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21.
Satellite imagery has proven potential in farm level applications, especially in the US Upper Midwest where the farm sizes are large enough to be studied using high and medium resolutions. In order for farmers to use this technology to improve their productivity and income, it is imperative that they be sufficiently exposed to the technology so that they are able to take full advantage of it. Training of farmers and ranchers in satellite imagery use started at the University of North Dakota in 2000 and has been refined over time. The basic ‘hands on’ training involves downloading imagery from the Upper Midwest Aerospace Consortium (UMAC) website, downloading and use of free visualization software programs available on the web and an introduction to the various application possibilities. Advanced training, which involves more complex extraction of useful information from digital images, is also available to those who complete the basic training. Over 500 farmers, ranchers, crop consultants and other end users have been trained through this programme and the results are beginning to show through the success stories of cost savings and environmental benefits that have emerged. 相似文献
22.
Abstract The San Diego Trough Geotechnical Test Area, located about 24 km southwest of San Diego in a water depth of about 1.2 km, lies near the base of the Coronado Escarpment directly north of the Coronado Fan. A new bathymetric map delineates a shallow basin in the soft, highly plastic, clayey silts flooring the Test Area. Measurements of shear strength by vane and static cone pene‐trometer, and bulk density by nuclear densitometer, were made in place from the submersible Deep Quest. Sixteen short (< 1.6 m) gravity cores were collected from ships. The geotechnical properties show little areal variation and generally change uniformly with depth within the 55 km2 Test Area. Silt is the predominant grain size, averaging about 62%. In‐place bulk density shows little change with increasing depth, values range from 1.23 to 1.26 Mg/m3; laboratory density values increase with depth, ranging from 1.30 to 1.52 Mg/m3 between the surface and a depth of about 1.1 m. The difference between the in place and laboratory values may indicate sampling densification of the cored sediment. Water content in the cores decreases uniformly within the range of 249 to 43% dry weight. Shear strength increases linearly with depth. The laboratory shear strength values are lower than the in place values, which range from 4 kPa at the surface to about 29 kPa at a depth of 3.27 m. Predictor equations relate Atterberg limits, bulk density, water content, and laboratory and in place shear strength to depth. Sedimentation‐compression e log p curves have an equivalent compression index of 1.5 to nearly 2. Excluding rurbidite layers and sampling disturbance effects, all cores indicate a uniform depositional environment in the surface to 1.6 m of sediment sampled. The geotechnical properties indicate that the sediments in the west central and southwest parts of the Test Area exhibit vertical heterogeneity due to thin silt‐sand layers, presumably of turbidity current origin, that originated from the Coronado Canyon. 相似文献
23.
Ayron M. Strauch 《水文科学杂志》2017,62(9):1381-1393
Statistical models poorly predict bacteria in near-shore environments of tropical islands due to inaccuracies in runoff and discharge characterization of storm events. Intense, short duration storms on small, steeply sloped watersheds produce high rates of runoff, resulting in rapid pulses of discharge that influence the physical and physiological conditions of the fate and transport of pathogens. As such, increasing rates of discharge are expected to have a different influence on sediment transport and pathogen load compared to decreasing rates of discharge. Regression modeling was used to examine the affect of antecedent streamflow on the interaction between environmental parameters and two fecal indicator bacteria, enterococci and Clostridium perfringens. Including the relative change in discharge incorporates a proximate representation of the energy available to transport particulates, improving predictions of near-shore water quality. Understanding factors that influence pathogen loads improves management of watersheds and protects public health. 相似文献
24.
