Use of satellite data and GIS for assessing the agricultural potentiality of the soils South Farafra Oasis, Western Desert, Egypt

Overpopulation and food security are the main global problems alert decision makers. In developing countries, such problem put extra pressure for horizontal expansion for agricultural development. The rapid sprawl of urbanized areas on the alluvial land of the River Nile and delta to accommodate the population growth has encouraged governmental and private sector for agricultural expansion in the desert. Unless there are reliable information and accurate studies for land and soil suitability, there will be a collapse of such investment. To evaluate the potential suitability of soil for agriculture development in areas of the western desert, satellite images, geographic information, and field survey including soil profiles and artesian water samples with laboratory analysis were integrated to classify the soils according their suitability for specific crop. The main land qualities of the different mapping units and the crop requirement were rated and matched to obtain the current and potential land suitability using Automated Land Evaluation System “ALES”. The study found that the main physiographic units are plateaus, hilland, mountain, and depression floor. But there are three limiting parameters for land suitability which are the lack of nutrient elements, wind erosion vulnerability, and soil texture. The study concluded that the best crops adapted with the soil conditions and could be feasible for economic use are: (1) native vegetation such as agol, sand trees, sammar, halfaa, bawaal, qordaob, bardi, and qortom; (2) filed crops such as onion, garlic, watermelon and wheat; and (3) fruits such as olive and date palms.     

Use of satellite remote sensing data in the mapping of global landslide susceptibility

Satellite remote sensing data has significant potential use in analysis of natural hazards such as landslides. Relying on the recent advances in satellite remote sensing and geographic information system (GIS) techniques, this paper aims to map landslide susceptibility over most of the globe using a GIS-based weighted linear combination method. First, six relevant landslide-controlling factors are derived from geospatial remote sensing data and coded into a GIS system. Next, continuous susceptibility values from low to high are assigned to each of the six factors. Second, a continuous scale of a global landslide susceptibility index is derived using GIS weighted linear combination based on each factor’s relative significance to the process of landslide occurrence (e.g., slope is the most important factor, soil types and soil texture are also primary-level parameters, while elevation, land cover types, and drainage density are secondary in importance). Finally, the continuous index map is further classified into six susceptibility categories. Results show the hot spots of landslide-prone regions include the Pacific Rim, the Himalayas and South Asia, Rocky Mountains, Appalachian Mountains, Alps, and parts of the Middle East and Africa. India, China, Nepal, Japan, the USA, and Peru are shown to have landslide-prone areas. This first-cut global landslide susceptibility map forms a starting point to provide a global view of landslide risks and may be used in conjunction with satellite-based precipitation information to potentially detect areas with significant landslide potential due to heavy rainfall.     

Flood monitoring, mapping and assessing capabilities using RADARSAT remote sensing, GIS and ground data for Bangladesh

Remote sensing is the most practical method available to managers of flood-prone areas for quantifying and mapping flood impacts. This study explored large inundation areas in the Maghna River Basin, around the northeastern Bangladesh, as determined from passive sensor LANDSAT data and the cloud-penetrating capabilities of the active sensors of the remote imaging microwave RADARSAT. This study also used passive sensor LANDSAT wet and dry images for the year 2000. Spatial resolution was 30 m by 30 m for comparisons of the inundation area with RADARSAT images. RADARSAT images with spatial resolution of 50 m by 50 m were used for frequency analysis of floods from 2000 to 2004. Time series images for 2004 were also used. RADARSAT remote sensing data, GIS data, and ground data were used for the purpose of flood monitoring, mapping and assessing. A supervised classification technique was used for this processing. They were processed for creating a maximum water extent map and for estimating inundation areas. The results of this study indicated that the maximum extent of the inundation area as estimated using RADARSAT satellite imaging was about 29, 900.72 km² in 2004, which corresponded well with the heavy rainfall around northeast region, as seen at the Bhairab Bazar station and with the highest water level of the Ganges–Brahmaputra–Meghna (GBM) Rivers. A composite of 5 years of RADARSAT inundation maps from 2000 to 2004, GIS data, and damage data, was used to create unique flood hazard maps. Using the damage data for 2004 and the GIS data, a set of damage maps was also created. These maps are expected to be useful for future planning and flood disaster management. Thus, it has been demonstrated that RADARSAT imaging data acquired over the Bangladesh have the ability to precisely assess and clarify inundation areas allowing for successful flood monitoring, mapping and disaster management.     

