多源土地利用地学知识的获取与应用

土地利用地学知识可应用于LIS智能化分析及辅助遥感影像解译,是国土信息化工程建设中值得深入研究的重要技术环节之一.明确了土地利用地学知识概念,构建了多数据源的土地利用地学知识体系,针对不同数据源分析了土地利用地学知识的获取及表达,并着重对土地利用地学知识辅助遥感影像解译进行了阐述,指出采用知识辅助高分辨率遥感影像解译是亟待深入开展研究的课题.     

水库型饮用水水源地一级保护区隔离防护工程研究

依托于地理信息系统空间数据管理和空间信息分析的功能,利用高分辨率遥感影像研究隔离方案划定的技术流程。该技术流程主要包括收集水源地基础资料、解译高分辨率遥感影像、提取土地覆盖分类信息、建立空间数据库、划定物理隔离和生物隔离的区段。该种技术流程也适用于地形复杂、一级保护区面积较大的地下型水源地。     

基于ETM影像多种特征的CART决策树分类——以延边州为例

分类回归树(CART)是一种非参数化的分类与回归方法,在用于遥感影像自动分类时,可方便地应用多源知识,提高分类精度.以延边州试验区土地利用/覆被分类为例,利用分类回归树分析从训练样本中集中发现分类规则,集成遥感影像的光谱特征、纹理特征和辅助地学特征进行分类试验,并与传统的最大似然分类方法进行比较.结果表明,基于CART的决策树分类结果的总精度和Kappa系数分别为90.37%和0.8863,分类精度比MLC监督分类方法有明显提高.     

基于QuickBird影像目视解译在土地利用类型调查中的应用——以遂宁市船山区新桥镇为例

利用高分辨率的QuickBird影像数据,对遂宁市船山区新桥镇的土地利用类型进行调查,参照四川省"金土地工程"农业地质遥感综合调查工作方案,通过对图像进行适当的处理,建立较为准确的解译标志,采用人工目视解译结合人机交互式解译的综合判读方法,从图像上获取相对准确的土地利用类型信息.     

干旱区绿洲土地覆盖变化遥感应用研究--以新疆于田绿洲为例

从人地关系理论出发以土地利用变化为切入点通过野外调查和遥感动态监测对干旱区绿洲土地覆盖变化规律进行了研究.在考察数据和对遥感图像的分类结果的评价的基础上对干旱区绿洲土地利用/土地覆盖空间动态变化进行规律性分析提出只有协调人地关系、加强区域地理建设才是使干旱区绿洲地区避免荒漠化的唯一道路.     

基于"3S"技术的城郊森林公园土地利用问题分析——以武汉市马鞍山森林公园为例

近年来城郊森林公园发展很快,然而城郊型森林公园的土地利用问题的研究却很少。分析了城郊森林公园土地利用的特点,并以武汉市马鞍山森林公园为例,借助3S技术,以1989年、1995年、1998年、2005年遥感影像为主要数据源,分析了马鞍山森林公园土地的现状、变化及存在的问题,并提出了建议。     

高分辨率遥感影像在城市绿地信息提取中的应用研究

高分辨率卫星遥感图像数据量大、空间分辨率高、结构信息复杂、地物同物异谱现象更为突出等特征给专题信息提取技术带来了新的挑战。基于植被的光谱特征,利用监督分类、植被指数分类和目视解译等方法对QuickBird高分辨率卫星遥感影像的绿地信息进行提取,并对分类精度作了比对分析。研究结果表明,监督分类方法不能得到令人满意的结果,运用植被指数分类方法则有明显改善,其中归一化植被指数(NDVI)精度最高,因此NDVI能有效地对植被进行分类与识别。     

伊犁河谷土地利用/土地覆盖遥感调查分析研究

伊犁河谷水土资源开发使得土地利用/土地覆盖类型这一区域生态环境演变的重要因素处在变化之中,由此产生的生态环境问题还没有得到有效控制。在解析2000和2005年伊犁河谷的Landsat TM遥感影像基础上,分析、探讨土地利用/土地覆盖现状和动态变化及其特征,揭示生态环境问题。为了防止生态环境问题进一步恶化,使生态环境效益与经济效益同步协调发展,提出调整产业结构、建设草业、设计生态用水、实行环境保护工作“一把手”负责制的建议。     

