基于GEE和Landsat时间序列数据的海南岛土地利用分类研究

土地利用/覆盖变化（land use/cover change,LUCC）是当前全球变化研究的核心内容之一。土地利用遥感监测是土地利用变化相关研究的重要技术手段,尤其是高分辨率遥感技术和谷歌地球引擎（Google Earth Engine,GEE）云计算平台的出现,为土地利用空间信息的获取提供了新的途径和方法。本研究基于GEE云平台提供的Landsat-8 OLI时间序列卫星影像数据,采用随机森林（random forest,RF）和支持向量机（support vector machines,SVM）分类算法,对海南岛土地利用类型进行了遥感分类研究。结果表明：RF与SVM算法对海南岛土地利用中水体和建筑用地的分类精度均较高,对耕地、园地和林地分类精度较低。与SVM方法相比,RF分类方法能够更准确识别各类地物信息,更适于海南岛土地利用分类的研究。海南岛林地（包括天然林、橡胶林等）所占比例最大,主要分布在海南岛中部;耕地和园地面积接近,相间分布于海南岛大部分区域;水体和建筑用地面积较小,在海南岛均呈零散的分布状态,以沿海地区为主。GEE平台对于开展大区域土地利用分类与遥感动态监测具有重要的意义。     

杂交稻新组合粤优938高产制种技术

粤优938是江苏省农科院原子能利用研究所用粤泰A与R938配组育成的中、晚籼基本型杂交稻新组合。稻米品质达新国标优三级,2000年龙岩市农科所从江苏引进.2000～2001年参加龙岩市晚稻新品种联合区试,连续2a单产名列参试品仲第一;2002年已经在闽西南、闽东试种示范60hm2,深受农民欢迎,有广阔的推广应用前景。为了给大面积推广做好种子生产技术筹备,笔者于2001～2002年对粤优938的制种技术进行了研究,实现单产200kg/666.7m2。总结出一套粤优938杂交稻新组合高产制种与防杂保纯技术,现将技术资料整理如下:     

闽江口琅岐岛土地利用景观格局变化及驱动力分析

以闽江入海口琅岐岛为研究对象,通过对1989、1997和2005年三期遥感图像数据的处理,运用景观格局指标,分析琅岐岛土地利用景观格局动态变化,并结合社会经济发展统计数据,探讨引起土地利用景观格局变化的驱动因子。结果表明:16a来,琅岐岛的景观以农业景观为主,耕地斑块逐渐破碎化,形状日趋复杂化;园地斑块小、分布比较集中;林地景观面积增加,其最大斑块指数也明显增加;交通景观要素面积较小,2005年仅有33.12hm2,占全岛面积的0.53%;总体景观多样性指数呈现出先升后降的变化趋势;景观转移矩阵表明,1989～1997年间,林地景观最稳定,园地景观变化较大,1997～2005年间,景观要素之间转化更为频繁;景观格局变化的主要驱动力因素是经济发展、政府政策的影响和人口变化等。     

海南人工林地、人工草地土壤易氧化有机碳和轻组碳含量初探

为了研究海南人工林地和草地土壤有机碳的性状,采用高锰酸钾氧化-比色法,重液分离法测定海南不同生态气候类型区人工林地和草地土壤易氧化有机碳、轻组有机碳含量。结果表明,海南牧草地土壤易氧化有机碳含量低于人工林地土壤的含量,但两者差异不显著。林、草地土壤轻组有机碳没有规律性,两者差异不显著。不同生态气候类型下的牧草地土壤易氧化有机碳、轻组有机碳存在差异,结果为潮湿区＞湿润区＞半湿润区＞半干旱区,且半干旱区与潮湿区的含量差异显著。     

盐丰47沿海滩涂直播高产栽培技术

合理开发利用沿海滩涂资源,是促进社会经济发展的重要途径之一[1]。江苏有954 km海岸线,沿海滩涂面积68.7万hm2,占全国滩涂面积的四分之一以上。2009年6月10日,国务院批准《江苏沿海地区发展规划》,使得江苏沿海开发正式上升为国家战略,目的是把江苏沿海滩涂地区建设成中国重要的土地后备资源开发区及国家重要的商品     

土地利用方式对南方红壤养分状况的影响

土壤养分是土壤学研究重点,是衡量土壤生产力的综合指标,而土地利用方式则是人类活动影响土壤养分变化最直接、最重要、最普遍的因素。随着人类活动对土地利用的范围不断扩大、强度不断加剧,进而对土壤养分造成了不同程度的影响,尤其是对南方红壤的影响。目前,该区域土壤养分退化严重,综述近10年国内外的相关文献,在土地利用方式改变下,以土壤的物理性质、有机质、氮磷钾的动态变化趋势对土壤养分进行分析和总结,以期更准确地预测和评估不同管理措施对土壤质量的影响,并及时采取有效措施,调整生产结构,降低土壤环境污染,提高土壤性能。     

灵丘县苦荞产业化开发初探

1 灵丘县自然概况 灵丘县位于山西省东北部、大同市东南端,东与河北省的涞源县交界,南与河北省的阜平县接壤,西邻山西省的繁峙、浑源,北靠山西广灵和河北蔚县,南北长84 km,东西宽66 km,总土地面积为27.32万hm2.全县共分南山、川下、北山三大区域.南部石山区面积13.79hm2,大部分耕地都在海拔900 m以下,年平均气温7～10 ℃,无霜期150～180 d,降雨量480～580 mm.     