Services of general interest fulfill people's daily needs and are important for their well-being. In Germany, interacting socioeconomic and demographic processes currently lead to a spatial concentration of such services. Rural areas are particularly affected, resulting in a deterioration of living conditions. Nevertheless, although in the media and in policy these processes are intensely discussed against the background of the German political and scientific discourse on ‘Daseinsvorsorge’, little is known about their dimensions. However, such knowledge is important for both policy and scientific policy advice, as ‘Daseinsvorsorge’ is a key concept in German spatial planning discourse, rooted in the normative political goal of guaranteeing comparable living conditions throughout Germany. This goal includes the aim of ensuring a sufficient offering of services indispensable for life throughout the country. One subject area where a spatial concentration can be observed is retail food sales. As a consequence, especially in rural areas, the network of food shopping locations becomes more wide meshed. Against this background, the German petrol-sector claims that in rural regions, petrol station shops (PSS) might replace a missing local food retailer. Based on the data from an accessibility analysis of petrol stations, supermarkets and discounters, together with considerations on the assortment of PSS, the article analyses the potential of such shops to fulfill this function in rural Germany through the lens of ‘Daseinsvorsorge’. The analysis reveals the following: (1) PSS still mainly serve impulse shopping needs, offering only a very limited assortment of staple foods; (2) in the majority of regions with no supermarket or discounter accessible by foot, PSS are also not accessible by foot; and (3) by car, the picture is very similar. Considering these points, it can be concluded that in Germany, PSS cannot at this time fully replace a missing local retail trade, especially in rural areas. 相似文献
25.
W. D. Birch 《Australian Journal of Earth Sciences》2013,60(1-2):85-87
Many Broken Hill (New South Wales) specimens labelled ‘zinco‐calcite’ in museum and private collections are snow‐white, globular forms with a sparkling appearance, on a coronadite or limonite matrix. X‐ray diffraction and microprobe analyses show the globules have a core of nearly pure calcite, overlain by colourless, drusy zincian dolomite with up to 4 mol % ZnCO3 and up to 7 mol % excess CaCO3. Although Zn is abundant in the Broken Hill orebody, it apparently entered carbonate, mainly as smithsonite, only during formation of the oxidised zone. 相似文献
26.
"一带一路"沿线国家或地区人才流动网络结构演化 总被引：4，自引：1，他引：3
基于高等学校留学生流动数据,构建加权有向网络模型,对2000~2015年“一带一路”沿线国家或地区人才流动网络结构演化进行研究。主要结论如下：① 沿线人才流动网络规模迅速扩大,人才流动的数量和路径在迅速增加。② 沿线人才流动网络呈“由中向西,自南到北”的空间格局特征,中亚地区的留学生主要向西流向俄罗斯、乌克兰等国,东南亚和南亚地区的留学生主要向北流向中国内地。③ 沿线人才流动网络分化为独联体社团、中国东盟社团、西亚北非社团、中东欧社团、南亚社团等5个社团。④ 中国内地和俄罗斯处于沿线人才流动网络的核心位置,东南亚、西亚和东欧部分国家处于边缘地带。 相似文献
27.
伴随着海洋遥感资料的大量积累,高效的“一站式”服务成为海洋遥感数据业务化应用的基本需求,同时也对系统在动态调度资源、易维护、弹性可扩展、复杂度可控和灵活部署等方面提出了更高的要求.针对上述问题,本文引入kubernetes容器编排管理平台,将单个业务系统拆分成多个独立运行在相互隔离容器中的服务,共享服务器软硬件资源,在保证系统具备高度可扩展性和灵活性的基础上,有效降低了开发的复杂度,设计和实现了海洋遥感数据产品生产和应用服务平台,满足了对海洋多源卫星数据从获取、预处理、产品自动生产、展示发布到应用服务的一体化需求. 相似文献
28.
