Assessment of Relationships Between Precipitation and Satellite Derived Vegetation Condition Within South Australia

The normalised difference vegetation index (NDVI) has evolved as a primary tool for monitoring continental‐scale vegetation changes and interpreting the impact of short to long‐term climatic events on the biosphere. The objective of this research was to assess the nature of relationships between precipitation and vegetation condition, as measured by the satellite‐derived NDVI within South Australia. The correlation, timing and magnitude of the NDVI response to precipitation were examined for different vegetation formations within the State (forest, scrubland, shrubland, woodland and grassland). Results from this study indicate that there are strong relationships between precipitation and NDVI both spatially and temporally within South Australia. Differences in the timing of the NDVI response to precipitation were evident among the five vegetation formations. The most significant relationship between rainfall and NDVI was within the forest formation. Negative correlations between NDVI and precipitation events indicated that vegetation green‐up is a result of seasonal patterns in precipitation. Spatial patterns in the average NDVI over the study period closely resembled the boundaries of the five classified vegetation formations within South Australia. Spatial variability within the NDVI data set over the study period differed greatly between and within the vegetation formations examined depending on the location within the state. ACRONYMS AVHRR Advanced Very High Resolution Radiometer ENVSAEnvironments of South Australia EOS Terra‐Earth Observing System EVIEnhanced Vegetation Index MODIS Moderate Resolution Imaging Spectro‐radiometer MVC Maximum Value Composite NDVINormalised Difference Vegetation Index NIRNear Infra‐Red NOAANational Oceanic and Atmospheric Administration SPOT Systeme Pour l’Observation de la Terre     

NDVI variation and its relation to climate in Canadian ecozones

Parks Canada began the Northern Satellite Monitoring Program in 1997, with the objective of tracking large‐scale vegetation variation in Canadian ecosystems and helping land managers to develop appropriate management practices in response to climate change. Under this program, a sequence of 10‐day composite Advanced Very High Resolution Radiometer (AVHRR)‐derived Normalized Difference Vegetation Index (NDVI) data from 1985 to 2007 was examined to study seasonal and inter‐annual relationships between vegetation and climate data over Canadian ecosystems using statistical and wavelet analysis. Statistical analysis showed that temperature was the principal driver for seasonal variability in greenness, explaining more than 70 percent of seasonal variation in vegetation for most Canadian ecozones. In comparison with temperature, the relationships between NDVI and precipitation were weaker but still significant. Maximum annual NDVI showed increasing trends in Canadian ecozones during the study period, although increasing rates were spatially heterogeneous. Wavelet analysis confirmed that inter‐annual variation in NDVI was different at two ecozones in Canada. NDVI variation in the Northern Arctic was significant at scales of 3–4 years from 1997 to 2001, which was associated with temperature and precipitation variation. Comparatively, NDVI variation in the Boreal Shield was significant at scales of 5–8 years from 1991 to 1999, but did not correspond with climate variation.     

Local Knowledge and Economic Realities Affecting Soil Erosion in the Rach Rat Catchment,Vietnam

Several parts of Binh Phuóc Province, southern Vietnam, suffer from degraded soils and vegetation as a result of both natural erosion of weak mud rocks and sandstones and intensive human activity, especially through land clearing for agriculture on unstable slopes, deforestation, and abandonment of poor farmland. The underlying cause of this land degradation has been the farming habits of migrants of varying ethnic groups who have settled in the area since 1980. The indigenous farming knowledge of these people and the role of that knowledge in soil erosion were examined by a series of household surveys. They enabled farming practices to be related to ground cover established from a 2002 Landsat 7 ETM (Enhanced Thematic Mapper), and erosion data from a series of erosion bridge measurements. A GIS (Geographical Information System) approach was piloted as a means of identifying areas vulnerable to erosion. This could then be combined with the understanding of farming practices to reveal the relative roles of farmer behaviour, crop cover, and slope and soil characteristics in the erosion process. Land use, local people's knowledge and economic realities are the main factors, as well as natural conditions, that drive this land degradation.     