Integrated geoelectrical survey for groundwater and shallow subsurface evaluation: case study at Siliyin spring, El-Fayoum, Egypt

Siliyin spring is one of the many natural fresh water springs in the Western Desert of Egypt. It is located at the central part of El-Fayoum Delta, which is a potential place for urban developments and touristic activities. Integrated geoelectrical survey was conducted to facilitate mapping the groundwater resources and the shallow subsurface structures in the area. Twenty-eight transient electromagnetic (TEM) soundings, three vertical electrical soundings (VES) and three electrical resistivity tomography (ERT) profiles were carried out around the Siliyin spring location. The dense cultivation, the rugged topography and the existence of infra structure in the area hindered acquiring more data. The TEM data were inverted jointly with the VES and ERT, and constrained by available geological information. Based on the inversion results, a set of geoelectrical cross-sections have been constructed. The shallow sand to sandy clay layer that forms the shallow aquifer has been completely mapped underneath and around the spring area. Flowing of water from the Siliyin spring is interconnected with the lateral lithological changes from clay to sand soil. Exploration of the extension of Siliyin spring zone is recommended. The interpretation emphasizes the importance of integrating the geoelectrical survey with the available geological information to obtain useful, cheap and fast lithological and structural subsurface information.     

Assessment of land degradation east of the Nile Delta, Egypt using remote sensing and GIS techniques

Land degradation is one of the most common issues in the eastern part of the Nile Delta area that threatens the ongoing agricultural activities and prohibits further reclamation expansions. The different degradation types and the associated risk assessment of some soils types of western Suez Canal region during the period from 1997 to 2010 is discussed. The assessment of the different degradation degrees in the investigated area has been carried out through integrating remote sensing, GIS and GLASOD approaches. Results revealed that the salinization, alkalization, soil compaction and water logging are the main types of land degradation in the area. The main causative factors of human induced land degradation types are; over irrigation, human intervention in natural drainage, improper time use of heavy machinery and the absence of conservation measurements. Low and moderately clay flats, gypsifferous flats, have high to very high risk in both salinization sodication and physical degradation. Values such as EC, ESP, and ground water level reach 104.0 dS/m, 176? % and 60 cm, respectively. These results will be of great help and be basic sources for the planners and decision makers in sustainable planning. The spatial land degradation model was developed based on integration between remote sensing data, geographic information system, soil characteristics and DEM.     

Detection of soil salinity changes and mapping land cover types based upon remotely sensed data

Soil salinity is a major environmental hazard. The global extent of primary and secondary salt affected soils is about 955 and 77 M?ha, respectively. Soil salinity tends to increase in spite of considerable effort dedicated to land reclamation. This requires careful monitoring of the soil salinity status. The objectives of this study were: (a) to evaluate the capability of thematic mapper (TM) and multispectral scanner (MSS) imagery for mapping land cover types, (b) to analyse the spectral features of sail crusts relative to bare soil and gravely soil surface conditions, and (c) to detect the soil salinity changes during the period 1975–2004 in the Ardakan area located in the central Iranian Deserts. The Landsat MSS and TM on two different dates of September 14, 1975 and September 11, 2004, respectively, were used. Due to great confusion between some classes, the TM 6 was included in the band combination. The result of the image classification based on the combination of TM bands 3, 4, 5, and 6 showed of the classification results. For multi-temporal analysis, both TM and MSS images were classified with the same method but with a different number of training classes. The TM-classified image was regrouped to make it comparable with MSS regrouped classified image. The comparison between the classified images showed about 39% of the total area had changed in 29 years. The result of this study revealed the possibility of detecting important soil salinity changes by using Landsat satellite data     

贵州省仁怀市耕地土壤养分地球化学特征及其影响因素研究

【研究目的】为仁怀市农业生产中土壤养分的合理利用、农业结构调整及土地利用价值的提升等提供科学依据。【研究方法】本文利用电感耦合等离子体发射光谱法、容量法及电位法获取了5486件表层土壤样品氮磷钾（全量和有效态）及有机质的含量，系统研究了其地球化学特征及含量影响因素。【研究结果】仁怀市耕地土壤氮、磷、钾、有机质、碱解氮、速效磷及速效钾的平均值分别为1.74 g/kg、0.75 g/kg、19.90 g/kg、30.90 g/kg、100.28 mg/kg、10.40 mg/kg和101.03 mg/kg。其中，氮、碱解氮、磷、钾及有机质的含量及分布与地层关系密切；速效磷及速效钾的含量及分布与地层关系较差。仁怀市耕地土壤肥力较好，以较丰富等级为主，较丰富及丰富等级占比为57.6%。其中，氮、磷及钾皆处于丰富水平；碱解氮及有机质处于中等水平；速效磷及速效钾处于缺乏水平。【结论】仁怀市耕地土壤养分的含量及分布不仅受地质背景、土壤类型、海拔高度、酸碱度及土壤深度等自然因素影响，还与土地利用方式等人为活动有关。创新点：系统统计了仁怀市耕地土壤氮磷钾（全量和有效态）及有机质的含量，对其地球化学等级开展了评价，并系统分析了它们的含量影响因素。耕地土壤养分的含量及分布不仅受地质背景、土壤类型等自然因素影响，还与土地利用方式等人为活动有关。     

