国外粮食产量业务预报系统

"国外粮食产量业务预报系统"是在Windows 9x/2000/NT平台下,应用Mierosoft Visual Basic 6.O工具研制的.主要包括数据管理、数据处理、数据统计分析、平均单产预报、种植面积估算和总产量预报等模块,利用该系统可分别对美国小麦、美国玉米、美国大豆、印度小麦、印度稻谷、巴西大豆、中国稻谷、中国小麦、中国玉米9种粮食作物进行生长期间农业气象条件分析、平均单产预报、种植面积估算和总产量预报.系统结构合理,操作简便、自动化程度高.以美国玉米为例对该系统进行介绍.美国玉米总产量预报2001～2004年最大误差8.4%(绝对值),平均误差2.4%.平均准确率在90%以上;2005年预报正确,能够满足业务服务的需要.     

承德春玉米需水量变化特征及其与气象因子的关系

利用1961-2009年气象资料和发育期资料,采用FAO推荐的Penman-Monteith公式计算春玉米生育期内逐日需水量,研究了承德春玉米需水量、水分盈亏的年内、年际变化规律,分析了气象因子对春玉米需水量的影响。结果表明：承德春玉米生育期平均需水总量、水分盈亏分别为522.5mm和69.4mm。在生育期内,春玉米逐日需水量的变化规律表现为先缓慢增加后减小|春玉米需水量与气象因子密切相关。     

气候变化对我国农作物种植结构的影响

气候变化引起水热条件的变化,从而影响到我国农业生产的方方面面,人们采取不同措施以适应气候变化带来的各种影响。为了清楚地认识气候变化对我国主要粮食作物生产的影响以及适应措施,利用《中国农业统计年鉴》1980-2007年资料和1961-2007年全国逐日平均温度观测数据及前人的研究成果,分析了气候变化对我国三大粮食作物布局和种植结构的影响。结果表明,由于气候变暖,粮食作物种植比例变化明显。小麦种植比例对气候变化最为敏感,波动大;水稻种植比例变化南北方反向,且变化幅度趋缓;玉米种植比例持续增加,增幅加大。三大粮食作物种植结构变化均以2000年为分界点,呈现不同增减趋势。而作物熟制、复种指数也发生明显变化,种植北界持续北推。黑龙江地区大面积扩种水稻,原来的玉米优势种植区为水稻所替代。     

Autumn daily characteristics of land surface heat and water exchange over the Loess Plateau mesa in China

The Loess Plateau, located in northern China, has a significant impact on the climate and ecosystem evolvement over the East Asian continent. In this paper, the preliminary autumn daily characteristics of land surface energy and water exchange over the Chinese Loess Plateau mesa region are evaluated by using data collected during the Loess Plateau land-atmosphere interaction pilot experiment （LOPEX04）, which was conducted from 25 August to 12 September 2004 near Pingliang city, Gansu Province of China. The experiment was carried out in a region with a typical landscape of the Chinese Loess Plateau, known as ＂loess mesa＂. The experiment＇s field land utilizations were cornfield and fallow farmland, with the fallow field later used for rotating winter wheat. The autumn daily characteristics of heat and water exchange evidently differed between the mesa cornfield and fallow, and the imbalance term of the surface energy was large. This is discussed in terms of sampling errors in the flux observations-footprint; energy storage terms of soil and vegetation layers; contribution from air advections; and low and high frequency loss of turbulent fluxes and instruments bias. Comparison of energy components between the mesa cornfield and the lowland cornfield did not reveal any obvious difference. Inadequacies of the field observation equipment and experimental design emerged during the study, and some new research topics have emerged from this pilot experiment for future investigation.     

