中国土地利用和土地覆被变化研究进展

受国际社会影响，中国加强了土地利用／覆盖变化研究的进程，在众多领域取得了瞩目的成就，主要包括动态监测、遥感分类和制图、LUCC驱动力和区域LUCC模型、环境效应等方面，但中国LUCC研究也存在很多突出的问题，包括跨学科、时空尺度、理论体系完善、研究方法、与全球和区域环境变化及可持续发展之间的关系等。为促进中国土地利用／覆盖变化研究的持续、健康发展，提出对中国LUCC研究的建议和展望包括建立LUCC理论体系，深入掌握LUCC动态研究的手段和方法，形成与中国国情密切结合的土地利用和覆被变化综合模型，转变研究重点，更加清晰地认识和把握LUCC有关的可持续发展问题，加强土地利用变化与生态安全机制的研究等。     

土地市场景气指标体系及评价模型的建立

以徐州市为例建立了土地市场景气指标体系及评价模型。首先在建立指标体系时运用定性的方法对大量指标进行了初选，然后用主成分分析法确定土地市场景气指标体系，并运用层次分析法确定各指标的权重。在建立景气评价模型时，分析了传统扩散指数模型的缺陷，提出了合理的改进模型。同时，针对扩散指数与合成指数反映的土地市场运行状况之间的差异，引入了精度比较概念，在此基础上选择精度较高的指数进行土地市场景气状况评价。最后运用建立的评价模型对徐州市2001-2006年土地市场景气状况进行了评价，并对2007年徐州市土地市场运行状况进行了预测。分析表明，建立的景气指标体系及其评价模型能够较准确地评价和预测土地市场景气状况．     

AERMOD模型在大气环境影响评价中的应用

通过实例,对AERMOD在大气环境影响评价中的应用进行讨论。根据2007年1月～12月达州市地面和高空气象数据、项目所在地的地形资料,应用AERMOD预测模型建立了空气扩散模型,对工程的大气环境影响进行了预测与评价。结果表明:AERMOD空气扩散模型实现了评价区域二维地形向三维地形的可视化转变,预测浓度分布能够反映出污染源分布和气象场变化以及地形等对大气污染物迁移和扩散的影响。     

基于RS的土地利用/土地覆盖变化信息提取方法--以甘肃石羊河流域为例

土地利用／土地覆盖变化是研究全球变化和可持续发展的一个重要方面,而LUCC信息提取技术是LUCC研究的基础性工作。以甘肃石羊河流域为例,利用TM、ETM 等遥感数据,有效探讨了LUCC的信息提取方法,建立了一套较为完善的计算机自动提取流程,并初步探讨了石羊河流域在近20年来各种地物时空分布规律。     

基于路面激励的Adams车身柔性体影响研究

本文基于悬架三自由度简化模型进行了路面传递函数的计算，并选择了典型特殊路面--随机比利时路面、非随机离散低频扭曲路面和非随机高频离散路面振动路对轮心载荷进行了计算。各路面轮心理论计算结果与VPG路面分析结果对比均在可接受范围内，说明了简化模型及轮心载荷理论公式的可用性和指导性。基于此公式，计算了车身柔性体变化导致的轮心载荷变化情况，从理论上看到各特征路面均有此规律：车身柔性体刚度越大则轮心载荷越大，因此，为更真实模拟车身变形情况，建议使用完整的TB柔性体模型。     

新建水库初期磷氮变化的动态模拟研究

本文首先建立磷氮时空分布模型并确定模型参数的率定方法。文章模拟了新建清平水库建库初期磷氮变化情况,得出由不稳定到稳定的过程。水库磷氮时空变化的模拟结果表明,空间分布是从库尾到大坝浓度逐渐递砬,时间分布是一年中Ｐ,Ｎ浓度七月份最高,年初年末最低,其分布央线类似高斯分布。     

小尺度热点地区土地利用/覆被变化研究--以淮南市为例

利用指数模型方法,从区域土地利用/覆被变化(LUCC)的速度、土地流向、空间结构和土地利用程度等方面对淮南市1996～2003年间土地利用变更数据进行了定量描述和分析,揭示了淮南市土地利用及变化的特征,并针对在工矿和居民点整理复垦、土地利用程度等方面存在的问题提出了相应建议,为实现土地资源的合理利用提供科学依据.     

