of the best indicators of climate change in mountainous environment. In French Alps, many temporal data are acquired by glaciologists at glaciers scale: geometrical parameters (surface area, thickness, length and front altitude) are surveyed since the end of the 19th century. Those parameters are necessary to estimate the mass-balance of glaciers and, then, an accurate temporal signal of glacier variation. However, the time-response of the glaciers can be highly variable because of the topoclimate, and more generally the local settings of the glaciers. Moreover, climatologists and hydrologists are requiring estimation of glacier variations at regional scale and not only at local scale. In this paper, we highlight that the Equilibrium Line Altitude (ELA) is a parameter prone to spatio-temporal reconstructions at regional scale. ELA can indeed be interpolated at a region scale from local data: for instance, many geographers have reconstructed spatial trends during 1980s. Here, we try to interpolate ELA from multi-dimensionnal regression analysis: ELA is explained by many local parameters (Incoming solar radiation, topographic indexes, snow-redistribution by wind, etc.). Regression model was adjusted from a spatio-temporal database of 50 glaciers, located in the Massif des Ecrins. ELA was estimated for each glacier thanks to the Accumulation Area Ratio (ratio = 0.65) at two stages: LIA maximum and at present. Results first show that the multiple regression analysis is efficient to interpolate ELA through space: the adjusted r2 is about 0.49 for the reconstruction during the LIA, and 0.47 at present. Moreover, the RMSE error is about 50 meters for the LIA period, 55 meters at present. Finally, a high spatial variability (standard deviation of about 150 meters) is highlighted: incoming solar radiation and snow redistribution by wind mostly explain the observed differences. We can also assess a rise of the ELA of about 250 meters during the 20th century.","PeriodicalId":93313,"journal":{"name":"Journal of geographic information system","volume":"8 1","pages":"232-241"},"PeriodicalIF":0.0,"publicationDate":"2011-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86882594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Land cover (LC) and land use (LU) dynamics induced by human and natural processes play a major role in global as well as regional patterns of landscapes influencing biodiversity, hydrology, ecology and climate. Changes in LC features resulting in forest fragmentations have posed direct threats to biodiversity, endangering the sustainability of ecological goods and services. Habitat fragmentation is of added concern as the residual spatial patterns mitigate or exacerbate edge effects. LU dynamics are obtained by classifying temporal remotely sensed satellite imagery of different spatial and spectral resolutions. This paper reviews five different image classification algorithms using spatio-temporal data of a temperate watershed in Himachal Pradesh, India. Gaussian Maximum Likelihood classifier was found to be apt for analysing spatial pattern at regional scale based on accuracy assessment through error matrix and ROC (receiver operating characteristic) curves. The LU information thus derived was then used to assess spatial changes from temporal data using principal component analysis and correspondence analysis based image differencing. The forest area dynamics was further studied by analysing the different types of fragmentation through forest fragmentation models. The computed forest fragmentation and landscape metrics show a decline of interior intact forests with a substantial increase in patch forest during 1972-2007.