Correlating Vegetation,Water Use,and Surface Temperature in a Semiarid City: A Multiscale Analysis of the Impacts of Irrigation by Single‐Family Residences

Urban heat islands (UHIs) and the vegetation that mitigates them vary across space and time, but little research has investigated this coupled natural–human system using both spatial and temporal analyses. Focusing on semiarid, water‐scarce Tucson, Arizona, we examined whether outdoor water use by residents of single‐family homes (a practice that uses close to half of residential water supplies) contributes to urban “greenness” and the mitigation of UHI effects. Specifically, we investigated how different types of residential development mediate vegetation–water use–temperature interactions. Our data sets include Landsat‐derived normalized difference vegetation index (NDVI) and surface temperatures, parcel‐level zoning and assessor data, and residential water use records at the quarter section level (0.63 km²). We analyzed these data at multiple spatial and temporal scales. Spatial analysis results demonstrate that cooling from vegetative evapotranspiration is mediated by development factors as well as by topography and wind patterns. Findings also suggest that outdoor water use aside from irrigation, particularly the use of swimming pools, promotes cooling without elevating the NDVI. Temporal analysis reveal that most residential areas maintained or increased greenness despite declining 1995–2008 water use due most likely to long‐term regional climate cycles. Only high‐density developments with little undeveloped ground cover and few natural drainage channels exhibit a strong relationship between household water use and NDVI trends. These results suggest that the preservation of natural drainage channels and limitation of impervious surfaces, as well as the siting of development in naturally cooled microclimates, may be sustainable strategies for UHI mitigation in water‐scarce regions. Análisis multi‐escalar de los impactos de riego en residencias unifamiliares: la correlación entre la vegetación, el uso del agua y la temperatura superficial en un área urbana semiárida Las islas de calor urbano (urban heat islands‐UHIs) y las áreas con vegetación que ayudan a mitigarlas varían en su distribución especial y temporal. Sin embargo, existe relativamente poca investigación dedicada al análisis espacio‐temporal de este sistema acoplado humano‐ambiental urbano. El artículo examina la medida en la cual el uso de agua al aire libre por parte de residentes de viviendas unifamiliares (practica que consume mas de la mitad de los recursos hídricos) contribuye al “verdor” de áreas urbanas y a la mitigación de los efectos de las UHs. El área de estudio es Tucson, Arizona, una ciudad ubicada en un ambiente semiárido que sufre de escasez hídrica. En términos más concretos, los autores investigan cómo los diferentes tipos de desarrollos urbanos residenciales sirven de mediadores en las interacciones entre la vegetación, la temperatura y el uso del agua. Como datos se utilizaron índices de vegetación (Normalized difference vegetation index‐NDVI) y temperaturas superficiales derivados de imágenes Landsat. Así mismo se usaron datos catastrales a nivel de parcela de zonificación, y registros de uso residencial de agua a nivel de cuarto de sección (quarter‐section) (0,63 km2). Los datos fueron analizados a múltiples escalas espaciales y temporales. Los resultados de análisis espacial demuestran que el enfriamiento de la evapotranspiración vegetal está influenciado por los factores de desarrollo urbano residencial así como por los patrones topográficos y climáticos (viento). Los resultados también sugieren que los usos de agua al aire libre, aparte de riego, en particular el uso de las piscinas (o albercas), promueven el enfriamiento sin elevar el valor del NDVI. El análisis temporal revela que la mayoría de zonas residenciales mantuvieron o aumentaron el ‘verdor’ a pesar de la disminución del uso del agua entre 1995 y 2008, debido probablemente a los ciclos climáticos regionales de largo plazo. Únicamente las zonas urbanas de alta densidad con escasas áreas verdes y pocos canales naturales de drenaje muestran una fuerte relación entre el uso del agua residencial y las tendencias del NDVI. Estos resultados sugieren que la preservación de los canales de drenaje natural y la reducción de superficies impermeables, así como el emplazamiento del desarrollo urbano en áreas con microclimas naturalmente más fríos, pueden ser estrategias sostenibles para la mitigación de UHIs en regiones con escasez de agua. 城市热岛与可缓解其效应的植被均随时间和空间变化,但鲜有研究从时空分析视角关注这一自然‐人文耦合系统。本文聚焦于半干旱、缺水的亚利桑那州图森市,主要调查独户家庭户外用水（其用水量大约是住宅供应水量的一半）是否对城市“绿化”和缓解城市热岛效应作出贡献。特别地,我们调查不同类型住宅开发是如何调节植物‐用水‐温度间的相互作用。数据集包括从美国陆地资源卫星获得的归一化植被指数（NDVI）和地表温度,地块区划和评估数据, 约160英亩（0.63 km²）用地面积的住户用水记录。我们从时空多尺度视角对这些数据进行了分析。 空间分析结果表明,植被蒸散作用导致的降温不仅受开发因素也受地形和风模式的调节。同时也发现：包括灌溉的户外用水,尤其是泳池用水,在促进地表降温时并未促使归一化植被指数（NDVI）提高。时间分析揭示,大多数居住区即使在1995–2008用水减少的情况下仍保持和增加“绿化”,最可能归因于长期的区域气候循环。只是在植被覆盖和自然排水系统均很少的高密度开发地区,家庭用水与NDVI趋势上显示出强相关性。这些结果昭示保留自然排水系统和限制不透水地表,以及在具有自然降温作用的微气候上选址发展区,或许是缺水地区缓解热岛效应的可持续策略。     