带内锥的扩散式分离器内两相流动的数值模拟

对于一种带内锥的切向进口扩散式方形分离器，利用考虑各向异性的雷诺应力湍流模型和颗粒随机轨道模型对其内部的两相流动情况进行了数值模拟，分析了其内部不同截面高度的气相流场的轴向、切向和径向速度分布，计算了颗粒分级分离效率，颗粒轨迹等。数值模拟结果表明，分离器内呈典型的双层流动结构，方形截面在其拐角处对气流存在扰动，主要影响其切向速度，该分离器对8μm以下颗粒分离效率较低。     

基于多源数据AnnAGNPS西枝江流域的污染模拟研究

以西枝江流域为研究对象，结合GIS技术，建立了AnnAGNPS模型数据库，对流域内非点源污染主要影响因素的特征以及非点源污染的时空分布特征进行了分析。结果表明：流域内降雨侵蚀力、径流深、土壤侵蚀和沉积负荷的年际问变化很大，降雨侵蚀力月问分布极不均匀，季节变化十分明显，后三者的变化趋势都与平均降水量表现出较好的对应关系，但是又并不完全一致；流域内的径流深空间分布极不均匀，而土壤侵蚀、沉积负荷空间变化相对不是十分明显，三者都有沿河道向两边逐渐递减的趋势，在人口密集地区及河塘密集地区，径流相对其他区域比较大。本文为西枝江流域的非点源污染模拟研究提供了基础数据平台，也为该模型在整个东江流域的合理应用奠定了科学基础。     

河流水质模型在双流县流域治理中的应用

研究利用现有的河流水质模型,构建了一个可实时模拟河流水环境质量变化状况的动态模型。模型采用一维稳态单组分水质模型对河流的CODCr、NH3-N的降解进行计算,采用多宾斯-坎普稳态模型对河流的BOD、DO变化情况进行计算。模型引入水文数据、水质监测数据、环境统计数据、社会统计公报数据,以Excel作为数据平台,可以反演出河流不同月份、不同区段的污染物降解系数。研究将该模型应用于双流县的流域治理,以在锦江双流段的应用为例进行了具体说明。根据2008年双流县河流的相关数据,研究使用该模型反演出了锦江双流段的污染物降解系数,并对其反映的流域污染状况进行了分析。随后,研究使用该模型已计算出的岷江中段河流的降解系数,模拟计算了4种情景下锦江双流段出境断面的可能水质变化,以验证拟定的双流县流域治理方案的预期效果。模型具有实用性和进一步扩展的功能。     

合肥市近19年来土地利用格局的时空变化分析

利用Landsat TM、ETM 、CBERS—2资源卫星数据,采用基于知识型光谱特性的增强与人机交互解译相结合的方法,提取了合肥市1987年、2000年和2006年土地利用类型的专题信息。利用GIS空间分析技术和数理统计方法,分析了合肥市近19年来的土地利用变化特征。结果表明:①在整个阶段—耕地减少了23.38%,建设用地增加了61.26%;城镇用地新增速度最快,且新增速率远大于转移速率,属高速扩张型;②区内最"敏感"的类型是交通用地,其新增速率在两个阶段分别达到1.64和1.62,远高于其它的类型;④从城市扩展的方向上看,合肥城市的发展主要以西南部、南部和东部为主,西南部最为明显;城市已经形成以老城区为核心,向东、北、西南三翼伸展,形成"南进—东拓—西缓—北抑"的空间发展布局。     

Land Use and Land Cover Change Analysis and Prediction in the Upper Reaches of the Minjiang River,China

Scientists have aimed at exploring land use and land cover change (LUCC) and modeling future landscape pattern in order to improve our understanding of the causes and consequences of these phenomena. This study addresses LUCC in the upper reaches of Minjiang River, China, from 1974 to 2000. Based on remotely sensed images, LUCC and landscape pattern change were assessed using cross-tabulation and landscape metrics. Then, using the CLUE-S model, changes in area of four types of land cover were predicted for two scenarios considering forest polices over the next 20 years. Results showed that forestland decreased from 1974 to 2000 due to continuous deforestation, while grassland and shrubland increased correspondingly. At the same time, the farmland and settlement land increased dramatically. Landscape fragmentation in the study area accompanied these changes. Forestland, grassland, and farmland take opposite trajectories in the two scenarios, as does landscape fragmentation. LUCC has led to ecological consequences, such as biodiversity loss and lowering of ecological carrying capacity.     