双矩阵算法的L波段多角度玉米微波辐射参数化模型

双矩阵MD(Matrix-Doubling)算法是辐射传输方程的一种数值解,考虑了植被层内的多次散射信号,具有较高的模拟精度。但受限于算法的复杂性,很难直接应用到地表参数的反演中。本文以玉米覆盖地表为研究对象,基于MD算法的模拟数据,发展了一种L波段多角度微波辐射参数化模型。基于模拟数据的对比结果表明,参数化模型具有与理论模型相当的精度,两者之间的发射率误差不超过0.004(V极化)和0.007(H极化)。同时,结合黑河流域的地面实测数据,利用本论文中发展的参数化模型模拟了纯玉米像元的辐射亮温。该模拟结果与相同像元尺度上机载L波段微波辐射计(PLMR)观测亮温之间的差异基本在10 K以内。     

农作物种植适应性选择系统的设计与实现

针对目前大量基础耕地评价成果尚未充分利用的问题,借助MapGIS K9的企业管理器与组件技术,结合Visual C#2008,提出了基于层次分析法的农作物种植适应性选择系统,实现了决策分析、作物销售、三维漫游与Google Map衔接等特色功能,并加入了空间查询、图档操作、空间数据分析等基础GIS功能,为农作物种植适应性选择提供了一个合理高效的平台。     

微波消解-电感耦合等离子体质谱测定玉米中铬、镉、铅

研究了微波消解-电感耦合等离子体质谱（ICP-MS）测定玉米中重金属元素的方法。详细讨论了微波样品溶液制备、质谱仪干扰扣除及校准等,在优化的试验条件下,根据国家标准参考物质（GBW10012）的分析结果评价方法的准确性。方法检出限为：Cd：0.003μg/g,Cr：0.04μg/g,Pb：0.1μg/g,相对标准偏差在2.5%-6.0%之间,加标回收率在90.9%-104.9%之间。     

CHARACTERISTICS OF SOILS ON DEBRIS APRONS IN THE SOUTHERN BLUE RIDGE,NORTH CAROLINA

Aprons of bouldery diamicton frequently have been observed in concave landscape positions in the Southern Blue Ridge. Because of their relatively flat topography, large aprons often are the focus of local economic activity. An environmentally sound development of these landforms can benefit from systematic pedological studies. The present research provides characterization data, and examines spatio-geomorphic variability, for some pedons that have developed on these debris aprons under a warm to temperate humid climate. This study also compares the pedons to those derived from nearby saprolite. Thirteen pedons, located variously on the foot slopes and the apices of the aprons, were studied in three sequences of multiple deposits. The pedons typically contain high amounts of rock fragments and have clay contents that are related to age. Most pedons have lithologic discontinuities. Some of these discontinuities result from the stacking of different deposits, whereas others represent internal variations within one deposit. Because of the heterogeneity in parent material, many soil characteristics do not possess systematic trends with depth. Depth to maximum clay mass and free-iron mass accumulation, however, systematically increase from foot to apex positions, and from topographically low to high deposits. deposits. [Key words: debris flows, soils, lithologic discontinuities, Blue Ridge.]     

夏玉米倒伏模拟试验及遥感监测

针对传统的玉米倒伏人工灾害评估方法效率低、随机性大等缺点,该文提出了一种基于遥感技术的方法,设计了田间模拟试验。利用ASD光谱仪采集倒伏玉米的冠层光谱数据,并与未倒伏玉米的光谱数据进行比较。结果显示了倒伏玉米和未倒伏玉米冠层光谱之间存在一定程度的差异。利用夏玉米NDVI值的改变,采用两期遥感影像对山东淄博市桓台县夏玉米倒伏情况进行了监测。结果表明,基于遥感数据的NDVI方法在一定程度上可以有效监测玉米倒伏。     

安徽省夏玉米干旱天气指数保险产品设计及应用

利用安徽省夏玉米种植区15个农业气象观测站点1971—2010年的逐日降水资料并结合区域夏玉米抽雄-乳熟期(产量形成关键期)的降水距平与夏玉米干旱减产率进行分析,建立了干旱天气指数模型。提出夏玉米干旱的保险赔付标准,并利用各市(县)的干旱风险评估结果修订干旱天气指数保险费率,最终得到各地区的夏玉米干旱天气指数保险产品。将设计的保险产品在安徽省淮北市濉溪县试验应用,该产品可以基本反映实际夏玉米干旱风险状况,有助于农业保险公司客观、快捷地提供农业灾害的经济补偿。