中国特色的精细农作的技术支持体系初探

在分析比较近十几年来西方精细农业思想和中国农业生态工程等精耕细作主要思想基础上，肯定了中国农业生态工程研究与实践在中国具有不可取代的独特作用。主张优先研究开发4S一体化的技术支持体系，结合吸纳西方精细农业的思想和技术，发展中国特色的精细农业。提出了4S一体化技术支持体系的基本构架，并且指出我国应以4S一体化技术支持体系为依托，结合各地具体情况逐步组装相关技术，由精细农作、精细养殖向精细农业发展的思路。同时指出精细农业要用数字地球的相关标准来规范自身的发展。     

Deriving river networks and catchments at the European scale from medium resolution digital elevation data

The extraction of drainage networks and catchment boundaries from digital elevation models (DEMs) has received considerable attention in recent years and is recognized as a viable alternative to traditional surveys and the manual evaluation of topographic maps. However, most studies have covered limited areas due to the lack of detailed information and/or the lack of highly efficient algorithms. In this paper we present an application that delineates river networks and catchment boundaries across the European continent from a medium resolution (250 m) DEM. We exploit novel algorithms based on the concepts of mathematical morphology and implement a landscape stratification for drainage density.A flow direction grid is computed using an efficient algorithm for the removal of spurious pits. River networks are then derived by imposing a variable threshold for the minimum contributing area needed to form and maintain a channel. This is achieved through a landscape stratification that reflects the ability of the terrain to develop different drainage densities. It is shown that the analysis of environmental characteristics coupled with the analysis of local slope versus contributing area enables river network mapping with a spatially varying drainage density. The result has been validated by comparing the derived data to digital river and catchment data from other sources and with varying scales of observation.     

利用土壤切片的数字图像定量评价土壤孔隙变异度和复杂度

研究结果表明 :利用土壤切片的数字图像 ,以孔隙周长和面积为基础数据 ,可以定量评价小尺度上的孔隙变异度 ,也可以对孔隙复杂度进行研究 ;土壤孔隙在mm尺度上也具有较高的变异度和复杂度 ;粒径 1～ 3mm和粒径 <2cm的重组土壤的孔隙在 2D空间多呈现网络状 ,而原状土壤的孔隙则多呈不规则的枝状或椭圆状 ;不同处理及不同土壤类型之间在孔隙周长、孔隙度以及孔隙变异度和复杂度方面存在不同程度的差异。     

玉米雄穗几何造型研究

通过对玉米雄穗形态结构的观测分析,提出了基于雄穗形态特征参数的三维形态数学模型及其实现方法。雄穗模型的建立过程包括拓扑结构设计、分枝造型和小穗造型三个阶段。模型具有较高的真实感效果,可控性强,可满足雄穗数字化设计的需要。     

工作流技术在数字林业建设中的应用初探

数字林业建设强调信息的数字化和资源的共享。根据数字林业建设的基本思想，分析数字林业的体系结构，提出了工作流在数字林业体系结构中的应用及优势。     

数字电视频道系统在顺德农业信息服务中的应用

顺德农业数字电视频道系统，包括农业政务、科技、市场信息的文本、图片、流媒体视频信息点播，通过手机与电视双向互动的农业供求即时通。该系统具有信息到户、操作便利、随时查看、随意选择、更新迅速、双向互动的先进性，易于在沿海发达地区的农村基层推广普及。从根本上解决农业信息服务的“最后一公里”问题。文章还介绍了目前基层农村的农业信息服务现状、缺陷，也介绍了推广新系统将带来的社会和经济效益。     

New surgical approach to the plantar fetlock joint through the digital flexor tendon sheath wall and suspensory ligament apparatus in cases of concurrent septic synovitis in two cattle

A new surgical approach to the infected fetlock joint is described in two cattle suffering from septic tenosynovitis of the lateral digital flexor tendon sheaths of the right lateral hind-digits with concurrent septic serofibrinous arthritis of the adjoining fetlock joints, caused by penetrating wounds. In both patients, the infected sheaths were opened and the superficial and deep digital flexor tendons were removed. Intraoperatively, a small entry through the fetlock joint capsule was detected, directly distal to the lateral proximal sesamoid bone. The tract was surgically enlarged and a second approach into the plantar fetlock joint pouch was created proximally by making a 3 cm long and 0.5 cm wide incision between the two lateral suspensory ligament branches. This allowed easy access to the plantar joint pouch, removal of fibrin clots and an effective joint lavage using 5L of sterile saline solution. The incisions of the fetlock joint capsules remained unsutured and were drained using soft polyurethane foam to preclude premature closure. The tendon sheath wounds remained unsutured. In both patients, the digital flexor tendon sheath and the fetlock joint were lavaged daily for the following three days. The infection was eliminated in both cattle and both fully recovered without residual lameness.     

开展我国数字草地建设

随着我国数字农业研究与建设的深化,数字草地的研究与建设也迫在眉睫.开展我国数字草地建设不仅是数字农业发展的需要,而且也是草业科技创新之急需.为此,主要从六个方面讨论了我国数字草地建设(1)建设的必要性;(2)发展数字草地的可能性;(3)建设的指导思想、基本原则和目标;(4)数字草地建设体系结构;(5)数字草地建设的内容;(6)数字草地建设的保障措施.     

Drought damage in the park forests of the city of Helsinki

During spring and summer 2003 severe drought-caused damage was observed in the park forests of the city of Helsinki; especially in barren site pine and spruce stands. The objectives of this study were to map and document the extent of the damage through the use of existing geographical information, digital aerial photography and field surveys and to examine the feasibility of assessing drought damage by visual interpretation of digital aerial photography. Our aim was also to assess the reasons for drought damage in Helsinki city park forests using geographic information system (GIS) analyses of existing interpretative and geographical data, i.e. digital aerial photographs, rainfall statistics and the compartmentwise GIS database of the park forest site and soil types.The total amount of area falling into serious damage classes represented approximately 25 ha (the total forested area in Helsinki is about 3700 ha). A majority of these areas were located on rocky sites having low stem volumes. The total proportion of damaged stock volume was estimated as 17 300 m³, which is 3.3% of the total stock volume in the study area. An accuracy assessment showed that visual interpretation of digital aerial photos is an excellent tool for assessing drought damage. The mean estimation error was 0.7 classes, and errors comprising 2 classes were found in all test grids. The overall correct percentage of photointerpretation was 46%, and estimation was unbiased (kappa 0.264). The forest site and soil type together with the tree species on site showed the greatest correlation with drought damage. The drier and more barren the site, the more likely that damage will occur. Roadside forests were in better condition than areas located further off the roads. Hills clearly impacted the condition of the trees through soil type and flow.     

北京市门头沟区数字沟域建设研究

"沟域经济"是从北京市门头沟区提出的一个新农村建设的新思路,对解决北京市的山区农村建设发展有巨大的推进作用。其中的"数字沟域"建设在中有重大作用。从"数字沟域"的提出、数字沟域建设的几个方面等做出了对"数字沟域"建设的一些研究分析。