Gardens and the Bush: Gardeners’ Attitudes,Garden Types and Invasives

Garden plants that invade native vegetation can be a threat to native ecosystems. The species composition of gardens near the bush in Hobart, Tasmania, Australia is shown to relate to environmental variation and the attitudes of gardeners to their recreation, to native plants and to the bush. Four types of gardens are discriminated: the species‐poor shrub garden; the local native garden; the woodland garden; and the gardenesque. A group of gardeners who valued functional gardens, and the hard work in creating a garden, largely produced gardenesque outcomes. A strongly conservationist group of gardeners had native, woodland or shrub gardens. A group of gardeners who valued romance and privacy largely had woodland gardens. A small group of gardeners who liked gardens to create themselves, and preferred to minimize the act of gardening, tended to the shrub garden outcome. Plant species that invade the bush are least frequent in the more manicured shrub and gardenesque styles of garden than in the more informal local native and woodland gardens, in a dissonance between expressed attitudes and outcomes. Most of the most invasive weeds in the bush are shown to be independent of their occurrence in adjacent gardens, suggesting that integrated control programs involving both all gardeners within dispersal range, and bush managers, are necessary. The existence of a small number of respondents who see benefits in environmental weeds in their gardens, suggests that such programs would be ineffective without regulation, a solution offered by no respondent. However, regulation might be ineffective without community understanding, the raising of which was the main solution suggested by the interviewed gardeners.     

Date Palms and Opobalsam in the Madaba Mosaic Map

Abstract

The Madaba mosaic map shows two main vegetal motifs: the date palm and a mysterious bush. The inclusion of the date palm testifies to its economic importance in the region, and it would follow that the bush should also have a similar importance. This bush is best identified as the Judaean balsam or opobalsam, which we know from literary sources to have been grown in the lower Jordan Valley, and elsewhere, in the Roman period. This was a lucrative product. In the Madaba mosaic map, the bush is situated on both sides of the Jordan, which gives us an indication of the extent of its cultivation in the sixth century C.E.     

Snow-tracking and GIS: using multiple species-environment models to determine optimal wildlife crossing sites and evaluate highway mitigation plans on the Trans-Canada Highway

Snow-tracking data were collected for cougars (  Felis concolor ), lynx (  Lynx canadensis ), martens ( Martes americana ) and wolves ( Canis lupus ) and combined with remotely sensed imagery in a geographic information system (GIS) to identify wildlife crossing sites on the Trans-Canada Highway in Banff National Park, Alberta. We used logistic regression to assess the dependent (species presence/absence) relative to measures of topography and vegetation. The exponent form of each logistic regression equation was used to predict crossing sites in a GIS, which were then contrasted with mitigation sites proposed by Parks Canada. We found that: (1) cougars were influenced positively by normalized difference vegetation index (NDVI); negatively by northness and distance to ruggedness, (2) lynx were influenced positively by wetness, greenness, rugged terrain, eastness and distance to rugged terrain; negatively by slope, (3) martens were related positively to wetness, elevation, eastness, and distance to rugged terrain; negatively to northness, (4) wolves were influenced positively by distance to ruggedness; negatively by brightness, elevation, eastness and terrain ruggedness. There were few sympatric crossing sites for all species, supporting the use of species-specific mitigation or wide structures that capture multiple species needs. Inconsistencies were observed between the crossing sites predicted in this study and the Parks Canada proposal. The usefulness of GIS and track data to enhance mitigation projects is illustrated.     

