Antarctica: measuring glacier velocity from satellite images

Many Landsat images of Antarctica show distinctive flow and crevasse features in the floating part of ice streams and outlet glaciers immediately below their grounding zones. Some of the features, which move with the glacier or ice stream, remain visible over many years and thus allow time-lapse measurements of ice velocities. Measurements taken from Landsat images of features on Byrd Glacier agree well with detailed ground and aerial observations. The satellite-image technique thus offers a rapid and cost-effective method of obtaining average velocities, to a first order of accuracy, of many ice streams and outlet glaciers near their termini.     

Method for estimation of ocean current velocity from satellite images

Barotropic instability waves on a shear interface propagate at the average speed of the water on the two sides. Assuming the instability to be excited by tidal oscillations, the phase speed is the wavelength divided by the tidal period. If the water is at rest on one side of the shear layer the current speed on the other side can be calculated. This method, applied to the Gulf Stream beyond Cape Hatteras as seen in satellite images, gives estimates of current speed in general agreement with in situ observations.     

Fast and accurate detection of kiwifruit in orchard using improved YOLOv3-tiny model

Precision Agriculture - Automatic detection of kiwifruit in the orchard is challenging because illumination varies through the day and night and because of color similarity between kiwifruit and...     

覆盖作物多样性对猕猴桃园土壤微生物群落功能的影响

以丹江口水源涵养区猕猴桃园为研究对象,运用Biolog微平板技术,研究不同种类覆盖作物处理(2、4、8种和清耕对照)下土壤微生物群落功能多样性的差异。结果表明,覆盖作物处理土壤微生物群落对碳源的利用程度、功能多样性指数和丰富度指数均高于清耕对照。覆盖作物及清耕对照处理土壤微生物Shannon-Wiener多样性指数、丰富度指数与土壤含水量、有机碳、pH、微生物量碳氮呈显著正相关关系。主成分分析与碳代谢图谱分析表明,猕猴桃园增加覆盖作物种类提高了土壤微生物对碳源的利用能力,且对D-甘露醇、L-精氨酸、L-天门冬酰胺、L-苯丙氨酸、γ-羟丁酸、α-丁酮酸、4-羟基苯甲酸、吐温40的利用能力显著高于清耕对照。此外,4种覆盖作物处理对猕猴桃园土壤生态环境的影响优于2种和8种。研究表明,猕猴桃园增加覆盖作物多样性改变了土壤环境因子,影响了土壤微生物群落的代谢活性和功能多样性。     

覆盖作物不同利用方式对猕猴桃园土壤微生物群落结构的影响

为探讨覆盖作物不同利用方式对猕猴桃园土壤微生物群落结构的影响,通过磷脂脂肪酸（PLFA）方法,研究覆盖作物处理对猕猴桃园土壤微生物群落结构的影响。试验设置3个处理,分别为种植覆盖作物+覆盖作物刈割后留在土壤表面自然腐解（T1）、种植覆盖作物+覆盖作物刈割后从园中清除（T2）和清耕对照（CK）。结果表明,T1、T2处理土壤微生物PLFAs总量和微生物量碳、氮均显著高于CK（P<0.05）;土壤pH和碳氮比是影响猕猴桃园土壤微生物群落的主要环境因子,pH与土壤微生物PLFAs总量呈极显著正相关（P<0.01）,与细菌PLFAs量、革兰氏阴性菌PLFAs量呈显著正相关（P<0.05）,碳氮比与革兰氏阳性菌PLFAs量/革兰氏阴性菌PLFAs量呈极显著正相关（P<0.01）。研究表明,猕猴桃园种植覆盖作物改变了土壤环境因子,影响土壤微生物群落结构组成。研究可为丹江口水源涵养区果园生态管理模式的探索提供理论依据。     