Groundwater potential zone assessment in Wadi Watir area,Egypt using radar data and GIS

The exploration of new locations for possible groundwater potentiality is required to support the needs of urban and agricultural activities in arid regions such as Wadi Watir basin. The aim of this study is to locate new groundwater wells that can help overcome the water shortage. In order to define favorable zones for groundwater potentiality, several essential factors contributing to groundwater potentiality were identified. These factors include textural classification of alluvial deposits, lithological units, surface and subsurface structures, topographic parameters, geomorphological features and land use/land cover. A hydrogeological prospective model was developed using spatial data which represent these factors. For final groundwater potential map, all factors were converted to raster data to integrate spatially as important thematic layers based on weightage analysis. The groundwater potential map was classified to five classes including very poor to very good potential. The classes of groundwater potential map were checked against the distribution of the groundwater wells, Bedouin communities and agriculture areas, which present a general knowledge of groundwater potential in the study area.     

Use of GEMAS data for risk assessment of cadmium in European agricultural and grazing land soil under the REACH Regulation

Over 4000 soil samples were collected for the “Geochemical Mapping of Agricultural and Grazing Land Soil of Europe” (GEMAS) project carried out by the EuroGeoSurveys Geochemistry Expert Group. Cadmium concentrations are reported for the <2 mm fraction of soil samples from regularly ploughed fields (agricultural soil, Ap, 0–20 cm, N = 2218) and grazing land soil (Gr, 0–10 cm, N = 2127). The samples were collected in 33 European countries, covering 5.6 million km² at a sample density of 1 sample each per 2500 km² and were analysed in an aqua regia extraction followed by an ICP-MS finish. The median Cd value is 0.181 mg/kg for the Ap and 0.202 mg/kg for the Gr soil samples. The data allow a directly comparable country-specific regional exposure and risk characterisation for all EU countries covered. Direct risks of Cd for terrestrial organisms are only predicted for a few isolated sample sites: 2.3% of the Ap and 4.5% of the Gr sites, respectively.     

Utilization of ASTER and OLI data for lithological mapping of Nugrus-Hafafit area,South Eastern Desert of Egypt

Lithological discrimination of Neoproterozoic rocks occupying Nugrus-Hafafit area, South Eastern Desert of Egypt, has been carried out using Operational Land Imager (OLI) and Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) sensors’ imagery data. The applicable processing enhancement techniques include optimum index factor (OIF), band ratioing, principal component analysis (PCA), and minimum noise fraction (MNF) transform. The area comprises varieties of low-grade metamorphosed ophiolitic mélange and island-arc rocks, thrusting over high-grade metamorphic gneissic core complexes, and intruded by syn-, late-, and post-tectonic granitoids. The OLI band ratio 6/7 discriminates clearly the ophiolitic serpentinites-talc-carbonate rocks, while 4/5 ratio image is able to separate between mafic and felsic rocks. Moreover, the ASTER band ratio 6/8 is used to distinguish the amphibole-bearing rocks, including amphibolite and hornblende gneiss. The OLI and ASTER second principal component (PC2) images reflect the contrast spectral behavior of ophiolitic mélange rocks through visible-near-infrared (VNIR) and shortwave (SWIR) regions. The OLI-PC3 shows the ability to delineate the Fe-rich rocks, including amphibolite and metamafics, while ASTER-PC3 is effective for quartz-feldspathic granites and psammitic gneisses. Visual interpretation and integration of processed data with petrography and field investigation resulted in complete differentiation for the different lithologies and creation of a new detailed geological map of Nugrus-Hafafit area.     

Simulation of land use dynamics and impact on land surface temperature using satellite data

GeoJournal - Increasing of global average surface temperature naturally leading to major problems as global warming, which has typically attracted the interest of multinational organizations, civil...     

