GIS and remote sensing as tools for conducting geo-hazards risk assessment along Gulf of Aqaba coastal zone,Egypt

Satellite remote sensing data, in addition to Geographic Information Systems (GIS), offers an excellent alternative to conventional mapping techniques in monitoring and mapping of geo-hazards areas. One of the most sustainable development projects in Egypt has been accomplished in Sinai, especially along and around the Gulf of Aqaba and the Gulf of Suez. Variations along the coastal zone of the Gulf of Aqaba have been identified through the analysis of multi-temporal satellite images with the aid of GIS analysis. The study area is subject to rapid and increasing changes in land-use/land-cover that resulting from natural and human activities such as flash flooding, seismic activity, landslides, and tourist and urban activities. This is in addition to the construction projects of roads, ports, PowerStation stations, mineral exploration, beaches, and tourist villages resulting from major environmental impacts. The current study aims to use Remote Sensing and GIS tools to investigate, monitor, and assess geo-hazards through the building of a geographical database. Several techniques have been developed over the last decade mostly to study the geological and geomorphologic characteristics of the terrain; land-use and land-cover changes. These are based on satellite imagery and Digital Elevation Models (DEM) to determine the topographic features, and geo-hazards maps. It is concluded that integrated approaches to monitoring can successfully be used to assess the environmental impacts along the Gulf of Aqaba coastal zone.     

Geo-environmental hazards assessment of the north western Gulf of Suez,Egypt

The aim of the present study is to assess the present geo-environmental hazards, both flash flooding and seismic activity in the western part of Gulf of Suez. Assessment includes the analysis of satellite images, topographical, geological and other ancillary geological data using GIS technology. GIS data integration and analysis, including morphometric, local seismic activity and structural data analysis indicated that the area is under threat from two types of geo-hazards. Morphometric analysis strongly supported the high probability of flash flooding in different sites within the study area. The structural lineaments, extracted from an enhanced ETM+7 image, showed that the majority of seismic activity is related to segments of the fault system of the Gulf of Suez and the Gulf of Aqaba. The seismic activity hazard was taken into consideration through the identification of the sources of events. Seismic activity in the study area markedly increases from north to south. The distribution of the seismic activity pattern and data analysis for the study area clearly exhibits the urgent need for an assessment and rehabilitation program to mitigate geo-hazard along the existing structures.     

Manifestation of an advanced fuzzy logic model coupled with Geo-information techniques to landslide susceptibility mapping and their comparison with logistic regression modelling

Landslides are very common natural problems in the Selangor area of Malaysia due to the improper use of landcover and tropical rainfall. There are many landslide susceptibility analyses such as statistical, bivariate and data mining approaches exist in the literature. This paper presents the use of fuzzy logic relations for landslide susceptibility mapping on part of Selangor area, Malaysia, using a Geographic Information System (GIS) and remote sensing data. At first, landslide locations were identified in the study area from the interpretation of aerial photographs and satellite images, supported by extensive field surveys. Topographic and geological data and satellite images were collected, processed, and constructed into a spatial database using GIS and image processing. Thirteen landslide conditioning factors such as slope gradient, slope exposure, plan curvature, altitude, stream power index, topographic wetness index, distance from drainage, distance from road, lithology, distance from faults, soil, landcover and normalized difference vegetation index (ndvi) were extracted from the spatial database. These factors were analyzed using fuzzy logic relations to produce the landslide susceptibility maps. Using the landslide conditioning factors and the identified landslides, the fuzzy membership values were calculated. Then fuzzy algebraic operators were applied to the fuzzy membership values for landslide susceptibility mapping. Finally, the ROC curves for all landslide susceptibility models were drawn and the area under curve values were calculated. Landslide locations were used to validate results of the landslide susceptibility maps and the validation results showed 94% accuracy for the fuzzy gamma operator employing all parameters produced in the present study as the landslide conditioning factors. Results showed that, among the fuzzy relations, in the case in which the gamma operator (λ =  0.975) showed the best accuracy (94.73%) while the case in which the fuzzy algebraic Or was applied showed the worst accuracy (84.76%). The landslide susceptibility maps produced by the fuzzy gamma operators shows similar trends as those obtained by applying logistic regression procedure by the same author and indicate that fuzzy relations results perform slightly better than the earlier method. Qualitatively, the model yields reasonable results which can be used for preliminary land-use planning purposes.     