湖南猕猴桃园土壤重金属含量分析及污染评价

土壤污染已日益成为制约经济社会发展的环境因素。以湖南猕猴桃主产区土壤为研究对象,系统采集分析了全省21个县(市)54个典型果园0-20 cm和20-40 cm土壤重金属Pb、Cd、Hg、As和Cr含量特征,采用单因子指数法、内梅罗综合污染指数法对全省土壤重金属污染状况进行了初步评价。结果表明,0-20 cm土层土壤重金属含量均高于20-40 cm土层土壤。按土壤环境质量二级标准,主产区果园土壤未有Pb、Cr污染,有弱度的Cd、Hg和As污染,且局部污染问题较为突出;有31.5%的土壤受到不同程度污染,20.4%的土壤处于警戒线以上,只有48.1%的土壤达到清洁标准。按绿色食品产地环境土壤标准,Pb、Cd、Hg、As、Cr指数小于1的分别占到68.5%、66.7%、72.2%、74.1%和96.3%;53.7%的果园综合污染指数小于1,达到绿色食品果园标准,有37.0%的果园轻度超标,9.3%的果园中度和重度超标。在表层土壤中,重金属元素之间具有正相关关系,其中Pb与Hg显著相关,Pb与Cd、As、Cr,Hg与As,As与Cr极显著正相关,表明土壤重金属污染具有较强的同源性。在重金属污染土壤上种植,猕猴桃果实对重金属的吸收累积较少。     

Deforestation history of the eastern rain forests of madagascar from satellite images

Madagascar is biologically one of the richest areas on Earth, and its plants and animals are among the most endangered. Satellite images and vegetation maps based on earlier aerial photographs were used to determine the extent of eastern rain forests in Madagascar and to monitor the rate of deforestation over a 35-year period. In 1985, 3.8 million hectares of rain forest remained, representing only 50 percent of the 7.6 million hectares existing in 1950 and 34 percent of the estimated orignal extent (11.2 million hectares). Between 1950 and 1985, the rate of deforestation averaged 111,000 hectares per year. Deforestation was most rapid in areas with low topographic relief and high population density. If cutting of forests continues at the same pace, only forests on the steepest slopes will survive the next 35 years.     

4个猕猴桃新品种生物学特性的观察比较

武汉植物园通过多年的实生、芽变以及杂交等多种育种手段,选育出多个优良性状的猕猴桃新品种,在我国猕猴桃产区进行区试、中试,并取得良好的经济效益和社会效应.2002～2004年,作者对武汉植物园培育的4个猕猴桃品种与传统"Hayward"在物候期、结果习性以及果实性状上进行了比较,结果显示,武汉植物园选育的4个猕猴桃新品种果肉颜色均为黄色,其中"金早"为极早熟品种,在武汉地区8月中旬成熟;"金霞"、"金桃"、"金艳"猕猴桃座果率高,Vc含量高,其中"金桃"、"金艳"猕猴桃综合性状优于传统猕猴桃品种"Hayward".     

国产高分系列遥感卫星影像的批量自动配准研究

【目的 】遥感影像的精确几何配准对于国产高分系列卫星影像处理以及后续的农情监测等应用至关重要。【方法 】文章基于自动配准和正射校正程序包AROP,选择16 m分辨率的高分1号、高分6号宽幅影像和3 m分辨率高分2号、高分7号多光谱影像作为实验数据,以经过几何精校正的10 m分辨率的Sentinel-2影像和3 m分辨率的谷歌影像为基准影像,在农业用地场景和城市用地场景下,进行批量的几何配准实验,对配准的结果进行目视检验和定量评价。同时,为了更好地匹配高分影像与Sentinel-2影像,将高分1号、高分6号宽幅数据重采样到15 m的分辨率进行几何配准。【结果 】在农业用地和城市用地场景下,配准精度大多达到了0.5个像元以内,满足了影像配准的精度标准。其中15 m分辨率的高分1号和高分6号的配准精度分别为0.31～0.54和0.33～0.53,均小于0.6个像元;3 m分辨率的高分2号的配准精度在0.47～0.6之间,小于0.6个像元;高分7号的配准精度在0.44～0.49之间,小于0.5个像元,而且所有高分系列遥感卫星在配准后均目视效果出色,接边良好。【结论 】利用AROP对15 m分辨...     

辽宁省山楂园桃小食心虫预测预报与防治研究

2006-2007年,在辽宁省抚顺市清原县海阳村西北天山楂园,应用桃小食心虫性诱剂,对桃小食心虫的成虫发生期进行预测预报。结果表明,通过性诱剂诱集成虫和查卵果率相结合的方法,预测桃小食心虫的成虫发生期比较准确。同时,采用5%高效氯氰菊酯乳油(山东中石化工有限公司)对桃小食心虫进行化学防治,当始见卵日卵果率>1%时,进行第1次化学防治,施药后7～10d,若卵果率仍>1%,则继续喷药防治,防治效果较好。据此方法,2006年试验喷药4次,2007年喷药1次,结果山楂虫果率由原来的70%以上降至2.65%,防治效果显著。     

Automated interpretation of protective forest plantings on high-resolution satellite images

An important problem in forestry interpretation of satellite images is the identification of areas with a different species composition. Visual interpretation is presently supported by means of computer technologies. The article presents the results of determining the reliability of automated interpretation of pure protective forest plantings on high-resolution satellite images in ENVI software.     