Spatial Patterns of Land Use Changes Across a Mediterranean Metropolitan Landscape: Implications for Biodiversity Management

Land use and land cover change (LUCC) is an acknowledged cause of the current biodiversity crisis, but the link between LUCC and biodiversity conservation remains largely unknown at the regional scale, especially due to the traditional lack of consistent biodiversity data. We provide a methodological approach for assessing this link through defining a set of major pressures on biodiversity from LUCC and evaluating their extent, distribution, and association with a set of physical factors. The study was performed in the Metropolitan Region of Barcelona (MRB, NE of Spain) between 1956 and 2000. We generated a LUCC map for the time period, which was reclassified into a set of pressures on biodiversity (forestation, deforestation, crop abandonment, and urbanization). We then explored the association of these pressures with a set of physical factors using redundancy analysis (RDA). Pressures encompassed 38.8 % of the MRB area. Urbanization and forestation were the dominating pressures, followed by crop abandonment and deforestation. RDA showed a significant distribution gradient of these pressures in relation to the studied physical factors: while forestation and deforestation are concentrated in remote mountain areas, urbanization mainly occurs in lowlands and especially on the coast, and close to previous urban centers and roads. Unchanged areas are concentrated in rainy and relatively remote mountain areas. Results also showed a dramatic loss of open habitats and of the traditional land use gradient, both featuring Mediterranean landscapes and extremely important for their biodiversity conservation. Implications of these results for biodiversity management are finally discussed.     

Effects of Land‐Use and Land‐Cover Change on Evapotranspiration and Water Yield in China During 1900‐20001

Abstract: China has experienced a rapid land‐use/cover change (LUCC) during the 20th Century, and this process is expected to continue in the future. How LUCC has affected water resources across China, however, remains uncertain due to the complexity of LUCC‐water interactions. In this study, we used an integrated Dynamic Land Ecosystem Model (DLEM) in conjunction with spatial data of LUCC to estimate the LUCC effects on the magnitude, spatial and temporal variations of evapotranspiration (ET), runoff, and water yield across China. Through comparisons of DLEM results with other model simulations, field observations, and river discharge data, we found that DLEM model can adequately catch the spatial and seasonal patterns of hydrological processes. Our simulation results demonstrate that LUCC led to substantial changes in ET, runoff, and water yield in most of the China’s river basins during the 20th Century. The temporal and spatial patterns varied significantly across China. The largest change occurred during the second half century when almost all of the river basins had a decreasing trend in ET and an increasing trend in water yield and runoff, in contrast to the inclinations of ET and declinations of water yield in major river basins, such as Pearl river basin, Yangtze river basin, and Yellow river basin during the first half century. The increased water yield and runoff indicated alleviated water deficiency in China in the late 20th Century, but the increased peak flow might make the runoff difficult to be held by reservoirs. The continuously increasing ET and decreasing water yield in Continental river basin, Southwest river basin, and Songhua and Liaohe river basin implied regional water deficiency. Our study in China indicates that deforestation averagely increased ET by 138 mm/year but decreased water yield by the same amount and that reforestation averagely decreased ET by 422 mm/year since most of deforested land was converted to paddy land or irrigated cropland. In China, cropland‐related land transformation is the dominant anthropogenic force affecting water resources during the 20th Century. On national average, cropland expansion was estimated to increase ET by 182 mm/year while cropland abandonment decreased ET by 379 mm/year. Our simulation results indicate that urban sprawl generally decreased ET and increased water yield. Cropland managements (fertilization and irrigation) significantly increased ET by 98 mm/year. To better understand LUCC effects on China’s water resources, it is needed to take into account the interactions of LUCC with other environmental changes such as climate and atmospheric composition.     