Application of remote sensing and geographical information system in mapping forest fire risk zone at Bhadra wildlife sanctuary, India

Fire is the most spectacular natural disturbance that affects the forest ecosystem composition and diversity. Fire has a devastating effect on the landscape and its impact is felt at every level of the ecosystem and it is possible to map forest fire risk zone and thereby minimize the frequency of fire. There is a need for supranational approaches that analyze wide scenarios of factors involved and global fire effects. Fires can be monitored and analyzed over large areas in a timely and cost effective manner by using satellite imagery. Also Geographical Information System (GIS) can be used effectively to demarcate the fire risk zone map. Bhadra wildlife Sanctuary located in Kamataka, India was selected for this study. Vegetation, slope, distance from roads, settlements parameters were derived for a study area using topographic maps and field information. The Remote Sensing (RS) and Geographical Information System (GIS)-based forest fire risk model of the study area appeared to be highly compatible with the actual fire-affected sites. The temporal satellite data from 1989 to2006 have been analyzed to map the burnt areas. These classes were weighted according to their influence on forest fire. Four categories of fire risk regions such as Low, Moderate, High and Very high fire intensity zones were identified. It is predicted that around 10.31% of the area falls undermoderate risk zone.     

Are existing vegetation maps adequate to predict bird distributions?

Bird species are selective on the vegetation types in which they are found but predictive models of bird distribution based on variables derived from land-use/land-cover maps tend to have limited success. It has been suggested that accuracy of existing maps used to derive predictors is in part responsible for the limited success of bird distribution models. In two areas of 4900 km² of Western Andalusia, Spain, we compared the predictive ability of bird distribution models derived from two existing general-purpose land-use/land-cover maps, which differ in their resolution and accuracy: a coarse scale vegetation map of Europe, the CORINE land-cover map, and a detailed regional map, the 1995 land-use/land-cover map of Andalusia from the SINAMBA (Consejerı́a de Medio Ambiente, Junta de Andalucı́a). We compared the bird distribution models derived from these general-purpose vegetation maps with models derived from two more accurate structural vegetation maps built considering directly variables that influence bird habitat selection, one built from satellite images for this study and another obtained by improving the resolution and accuracy of the SINAMBA map with satellite data. We sampled the presence/absence of bird species at 857 points using 15-min point surveys. Predictive models for 54 bird species were built with generalised additive models (GAMs), using as potential predictors the same set of landscape and vegetation structure variables measured on each map. We compared for each bird species the predictive accuracy of the best model derived from each map. Vegetation structure measured at bird sample points was used as ground-truth for comparing the accuracy of vegetation maps. Although maps differed in their resolution and accuracy, the results show that all of them produced similarly accurate bird distribution models, with a mixed map produced with both thematic and satellite information being the best. The models derived from the more accurate vegetation structure maps obtained from satellite data were not more accurate than those derived directly from the SINAMBA or CORINE maps. Our results suggest that some general-purpose land-use/land-cover maps are accurate enough to derive bird distribution models. There is a certain limit to improve vegetation maps above which there is no effect in their power to predict bird distribution.     

The potential implementation of green infrastructure assessment using high-resolution National Agriculture Imagery Program data for sustainable hazard mitigation

As green infrastructure gets its attention in hazard mitigation, it is necessary to improve general understanding on what makes green infrastructure important for hazard and resiliency research. To better understand how green infrastructure fits with more traditional notions of structural and nonstructural mitigation, this study examines the relationship between green infrastructure and ‘structural and nonstructural’ mitigation approaches for hazard mitigation. Also, this study discusses a new measurement of locational aspects and spatial patterns of green infrastructure by utilizing high-resolution data in urban areas, and its potential implementation in hazard mitigation. Compared to previous research using land-use land-cover datasets, the normalized difference vegetation index (NDVI) utilizing National Agriculture Imagery Program dataset provides an ability to capture green infrastructure in greater detail. A visual comparison suggests that the NDVI data are able to capture and identify more types of ‘green’ land uses in Harris County. The total green infrastructure percentages for Harris County, Texas, based on 1-m high resolution were found to be 61.5% of the area, compared to the 51.5% based on the National Land Cover Database. This study provides support for utilizing high-resolution data to establish guidelines for green infrastructure’s spatial characteristics and sustainable hazard mitigation. The outcomes of this study will be helpful in the strategic planning and implementation of green infrastructure in urban areas with hazard issues.     