基于GIS-CA-Markov的白马河流域土地利用变化模拟分析

土地利用/覆被变化的预测模拟研究对探索土地利用变化的规律与方向,实现可持续发展具有十分重要的意义。以济宁市白马河流域为例,以不同时期的Landsat TM遥感影像为数据源,首先利用CA-Markov模型对2010年和2015年白马河流域的土地利用进行预测并检验其模拟精度,在较适宜的尺度条件下预测研究区2020年的土地利用分类。结果表明:对2015年白马河流域实际土地利用图与预测图进行Kappa系数一致性检验,模拟精度较高为0.9121,表明预测与实际几乎完全一致。2005—2020年,白马河流域建设用地和水域增加,建设用地增加最明显,增加了89.04%;耕地、林地、草地和未利用地减少,草地减少最明显,减少了31.06%。2020年白马河流域土地利用变化的预测研究结果可以为该区土地利用/覆被动态监测和可持续发展提供依据。     

基于TM影像的石羊河流域土地利用变化研究

根据1999年和2010年两期影像数据,在遥感软件EDARS IMAGINE9.1的支持下对图像进行技术处理,通过计算机自动分类方法提取土地利用信息,将石羊河流域土地利用类型分为耕地、草地、林地、建筑用地、水域及未利用地,同时利用数学模型和景观生态学理论,分析了石羊河流域土地利用变化的时空特征和格局变化。研究结果表明,1999-2010年间耕地和未利用地的面积变化最大,变化量占到总流域面积的比例分别为3.94%和2.42%;水域、林地、耕地的土地利用动态度明显,依次为3.06%,1.82%和1.12%;11年间草地、耕地和水域的流转较为剧烈,变化速率较快;11年间石羊河流域的土地利用偏离度为持续缓慢下降的趋势,下降幅度达到0.04,土地利用活动对自然景观的干预趋于缓和;景观优势度增大,景观多样性和景观均匀度有所减少,人类活动对景观格局影响明显;人口、经济因素和政策因素在短时间尺度上对土地利用变化的影响较为显著。     

Conversion of temperate forests into heaths: Role of ecosystem disturbance and ericaceous plants

Fire and logging in nutrient-poor temperate forests with certain ericaceous understory plants may convert the forests into heaths. The process of disturbance-induced heath formation is documented by using examples ofCalluna in western Europe,Kalmia in Newfoundland, andGaultheria (salal) in coastal British Columbia. In a cool, temperate climate, rapid vegetative growth ofCalluna, Kalmia, and salal following disturbance results in increasing organic accumulation (paludification), nutrient sequestration, soil acidification, and allelochemicals. These are thought to be the main reasons to conifer regeneration failure in disturbed habitats. If continuation in forest is a land-use objective, then temperate forests with an ericaceous understory should not be logged unless effective silvicultural methods are devised to control the ericaceous plants and restore forest regeneration. Preharvest vegetation control may be considered as an option. Failure to control the understory plants may lead to a long-term vegetation shift, from forest to heathland, particularly in nutrient-poor sites. Successful methods of controllingKalmia andGaultheria, however, have yet to be developed. While theKalmia- andGaultheria- dominated heathlands are undesirable in Canada and the Pacific Northwest, a wide range ofCalluna heathlands of western Europe are being conserved as natural and seminatural vegetation.     

BIOLOGICAL INDICATORS AND BIOLOGICAL EFFECTS OF ESTUARINE/COASTAL POLLUTION1

ABSTRACT: Sustained interest in and concern about the health status of the aquatic environment has resulted in extensive research focused on (1) effects of pollution on survival, growth, and reproduction of resource species at all life stages; (2) diseases of fish and shellfish, as they may be related to pollution and as they may serve as indicators of environmental stress; and (3) contaminant body burdens in fish and shellfish - their effects on the aquatic animals and their potential effects on humans. Effects, lethal and sublethal, of pollutants on life history stages of fish and shellfish have been documented, as have impacts on local stocks in badly degraded habitats, but as yet there has been no adequate quantitative demonstration of effects on entire aquatic species - probably because of the difficulty in sorting out relative effects of the many environmental factors that influence abundance. Sublethal effects, especially those that result in disease, have been examined intensively, and some diseases and disease syndromes have been associated statistically with pollution. Other pollution indicators (biochemical, physiological, genetic, behavioral, and ecological) have also received some attention, as have body burdens of contaminants in aquatic species. Research, especially that conducted during the past decade, has done much to clarify the many pathways and toxic effects of contaminants on aquatic animals, and has also helped to identify mechanisms for survival of fish and shellfish in the presence of environmental changes caused by human activities.     