Flash flood risk estimation along the St. Katherine road,southern Sinai,Egypt using GIS based morphometry and satellite imagery

Flash floods are considered to be one of the worst weather-related natural disasters. They are dangerous because they are sudden and are highly unpredictable following brief spells of heavy rain. Several qualitative methods exist in the literature for the estimations of the risk level of flash flood hazard within a watershed. This paper presents the utilization of remote sensing data such as enhanced Thematic Mapper Plus (ETM+), Shuttle Radar Topography Mission (SRTM), coupled with geological, geomorphological, and field data in a GIS environment for the estimation of the flash flood risk along the Feiran–Katherine road, southern Sinai, Egypt. This road is a vital corridor for the tourists visiting here for religious purposes (St. Katherine monastery) and is subjected to frequent flash floods, causing heavy damage to man-made features. In this paper, morphometric analyses have been used to estimate the flash flood risk levels of sub-watersheds within the Wadi Feiran basin. First, drainage characteristics are captured by a set of parameters relevant to the flash flood risk. Further, comparison between the effectiveness of the sub-basins has been performed in order to understand the active ones. A detailed geomorphological map for the most hazardous sub-basins is presented. In addition, a map identifying sensitive sections is constructed for the Feiran–Katherine road. Finally, the most influenced factors for both flash flood hazard and critical sensitive zones have been discussed. The results of this study can initiate appropriate measures to mitigate the probable hazards in the area.     

Utilization of remote sensing data and GIS tools for and use sustainability analysis: case study in El-Hammam area, Egypt

The North-Western Coast of Egypt (NWCE) represents one of the high priority regions for future development in the country. El-Hammam area is located in the NWCE with an area of 94752 acres and is one of the main challenging regions for sustaianble development. In this study, we have used remote sensing and soil data in combination with GIS tools, for land use sustainable analysis (SLU) in El-Hammam area. The SLU was established based on various factors such as: land capability and suitability, water resources availability, economic return from water and financial return from land and water. A physiographic soil map for the study area was prepared using remote sensing and GIS. Multiple field surveys were carried out for collecting information on various soil map units (SMUs) and their profiles. Laboratory analysis for the collected samples was performed, and then the soil properties were stored as attributes in a geographical soil database linked with the SMUs. Furthermore, land capability assessment was done to define the suitable areas for agricultural production using a capability model built in ALES software. Results indicate that the area currently lacks high capability and moderate capability classes. By improving the soil properties, the soil can attain potential capability; and 55630 acres will become marginally capable. The assessment of soil physical suitability for different land use types (LUTs) were analysed in ALES software, in order to generate the most suitable areas. The results from the land suitability analysis indicated that, 17114 acres are moderately suitable for wheat and sorghum; whereas 15823 acres are moderately suitable for barley and 12752 acres are moderately suitable for maize, olive and figs. Finally, the SLU was investigated based on two scenarios; (1) the most SLU under the conditions of shortage of irrigation water: clover, barley and sorghum against figs, as the irrigation requirements for barley and sorghum are low; (2) the most sustainable land use in the conditions of irrigation availability will be wheat and maize against figs and guava. From the results it is quite evident that GIS combined with modeling approaches are powerful tools for decision making in the study area.     

Monitoring land use/land cover change using multi-temporal Landsat satellite images in an arid environment: a case study of El-Arish,Egypt

Environment in arid conditions is dynamic and needs more investigation to understand the complexity of change. This spatiotemporal study will help to assess and monitor the land use and land cover change in the arid region of El-Arish area, where the climate and human activities are the major threats to rural development. In the past 11 years, dramatic changes of environment have been recorded in case studies. The post-classification comparison method was used to observe the changes using multi-temporal satellite images which were captured in the years 1999, 2001, 2005, and 2010. The overall accuracy of the produced thematic images was assessed regarding to the quantity and allocation disagreements. Five classes were defined in this investigation: bare soil, vegetation, urban, sand dunes, and fertile soil. From the year 1999 to 2010, fertile soil was increased by 13 %. Bare soil class occupied more than 50 % of land in the case study during for over a decade. From year 1999 to 2010, vegetation cover witnessed a dramatic increase. Soil and water management are the keys of land development and positive land use and land cover dynamics. Changing agricultural policies of using the available water resources are needed in the case study to prevent severe food shortage in the future.     

