全国农情监测与估产的运行化遥感方法

农作物遥感估产包括农作物的长势与产量趋势监测及产量的早期预报。在总结１５年来国内遥感估产成果的基础上,提出了以充分利用已有成果为基础的全国范围农作物估产运行化遥感方法。建成了ＮＯＡＡ ＡＶＨＲＲ数据实时预处理系统,并利用每旬的ＡＶＨＲＲ最大ＮＤＶＩ图像与上年同期数据对比实现全国范围的家作物遥感长势监测。在高精度耕地数据库的支持下,通过提取不同作物种植成数估算作物种植面积。种植成数可以用ＴＭ和多时相     

基于RS与GIS的干旱区棉花信息提取及长势监测

以CBERS—1卫星图像为信息源，在新疆石河子地区，通过三种不同分类方法的对比，得出Fuzzy—ARTMAP的分类结果精度最高。在GIS的支持下，根据Fuzzy—ARTMAP的分类结果提取了棉田信息。利用2001年和2002年不同时相的MODIS和TM图像计算得到归一化植被指数(NDVI)和NDVI差值图像，将NDVI差值图像与棉田信息叠加后并分级，得到年际间和年内棉花长势的动态分布图和相同时相棉花长势的区域差异图。     

草原植被长势遥感监测研究进展

草原植被长势监测是草原监测的重要领域, 它能从宏观上揭示草原的生长状况及其动态变化, 从而为草原科学管理提供快速、准确的参考依据。目前长势监测主要利用遥感的方法, 即选择归一化植被指数NDVI作为反映植被生长状况的指标, 方法有同期对比法、植被生长过程曲线法、直接监测法。本文在总结草原长势监测进展与方法的同时, 指出了其中存在的问题--监测中过分依赖NDVI、不区分草原类型而使用同一种方法进行监测;对未来发展方向做了展望--监测中选用适宜植被指数、监测方法, 分区域、分类型的监测长势, 提高监测精度, 将长势监测与草原产草量、生产力结合, 为牧民生产提供指导。     

大面积棉花长势的MODIS监测分析方法与实践

大面积棉花的生长状况监测比较复杂,目前还没有比较成熟的方法。以往遥感监测应用较多的是NOAA—AVHRR数据,监测精度和监测效果不高。本文利用新一代传感器MODIS数据,结合实测的地面农作物生长发育农学参数,系统地分析了石河子地区棉花播种到收获整个田间遥感归一化指数(NDVI)及其对应的叶而积指数(LAI)的变化规律,证明MODIS叶面积指数和实测LAI有很高的一致性,MODISIAI的变化状况与棉花长势变化基本一致,实现了较为精确的石河子地区大面积棉花长势的遥感动态监测。     

遥感图像生态土地分类法在农作物种植面积提取中的应用

农作物遥感估产技术系统的中心环节之一是农作物种植面积的信息提取,快速、准确地获取农作物有关信息是一个关键性技术问题,针对松辽平原玉米遥感估产地区的自然环境和经济条件及玉米生长发育特征,利用以ＴＭ图像为主的多种遥感信息源,结合地面波谱测试等数据,运用生态土地分类方法实现主枯农作物种植面积信息提取。     

种植业可持续发展的支持系统——农作物卫星遥感估产

本文从种植业可持续发展需要出发,指出建立农作物卫星遥感估产系统是实现种植业可持续发展地面信息准确、快速、经济获取的最有效手段,并能成为种植业可持续发展的支持系统。本文还分析了我国种植业地面信息统计现状和卫星遥感估产国内外研究进展,一个实际运行的农作物卫星遥感估产系统可以监测作物长势、种植面积和作物产量,与其它信息相配合有利于种植业可持续发展战略的实施。     

黔南州主要农作物病虫害监测预警专家系统的构建与实现

通过对1981～2010年30年的贵州黔南地区气象资料与植保病虫害资料的对比研究,得出了农作物病虫害发生的一系列气象条件指标,研究结果表明,作物病虫害的发生与气象条件有密切的关系,主要与气温、相对湿度、日照和降水量有关,而不同种类的病虫害发生的气象条件指标不尽相同。在指标结论的基础上,利用VB.NET设计并开发了黔南州主要农作物病虫害监测预警专家系统,将气象资料实时入库监测分析,达到某种病虫害发生条件即预警,从而实现了农作物病虫害监测预警专家系统的构建。     

气候变暖对西北干旱区农作物种植结构的影响

采用年平均气温与冬小麦、春小麦、玉米和棉花种植面积的相关分析得出：年平均气温与新疆冬小麦种植面积呈显著负相关,与西北干旱区大部地方春小麦种植面积呈显著负相关,与西北干旱区大部地方玉米种植面积呈显著正相关,与新疆和甘肃河西棉花种植面积呈显著正相关。气候变暖、热量资源增加,使喜凉的春小麦和冬小麦种植面积呈迅速减少趋势,喜温的玉米和棉花种植面积呈迅速扩大,夏秋作物种植结构发生明显改变。     

