近10年来中国耕地资源的时空变化分析

根据中国资源环境数据库中的耕地数据以及20世纪80年代末期、1995年和2000年3期覆盖全国时间跨度约为10年的遥感数据,对中国耕地时空变化进行分析。总趋势表明,近10年来我国耕地资源总量有所增加;东部及沿海地区优质耕地迅速减少;东北地区和内蒙古自治区耕地大量开垦;水田旱地转换明显。利用GIS方法将耕地变化数据与中国生态环境质量数据进行叠加,表明近10年来耕地的生态环境质量下降了。近10年耕地动态变化的空间分布表现出13种动态格局。对80年代末至1995年 (前5年) 和1995年至2000年 (后5年) 这2个时间段内的耕地变化进行对比分析,表明了前5年与后5年耕地变化的动态格局有空间上的相似性,但前后变化幅度相差较明显。近10年来气温的升高与中国水田北移有较好的一致性,而降水的减少对西北地区耕地的撂荒和开垦有明显作用。中国经济的发展所导致的城市化过程使得大量耕地被占用。近10年来相关的耕地政策对控制耕地面积的减少有作用,但耕地的总体质量却下降了,这直接影响了粮食产量。     

Impact of Land-use Patterns on Distributed Groundwater Recharge and Discharge——A Case Study of Westem Jilin, China

The impact of land-use on distributed groundwater recharge and discharge in the western Jilin (WJ) was analyzed in this study. WJ is a transitional, semi-arid zone with a fragile, hydrological closed ecosystem in the Songhua River Basin (SRB). The research tool includes a seamlessly linked MODFLOW, WetSpass, the Seepage packages, and ArcGIS. The model calibration showed good agreement between simulated water table elevation and measured water table depths, while predicted groundwater discharge zones showed strong correlations with field occurrences of drainage systems and wetlands. Simulated averages for distributed recharge, water table elevation and groundwater drawdown were 377.42mm/yr, 194.43m, and 0.18m respectively. Forest vegetation showed the highest recharge, followed by agricultural farmlands, while open-water and other drainage systems constituted groundwater exit zones. When present land-use conditions were compared with the hypothetical natural pre-development scenario, an overall loss of groundwater recharge (24.09mm/yr) was observed, which for the project area is 18.05 × 10⁸m³. Groundwater abstraction seemed to be the cause of water table drawdown, especially in the immediate vicinities of the supply wells. An important issue of the findings was the ability of the hypothetical forest vegetation to protect, and hence sustain aquifer reserves and dependent ecosystems. The profound data capture capability of ArcGIS makes it particularly useful in spatio-temporal hydroecological modeling. Biography: Moiwo Juana PAUL (1967–), male, a native of Sierra Leone of West Africa, Ph.D. candidate, specialized in wetland ecology.     

The possibilities and pitfalls presented by a pragmatic approach to ecosystem service valuation in an arid biodiversity hotspot

Arid regions are home to unique fauna, flora, and vulnerable human populations, and present a challenge for sustainable land-use management. We undertook an assessment and valuation of three key services, grazing, tourism and water supply in the arid Succulent Karoo biome in western South Africa - a globally recognised biodiversity hotspot. We were looking for ways and values that could be used to promote conservation in this region through the adoption of sustainable land-use practices which have human welfare benefits. Our study adopted a variety of methods in valuing these services in developing ranges of values for these services. At the biome level, total annual values ranged from $ 19-114 million for grazing, $ 2-$ 20 million for tourism, and $ 300-3120 million for water. These values are generally low compared with values derived for other biomes and regions and do not adequately reflect known dependence and the importance of ecosystem services to the residents of this biome. The ecosystems here provide small but critical benefits enabling communities to sustain themselves and small changes in service levels can have major welfare effects. Highlighting these sensitivities will require finding more appropriate ways to link ecological and social factors.     

Numerical Simulations of Impacts of Urbanization on Heavy Rainfall in Beijing Using Di erent Land-Use Data

A summer strong convective precipitation event on 10 July 2004 over Beijing is numerically simulated in this paper, and the impact of urban heat island (UHI) on summer convective rain is investigated. The analysis reveals that a mesoscale convective cloud cluster system leads to this heavy rainfall event, suggesting the supply of moisture by the large scale circulation before the initiation of precipitation, a generally weaker UHI of 2-3℃ existed in the urban area. Much like a sea breeze, the anomalously warm urban air created relatively low pressure, inducing the inflow of cooler rural air towards the urban center, which is favorable to the ascending motion and the formation of convective precipitation over the urban area. In addition,the numerical simulation of the strong convective precipitation event suggests that the simulated result of precipitation using the 2002 LANDSAT-7 land-use data with 30-m resolution is much better than that using the 1992-1993 USGS land-use data with 1-km resolution, whether in the magnitude of rainfall or in the location of precipitation. The simulation confirms to some extent that the UHI has a significant role in causing extreme rainfall event.     

