小区地表温度与下垫面结构关系研究

以北京市为例,选取了商业区、学校、生活区和公园4种典型小区24个,基于遥感及GIS的方法反演地表温度,获取下垫面覆盖信息;研究了不同类型小区地表温度热场与下垫面结构的关系.结果表明:水体、绿地具有明显的降温功能,建筑地面则增温效果明显,这3种地表所占的面积比例与小区平均地表温度关系密切;在所选取的绿地结构指数中,对温度影响从大到小依次为绿地覆盖率、分离度、缀块平均面积、连通指数、形状指数和分维数,其中,分离度与温度呈现正相关,其它指数与温度呈负相关;在所有类型小区中,温度从高到低依次为商业区、学校、生活区和公园;公园的温度分布在所有类型小区中最分散,商业区最集中.     

Measuring runoff by plots at different scales: Understanding and analysing the sources of variation

The decrease of runoff with the increase in area is not a new fact. The scale effect depends on the spatial and temporal variability of different factors, including the surface characteristics and hydrodynamic properties of the soil and the vegetation development. The purpose of our work is to study the relative influence of the sources of variation of runoff from a small Sahelian catchment on several types of soil surfaces features. Plots of different sizes (1, 50 and 150 m²) on cultivated soils and degraded soils (non-cultivated with three different types of crusts) were monitored for two consecutive years. The results show that the runoff coefficients of rainfall events range from 4 to 65% on cultivated soils and 16 to 96% on uncultivated bare and degraded soils. A statistical and dimensionless analysis shows that in degraded environments, the processes generating runoff on plots of 50 and 150 m² are identical and significantly different from the unit plot (1 m²). The decrease in runoff with increasing scale becomes more pronounced when rainfall duration decreases. In cultivated areas, this result is not observed. Additional measurements are needed to better understand the differences in functioning at various scales of observations.     

Effects of cattle trampling on vegetation, infiltration, and erosion in a tropical rangeland

Cattle trampling without forage consumption at stocking densities of 0.03-1.4 cows ha⁻¹ was simulated on two dry-season rangelands in Kenya. Experiments under artificial rainfall documented the response of plant cover and production, infiltration, and erosion on a Luvisol and a Vertisol. Trampling reduced plant cover, biomass, and, at the highest rate, regeneration in the ensuing wet season. Infiltration was reduced on the Vertisol but not the Luvisol, although increases in runoff due to trampling were slight. Trampling increased soil loss partly by reducing vegetation cover but mainly by disrupting surface layers of sand on the Luvisol and of clay aggregates on the Vertisol. Soil loss normalized by runoff and rainfall energy declined in a sequence of erosive rainstorms as the sandy surface layer became re-established, but before vegetation recovered. Establishment of a sandy armor layer during runoff events and its disruption by dry-season trampling thus strongly affect soil-loss rates. Trampling limits plant recovery in the ensuing wet season only at intensities typical of settlement and watering centers. The experimental results, generalized with a spatial model of stock density, can be used to estimate the contribution of trampling to forage production and erosion as herding patterns change in response to sedenterization and water development.     

基于Google Map API的国界信息发布系统研究

边界工作是我国外交工作中一项长期而重要的任务,如何实现周边事务的快速标绘、实时共享和制图输出,对于政府决策者以及外交工作人员具有重要意义。然而目前的国界信息系统大多存在地理空间数据更新工作繁重、缺乏实时标注工具和地理事件难以共享等问题,已严重制约了边界工作的顺利开展。地理信息技术的进步与发展为解决上述问题提供了可能。文中采用四层B/S体系结构,在Google地图服务支持下,基于ASP.NET+C#网页开发技术和Ajax技术设计并实现了国界信息发布系统。为政府决策者及外交工作人员实时标注和共享周边信息提供辅助决策支持。实践证明,系统具有良好的可用性和较强的实时性。     

Study on Distribution Characteristics of Modern Agricultural Function of Basins in Guizhou,China