西北地区主要农作物遥感估产信息系统设计

阐述了西北地区主要农作物遥感估产过程中背景数据的类型及获取,信息系统的基本内容和基本结构。介绍了资源环境(背景)信息系统、数据库系统、GIS空间信息提取、估产模型库系统、专家知识库系统和人工神经网络、基于INTERNET的数据发布等各个子模块的基本结构和功能。并描述了各个模块之间的相互关系。西北地区农作物遥感估产信息系统的建成,可及时、客观、准确地提供农作物的长势情况,粮食产量,为有关部门(如农业部门、政府决策部门)的相关决策提供科学数据和依据。     

基于改进型TVDI在干旱区旱情监测中的应用研究

干旱是全球范围内影响最为广泛的自然灾害之一,其所导致的土壤沙漠化、荒漠化和盐碱化给生态环境造成不可逆的危害。通过对MODIS数据进行投影转换、去云等预处理的基础上,利用地形校正对TVDI模型进行改进,构建了改进型的温度植被干旱指数（mTVDI）用于新疆干旱区旱情监测。利用土壤实测数据对mTVDI及传统的TVDI模型进行对比验证。研究结果表明：（1） 利用EVI与校正后的LST构建的mTVDI_E对干旱区旱情的敏感度最高,与实测土壤水分数据的相关性R²为0.74。（2） 从空间上看,新疆2015年旱情分布以塔里木盆地和准噶尔盆地为两个干旱中心,旱情状况由严重逐步向周围山区递减至湿润状态。从时间上看,新疆6月、7月和8月旱情最为严重。（3） 研究利用TRMM降水数据对基于mTVDI_E反演的新疆旱情时空分布特征进行对比分析,结果表明二者所表现出的旱情时空分布较为一致,不同时间段内的降水量与mTVDIE之间具有一定的相关性,且均通过了P<0.01显著性检验。综上,基于TVDI所提出的mTVDI_E 能够有效开展新疆干旱区旱情监测,且精度较高,从而为今后定量化开展大区域尺度旱情监测研究提供参考。     

A review of mass flux monitoring and estimation methods for biogeochemical interface processes in watersheds

The magnitude of mass flux is closely associated with biogeochemical watershed processes, which can generate a considerable amount of pertinent information. Moreover, both the accuracy and precision of mass flux estimation results directly affects the perception of the ecological environmental status, which in turn affects both the formulation and implementation of river basin management planning. In practical applications, the true value of flux is unknown and can only be estimated. Flux results obtained using different monitoring and estimation methods also differ significantly. However, in existing studies on mass flux associated with biogeochemical watershed interfaces, the application of monitoring and estimation methods lacks uniform criteria or references. Accordingly, this study summarizes and deconstructs results from recent studies on biogeochemical watershed interface processes and compares the advantages, disadvantages and applicability of the monitoring and estimation methods used by these studies. This particular study is intended to be used as a reference for the selection of flux calculation methods.     

The supporting capability of Water and land resources for sustainable increase of yield in North China Plain

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Spatio-temporal Characteristics of the Extreme Climate Events and Their Potential Effects on Crop Yield in Ethiopia

Extreme climate events exhibit an increasing spatio-temporal trend globally, and the increasing intensity and frequency may have severe impacts on the human society and natural ecosystems. This study analyzed the extreme temperature and precipitation variability from 1956 to 2016, and evaluated their potential effects on crop yield in Ethiopia. Relative extreme temperature indices exhibited a decreasing trend with low-temperature events, but a significantly upward trend with extreme high temperature events. The frequency of annual warm nights increased to a greater degree than that of cold days. The total annual wet-day precipitation decreased significantly at a rate of -46 mm/decade. Further, the succession of dry days gradually increased by 5.6 day/decade, while an opposite trend of wet days was found with a decline of 1.4 day/ decade. The correlation between annual precipitation and crop production was 0.422, indicating that extreme precipitation indices may have higher explanatory power than extreme temperature indices in the crop yield variations. Moreover, the extreme climate changes have induced significant adverse impacts on crops yield particularly in Ethiopia where no proper adaptation measures have been implemented.     

产量红线与耕地红线耦合研究

基于实际粮食产量与抛荒耕地种植粮食作物条件下粮食总产量关系的分析方法有助于促进耕地红线制度改进。依据全国粮食总产量、种植面积与耕地面积数据,构造2016-2033 年粮食产量与耕地面积红线耦合的基本、法定、过渡、新型与理想耦合红线标准;分析阶段性耦合与可持续耦合两种升级路径。研究表明：2001-2015 年,全国耕地面积与粮食产量耦合不足。据此,提出以新增建设用地指标与抛荒治理面积挂钩的政策建议;在抛荒比例11.12%的条件下,新增单位面积建设用地,治理28.85 倍抛荒耕地;2017、2021、2025、2029、2033 年分别实现有效利用1.200×10⁸ hm²、1.243×10⁸ hm²、1.279×10⁸ hm²、1.314×10⁸ hm²、1.349×10⁸ hm² 耕地,粮食总产量分别比基期增加4.838×10⁶、2.4190×10⁷、4.354 2×10⁷、5.321 8×10⁷、8.824 6×10⁷ t;红线耦合系数分别达到0.882 471、0.909 740、0.937 008、0.950 643与1;有效利用耕地增加12.5%,粮食总产量提升14.2%。     