基于CFD果园风送式喷雾机雾滴沉积特性研究

自制应用于柑橘园施药的风送式喷雾机,并基于CFD建立喷雾机雾滴运动轨迹及沉积模型,考察该喷雾机雾滴沉积特性及送风方向对雾滴沉积的影响。根据喷雾机尺寸参数,建立喷雾流场二维模型,并确定DPM模型参数,模拟获得距喷头不同距离的垂直截面上雾滴沉积量。试验结果显示:在距喷头1.0 m的范围内,雾滴沉积特性与试验结果相符,且在1.0 m范围内,送风角度的增加对雾滴飘移影响较小,随着与喷头距离的增大,送风角度对底部雾滴飘移损失的影响逐渐加剧;在距喷头1.0 m范围以外,雾滴沉积特性与实际试验结果偏差较大,但雾滴沉积量随与喷头距离的增大而逐渐减少的规律是一致的。     

Analytical models integrated with satellite images for optimized pest management

The global field protection (GFP) was developed to protect and optimize pest management resources integrating satellite images for precise field demarcation with physical models of controlled release devices of pesticides to protect large fields. The GFP was implemented using a graphical user interface to aid the end-user to select location and define an arbitrary perimeter for protection. The system provides coordinates of drop points for the controlled release devices which can be delivered using drone technology, e.g. unmanned air vehicles. In this work, we present the first proof of concept of this technology. A vast number of pest management applications can benefit from this work, including prevention against vector-borne diseases as well as protection of large agriculture fields.     

油茶食叶害虫胶刺蛾的生物学特性

采用室内外观察法和最小二乘法研究胶刺蛾（Chalcocelis albigutataSnellen）的生物学特性。结果表明：胶刺蛾以幼虫危害油茶叶片,老熟幼虫在叶面处结茧化蛹,每年11月中旬至次年4月上旬以第4代蛹越冬;幼虫共5龄,在25℃下,该虫的世代历期为（89.8±2.3）d;成虫具有正趋性,雌虫平均寿命5.8 ...     

秦岭山区野生猕猴桃资源遗传多样性分析

【目的】利用有效的分子标记技术,对秦岭山区野生猕猴桃的遗传多样性及系统进化关系进行研究,为猕猴桃新种质的挖掘和品种遗传改良奠定基础。【方法】利用随机扩增多态性DNA标记(RAPD)技术,对采自秦岭山区的野生猕猴桃24个优良单株和中华猕猴桃等6个种或变种及其品种的22份资源进行了遗传多样性和亲缘关系分析。【结果】通过引物筛选,用16个RAPD引物对46份猕猴桃资源扩增出235条带,其中227条为多态性条带,多态性位点比例为96.29%;各猕猴桃资源间的遗传距离为0.139 53~0.807 34;UPGMA聚类分析结果显示,‘野生99-13’与‘武植2号’、‘魁蜜’、‘金阳1号’、‘武植6号’、‘中华♂’和‘广西红肉’等中华系列猕猴桃(A.chinensis Planch.)聚在一起,其余23份野生猕猴桃与‘哑特’、‘秦美’、‘徐冠’、‘徐香’等猕猴桃品种遗传距离较近。【结论】24份秦岭野生猕猴桃资源中,‘野生99-13’属中华系列猕猴桃,其余23份均属于美味猕猴桃(A.deliciosa var.deliciosa)。     

苹果园中土壤水分空间分布特性初探

无线传感器(WSN)能通过互联网感知客体环境信息,已经广泛应用于农业生产环境监测.将WSN应用在苹果园中,监测果园环境信息,为苹果生产提供决策支持.土壤水分是影响苹果品质和产量的重要因素之一.研究果园中土壤体积含水量的分布规律能为WSN在果园应用中土壤水分传感器部署策略提供支持.在北京一个普通的苹果园进行实地试验,采用土壤水分测量仪测量3个典型子区域不同土壤深度及不同水平位置多个点的土壤体积含水量,结果表明:总体上在果树周围土壤体积含水量随着树根距离的增加而增加;计算了3个典型子区域及整个果园3个土壤深度的均方差,91.7％的均方差均为2％～3％,在各个子区域及整个果园,土壤水分具有相似的分散程度;计算了每个子区域每个测量点的土壤水分均方差.1％～2％之间的均方根误差所占比例最大,为48.2％.当土壤深度小于300 mm时,水平层面的均方差大于垂直方向.根据试验结果,提出了一种“以单棵树为目标,着眼于整个果园”的土壤水分传感器部署方法.     