Ecological effects associated with land-use change in China's southwest agricultural landscape

Research on land-use and land-cover change, with associated effects on the ecoenvironment, is a key to understanding global change. The concept of 'ecosystem services' is also a hot issue in ecology and ecological economics. In this study, ecosystem service values are used to assess the ecological values of corresponding land-use types, so as to evaluate the ecological effects of regional land-use change. China's southwest agricultural landscape has unique ecological functions; but it also belongs to an ecologically fragile zone. Consequently, land-use change and associated ecological effects must be monitored to assure sustainable development of this area. Based on TM images in 1988, 1994 and 1999, the landscape classification maps of Yongsheng County were assessed using supervised classification and interactive modification methods. The transition matrix of land-use types and three indices of spatial patterns, patch-level, class-level and landscape-level indices, were calculated using models and GIS to examine the spatial patterns and dynamics of land use in the study area. The results show the influences of human activities and natural environmental elements, and that unused land has decreased rapidly, together with a continuous increase in forest during the past 11 years. There are also frequent intermediate transitions between farmland and unused land. An index for landscape diversity shows a tendency to increase, indicating that the proportions of each landscape element tended to average. Also, the decrease in the fractal dimension of unused land reveals that the effects of human activity are increasing. Ecological value calculations show that land-use change in Yongsheng County from 1988–1999 has resulted in positive ecological effects, with distinct spatial differences.     

A GIS-based model for rating natural protection areas according to natural protection priorities

There has been a major urban shift of population in Turkey over the last century. Most people lived in rural areas until 1960, but now more than half live in urban areas. This trend has continued over the last 20 years, as families moved further away from city centres to find houses in the country, and this has caused land use to change rapidly. In decision-making studies to protect nature areas, rating and assessment of ecological data by scientific verification is difficult due to the huge volume and diversity of data. Therefore, the search for the most suitable and applicable method to achieve physical planning based on ecological understanding has been sought. The necessity for numerous parameters to be taken into account has stimulated the use of geographic information systems (GIS). This study assesses the usefulness of a GIS-based model in the protected area of Kaynaklar County, to the south of the city of Izmir. Existing cultural and natural land-use types, as well as soil, hydrologic, geologic and geomorphologic data layers (future classes) were gathered from field observation and using Landsat and IKONOS satellite images, and transferred to a database according to GIS rules. Index values were determined by taking impact on attributes of natural protection as a priority and these were attached to each feature class. Layers of data were merged by spatial intersection methods and new polygons were created for both cultural and natural features. A three-grade final map of the study area was generated using total index values of each new polygon.     

Land-cover change within and around protected areas in a biodiversity hotspot

The landscape surrounding protected areas influences their ability to maintain ecosystem functions and achieve conservation goals. As anthropogenic intensification continues, it is important to monitor land-use and land-cover change in and around protected areas. We measure land-cover change surrounding protected areas in the Maputaland-Pondoland-Albany Biodiversity hotspot from the 1980s to present. Using Landsat imagery, we classified land cover within and around each protected area. Agricultural land uses were increasing and often directly border protected area boundaries. Human settlements increased around every protected area, potentially increasing human activity along the edges of protected areas and threatening their ecological integrity. Urban expansion around protected areas varied but increased as much as 10%. Woody vegetation cover varied both within and around protected areas with possible evidence of deforestation and shrub encroachment throughout the hotspot. We recommend monitoring land cover across southeastern Africa to better understand regional trends in land-use impacts to protected areas.     

内蒙古皇甫川五分地沟小流域土地覆盖空间格局特征及其持续性分析

基于1979、1987和2002年3个时期的土地覆盖类型图，从斑块面积、形状、空间关系3方面着手。利用斑块面积百分比、面积变异系数、分维数3个景观格局指数对内蒙古皇甫川五分地沟小流域的土地覆盖格局及变化特征进行研究；并以流域为尺度，测算土地覆盖破碎度、多样性指数、分维数、合理性指数4个指标随时间变化的持续性。结果表明：研究区土地覆盖现状呈现各类型相对较均衡的镶嵌状分布格局，土地覆盖类型较稳定，斑块形状较简单，受人类干扰较大。土地覆盖特征指数的持续性分析结果与对应的指标分析结果相吻合。     

内蒙古皇甫川五分地沟小流域土地覆盖空间格局特征及其持续性分析

基于1979、1987和2002年3个时期的土地覆盖类型图,从斑块面积、形状、空间关系3方面着手,利用斑块面积百分比、面积变异系数、分维数3个景观格局指数对内蒙古皇甫川五分地沟小流域的土地覆盖格局及变化特征进行研究;并以流域为尺度,测算土地覆盖破碎度、多样性指数、分维数、合理性指数4个指标随时间变化的持续性。结果表明:研究区土地覆盖现状呈现各类型相对较均衡的镶嵌状分布格局,土地覆盖类型较稳定,斑块形状较简单,受人类干扰较大。土地覆盖特征指数的持续性分析结果与对应的指标分析结果相吻合。     

