Land Suitability Evaluation of Food Crops in Vulnerably Ecological Area Based Upscalin Method

In order to provide some preliminary recommendations for the sustainable use and management of croplands, land suitability evaluation for crops was carried out in Shouyang County which partly locates on the Loess Plateau suffering severe soil and water erosion and is characterized by ecological vulnerability and semi-arid climate. Here, land suitability for 4 local crops of maize, wheat, sorghum and millet under 2 cultivation senarios of tradition and mechanization was evaluated by a upscaling approach. The upscaling was implemented in a land form hierarchy which was composed of land unit, land facet and land site at 3 spatial levels. The IAO land suitability evaluation model for crops was revised by applying a meteorological revision index. Rresults showed that a polarized phenomenon occurred, which means that the most suitable class （S1） and the most unsuitable class （N2） were predominant in acreage percentage for all the 4 crops. Maize, millet and wheat were relatively more adaptive to be grown and should be ploughed in the traditional mode. Hence, future cropland use policy should pay more attention to the conversion of arable land to forestland and grassland in unsuitable areas and to more investment for agricultural production in suitable regions, and it is necessary to balance the relationship between the livelihood of local farmers and environmental protection to maintain a healthy and stable ecosystem.

来自“蛮族”的饮器——再议新疆所见磨面纹玻璃杯

长期以来,对新疆营盘和扎滚鲁克墓地发现的3件磨面纹玻璃杯的产地的认识以罗马或萨珊为主,本文即尝试对它们的来源进行重新考察。对罗马和萨珊的典型磨面纹玻璃器的仔细勾稽排除了上述任一可能,而新疆玻璃杯与Hans Jürgen Eggers所定义的223,226或228等3型存在诸多相似性则表明它们应属欧洲"蛮族"玻璃,其具体产地很可能在黑海北岸地区。它们既可由罗马玻璃料加工成型,亦可在罗马成品玻璃器上直接再造而成;后一种可能性从扎滚鲁克玻璃杯上所呈现的人为改造迹象上略见端倪。此外,本文还根据其前身Varpelev类型和后继E 230类型的年代范围推断此3型玻璃杯的时间框架大致为公元3世纪中期至4世纪中期。

第三次全国土地调查中线状地物面化方法研究

第三次全国土地调查要求线状地物以地类图斑形式表示。本文在分析土地利用数据库模型基础上,提出线状地物自动面化方法。该方法基于线状地物图形和地类编码、权属单位代码、宽度、扣除图斑等属性信息,综合利用缓冲区生成、基于规则的多边形叠加分析、多边形融合和节点吸附等算法,通过计算机编程,批量实现了线状地物到地类图斑的转换。实验结果表明:线物面化成果准确性达到80%以上,线状地物图斑化采集效率提升6倍以上,具有一定的实用价值。

基于面元法的陆海交界复合粗糙面电磁散射研究

针对海陆交界处由于电磁特性复杂难以建立电磁散射模型的问题,提出了一种基于面元法的电磁散射计算方法。该方法首先对陆地区域采用指数谱建模,对海面区域采用文氏谱建模,并采用加权反正切方法建立陆海交界处的三维几何模型;其次对陆地和海面区域分别根据粗糙度的不同进行三角剖分,对每个三角面元设置不同的电参数,并采用积分方程模型(IEM)算法计算其电磁散射回波;最后将整体的电磁散射回波进行相干叠加得到海陆交界区域的雷达散射系数,进一步分析表明相较于深海面而言其电磁散射系数具有较高的回波截面积。

黄土丘陵沟壑区土地演化地理过程的物流分析——以晋西三川河流域为例

本文认为在黄土丘陵沟壑区土地演化的基本地理过程是由流水侵蚀所造成的水土流失过程,并分别讨论了该区土地素与上地单元的物流特征,通过数学计算和相关分析,证明黄土沟坡土地素物流强于红土沟坡,梁地和谷地土地单元的迳流和泥沙输移达到0.921和0.923的相关程度。