LAND USE AND LAND COVER IN EASTERN CHINA: A LANDSAT ANALYSIS

Landsat imagery is a valuable source of information about the land use and land cover of inaccessible areas. In this study, the objective was to compile a map of eastern China, with particular emphasis on agricultural activity, from enhanced Landsat imagery using the diazo and density slicing techniques. Area measurement of major land uses was based on the land-use interpretation map, but because of the lack of ground verification it was necessary to turn to other sources of published and unpublished information as a control.
L'objectif de cette étude est la compilation d'une carte géographique de l'Est de la Chine, avec accentuation particulière des activités agricoles. Comme les images Landsat sont souvent la source unique d'information sur la végétation et l'utilisation de terrains inaccessibles, cette carte a éte cornpilée à l'aide d'images Landsat agrandies par les techniques diazo et density slicer. Les mesures des surfaces des régions principales sont celles de la carte d'interprétation de l'utilisation des terres. Faute d'une méthode de calibrage, il a fallu accepter les données de sources secondaires publiées et nonpubliées comme base de contrôle.     

NDVI Variability in North East India

Abstract

The variability of the Normalized Difference Vegetation Index (NDVI) in north east India in response to rainfall and temperature was analysed using twice-monthly NOAA/AVHRR satellite imagery acquired during 1982–2002 from the GIMMS (Global Inventory Modeling and Mapping Studies) data-set. Corresponding rainfall and temperature estimates were extracted from the Climate Research Unit's CR TS 2.1 data-set for 34 study sites, chosen using the GLC 2000 land use categories. The selected sites represent nine land use categories under differing institutional frameworks. Results showed a weak linear relationship between the growing season rainfall and NDVI range when plotted in a scatter diagram. The negative correlation between NDVI and rainfall and temperature and NDVI in the study area was accentuated during the growing season and a one- and two-month lag for rainfall and temperature respectively was operating. A gain coefficient image to determine the temporal change in NDVI during the 21-year period indicated a consistent decline for much of the study area. Among the study sites those under state protection fared better than sites under other institutional frameworks. Along with rainfall and temperature, land use and institutional frameworks emerged as causative factors in the dynamics of vegetation greenness in north east India.     

Measuring biological heterogeneity in the northern mixed prairie: a remote sensing approach

Biological heterogeneity, defined as the degree of dissimilarity between biological variables (e.g., biomass, green vegetation and Leaf Area Index [LAI]), is one of the most important and widely applicable concepts in ecology due to its close link with biodiversity. To investigate grassland biological heterogeneity, we selected three transects extending from upland to valley grasslands at Grasslands National Park (GNP), Canada, representing the northern mixed grassland. For the purposes of our analysis, three types of data were collected: remote sensing ground level hyperspectral data, biological data (LAI, biomass, and vegetation cover) and environmental data (soil moisture, organic content, and bulk density). Methodologically, field-level remote sensing data were used to calculate spectral vegetation indices. These indices, plus the biological variables, were then used in regression analyses with the goal of assessing the feasibility of using remote sensing data to study biological heterogeneity. The results indicate that it is feasible to use ground-level remote sensing data to represent biological variables. These indices can explain about 40–60 percent of the biological variation. Semivariogram analyses were further applied on these data to investigate their range of spatial variation. Spatial variations in the     

Satellite Remote Sensing Methods for Monitoring Archaeological Tells in the Middle East

Abstract

Using a variety of types of satellite imagery (SPOT, Corona, Landsat, and Quickbird) and concentrating on archaeological sites in the Egyptian floodplain, this paper proposes methods for monitoring the rate of archaeological site destruction in the Middle East. This image analysis shows how tells can be documented and monitored from computers anywhere in the world, emphasizing the multispectral capabilities and applications of satellites. The effects of population growth, looting, urban expansion, and war on archaeological sites in Egypt are reviewed, and a system is proposed to record sites by focusing on their individual spectral profiles. The analysis demonstrates how satellite imagery analysis can be applied to similar flood plain environments in Israel, Jordan, Syria, Turkey, Iran, Afghanistan, and Iraq.     