江苏省沿海地区林、棉间作高产栽培技术

江苏省沿海地区包括连云港、盐城和南通三市,海岸线长954km,是国家沿海防护林体系工程建设的重点区域,上述三市也是国家和江苏省棉花生产优势区域。2009年江苏省沿海地区植棉面积20万hm^2左右,约占全省棉花面积的75%。     

不同密度与施氮水平对高油大豆产量及品质的影响

为探讨密度与施肥对大豆产量及品质的影响,2007～2008年于内蒙古民族大学试验农场,以吉育35为试验材料,采用裂区田间试验设计,以密度为主区,以氮肥施用水平为副区,对高油大豆产量及品质进行了研究.结果表明:密度、施氮通过对高油大豆叶面积指数与叶绿素含量动态变化来影响植株的干物质积累最终对产量和品质产生影响.密度与施氮...     

漫长之路

<正>45年精心的研究表明,现代的集约化水稻种植方式可持续不衰甚至能增进土壤的健康马尼拉以南约60km的洛斯巴诺斯镇郊外,有一块1hm2的土地。对于不少亚洲人来说,一块土地很可能是他们最有价值的财产。这片土地不是用来出售的,即使如此,也不会用来建房屋、停车场或     

Estimation of evaporation from arid-irrigated region using MODIS satellite imagery

For sustainable development of irrigated agriculture in arid regions, improvement of water use efficiency is essentially required to maintain current production levels and meet food and fiber for population growth in future. To achieve high water use efficiency, a key consideration is to reduce unnecessary soil water loss due to evaporation. In this article, regional daily evaporation over Hetao Irrigation District in a typical arid region during the irrigation period of 2009 was determined by a developed maximum surface temperature model combining Moderate Resolution Imaging Spectroradiometer (MODIS) satellite imagery. The results showed that maximum land surface temperature (LST) from MODIS satellite imagery was relatively higher in the western and middle parts than that of the eastern part of the district. At the same time, the mean minimum LST was shown somewhat higher in the eastern part. Mean daily evaporation was relatively higher in the eastern part, which showed water consuming is higher in the eastern part of the district. During the irrigation period of 2009, the total income water (irrigation water and rainfall) amount is 590.3 mm, and the outcome water (drainage discharge and evaporation) amount is 497.5 mm. The surplus of 92.8 mm in the irrigated season is considered to be consumed in winter season. Throughout the irrigated season, income and outcome almost equals each other. The daily evaporation distribution map could specify particular water consuming areas over the district where high daily evaporation may be occurred.     

江苏沿海地区耕地质量研究进展及提升对策——以盐城沿海地区为例

在沿海大开发战略的宏观背景下,江苏沿海地区各土地利用类型之间的竞争日益激烈,耕地资源由于其稀缺性越来越受到重视。本文阐述了江苏沿海地区耕地质量研究现状及发展趋势,分析了现阶段该地区耕地存在的问题,结合国内外耕地质量提升相关技术,提出新形势下江苏沿海地区地力提升和生态保护相结合的相关建议和对策,为促进该地区耕地质量可持续发展提供参考。     

福建省沿海地区橄榄发展情况调查与分析

根据福建省东南沿海地区的20个县市,从1975～2005年每5年橄榄的栽培面积和产量变化,分析近30年来福建省沿海地区橄榄生产经过了低迷、大发展、滑坡以至稳定健康发展等多个阶段性过程,探讨其原因并提出发展建议。     

基于PALSAR雷达数据与多时相TM/ETM+影像的海南岛土地利用分类研究

大面积范围内准确获取土地利用/覆盖变化信息对生产管理和生态环境评价都具有重要的意义。本研究联合2010年25 m分辨率的ALOS PALSAR L波段雷达和2009~2010年多时相Landsat TM/ETM+影像，利用决策树分类方法对海南岛土地利用类型进行分类。结果表明，PALSAR雷达对森林和水体均有较高的识别精度，生产者精度和用户精度均超过88％，但耕地与建筑分类精度最高仅为77％。通过结合森林、建筑与耕地的光谱信息及其年际变化特征，采用多时相TM/ETM+影像合成的NDVI最大值和最小值对PALSAR分类结果进行修正。修正后结果的精度均有显著提升，森林、水体和建筑的生产者和用户精度均超过了92％，相应耕地的精度也分别达到了91％和74％，总体分类精度达到94％，Kappa系数为0.92。本研究表明，联合PALSAR雷达和多时相Landsat系列光学遥感影像，在解决热带地区影像数据源匮乏的同时，能够显著提高土地利用分类精度，具有良好的应用前景。     