{"title":"Characterisation of Landscape with Forest Fragmentation Dynamics","authors":"T. Ramachandra, U. Kumar","doi":"10.4236/jgis.2011.33021","DOIUrl":"https://doi.org/10.4236/jgis.2011.33021","url":null,"abstract":"Land cover (LC) and land use (LU) dynamics induced by human and natural processes play a major role in global as well as regional patterns of landscapes influencing biodiversity, hydrology, ecology and climate. Changes in LC features resulting in forest fragmentations have posed direct threats to biodiversity, endangering the sustainability of ecological goods and services. Habitat fragmentation is of added concern as the residual spatial patterns mitigate or exacerbate edge effects. LU dynamics are obtained by classifying temporal remotely sensed satellite imagery of different spatial and spectral resolutions. This paper reviews five different image classification algorithms using spatio-temporal data of a temperate watershed in Himachal Pradesh, India. Gaussian Maximum Likelihood classifier was found to be apt for analysing spatial pattern at regional scale based on accuracy assessment through error matrix and ROC (receiver operating characteristic) curves. The LU information thus derived was then used to assess spatial changes from temporal data using principal component analysis and correspondence analysis based image differencing. The forest area dynamics was further studied by analysing the different types of fragmentation through forest fragmentation models. The computed forest fragmentation and landscape metrics show a decline of interior intact forests with a substantial increase in patch forest during 1972-2007.","PeriodicalId":93313,"journal":{"name":"Journal of geographic information system","volume":"97 1","pages":"242-253"},"PeriodicalIF":0.0,"publicationDate":"2011-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82379645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Since land resource database development in 1987/1988, a large amount of digital data in spatial, tabular and metadata format has been collected and generated. There are some application softwares of soil database to manage such a large amount of data, i.e.: Side & Horizon (SHDE4), Soil Sample Analysis (SSA), and Land Unit in dbf file, while Site and Horizon is in DataEase formats. The database contains soil physics and chemical property data of each soil horizon from surface to effective soil depth, climate, land surface condi- tions, and other parameters required for soil classification. Currently, database management software for land resources is still based on DOS and is stand alone. The system is not efficient and effectively used as Agri- cultural Land Resource Information System. At present, as a key component of this system requires review and development of new database software is compatible with the development of information technology. This paper explains about development of interactive agricultural land resources information system for op- timizing land resources data utilization. Hopefully, the software can give contributions in national Agricul- tural Land Resources System Information development for supporting food security.
{"title":"Soil Database Management Software Development for Optimizing Land Resource Information Utilization to Support National Food Security","authors":"R. Shofiyati, Saefoel Bachri","doi":"10.4236/JGIS.2011.33017","DOIUrl":"https://doi.org/10.4236/JGIS.2011.33017","url":null,"abstract":"Since land resource database development in 1987/1988, a large amount of digital data in spatial, tabular and metadata format has been collected and generated. There are some application softwares of soil database to manage such a large amount of data, i.e.: Side & Horizon (SHDE4), Soil Sample Analysis (SSA), and Land Unit in dbf file, while Site and Horizon is in DataEase formats. The database contains soil physics and chemical property data of each soil horizon from surface to effective soil depth, climate, land surface condi- tions, and other parameters required for soil classification. Currently, database management software for land resources is still based on DOS and is stand alone. The system is not efficient and effectively used as Agri- cultural Land Resource Information System. At present, as a key component of this system requires review and development of new database software is compatible with the development of information technology. This paper explains about development of interactive agricultural land resources information system for op- timizing land resources data utilization. Hopefully, the software can give contributions in national Agricul- tural Land Resources System Information development for supporting food security.","PeriodicalId":93313,"journal":{"name":"Journal of geographic information system","volume":"37 1","pages":"211-216"},"PeriodicalIF":0.0,"publicationDate":"2011-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77281849","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Flash floods occur periodically in Makkah city, Saudi Arabia, due to several factors including its rugged to-pography and geological structures. Hence, precise assessment of floods becomes a more vital demand in development planning. A GIS-based methodology has been developed for quantifying and spatially mapping the flood characteristics. The core of this new approach is integrating several topographic, metrological, geological, and land use datasets in a GIS environment that utilizes the Curve Number (CN) method of flood modelling for ungauged arid catchments. Additionally, the computations of flood quantities, such as depth and volume of runoff, are performed in the attribute tables of GIS layers, in order to assemble all results in the same environment. The accomplished results show that the runoff depth in Makkah, using a 50-years re-turn period, range from 128.1 mm to 193.9 mm while the peak discharge vary from 1063 m3/s to 4489 m3/s. The total flood volume is expected to reach 172.97 million m3 over Makkah metropolitan area. The advan-tages of the developed methodology include precision, cost-effective, digital outputs, and its ability to be re-run in other conditions.