Sustainable multivariate analysis for land use management in El-Sharkiya,Egypt

In Egypt, major sustainability variables could be identified as scarce of soil and water resources, environmental degradation, rapid population growth, institutional arrangement that includes land tenure and farm fragmentation, agricultural administration, lack of infrastructure, and credit utilization. The main objective of the current work is to evaluate the sustainable land use management (SLM) model through biophysics and socioeconomic elements for the purpose of combating sustainability constraints that preclude the agricultural development geospatially. In this research, from the geomorphologic point of view, the obtained results showed three main landscapes. They were identified in the study area as: fluviolacustrine plain, Aeolian deposits, and flood plain. The study area was dominated by some physical and chemical degradation processes with different scales breaking down the equilibrium of soil stability. The SLM model was implemented and assessed from multivariate perspective points of productivity, security, protection, economic viability, and social acceptability. Four SLM classes were outlined as follows: class I, land management practices that did meet sustainability requirements with a score ≥0.65, which represented 31.0 % of the considered agricultural study area; class II, land management practices that were marginally above the sustainability threshold and represented 12.6 %; class III, land management practices that were slightly below the threshold of sustainability and represented 8.60 %; class IV, land management practices that did not meet sustainability requirements with index values >0.1 that represented 47.86 %. As a general conclusion, it is found that land management practices tend to be unsustainable in the area under investigation for certain constraints that play motivated roles in lowering the targeted land sustainability.     

Characterization and assessment of groundwater resources using hydrogeochemical analysis,GIS, and field data in southern Wadi Qena,Egypt

An integrated approach using hydrogeochemical analysis, remote sensing, GIS, and field data was employed to characterize the groundwater resources in southern Wadi Qena, Egypt. Various thematic maps showing topography, lineaments, wadi deposits, slope, and stream networks were combined through GIS analysis to discriminate groundwater potential zones on the valley floor. The resulting map classifies the area into five groups of groundwater potentiality from very high to very low zones, supported by the groundwater level, well locations, and by the results of previous geophysical studies. Thirty-seven groundwater well data were tested from the Quaternary and Nubian Sandstone aquifers and analyzed for physio-chemical parameters. Results of hydrochemical analysis show that water quality varies widely through the aquifers, and groundwater in the Quaternary aquifer shows the highest salinity values and a predominance of Na and Cl in water chemical facies. Overlay GIS maps of alkalinity (SAR and RSC) and salinity hazards (EC and Cl) of the Quaternary aquifer were prepared. The resulting maps show that samples do not present an alkalinity hazard in most areas but are potentially salinity hazard. Therefore, the water is fit for agricultural use with certain restrictions, but is not suitable for direct human consumption because it is either very hard or too saline.     

贵州省万山区耕地土壤硒元素分布特征与相关性分析

硒是环境中重要的生命元素,缺硒和硒过剩都将引起生物及人体的不良反应。本文以贵州省万山区耕地土壤为研究对象,通过系统采样及化验分析耕地土壤硒含量,结果发现万山区耕地土壤硒含量在005801 mg/kg,平均值为050 mg/kg,总体上达到富硒区标准,富硒土壤面积2278万亩,占万山区耕地总面积的7743%,硒元素高值区分布在万山区东部的熬寨乡。同时,对影响万山区耕地土壤硒元素含量的相关性进行研究,得知影响土壤硒含量的主要因素是成土母岩、土壤类型,土地利用方式,土壤硒含量只与Hg、Cd、Mo、SOM呈弱相关性,与其余元素均无相关性。本研究成果对万山区土地合理规划利用,富硒产业的科学发展具有重要价值。     

基于GIS的国土资源综合监测需求程度区划研究

本文提出了国土资源综合监测需求程度区划的基本思路,明确了区划的四个基本原则,即:前瞻性、现势性、客观性和动态性.结合国土资源部的管理职责,首次确定了国土资源综合监测需求程度区划的指标体系,并把除港澳台外的全国陆域进行了综合监测需求程度区划研究,其结果可以为今后监测工作部署及综合监测网络优化提供参考依据.     

Groundwater potential zonation for basaltic watersheds using satellite remote sensing data and GIS techniques

This paper summarizes the findings of groundwater potential zonation mapping at the Bharangi River basin, Thane district, Maharastra, India, using Satty’s Analytical Hierarchal Process model with the aid of GIS tools and remote sensing data. To meet the objectives, remotely sensed data were used in extracting lineaments, faults and drainage pattern which influence the groundwater sources to the aquifer. The digitally processed satellite images were subsequently combined in a GIS with ancillary data such as topographical (slope, drainage), geological (litho types and lineaments), hydrogeomorphology and constructed into a spatial database using GIS and image processing tools. In this study, six thematic layers were used for groundwater potential analysis. Each thematic layer’s weight was determined, and groundwater potential indices were calculated using groundwater conditions. The present study has demonstrated the capabilities of remote sensing and GIS techniques in the demarcation of different groundwater potential zones for hard rock basaltic basin.