Using Paleo Reconstructions to Improve Streamflow Forecast Lead Time in the Western United States

In water stressed regions, water managers are exploring new horizons that would help in long‐range streamflow forecasts. Oceanic‐atmospheric oscillations have been shown to influence streamflow variability. In this study, long‐lead time streamflow forecasts are made using a multiclass kernel‐based data‐driven support vector machine (SVM) model. The extended streamflow records based on tree ring reconstructions were used to provide a longer time series data. Reconstructed data were used from 1658 to 1952 and the instrumental record was used from 1953 to 2007. Reconstructions for oceanic‐atmospheric oscillations included the El Niño‐Southern Oscillation, Pacific Decadal Oscillation, Atlantic Multidecadal Oscillation, and North Atlantic Oscillation. Streamflow forecasts using all four oscillations were made with one‐year to five‐year lead times for 21 gages in the western United States. This is the first study that uses both instrumental and reconstructed data of oscillations in SVM model to improve streamflow forecast lead time. SVM model was able to provide “satisfactory” to “very good” forecasts with one‐ to five‐year lead time for the selected gages. The use of all the oscillation indices helped in achieving better predictability compared to using individual oscillations. The SVM modeling results are better when compared with multiple linear regression model forecasts. The findings are statistical in nature and are expected to be useful for long‐term water resources planning and management.     

Urban ecological systems: scientific foundations and a decade of progress

Urban ecological studies, including focus on cities, suburbs, and exurbs, while having deep roots in the early to mid 20th century, have burgeoned in the last several decades. We use the state factor approach to highlight the role of important aspects of climate, substrate, organisms, relief, and time in differentiating urban from non-urban areas, and for determining heterogeneity within spatially extensive metropolitan areas. In addition to reviewing key findings relevant to each state factor, we note the emergence of tentative "urban syndromes" concerning soils, streams, wildlife and plants, and homogenization of certain ecosystem functions, such as soil organic carbon dynamics. We note the utility of the ecosystem approach, the human ecosystem framework, and watersheds as integrative tools to tie information about multiple state factors together. The organismal component of urban complexes includes the social organization of the human population, and we review key modes by which human populations within urban areas are differentiated, and how such differentiation affects environmentally relevant actions. Emerging syntheses in land change science and ecological urban design are also summarized. The multifaceted frameworks and the growing urban knowledge base do however identify some pressing research needs.     

Neighbourhood characteristics and urban gardens in the Toledo metropolitan area: staffing and voluntarism,food production,infrastructure, and sustainability practices

Urban gardens are important sources of sustenance for communities with limited access to food. Hence, this study focuses on food production in gardens in the Toledo metropolitan area in Northwest Ohio. We administered surveys to 150 garden managers from November 2014 to February 2015 in our attempt to better understand how neighbourhood racial composition and poverty levels are related to staffing and voluntarism, food production and distribution, the development of infrastructure, and the adoption of sustainability practices in urban gardens. The results from 30 gardens are presented in this paper. We used Geographic Information Systems to map the gardens and overlay the map with 2010 census data so that we could conduct demographic analyses of the neighbourhoods in which the gardens were located. Though the gardens were small – two acres or less – up to 46 varieties of food were grown in a single garden. Gardens also operated on small budgets. Food from the gardens was gifted or shared with friends, family, and neighbourhood residents. Gardens in predominantly minority neighbourhoods tended to have fewer institutional partners, less garden infrastructure, and had adopted fewer sustainable practices than gardens in predominantly White neighbourhoods. Nonetheless, residents of predominantly minority and high-poverty neighbourhoods participated in garden activities and influenced garden operations. Volunteering and staffing were racialised and gendered.     

Journalists' views of advertiser pressures on agricultural news

All major journalism ethical codes explicitly state that journalists should protect editorial copy from undue influence by outside sources. However, much of the previous research on agricultural information has concentrated on what information various media communicate (gatekeeping studies) or communication's role in increasing innovation adoption (diffusion studies). Few studies have concentrated specifically on organizational and structural constraints that might adversely affect agricultural journalists' ethical standards; those that have, focus largely on farm magazines. A study of newspaper reporters who cover agricultural news found that the most pressing ethical concern is the effect of advertiser (agri-business) pressure on editorial copy, and that their concerns in general parallel those of farm magazine writers and editors. The majority reported being in situations in which they might be exposed to advertiser pressure, including pressures to change or withhold editorial copy. Large minorities suggested that advertising pressures affect the overall environment in which agricultural journalists work, and more than one in ten said they allow advertiser pressures to influence editorial decisions. The newspaper reporters who cover agricultural beats showed slightly more resistance to advertiser pressure than did farm magazine editors in a parallel study.     