Targeting Conservation Action through Assessment of Protection and Exurban Threats

Abstract:   Landscape-level assessments of biodiversity strive to guide land-use planning and conservation activities by providing information about areas of high biodiversity value and low protection status. I developed a methodology to assess the level of threat to conservation of biodiversity to help guide conservation action. This method incorporates socioeconomic indicators of risk, including developed and roaded areas, and measures the proportion of conservation lands affected by developed areas. In addition, I developed a metric called conservation potential to measure the degree of fragmentation of patches caused by development. As an illustration I applied this methodology to Colorado (U.S.A.). Protection levels were determined by examining land ownership, resulting in protected lands (status levels 1 and 2) and unprotected lands (status levels 3 and 4). Areas were considered threatened (at risk) if a land-cover patch had >20% roaded area, >15% developed area, or was highly fragmented. Although 24 of 43 natural land-cover types were unprotected (49% of the state), 9 additional types were threatened. Combining conservation-status protection levels with patterns of threat targets the geographic area where conservation action is needed, provides a way to determine where so-called protected areas are at risk, and allows conservation strategies to be better refined.     

Soil erosion hazard evaluation—An integrated use of remote sensing,GIS and statistical approaches with biophysical parameters towards management strategies

Soil erosion hazard maps can be an essential tool in erosion prone areas as they explain and display the distribution of hazards and areas likely to be affected to different magnitudes. Therefore, it is very useful to planners and policy makers initiating remedial measures and for prioritizing areas. In this study, a numerical model was developed for soil erosion hazard assessment, in which Z-score analysis was combined with a geographical information system (GIS) to compute a synthetic soil erosion hazard index (SEHI). For this model, nine factors which have notable impact on soil erosion were selected. To generate the selected factors remote sensing, analytical hierarchy process (AHP) and GIS techniques along with spatial models were applied. To standardize all of the factors and establish the factor weights, the AHP method was adopted. For Z-score analysis with selected standardized factors, the Integrated Land and Water Information System (ILWIS) software was used and nine individual layers with Z-scores were prepared. Afterwards, the layers were integrated with their factor weights by means of a weighted linear combination to derive a SEHI value for each pixel. To classify the discrete SEHI map to represent a meaningful regionalization of soil erosion hazard, the equal distance cluster principle was used and graded into four levels of hazard; very high, high, moderate and low. The results depicted that in general, a moderate hazardous condition of soil erosion was found in the study area and the proposed approach was also able to identify the areas under high and very high hazards that require urgent intervention on a priority basis. Based on this study, comprehensive erosion hazard management strategies were anticipated for the efficient management of present and future erosion disaster in the area.     

Assessment of forest fire vulnerability zones in Missouri,United States of America

Forest fire is one of the major disasters that distresses the terrestrial environment and causes economic disruptions for people and communities in areas prone to forest fire. Information on forest fire risk zones is therefore essential for effective and sound decision-making in forest management. Forest fire risk assessment is a critical part and the most important step in forest management because it enables us to know where the risk is higher in order to minimize threats to life, property and natural resources. This study used a hazard assessment model to assess forest fire risk in Missouri based on several measurable environmental parameters influencing forest fire risk vulnerability. Using the four ecological zones in Missouri as the basis of analysis, three forest risk zones were identified. These were high forest fire risk zones, moderate forest fire risk zone and low forest fire risk zone. Strategies for the mitigation of the hazard of forest fire in the state were also recommended.     

Remote sensing of global change: growth in China's Jiangsu Province

SUMMARY

This paper examines how remote-sensing data and regional social and economic data can be used together to identify changes in land-use patterns in particular regions. Study of the spatiotemporal dynamics of remote-sensing data can identify trends in competing uses of land, water and other natural resources for agriculture, industrial development and urban settlements. When combined with information on trends in industrial production, population, agricultural production, pollutant releases, water usage and natural forest coverage, these data reveal patterns of anthropogenic disturbance that can provide early signals of problems in resource decline or land-use management. This study focuses on land-cover changes in southern Jiangsu Province of the People's Republic of China between 1976 and 1984. This region, to the west of Shanghai and to the south of the Yangtze River, experienced unprecedented economic growth after the end of the Cultural Revolution. Remote-sensing imagery reveals the rapid growth of urban centres, commensurate declines in surface water area, and changing patterns of agriculture. The observed changes cast doubt on the ability of the region to sustain such rapid and intense land-use conflicts over a long period.     