GIS-BASED ANALYSIS OF URBAN LAND-USE CHANGES——A Case Study of Haizhu District of Guangzhou City,China

１INTRODUCTIONMajorcharacteristicsofurbanizationinclude：ur－banconstructioniscontinuouslyspreading，thedemandforurbanlanduseisrapidlyswelling，andalotofa－griculturallandisconvertingintonon－agriculturalland．Whenthesecharacteristicsarereflectedinurbansys－tem，thedevelopingspeedsofbigcitiesandsupercitiesarequickening（CHEN，１９９９）．Basedonthecondi－tionofmarket，landresourcebearsthreetypesofvalueswhicharerespectivelysocialvalue，economicvalueandecologicalvalue．Theexternalexpressiv…     

GIS-BASED ANALYSIS OF URBAN LAND-USE CHANGES—A Case Study of Haizhu District of Guangzhou City, China

This paper describes a GIS-based spatial analysis method that combines qualitative analysis and quantita-tive analysis to characterize land-use patterns and predict the trend of future land-use changes in Halzhu District ofGuangzhou City, China. Spatial technique is introduced to manage land-use data and derive information of land-usechanges. Through the case study for the selected area, it is demonstrated that the method and technique introduced in thepaper can be effectively utilized for the analysis of urban land-use changes. Based upon this analysis, the paper also pro-vides discussions and recommendation on urban land-use planning, urban planning and land management. Both land-usemaps of Haizhu District of Guangzhou in 1995 and 1997 and the remote sensing images of 1999 are utilized in the cur-rent research. It is convenient to get various statistic data and to combine attribute data with spatial data so as to analyzeland-use changes in a geographic context, which is especially suitable for the need of urban construction department, ur-ban management department and urban planning department.     

20世纪80年代以来中国土地利用变化的基本特征与空间格局(英文)

Land-use/land-cover changes(LUCCs) have links to both human and nature interactions. China's Land-Use/cover Datasets(CLUDs) were updated regularly at 5-year intervals from the late 1980s to 2010, with standard procedures based on Landsat TM\ETM+ images. A land-use dynamic regionalization method was proposed to analyze major land-use conversions. The spatiotemporal characteristics, differences, and causes of land-use changes at a national scale were then examined. The main findings are summarized as follows. Land-use changes(LUCs) across China indicated a significant variation in spatial and temporal characteristics in the last 20 years(1990–2010). The area of cropland change decreased in the south and increased in the north, but the total area remained almost unchanged. The reclaimed cropland was shifted from the northeast to the northwest. The built-up lands expanded rapidly, were mainly distributed in the east, and gradually spread out to central and western China. Woodland decreased first, and then increased, but desert area was the opposite. Grassland continued decreasing. Different spatial patterns of LUC in China were found between the late 20th century and the early 21st century. The original 13 LUC zones were replaced by 15 units with changes of boundaries in some zones. The main spatial characteristics of these changes included(1) an accelerated expansion of built-up land in theHuang-Huai-Hai region, the southeastern coastal areas, the midstream area of the Yangtze River, and the Sichuan Basin;(2) shifted land reclamation in the north from northeast China and eastern Inner Mongolia to the oasis agricultural areas in northwest China;(3) continuous transformation from rain-fed farmlands in northeast China to paddy fields; and(4) effectiveness of the "Grain for Green" project in the southern agricultural–pastoral ecotones of Inner Mongolia, the Loess Plateau, and southwestern mountainous areas. In the last two decades, although climate change in the north affected the change in cropland, policy regulation and economic driving forces were still the primary causes of LUC across China. During the first decade of the 21st century, the anthropogenic factors that drove variations in land-use patterns have shifted the emphasis from one-way land development to both development and conservation. The "dynamic regionalization method" was used to analyze changes in the spatial patterns of zoning boundaries, the internal characteristics of zones, and the growth and decrease of units. The results revealed "the pattern of the change process," namely the process of LUC and regional differences in characteristics at different stages. The growth and decrease of zones during this dynamic LUC zoning, variations in unit boundaries, and the characteristics of change intensities between the former and latter decades were examined. The patterns of alternative transformation between the "pattern" and "process" of land use and the causes for changes in different types and different regions of land use were explored.     

基于ArcGIS的县级土地利用现状调查的研究

针对土地利用现状调查的需要,介绍了土地利用现状调查的意义、国内外所采用的技术手段。着重阐述了ArcGIS在土地利用数据库的构建,土地利用现状的分析中的关键技术,从而大大提高了相关过程的效率及技术应用的层次。     

重庆市土地利用空间数据库建设及数据发布的研究与应用

在国家第二次土地调查成果数据汇总工作完成后,重庆市将建立全市统一的土地利用空间数据库,同时也要进行数据发布以便于工作成果的各类应用.本文介绍了该市土地利用空间数据库建设及数据发布的工作流程,重点阐述了该项工作中的基础地理空间框架的选取、批量空间数据的坐标转换、DEM数据问题的处理及建模、数据发布等环节的技术处理,可为其...