Definition Procedures Have Little Effect on Performance of Environmental Classifications of Streams and Rivers

Mapped environmental classifications are defined using various procedures, but there has been little evaluation of the differences in their ability to discriminate variation in independent ecological characteristics. We tested the performance of environmental classifications of the streams and rivers of France that had been defined from the same environmental data using geographic regionalization and numerical classification of individual river valley segments. Test data comprised invertebrate assemblages, water chemistry, and hydrological indexes obtained from sites throughout France. Classification performance was measured by analysis of similarity (ANOSIM). Geometric regions defined by a regular grid and without regard to environmental variables and a posteriori classifications based on clustering the test datasets defined lower and upper bounds of performance for a given number of classes. Differences in classification performances were generally small. The ANOSIM statistics for the a posteriori classifications were around twice that of all environmental classifications, including geometrically defined regions. The hydro-ecoregions performed slightly better for the invertebrate data and the network classification performed slightly better for the chemistry and hydrological data. Our results indicate that environmental classifications that are defined using different procedures can be comparable in terms of their ability to discriminate variation of ecological characteristics and that alleged differences in performance arising from different classification procedures can be small relative to unexplained variation. We conclude that definition procedures might have little effect on the performance of large-scale environmental classifications and decisions over which procedures to use should be based primarily on pragmatic considerations.     

Predicting deer-vehicle collisions in an urban area

Collisions with deer and other large animals are increasing, and the resulting economic costs and risks to public safety have made mitigation measures a priority for both city and wildlife managers. We created landscape models to describe and predict deer-vehicle collision (DVCs) within the City of Edmonton, Alberta. Models based on roadside characteristics revealed that DVCs occurred frequently where roadside vegetation was both denser and more diverse, and that DVCs were more likely to occur when the groomed width of roadside right-of-ways was smaller. No DVCs occurred where the width of the vegetation-free or manicured roadside buffer was greater than 40 m. Landscape-based models showed that DVCs were more likely in more heterogeneous landscapes where road densities were lower and speed limits were higher, and where non-forested vegetation such as farmland was in closer proximity to larger tracts of forest. These models can help wildlife and transportation managers to identify locations of high collision frequency for mitigation. Modifying certain landscape and roadside habitats can be an effective way to reduce deer-vehicle collisions.     

MANGANESE CYCLE IN IMPOUNDMENT WATER

Manganese entering impounded water will undergo a cyclic transformation. Oxidation precipitates manganese from top waters. At the bottom of the lake, biological activity will render manganese soluble by both intracellular as well as extracellular activity. The study was made to demonstrate that biological reduction and transformation, organometallic complexation, together with the presence of carbon dioxide and the lowering of pH all have some effect on the solubility of manganese. Dissolved manganese may be brought back to top waters during the lake overturn and therefore deteriorates the water quality.     

Effect of Light on Biodegradation of Estrone, 17β‐Estradiol,and 17α‐Ethinylestradiol in Stream Sediment

Biodegradation of [A‐ring ¹⁴C] Estrone (E1), 17β‐estradiol (E2), and 17α‐ethinylestradiol (EE2) to ¹⁴CO₂ was investigated under light and dark conditions in microcosms containing epilithon or sediment collected from Boulder Creek, Colorado. Mineralization of the estrogen A‐ring was observed in all sediment treatments, but not epilithon treatments. No difference in net mineralization between light and dark treatments was observed for ¹⁴C‐E2. Net mineralization of ¹⁴C‐E1 and ¹⁴C‐EE2 was enhanced in light treatments. Extents of ¹⁴CO₂ accumulation and rates of mineralization were significantly greater for E2 than E1 under dark conditions, but were comparable under light conditions. These results indicate substantial differences in the uptake and metabolism of E1 and E2 in the environment and suggest biorecalcitrance of E1 relative to E2 in light‐limited environments. The extent of ¹⁴CO₂ accumulation and rate of mineralization for EE2 in dark treatments were less than half of that observed for E2 and generally lower than for E1, consistent with previous reports of EE2 biorecalcitrance. However, ¹⁴CO₂ accumulation and rates of mineralization were comparable for EE2, E2, and E1 under light conditions. These results indicate photoactivation and/or phototransformation/photodegradation processes can substantially enhance heterotrophic biodegradation of estrogens in sunlit environments and may play an important role in estrogen transport and attenuation.