First principles of the MameLuke multi-actor modelling framework for land use change, illustrated with a Philippine case study

This paper presents the first principles of the MameLuke framework, an agent-based modelling framework for studying environmental issues and land use and cover change (LUCC). The MameLuke framework enhances the understanding of the relationship between societal processes and LUCC by modelling individual and group decisions and human-environment interactions. The framework allows for the transformation of real-life stories into computerised models following a predetermined sequence. By doing so, the framework allows for a truly integrative approach, because it is not bound to any particular scientific discourse. Even better, the framework enables its users to combine scientific discourses regarding human decisions and behaviour on multiple scales and levels. The agents (actors and locations) in the framework are heterogeneous. This heterogeneity of agent behaviour is established by dividing the agents into categories. If an agent is a member of an agent category or combination of categories, it has access to a defined set of implementable actions. The actions are constructed out of potential option paths (POPs) and potential option nodes (PONs). The whole of POPs represent a theoretical construct of agent behaviour and decisions that the framework user wishes to explore. The POP defines a sequence of PONs. The PON is a transaction interface between an initialising agent and a recipient agent where they exchange material and immaterial capital. This paper explains the basic architecture of the MameLuke framework and shows its applicability with a model of a Philippine case study. This case study concerns the dynamics of migration and deforestation. It is part of a larger study on land use change in the San Mariano watershed area at the forest fringe of the Sierra Madre mountains in the Philippines.     

Modeling the Driving Forces of the Land Use and Land Cover Changes Along the Upper Yangtze River of China

Induced by high population density, rapid but uneven economic growth, and historic resource exploitation, China’s upper Yangtze basin has witnessed remarkable changes in land use and cover, which have resulted in severe environmental consequences, such as flooding, soil erosion, and habitat loss. This article examines the causes of land use and land cover change (LUCC) along the Jinsha River, one primary section of the upper Yangtze, aiming to better understand the human impact on the dynamic LUCC process and to support necessary policy actions for more sustainable land use and environmental protection. Using a repeated cross-sectional dataset covering 31 counties over four time periods from 1975 to 2000, we develop a fractional logit model to empirically determine the effects of socioeconomic and institutional factors on changes for cropland, forestland, and grassland. It is shown that population expansion, food self-sufficiency, and better market access drove cropland expansion, while industrial development contributed significantly to the increase of forestland and the decrease of other land uses. Similarly, stable tenure had a positive effect on forest protection. Moreover, past land use decisions were less significantly influenced by distorted market signals. We believe that these and other findings carry important policy implications.     

基于遥感技术的土地利用/土地覆盖提取信息精度研究——以艾比湖湿地保护区为例

利用中巴资源卫星资料提取艾比湖湿地保护区LUCC的现状信息作为基础资料进行精度检验,主要运用实地景观的比对,并充分考虑了点的空间分布,在采点方面,研究分层采点法,在误差矩阵法和Kappa系数法的基础上尝试了权重法和平均法,用这几种方法对该区LUCC的现状数据进行检验,结果相吻合.     

SYSTEMS ENGINEERING AND WATER RESOURCES IN SOUTHERN NEVADA1

ABSTRACT The Las Vegas Valley in southern Nevada has provided ample opportunity for mission oriented water resources research, and, to some extent, application of those research results. Past studies of the ground-water systems have resulted in the construction of a direct electrical analog, two digital simulation models, a Hele-Shaw fluid analog, a linear programming model, and two dynamic programming models. The work accomplished has dealt with the problems of groundwater management, waste water reclamation and artificial recharge, and conjunctive use water management. The current study is attempting to integrate previous results and new work into a detailed and realistic conjunctive use water resource management model to achieve system efficiency under more than one criteria. The research team is interdisciplinary in nature and encompasses the physical and social sciences.     

基于遥感技术的土地利用/土地覆盖现状信息提取研究——以艾比湖湿地保护区为例

艾比湖地区是中国沙尘暴的起源地之一,而且对该区域的生态环境变化具有指征作用。利用中巴资源卫星影像,结合Modis数据,采用遥感数据分类与实地验证相结合的方法。利用植被指数模型,建立解译标志,采用无监和有监相结合的分类方法,提取了艾比湖湿地保护区LUCC的现状信息,为进一步研究提供了基础性数据。