中国碱蓬属Suaeda植物研究中的分类学错误     

邢亦谦  邢军武 《海洋科学》2019,43(5):97-102

以纠正碱蓬属Suaeda盐生植物研究中广泛存在的分类错误为目的,针对碱蓬属研究中因缺乏正确的种属鉴定与使用错误种名等导致无法确定研究对象是何植物,使研究结果丧失确定性和科学价值的问题,通过对相关错误文献的梳理,对包括《中国高等植物图鉴》在内的有关碱蓬属植物研究文献进行了初步分析,指出了有关碱蓬属植物研究中的同物异名、同名异物以及中文名与拉丁名错乱等问题并予以纠正。对提高碱蓬属植物研究的科学性与可靠性具有重要参考价值。  相似文献   

地理国情监测成果在农业、旅游领域中的应用     

齐忠华  邱剑南  张力仁  吴长俊 《测绘通报》2019,(11):149-152,162

开展地理国情监测工作的目的是为了获取自然与人类社会经济活动引起的地表变化信息,具体包括地表自然要素、人文地理要素和社会经济信息的空间分布特征及其相互关系,是基本国情的重要组成部分,为政府管理决策、企业生产运营、人民群众生活提供数据基础和决策依据。本文基于地理国情监测数据,结合多种测绘地理信息数据和技术手段,探讨如何利用地理国情监测成果促进农业与旅游业的发展,以期深入挖掘和提升监测成果价值,全面拓展监测成果应用服务的新思路、新方向。  相似文献   

基于AHP-PSR模型的西南丘陵地区农用地集约利用动态评价     

贺光琴  李永树 《测绘与空间地理信息》2019,42(2):25-29

针对西南丘陵地区农用地利用效率低、耕地质量锐减、人地关系逐步恶化等问题构建了基于AHP-PSR模型的西南丘陵地区农用地集约利用评价系统。采用专家打分法进行指标筛选后,基于AHP-PSR模型进行农用地集约利用动态评价,对系统内部协调及稳定性进行分析、评估,较深入地研究农用地集约利用驱动因子,并采用最优子集选取策略分析集约利用驱动力,以避免仅以简单相关性就加入或剔除驱动力因素导致回归系数不符合实际内涵的现象。实验表明:可利用系统调整指标间权重,动态展示人地关系协调可持续发展关系,其分析结果可供有关部门决策参考。  相似文献   

广西农业干旱动态评估模型     

李艳兰  罗莹  黄雪松 《气象研究与应用》2006,27(2):11-14

以自然条件下大气-作物-土壤系统的水量平衡方程为基础,结合广西干旱灾害特点,建立广西农业干旱评估模型。与广西历史农业旱情实况对比分析表明,该模型能够较客观、定量地对农业干旱的发生、发展过程进行逐日动态监测和灾中、灾后评估。  相似文献   

Winter cover crops in Dutch maize fields: Variability in quality and its drivers assessed from multi-temporal Sentinel-2 imagery     

《International Journal of Applied Earth Observation and Geoinformation》2020

Planting a cover crop between the main cropping seasons is an agricultural management measure with multiple potential benefits for sustainable food production. In the maize production system of the Netherlands, an effective establishment of a winter cover crop is important for reducing nitrogen leaching to groundwater. Cover crop establishment after maize cultivation is obliged by law for sandy soils and consequently implemented on nearly all maize fields, but the winter-time vegetative ground cover varies significantly between fields. The objectives of this study are to assess the variability in winter vegetative cover and evaluate to what extent this variability can be explained by the timing of cover crop establishment and weather conditions in two growing seasons (2017–2018). We used Sentinel-2 satellite imagery to construct NDVI time series for fields known to be cultivated with maize within the province of Overijssel. We fitted piecewise logistic functions to the time series in order to estimate cover crop sowing date and retrieve the fitted NDVI value for 1 December (NDVI_Dec). We used NDVI_Dec to represent the quality of cover crop establishment at the start of the winter season. The Sentinel-2 estimated sowing dates compared reasonably with ground reference data for eight fields (RMSE = 6.6 days). The two analysed years differed considerably, with 2018 being much drier and warmer during summer. This drought resulted in an earlier estimated cover crop sowing date (on average 19 days) and an NDVI_Dec value that was 0.2 higher than in 2017. Combining both years and all fields, we found that Sentinel-2 retrieved sowing dates could explain 55% of the NDVI_Dec variability. This corresponded to a positive relationship (R² = 0.50) between NDVI_Dec and the cumulative growing degree days (GDD) between sowing date and 1 December until reaching 400 GDD. Based on cumulative GDD derived from two weather stations within Overijssel, we found that on average for the past three decades a sowing date of 19 September (± 7 days) allowed to attain these 400 GDD; this provides support for the current legislation that states that from 2019 onwards a cover crop should be sown before 1 October. To meet this deadline, while simultaneously ascertaining a harvest-ready main crop, in practice implies that undersowing of the cover crop during spring will gain importance. Our results show that Sentinel-2 NDVI time series can assess the effectiveness and timing of cover crop growth for small agricultural fields, and as such has potential to inform regulatory frameworks as well as farmers with actionable information that may help to reduce nitrogen leaching.  相似文献   