Grassland and globalization – challenges for north‐west European grass and forage research

The concept of sustainable intensification has recently been developed to raise productivity (as distinct from increasing volume of production) while reducing environmental impacts. This means increasing yields per unit of inputs (including nutrients, water, energy capital and land) as well as per unit of undesirable outputs (such as greenhouse gas emissions, water pollution or loss of biodiversity). It is thus helpful to understand ‘intensification’ as referring to ‘environmental factor productivity’ or ‘eco‐efficiency’. Worldwide, grassland is the most important agroecosystem delivering ecosystem services ranging from feed supply for ruminants and soil carbon storage to habitats of biodiversity. However, worldwide, grassland is under threat due to intensified land use and land‐use changes from grass to arable. In this article, we (i) highlight ecosystem services of selected grassland biomes abroad of Europe, (ii) show evidence of sustainable as well as non‐sustainable intensification options in these grassland biomes linked to European agriculture by exports of agricultural commodities (e.g. soy) and (iii) derive research strategies for north‐west European grassland research and management to match sustainable intensification strategies for the grassland‐based dairy industry.     

Introduction of seasonal and spatial specification to grass production and grassland use in a dairy farm model

A linear programming model of a dairy farm, in which grass production and grassland use was originally modelled using one growing period and one area of land, is extended. To include seasonal and spatial elements of variation not allowed for in the original model, the model was modified to reflect three growing periods in the season and then to reflect management of two separate areas of land. The resulting three models were used to assess farm physical planning, economic results and nutrient balances for an average Dutch dairy farm in a situation without and with levies on nutrient surpluses. It is concluded that incorporating seasonal and spatial elements provides greater insight into grassland management. Seasonal model specification does not result in significant changes in farm physical planning, income and nutrient surpluses. Spatial specification has a larger impact if one of the two areas cannot be grazed by dairy cattle.     

福建茶叶海上贸易的起源与发展

茶叶海上贸易在福建的文化经济史上占有非常重要的地位。从历史的角度探究海洋文化的起源发展及其与茶结下的不解之缘;通过不同历史时期外贸政策的变更和海洋文化的成长,揭示福建茶叶贸易的连续性和生命力;结合时下倡导的"一带一路"经贸战略,分析了福建茶海文化和区域贸易平台建立带来的机遇与挑战。     

滨海沙地不同竹林土壤理化性质与综合评价

研究滨海沙地不同竹林土壤理化性质差异并评价土壤质量，旨在充分了解滨海沙地竹林防护林土壤肥力状况，指导滨海沙地竹林防护林建设和经营。在福建省东山县赤山国有防护林场选取8种滨海沙地适生竹林，分别测定各竹林0～20 cm土层土壤理化性质；采用单因素方差分析对各项指标进行显著性检验，运用主成分分析、加权综合指数法和模糊数学法，对不同竹林土壤肥力质量进行综合评价。四季竹（Oligostachyum lubricum）的土壤含水率、土壤密度、毛管孔隙度、非毛管孔隙度、土壤总孔隙度等物理性质指标与其他竹林对应物理性质指标皆存在显著性差异（P<0.05）。土壤pH平均变化范围为5.01～7.36，除绿竹（Bambusa oldhamii）土壤pH偏中性外，其他竹林土壤pH呈弱酸性，且均不存在显著性差异（P>0.05）。土壤有机质平均变化范围为4.43～11.06 g/kg，福建茶秆竹（Pseudosasa amabilis var.convexa）有机质含量显著低于其他竹林。土壤全钾和速效钾平均变化范围分别为4.59～79.33 g/kg和0.78～43.11 mg/kg，土壤全氮和全磷平...     

Prediction of paddy field change based on climate change scenarios using the CLUE model

This study simulated land-cover change using the Conversion of Land Use and its Effects (CLUE) model and predicted future changes in paddy field area under climate change scenarios A1B, A2, B1, and B2 of the Special Report on Emissions Scenarios (SRES). The CLUE model is a dynamic spatial land-use simulation model considering competition among land-use types in relation to socioeconomic and biophysical driving factors. Yongin, Icheon, and Anseong, South Korea, were selected as study areas, and scenarios were developed for regional-level simulation of land-use change. Binary logistic regressions were also conducted to evaluate the relationships between land uses and its driving factors. Finally, the simulation results suggested future changes of paddy field area under the scenario conditions. In all the scenarios, demand for cropland, including paddy and upland, decreased continuously throughout the simulation period of 2000–2100. The decrease in cropland area was particularly steep in scenario A2 in 2050. The receiver operating characteristic (ROC) values indicated that the spatial patterns of land-cover types based on the regressions were reasonably explained by the driving factors. According to the scenarios developed and location characteristics, in scenario A1B, paddy field areas were mainly transformed into built-up areas, while in the other scenarios paddy field areas were mainly transformed into forest. The approach used in this study is expected to enable exploration of future land-use changes under other development constraints and detailed scenarios.