Characterizing Core and Corridor Use by Nubian Ibex in the Negev Desert, Israel

Abstract: Corridors have become a key element of conservation efforts. To identify and characterize corridors used by Nubian ibex ( Capra ibex nubiana ), we analyzed sighting data recorded for the past 20 years in the Israel Nature Reserves Authority data banks. We categorized each recorded sighting as belonging to a corridor or a core zone based on the total number of sightings in its vicinity. We identified three main core populations, a natural corridor connecting two of them, and a corridor that was not evident connecting the third population. Ibex inside and outside core zones were sighted on steeper terrain than expected by chance; this was more pronounced inside the core zones than outside them. We hypothesize that because ibex outside core zones must move rapidly and directionally across unfamiliar habitats, they must use more moderate terrain. Although ibex sightings in core zones were mostly in the vicinity of water, we found no relationship between the location of the sightings and proximity to water sources in the corridor. Hence, water does not appear to be an important factor in movement through corridors. It was more common to observe ibex out of the core zones during the summer. Males, which can be twice the size of females, were found traveling alone in corridors more often than in core zones. There was no difference between males and females in the steepness of terrain in which they were sighted outside core zones. Our data show that protecting ibex habitat in core zones and corridors is important to ibex conservation in Israel's arid zones. In addition, protecting this habitat may benefit other rock-dwelling species in the area.     

基于遥感技术的松辽平原盐渍化动态研究

运用.RS、GIS手段,以航天遥感MSS/TM/ETM为主要信息源,运用参数构造法、空间叠加分析法和网格等值线追踪法.对松辽平原盐渍化进行多时相遥感动态监测.研究结果表明.近30年来松辽平原盐渍化面积持续增加.强度持续增强.盐渍化面积变化总动态度为-1.03%,其中,1975-1989年为-1.67%,1989-2003年为-0.31%.盐渍化强度中心位于大安与乾安之间,1975-1989年,强度中心向北东方向移动22.81 km;1989-2003年,强度中心向西南方向移动16.50 km.松辽平原盐渍化是自然因素和不合理人类活动共同作用造成的.     

厦门环同安湾海岸带景观空间格局动态变化分析

利用遥感和地理信息技术,运用平均斑块面积与分离度指数、多样性指数、破碎度指数、优势度指数和分维数等景观格局指数,以厦门环同安湾区1989年、1997年和2007年3个时期遥感影像解译数据作为基本信息源,对过去18年间环同安湾海岸带的景观格局的时空变化过程和演变趋势进行了研究。结果表明：1989—2007年,农田面积大量...     

A review on historical trajectories and spatially explicit scenarios of land-use and land-cover changes in China

ABSTRACT

Land use in China has changed remarkably over the past centuries with manifold implications for sustainable development. Investigation and projection of the land-use and land-cover changes (LUCC) have therefore become critical to promote the understanding of the LUCC process and the interactions with human societies. Scientists had devoted great efforts to create, process, and interpret comprehensive historical land-use/cover datasets, and to simulate future land-use systems under different scenarios. We synthesize the literature on the historical trajectories of LUCC in China, and summarize existing efforts of scenario developments for the projection of spatially explicit LUCC. Our review therefore provides salient suggestions for future land-use change analysis.     

The Trifinio Region: a case study of transboundary forest change in Central America

Strategic planning to increase forest cover in Central American transboundary areas of the Mesoamerican Biological Corridor requires understanding land-cover and land-use change trends and drivers. We estimated forest cover change from remotely sensed land-cover and land-use classifications from 1986, 2001, and 2010, in the tri-national Trifinio Region, bordering El Salvador, Guatemala, and Honduras. Our analysis spanned subnational, national, regional, and protected border areas. We determined correlations with direct drivers of deforestation, developing a multilevel linear regression model. Higher population density significantly correlated with deforestation; coffee, agroforestry, and pasture replaced forests. The tri-national park retained forests compared to neighboring areas, but additionality requires more research. The literature on drivers suggests similar processes and factors in other tropical regions. Forest cover governance efficacy is highly variable. Results indicate relationship between governance and forest cover though more comprehensive understanding of this complex region is needed to determine their causality.