珠三角基塘系统研究回顾及展望   总被引：2，自引：0，他引：2  

龚建周  蒋超  胡月明  杨颢 《地理科学进展》2020,39(7):1236-1246

基塘系统是中国劳动人民独创的低洼地利用方式和生态循环农业模式,珠三角基塘系统在历史上曾起到重要的作用,但目前其面积萎缩、生态功能退化。为了推动珠三角传统农业文化遗产的保护、促进区域人地关系协调发展,论文结合文献计量学方法对珠三角基塘系统研究文献进行梳理和概括,发现在基(田)塘生产力、区域水陆生态农业循环模式规律、社会经济发展与传统农业文化遗产保护的关系等方面已经展开研究;但是珠三角基塘系统演变机理研究比较薄弱,区域特色的农业文化遗产保护途径探索还鲜见。建议未来加强珠三角基塘系统演变机理、系统重构技术、农业文化遗产保护价值与途径的研究,以此深化基塘系统理论及实践研究,为协同区域农业生产格局与农业生态系统耦合关系提供支撑。  相似文献   

Preprocessing of gravity gradients at the GOCE high-level processing facility   总被引：3，自引：0，他引：3  

Johannes Bouman  Sietse Rispens  Thomas Gruber  Radboud Koop  Ernst Schrama  Pieter Visser  Carl Christian Tscherning  Martin Veicherts 《Journal of Geodesy》2009,83(7):659-678

One of the products derived from the gravity field and steady-state ocean circulation explorer (GOCE) observations are the gravity gradients. These gravity gradients are provided in the gradiometer reference frame (GRF) and are calibrated in-flight using satellite shaking and star sensor data. To use these gravity gradients for application in Earth scienes and gravity field analysis, additional preprocessing needs to be done, including corrections for temporal gravity field signals to isolate the static gravity field part, screening for outliers, calibration by comparison with existing external gravity field information and error assessment. The temporal gravity gradient corrections consist of tidal and nontidal corrections. These are all generally below the gravity gradient error level, which is predicted to show a 1/f behaviour for low frequencies. In the outlier detection, the 1/f error is compensated for by subtracting a local median from the data, while the data error is assessed using the median absolute deviation. The local median acts as a high-pass filter and it is robust as is the median absolute deviation. Three different methods have been implemented for the calibration of the gravity gradients. All three methods use a high-pass filter to compensate for the 1/f gravity gradient error. The baseline method uses state-of-the-art global gravity field models and the most accurate results are obtained if star sensor misalignments are estimated along with the calibration parameters. A second calibration method uses GOCE GPS data to estimate a low-degree gravity field model as well as gravity gradient scale factors. Both methods allow to estimate gravity gradient scale factors down to the 10⁻³ level. The third calibration method uses high accurate terrestrial gravity data in selected regions to validate the gravity gradient scale factors, focussing on the measurement band. Gravity gradient scale factors may be estimated down to the 10⁻² level with this method.  相似文献   

公共服务设施可达性及其对新建住房价格的影响——以北京中心城为例   总被引：8，自引：0，他引：8  

王松涛  郑思齐  冯杰 《地理科学进展》2007,26(6):87-94

本文基于北京市公共服务设施的地理空间信息数据, 采用最短距离指标定量分析了商品 住房对教育、医疗、体育、文化、商业、绿地公园等6 大类公共服务设施的空间可达性( 以下简称 “可达性”) , 并通过Hedonic 特征价格模型定量分析可达性对商品住房价格的影响。研究结果表 明: 1) 按照“最短距离”可达性比较, 商品住房对绿地公园、医院和健身场所可达性最好, 而对大型 商场、文化设施、体育场馆的可达性较差; 2) 按照商品住房的区位和价格比较, 城市四环以内和高 价商品住房组别对公共服务设施的可达性明显优于其它组别; 3) 特征价格模型的定量分析表明, 重点高中、球类场馆、文化设施和绿地公园这4 种公共服务设施的可达性越好, 则商品住房价格 越高, 即目前北京市公共服务设施的规划布局在一定程度上被资本化入商品住房价格。  相似文献   

基于高分辨率遥感影像的设施农业资源信息采集技术研究   总被引：1，自引：0，他引：1  

罗军  潘瑜春  王纪华  陆洲  曹荣龙  阎广建 《地理与地理信息科学》2007,23(3):51-54

结合设施农业空间位置分布规律及其在高分辨率遥感影像上的纹理特征体现,设计了批量设施自动生成算法,并基于GIS组件开发了基于高分辨率遥感影像的设施农业信息采集系统;该系统以高分辨率遥感影像为基础底图,结合批量设施自动生成算法进行数字化,实现了人机交互式半自动化信息采集。  相似文献   

地质为农业服务的初步探讨：盱眙县农业环境地质评价简介     

谭东林 《水文地质工程地质》1993,20(4):50-52

通过介绍“盱眙县农业环境地质评价”,提出了开展农业地质工作的思路、方法及成果的编制。对如何开发地质资源,控制地质灾害,以服务于农业,进行了有益地探索。  相似文献