明清时期广西的虎患及相关生态问题研究

在历史上,广西曾是华南虎的重要栖息地,明清时期广西经历了一个较严重的虎患过程,特别是明代中后期、清初和清末三个时期的虎患非常严重,这反映出三个时期广西的人工生态环境因受战乱的影响而呈现出某种程度的自然退化,田地荒芜导致次生性植被复萌,为虎患的爆发提供了条件。随着社会的安定和人类开发活动的加强,特别是清代乾、嘉、道时期的山地垦殖运动兴起以后,广西的生态环境发生了巨大的变迁,森林植被覆盖率不断下降,虎患逐渐减轻。但人类在免受虎害的同时,却不得不面临生态恶化的威胁。     

Potential Use of Radiometric Data for Wildlife Habitat Modelling

The potential use of existing radiometric data sets, previously collected for prospecting purposes, has very rarely been used as a variable predictor in wildlife habitat modelling. The utility of radiometric data for predicting vegetation community patterns and wildlife habitat was investigated in the Australian arid zone using the Burt Plain bioregion as a case study. Using spatial datasets and a Species Distribution Modelling Toolkit, arid zone vertebrate species were modelled with Generalised Linear Modelling (GLM) regression modelling techniques. These models were used to predict the probability of occurrence of a species at any given location, defined in terms of its environmental attributes. A statistical correlation between the radioactive elements uranium, thorium and potassium, and terrain aspect was found. No statistical correlations were established between the radioactive elements and vegetation patterns; although we suspect these exist at finer scales of mapping. Radiometric data were identified as explanatory variables in the habitat models of all of the 32 vertebrate species examined, and used as illustration in the development of probabilistic spatial predictions of three species (Red Kangaroo, Macropus rufus; Lesser Hairy‐footed Dunnart, Sminthopsis youngsoni; and Rabbit, Oryctolagus cuniculus) in the bioregion. Our analyses suggest that radiometric data sets involving the radioactive elements: (uranium, thorium, and potassium), and vegetation could be used as predictors of biodiversity patterns at the bioregional and landscape level. This is an important finding given the challenges posed in undertaking broad‐scale biological surveys in the arid zone of Australia.     

Integration of geophysical surveys,ground hyperspectral measurements,aerial and satellite imagery for archaeological prospection of prehistoric sites: the case study of Vésztő-Mágor Tell,Hungary

An integration of geophysical surveys, ground hyperspectral data, aerial photographs and high resolution satellite imagery for supporting archaeological investigations at the multi-component Vészt?-Mágor Tell, located in the southeastern Great Hungarian Plain, is presented in this study. This is one of the first times that all these techniques have been combined and evaluated for retrieving archaeological information. Geophysical explorations, specifically magnetic gradiometry and ground penetrating radar methods, have revealed shallow linear anomalies and curvilinear rings at the Tell. The use of remote sensing images has confirmed the diverse anomalies with respect to geophysics through photointerpretation, radiometric and spatial enhancements. Moreover, several indices from ground hyperspectral data also have revealed stress vegetation anomalies. These integrated results were used to map the main areas of archaeological interest at the Vészt?-Mágor Tell and plan future excavations. It was found that these multiscalar data can be used efficiently for detecting buried archaeological features.     

基于GIS的西安市城市扩展与模拟研究

本文以西安市为研究区域,以2002年ETM影像和2007年TM影像遥感数据为城市扩展动态变化的主要信息来源,采用逻辑回归模型并结合GIS技术对西安市的城市空间扩展进行模拟。研究选取了道路、河流、地裂缝、地面沉降、人口和GDP等6个因子,建立了西安市城市扩展的逻辑回归模型,并根据所建立的模型对西安市的城市扩展进行了模拟,结果表明,所建立的逻辑回归模型能够较好地模拟西安市的城市扩展,对西安市城市扩展的驱动力具有较强的解释作用,其中对城市扩展影响最重要的因素为距道路距离。     

Monitoring Saline Discharge Areas: Farrell Flat,a Case Study

By monitoring saline groundwater discharge areas, an indication of the extent of dryland salinisation processes occurring in an area may be determined. Processed remotely sensed data (SPOT MS and aerial photography) has been analysed within a geographic information system database to identify the dynamic relationship between changing vegetation cover and increasing salt levels on a saline groundwater discharge area. Temporal analysis of this database was conducted for a saline discharge area on a wheat/sheep property in South Australia from the period 1966 to 1990. The results provide a directional and quantitative assessment of the change in salt affected areas during the study period. Information of this type benefits land managers at the regional scale by quantifying salinisation trends.     