《Geoforum》2017
Two key figures analyzed in Donna Haraway’s monograph, Primate Visions: Gender Race and Nature in The World of Modern Science (1989) warrant further analysis in the emerging cyber politics of environmental conservation. These figures are Koko, a female lowland gorilla born in the San Francisco Zoo and her companion Dr. Francine (Penny) Patterson, a developmental psychologist who taught Koko how to communicate with a modified form of American Sign Language (ASL). Nine years after Haraway’s initial analysis, Koko and Patterson became early examples of conservation-related Web 2.0 engagement with their unprecedented inter-species America Online chat room encounter with 7811 member participants. Today, Koko has a Twitter account (@kokotweets), a Facebook page, a YouTube channel and a website where users watch videos of Koko celebrating birthdays and donate to ‘distant’ conservation projects. One project site is a gorilla reserve in Cameroon and another is a former pineapple plantation turned private nature preserve in Maui, Hawai’i. Inspired by recent analytical work in animal geographies and feminist political ecology, this article explores complex landscapes of caring, aging and conservation in a time of proliferating social media engagement from colonized sites of enduring privilege. The article argues that new media adds layers of violence, disciplinary techniques and co-dependence to the aging bodies, caring practices and landscapes that Koko, Patterson and others inhabit in California and in the proposed physical spaces of a repurposed pineapple field in Maui. 相似文献
29.
利用室内概化模型试验,研究了"藕节"辫状河的发育和演变过程。从初始顺直小河开始,以黄河花园口水文站枯水期和洪水期流量为背景,概化试验入口水沙条件,成功塑造了具有典型藕节的辫状小河。模型小河的试验发现:① 原顺直河道交错边滩的发育对辫状河道"藕节"的形成起到关键作用;② 结合自然河流和试验小河,"藕节"河段形态特征系数I与河道稳定性参数θ呈较好的非线性关联性,说明辫状河道除了沙粒阻力和床面形态阻力,也可以采取断面形态一收一放的"河势形态阻力"方式消耗,制衡部分水流能量;③ 流量过程是控制河段形态特征的决定因素之一,大洪水不仅破坏了原交错边滩的特点,也使"藕节"形态遭到破坏;但在中小流量下,河段保持了较好的"藕节"驻点、"藕身"收放的特点。本研究对黄河下游收放相间的"藕节"河段防洪起到借鉴作用。 相似文献
30.
Hawai‘i's agricultural landscape was previously dominated by large monocrop plantations of sugar cane and pineapple, but following a sweeping series of plantation closures beginning at the end of the twentieth century, that era has concluded. The last spatial assessment of Hawai‘i's agricultural footprint was completed in 1980, during the active plantation period. Here we present the results of a 2015 statewide assessment of the commercial crop footprint for Hawai‘i, based on World-View 2 satellite imagery and supporting datasets. We analyzed changes relative to the 1980 baseline on both a statewide and regional basis, to better understand how Hawai‘i's agricultural system has evolved in the post-plantation era. Sugar cane and pineapple saw dramatic reductions during this period, collectively losing more acres (257,000) than were planted for all crops combined (152,000) in 2015. Idle plantation lands and past plantation-era investments in irrigation and other infrastructure have created opportunities for other types of agriculture, despite rising land values, new and existing tropical diseases, and other challenges. Seed crops, primarily for genetically modified corn trials, were the second largest crop in 2015 (24,000 acres) despite having no mapped footprint in 1980. Commercial forestry, also absent in 1980, covered 23,000 acres in 2015. Macadamia nut, coffee, and diversified agriculture also all saw significant gains in their footprints, with coffee plantings increasing >250% during this period. Despite these gains, the Hawaiian Islands continue to have an extremely low degree of self-reliance for food production. The Oahu plain, adjacent to the major population center of Honolulu, has the most potential for considerably increasing the production of local produce, but without changes in consumption patterns and significant efforts to protect agricultural land from development, any increases in local food production will continue to be incremental. The post-plantation agricultural landscape in Hawaii is smaller, more diversified, and more nimble than it was in 1980, reflecting inter-island geographic differences in land use, history, and ownership. Mapping and assessing spatial changes in agricultural activity over time can provide valuable insights for decision-makers and communities as they continue to define what agriculture should look like in the post-plantation era. Our results suggest that Hawai‘i's agricultural landscape and overall production capability will continue to contract without substantial changes in policy and practice. 相似文献