地表覆盖方式对广西柑橘果园土壤水分特征的影响

【目的】探究不同覆盖方式对广西柑橘果园土壤性质及土壤水分变化的影响,为该区域果园杂草管理及水分管理提供参考依据。【方法】以广西柑橘果园为研究对象,设喷施除草剂对照(CK)、防草布覆盖(GPC)和自然生草割刈(NGM)3种果园地表覆盖处理,并于处理一年后测定0~10 cm、10~30 cm、30~50 cm和50~70 cm土层的土壤基本理化性质和果园土壤水分变化特征。【结果】不同地表覆盖处理对柑橘果园表层0~10 cm土壤的容重、总孔隙度和有机质含量有明显影响,对深层土壤影响较小。NGM处理使0~10 cm土层土壤容重显著降低7.52%(P<0.05,下同),土壤有机质含量提高7.99%;GPC处理使0~10 cm土层土壤容重降低3.01%,土壤有机质含量降低14.15%。相同土壤水吸力下,0~10 cm和10~30 cm土层土壤含水量表现为GPC>CK>NGM;30~50 cm土层表现为CK≈GPC>NGM;50~70cm土层表现为CK>NGM>GPC。在0~10 cm土层中,NGM处理的速效水含量(0.079 cm3/cm3)最高;在30~50 cm和50~70 cm土层,GPC处理的速效水含量最高,分别较CK提高11.00%和18.12%。GPC和NGM处理均可提高各土层的土壤含水量,其中GPC处理0~10 cm和10~30 cm土层含水量增幅更大,而NGM处理30~50 cm和50~70 cm土层含水量增幅更明显。GPC和NGM处理均可显著提高0~70 cm各土层土壤贮水量,其中GPC处理提高2.83%~4.26%,NGM处理提高4.02%~4.55%。【结论】自然生草割刈处理在改善柑橘园表层土壤环境、增强土壤蓄水保墒和供水能力方面具有较好的效果,而防草布覆盖处理在保水方面也有较大优势。在生产中建议采用自然生草割刈的管理方式。     

Spatial variation in tree characteristics and yield in a pear orchard

We examined the spatial structure of fruit yield, tree size, vigor, and soil properties for an established pear orchard using Moran’s I, geographically weighted regression (GWR) and variogram analysis to determine potential scales of the factors affecting spatial variation. The spatial structure differed somewhat between the tree-based measurements (yield, size and vigor) and the soil properties. Yield, trunk cross-sectional area (TCSA) and normalized difference vegetation index (NDVI, used as a surrogate for vigor) were strongly spatially clustered as indicated by the global Moran’s I for these measurements. The autocorrelation between trees (determined by applying a localized Moran’s I) was greater in some areas than others, suggesting possible management by zones. The variogram ranges for TCSA and yield were 30–45 m, respectively, but large nugget variances indicated considerable variability from tree to tree. The variogram ranges of NDVI varied from about 14–27 m. The soil properties copper, iron, organic matter and total exchange capacity (TEC) were spatially structured, with longer variogram ranges than those of the tree characteristics: 31–95 m. Boron, pH and zinc were not spatially correlated. The GWR analyses supported the results from the other analyses indicating that assumptions of strict stationarity might be violated, so regression models fitted to the entire dataset might not be fitted optimally to spatial clusters of the data.     

南丰县桔园土壤相对湿度变化特征

分析了南丰县2012～2020年桔园土壤平均相对湿度随年际和土层深度变化、桔园土壤10～20cm、40～50cm、80cm等深度平均相对湿度旬际变化、桔园土壤平均相对湿度与环境因子的相关关系和对柑桔生育的影响,得出了“桔园土壤10～20cm(浅层)旬平均相对湿度与旬平均气温、旬平均最高气温、旬平均空气相对湿度、旬平均地面温度、旬平均最高地面温度、旬降水量、旬日照时数、旬≥0.1mm、≥1.0mm、≥5.0mm、≥10.0mm、≥25.0mm、≥50.0mm降水日数等环境因子相关极显著;随着土层深度的增加,旬降水量和旬≥5.0mm以上降水日数对土壤湿度的影响逐渐增强,旬日照、旬空气湿度、旬气温、旬地面温度和旬≥0.1mm、≥1.0mm降水日数等对土壤湿度的影响逐渐减弱。”结论,提出了相应的措施和建议。