Revegetated Sand Mining Areas,Swamp Wallabies and Remote Sensing: North Stradbroke Island,Queensland

Mining of mineral sands has taken place on North Stradbroke Island for over 40 years. Revegetation of mined areas creates a mosaic of seral classes. For a mine site in the northwest of the island, Landsat Thematic Mapper data were used successfully to map the distribution of seven seral classes resulting from mining rehabilitation. Faecal pellet counts were used to assess usage of these areas and surrounding natural forest by swamp wallabies, Wallabia bicolor. Results indicated that revegetated sites from 2 to 4 years in age were heavily used by wallabies. Older revegetated sites, dominated by senile Acacia cunninghamii, and offering little or no forage, were avoided. Swamp wallabies used revegetated sites for night-time feeding sessions and rested, during the day, in surrounding eucalypt forest.     

Shoreline Change and Coastal Vulnerability Characterization with Landsat Imagery: A Case Study in the Outer Hebrides,Scotland

Abstract

Observation of cause–effect patterns of change in coastal environments provides insights into vulnerable areas and supports prediction and adaptation to flooding and erosion. Historic and periodic (6–8 year intervals) imagery from the Landsat archive is used to investigate transformations in the Atlantic coast of two Scottish islands over the period 1989–2011. Supervised classification of spectrally normalized images followed by change detection and spatial analysis reveals the patterns of change and the location of the most dynamic coastal areas. Quantitative measures of recent shifts and movement rates of relevant coastal lines, such as the lower limit of land-based vegetation, are assessed with the Digital Shoreline Analysis System. While very low rates are indicated for horizontal changes in the position of the lower limit of land-based vegetation (0.3?m?y^?1), specific areas have been subjected to high rates of coastal progradation as well as erosion (e.g. 2.5?m?y^?1 at Stilligarry). Information derived from satellite data supports the characterization of geomorphologically dynamic coasts at regional scales. With a rich and open access archive of imagery, a commitment to continuity, and compatibility with the Earth observation missions of other space programs, the Landsat mission offers useful and otherwise unavailable data for monitoring of coastal areas.     

Observatory validation of Neolithic tells (“Magoules”) in the Thessalian plain,central Greece,using hyperspectral spectroradiometric data

This paper presents the results obtained from field spectroradiometric campaigns over Neolithic tells (“magoules”) located at the Thessalian region in Greece. In each one of the four archaeological sites selected, three sections were carried out using the GER 1500 handheld spectroradiometer. Spectral profiles of the sections and several vegetation indices such as Normalized Difference Vegetation Indices (NDVI) and Simple Ratio (SR) have been examined in this study. This is one of the first times that ground hyperspectral data are evaluated in such context of archaeological research for the spectral characterization of archaeological features. As it was found, ground spectroradiometric measurements can be efficiently used in order to support and validate satellite imagery results for the detection of archaeological sites.     

Monitoring Land‐Cover and Land‐Use Change in a Rapidly Urbanising Coastal Environment: the Maroochy and Mooloolah Rivers Catchments,Southeast Queensland, 1988–1997

Effective catchment monitoring requires an integrative approach for selecting remotely sensed data to monitor land‐cover change. Catchment analyses and monitoring requirements in the Maroochy and Mooloolah River Catchments (south‐east Queensland) were addressed by linking government and community information needs to appropriate scales of remotely sensed data and processing routines. A hybrid image classification approach applied to Landsat Thematic Mapper image data acquired in 1988 and 1997 provided catchment scale land‐cover maps (with accuracies of 73% and 84%). Land‐cover change maps derived from post‐classification comparison provided information on the spatial distribution and type of land‐cover changes between 1988–1997. Land‐cover change was dominated by activities related to urban residential expansion (suburban and rural residential) and agricultural expansion (sugar cane farms). Significant spatial variations in the geometric registration accuracy of the image data sets and classification accuracies produced moderate to low change detection accuracies. However, the framework and community consultation used for selecting and processing data ensured the resource managers and community groups were fully aware of the limitations of the land‐cover change mapping process and that the output images were suitable for incorporating in resource monitoring activities.