{"title":"GIS-Based Spatial Mapping of Flash Flood Hazard in Makkah City, Saudi Arabia","authors":"G. Dawod, M. N. Mirza, K. Al-Ghamdi","doi":"10.4236/jgis.2011.33019","DOIUrl":"https://doi.org/10.4236/jgis.2011.33019","url":null,"abstract":"Flash floods occur periodically in Makkah city, Saudi Arabia, due to several factors including its rugged to-pography and geological structures. Hence, precise assessment of floods becomes a more vital demand in development planning. A GIS-based methodology has been developed for quantifying and spatially mapping the flood characteristics. The core of this new approach is integrating several topographic, metrological, geological, and land use datasets in a GIS environment that utilizes the Curve Number (CN) method of flood modelling for ungauged arid catchments. Additionally, the computations of flood quantities, such as depth and volume of runoff, are performed in the attribute tables of GIS layers, in order to assemble all results in the same environment. The accomplished results show that the runoff depth in Makkah, using a 50-years re-turn period, range from 128.1 mm to 193.9 mm while the peak discharge vary from 1063 m3/s to 4489 m3/s. The total flood volume is expected to reach 172.97 million m3 over Makkah metropolitan area. The advan-tages of the developed methodology include precision, cost-effective, digital outputs, and its ability to be re-run in other conditions.","PeriodicalId":93313,"journal":{"name":"Journal of geographic information system","volume":"32 1","pages":"225-231"},"PeriodicalIF":0.0,"publicationDate":"2011-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79705871","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The spatial characteristics of land cover are useful for understanding the various impacts of human activity on the overall ecological conditions of the urban environment. The multi-temporal Landsat images (TM) between the years of 1990 and 2003 were used together with the Geographic Information System (GIS) techniques to evaluate the environmental changes in the area around Gabal El Hamza and the surrounding urban expansion in the new urban cities at the northeast side of the Greater Cairo by using the post classification change detection technique and field investigation. Five major units were determined including: urban, cultivated land, Holocene sand dunes, Oligocene basalt and Miocene–Pleistocene sediments. The cultivated cover changed from 89.6 to 150.4 km2 for the years of 1990 and 2003 respectively. The urban area increased from 49.5 to 120.9 km2 with a great value of change reached 71.3 km2 . The basaltic exposures changed from 3 to 3.75 km2 . The sandy cover decreased from 68.9 to 60.1 km2 and the exposures of the rock units changed from 904.8 to 780.8 km2 with removing 124 km2 in 13 years. The total accuracy of the Landsat-derived land cover data was 95 and 92% for the years 1990 and 2003 respectively. Landsat TM thermal infrared data indicated that the surface temperature was strongly affected by the land cover changes.
{"title":"Land Use and Land Cover Changes in Arid Region: The Case New Urbanized Zone, Northeast Cairo, Egypt","authors":"R. Zaki, Abotalib Zaki, Saad Ahmed","doi":"10.4236/jgis.2011.33015","DOIUrl":"https://doi.org/10.4236/jgis.2011.33015","url":null,"abstract":"The spatial characteristics of land cover are useful for understanding the various impacts of human activity on the overall ecological conditions of the urban environment. The multi-temporal Landsat images (TM) between the years of 1990 and 2003 were used together with the Geographic Information System (GIS) techniques to evaluate the environmental changes in the area around Gabal El Hamza and the surrounding urban expansion in the new urban cities at the northeast side of the Greater Cairo by using the post classification change detection technique and field investigation. Five major units were determined including: urban, cultivated land, Holocene sand dunes, Oligocene basalt and Miocene–Pleistocene sediments. The cultivated cover changed from 89.6 to 150.4 km2 for the years of 1990 and 2003 respectively. The urban area increased from 49.5 to 120.9 km2 with a great value of change reached 71.3 km2 . The basaltic exposures changed from 3 to 3.75 km2 . The sandy cover decreased from 68.9 to 60.1 km2 and the exposures of the rock units changed from 904.8 to 780.8 km2 with removing 124 km2 in 13 years. The total accuracy of the Landsat-derived land cover data was 95 and 92% for the years 1990 and 2003 respectively. Landsat TM thermal infrared data indicated that the surface temperature was strongly affected by the land cover changes.","PeriodicalId":93313,"journal":{"name":"Journal of geographic information system","volume":"60 1","pages":"173-194"},"PeriodicalIF":0.0,"publicationDate":"2011-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77768134","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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