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71.
72.
基于surfer8.0的高密度电阻率法在水利水电工程灾害性评价中的应用 总被引:1,自引:1,他引:0
surfer8.0是一款画三维图的软件,结合高密度电阻率法在水利水电工程灾害性评价中的应用实例,验证了高密度电阻率法在水利水电工程中具有的可行性、有效性和实用性. 相似文献
73.
浅谈遥感解译技术在生态环境状况评价中的应用 总被引:1,自引:0,他引:1
简述了遥感解译这一新兴学科的技术特点,以及它在生态环境状况监测和评价中所起的重要作用。详细介绍了利用遥感解译手段对影像进行处理的技术流程和方法,提出了用来判定生态环境状况的各类生态指数的计算方法。 相似文献
74.
Xiangyang Ye Jian e Zuo Ruohan Li Yajiao Wang Lili Gan Zhonghan Yu Xiaoqing Hu 《Frontiers of Environmental Science & Engineering》2019,13(2):17
75.
Methods that are more cost-effective and objective are needed to detect important vegetation change within acceptable error
rates. The objective of this research was to compare visual estimation to three new methods for determining vegetation cover
in the sagebrush steppe. Fourteen management units at the US Sheep Experiment Station were identified for study. In each unit,
20 data collection points were selected for measuring plant cover using visual estimation, laser-point frame (LPF), 2 m above-ground-level
(AGL) digital imagery, and 100-m AGL digital imagery. In 11 of 14 management units, determinations of vegetation cover differed
(P < 0.05). However, when combined, overall determinations of vegetation cover did not differ. Standard deviation, corrected
sums of squares, coefficient of variation, and standard error for the 100 m AGL method were half as large as for the LPF and
less than the 2-m AGL and visual estimate. For the purpose of measuring plant cover, all three new methods are as good as
or better than visual estimation for speed, standard deviation, and cost. The acquisition of a permanent image of a location
is an important advantage of the 2 and 100 m AGL methods because vegetation can be reanalyzed using improved software or to
answer different questions, and changes in vegetation over time can be more accurately determined. The reduction in cost per
sample, the increased speed of sampling, and the smaller standard deviation associated with the 100-m AGL digital imagery
are compelling arguments for adopting this vegetation sampling method. 相似文献
76.
77.
John C. Besley 《Environmental Communication: A Journal of Nature and Culture》2018,12(8):1005-1022
ABSTRACTThe US National Science Foundation collects biennial data on views about science and technology (S&T). Analyses have typically focused on the degree to which demographics, knowledge, and attitudes predict S&T support or views about specific technologies or issues. Published efforts do not appear to have focused on identifying latent classes within the data. Initial analyses using latent profile analysis suggests that Americans can be categorized into six substantive audience groups when it comes to views about S&T. These groups vary by demographics, including scientific background and ideology, as well as in views about S&T. Post hoc analyses explore how “class-focused” analyses may provide additional insight beyond what can be obtained from “variable-focused” analyses. 相似文献
78.
结合实际林火图像的特点,提出了一种基于彩色图像分割策略的林火图像的火焰分割算法。该算法首先将图像转化为HSI彩色模型,然后根据各个分量的特点进行分割,并且进行了仿真实验,实验结果表明此算法能够很好地将火焰从复杂的背景中分割出来,克服了基于灰度图像分割不能准确分割烟雾和火焰的弊端,为今后对林火图像进一步分析提供了良好的基础。 相似文献
79.
Wyoming’s Green Mountain Common Allotment is public land providing livestock forage, wildlife habitat, and unfenced solitude,
amid other ecological services. It is also the center of ongoing debate over USDI Bureau of Land Management’s (BLM) adjudication
of land uses. Monitoring resource use is a BLM responsibility, but conventional monitoring is inadequate for the vast areas
encompassed in this and other public-land units. New monitoring methods are needed that will reduce monitoring costs. An understanding
of data-set relationships among old and new methods is also needed. This study compared two conventional methods with two
remote sensing methods using images captured from two meters and 100 meters above ground level from a camera stand (a ground,
image-based method) and a light airplane (an aerial, image-based method). Image analysis used SamplePoint or VegMeasure software.
Aerial methods allowed for increased sampling intensity at low cost relative to the time and travel required by ground methods.
Costs to acquire the aerial imagery and measure ground cover on 162 aerial samples representing 9000 ha were less than $3000.
The four highest correlations among data sets for bare ground—the ground-cover characteristic yielding the highest correlations
(r)—ranged from 0.76 to 0.85 and included ground with ground, ground with aerial, and aerial with aerial data-set associations.
We conclude that our aerial surveys are a cost-effective monitoring method, that ground with aerial data-set correlations
can be equal to, or greater than those among ground-based data sets, and that bare ground should continue to be investigated
and tested for use as a key indicator of rangeland health. 相似文献
80.
Robert A. Van Zuidam Jamshid Farifteh Marieke A. Eleveld Cheng Tao 《Journal of Coastal Conservation》1998,4(2):191-202
The International Institute for Aerospace Survey and Earth Sciences (ITC) has a research programme that should result in an
integrated environmental coastal zone management system through three subprojects. The programme aims to develop methodologies
and tools for assessing coastal zone changes, and for the evaluation of scenarios for coastal zone management, based on a
spatio-temporal Geographical Information System (GIS) working platform which integrates remote sensing data, physical-morphodynamic
and eco-hydrologic modelling, and a decision support system.
The first subproject develops methodologies for the generation of optimum Remote Sensing (RS) data sets, leading to better
interpretation and complementary use of conventional and new remote sensing imagery. It also integrates RS, GIS, and modelling
through hypothesis generation, parameter estimation, evaluation and validation.
The second subproject facilitates qualitative and quantitative analysis and prediction of the physical aspects of coastal
landscape development under the influence of natural processes and human impacts. This subproject is based on the application
of remote sensing and dynamic modelling.
The third subproject leads to a spatio-temporal working platform which supports data integration of RS and in-situ measurements,
and qualitative and quantitative analysis for the prediction of coastal landscape development. Both support decision making
in Integrated Coastal Zone Management. 相似文献