Warming effect of desert and its impact on oasis heat resources and agricultural productivity in arid land, China

This paper provides a positive view of the desert, in terms of the warming effect of deserts on oases and the impact of heat resources and agricultural production. We use data from experimental sites in the Manas River Basin in China to characterize these relationships. We note that the warming effect of the desert was found to be significant but gradually reduced with increased distance of the oasis from the desert. The range of warming effect is about 100 km, and the improvement in temperature is about 1.8 °C. Due to this warming effect, the desert serves as the second heat source for the oasis, which represents one important aspect of the ecologic value of the desert. Our results also show the warming effect has a strong spatial impact on agricultural productivity. Crop productivity fell by about 49 kg/ha with every 10 km increase in distance away from the desert. Our results imply that crop suitability must correspond to the warming effect of the desert. More efficient use of heat resources can contribute towards achieving potential productivity.     

运用RS、GPS和GIS技术进行大比例尺土地利用动态监测的实验研究

土地利用数据的更新是土地管理工作的重要内容之一。依靠常规的手段不仅更新速度慢、难以主动发现变化区域,而且成图周期长、误差大。依靠遥感（RS）手段可以主动快速地发现变化区域,运用差分GPS技术可以精确获取土地利用变化的数量和性质,GIS则是管理土地利用的图形数据和属性数据（如土地利用类型、权属、图斑号等）的有效工具。基于RS、GIS和GPS的集成技术建立面向工程目标的土地利用动态监测新方法是本文研究的内容。     

1950—2014年印度粮食单产对气候变化的响应

利用1950—2014年印度粮食单产统计资料及气候变化资料,从实证的角度,定量分析了小麦、水稻单产对气候的年际变化和年代内趋势性变化的响应。结果表明：1）年际变化方面,粮食单产与降水量和雨日数呈显著正相关,与温度和潜在蒸发量呈显著负相关,其中小麦单产与四者的相关系数分别为0.35（P＜0.01）、0.24（P＜0.10）、-0.32（P＜0.05）和-0.41（P＜0.001）,水稻的相关系数分别为0.32（P＜0.05）、0.32（P＜0.05）、-0.26（P＜0.05）和-0.33（P＜0.01）。这表明,高温、少雨导致的水分胁迫不利于粮食增产。2）在年代内趋势性变化方面,1996—2005年印度气候呈现暖、干化趋势,全国平均粮食单产呈下降趋势;从变化速率的空间分异看,单产下降速率与暖、干化速率的空间分异规律基本吻合,单产快（慢）速下降区域与降水量快（慢）速减少、潜在蒸发量快（慢）速增加区域基本一致。水稻和小麦单产变化速率与降水量变化速率的空间分异均呈正相关,与潜在蒸发量变化速率的空间分异均呈负相关。由此表明,降水减少和温度升高导致的水分胁迫是印度粮食单产时空变化的主要气象成因。     

Cluster planting impact on cotton growth,yield and biomass accumulation in an arid region oasis

The cluster planting pattern(3 plants per hole) for cotton(Gossypium hirsutum L.) may increase economic yield over those of the traditional planting pattern(1 plant per hole) in arid regions of China. This increase in yield depends on either increased biomass production or greater partitioning to fruit. This study was conducted to determine whether differences in biomass accumulation or partitioning to reproductive growth contributed to higher yield in the cluster planting pattern compared with the traditional one. Growth parameters, biomass accumulation, crop growth rate and partitioning between cluster planting pattern and traditional planting pattern was compared in northwest of China. The biomass production and partitioning in cluster planting plot was higher than in traditional planting one. Biomass accumulation was faster early in the clustered treatment, and it was also higher at harvest time. Total dry matter production per unit area was significantly higher than in the traditional planting. On a per plant basis, dry matter accumulation was faster and total biomass production was significantly higher in the cluster planting pattern. Numbers of sympodia and boll sizes were also larger, indicating that facilitation among plants was promoting crop yield. The increase in yield in the cluster planting treatment occurred through increased partitioning of dry matter to fruits than in the traditional planting pattern, resulting in more bolls and increased lint yield in arid regions.     

基于作物植被指数和温度的产量估算模型研究

该文利用冬小麦返青初期至抽穗初期的累积植被指数和孕穗—灌浆阶段的温度累积值为模型因子 ,建立冬小麦产量估算模型 ,在建模过程中 ,分析了模型变量与产量的关系并对变量获取方法进行了适当改进 ,简化了变量的获取途径 ,为模型的业务化应用奠定了基础。