Agricultural modernization is the engine of rural development. Guizhou's landforms are mainly mountainous and hilly areas and there are few basins that are conducive to the development of modern agriculture. Therefore, the study of the modern agricultural function distribution of basins can provide scientific reference for the adjustment of Guizhou's agricultural industrial structure. This research used ArcGIS 10.2 to interpret the high-definition remote sensing images from 2016 to identify modern agricultural functional plots and modern agricultural functional basins in Guizhou Province, and used kernel density and bivariate local spatial autocorrelation to analyze the spatial distribution characteristics of the plots and basins, and the local spatial autocorrelation between the plots and the basins. The results show that: i. The area and number of modern agricultural functional plots in Zunyi Municipality, Qian Nan Buyi and Miao Autonomous Prefecture, and Bijie Municipality are all within the first three columns in the whole province, and the spatial autocorrelation between plot and basin area is the strongest; ii. The basins form a high-density core area at the intersection of Bozhou District and Honghuagang District in Zunyi Municipality. The plots form a high-density core area at the intersection of Huishui County, Changshun County, Pingba District and Huaxi District; iii. There is a strong positive correlation between the area of the plots and the area of the basins; iv. The proportion of the plot in the basin is mainly between 0 and 10%.     

浅议房产测绘制图、面积分摊系统的开发

本文针对房屋分层分户面积测算特点，设置三个级别功能模块及流程，运用灵活方便的绘图与编辑功能，采集面积自动校验功能及合理的分摊方法、步骤，科学合理地开发出一套方便实用，面积分摊计算和管理系统。     

使用Surfer Automation实现海洋要素等值线图的批量绘制

介绍了基于Automation对象技术的使用程序控制Surfer自动绘图的方法,使用Surfer自带的Scripter实现海洋要素等值线图的批量绘制,为在海洋科学研究中批量绘制等值线图提供了一种简捷、高效的途径。     

What indicators can capture runoff-relevant connectivity properties of the micro-topography at the plot scale?

Although connectivity is acknowledged as a key factor of a catchment hydrological behaviour, it still misses reference evaluation methodologies. Therefore the objective of the paper is to evaluate different quantitative indicators of hydrological connectivity, using the concepts of structural and functional connectivity commonly used in ecology. The indicators were tested on contrasted numerical fields of micro-topography that present distinct hydrological responses.     

Effects of national forest inventory plot location error on forest carbon stock estimation using k-nearest neighbor algorithm

This paper suggested simulation approaches for quantifying and reducing the effects of National Forest Inventory (NFI) plot location error on aboveground forest biomass and carbon stock estimation using the k-Nearest Neighbor (kNN) algorithm. Additionally, the effects of plot location error in pre-GPS and GPS NFI plots were compared. Two South Korean cities, Sejong and Daejeon, were chosen to represent the study area, for which four Landsat TM images were collected together with two NFI datasets established in both the pre-GPS and GPS eras. The effects of plot location error were investigated in two ways: systematic error simulation, and random error simulation. Systematic error simulation was conducted to determine the effect of plot location error due to mis-registration. All of the NFI plots were successively moved against the satellite image in 360° directions, and the systematic error patterns were analyzed on the basis of the changes of the Root Mean Square Error (RMSE) of kNN estimation. In the random error simulation, the inherent random location errors in NFI plots were quantified by Monte Carlo simulation. After removal of both the estimated systematic and random location errors from the NFI plots, the RMSE% were reduced by 11.7% and 17.7% for the two pre-GPS-era datasets, and by 5.5% and 8.0% for the two GPS-era datasets. The experimental results showed that the pre-GPS NFI plots were more subject to plot location error than were the GPS NFI plots. This study’s findings demonstrate a potential remedy for reducing NFI plot location errors which may improve the accuracy of carbon stock estimation in a practical manner, particularly in the case of pre-GPS NFI data.     

面向地块对象的土地利用总体规划前期研究

计算机软件工程领域中面向对象的思想和方法,可以引入土地利用总体规划的研究和实践中。本文通过对面向对象思想和方法的分析总结,将其应用在土地利用总体规划的前期研究中,以地块为对象,在总体规划层次上对其进行探讨。识别出若干土地利用规划的基本对象,分析其属性及主要功能,并在此基础上,定义对象之间的连接关系,构建面向对象土地利用总体规划的一般框架模式。