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151.
淄博市大武水源地地下水水位总体预测 总被引:1,自引:0,他引:1
本文采用水均衡法对淄博市大武水源地地下水位变动进行研究,并对降水量与人渗补给量的关系以及平均给水度随地下水位的变化关系进行了分析。通过历史资料的验证,表明本文所建立的水均衡模型对于地下水位变动的预测是可靠的,而且简单可行,随后根据不同的地下水开采量等对未来地下水位的变动趋势进行了预测。 相似文献
152.
振幅处理技术在探地雷达资料处理中的应用 总被引:4,自引:1,他引:4
作者在文中简述了在自激自收(10天线距)的探地雷达资料处理中,振幅处理(振幅恢复、道内振幅平衡)和道间振幅均衡的方法原理。在实现编程后,应用于实际资料处理,用以增强雷达的深部弱信号,平衡道内的振幅能量和滤除干扰噪声,取得了良好的效果。 相似文献
153.
Sven-Erik Gryning Ekaterina Batchvarova H. A. R. De Bruin 《Boundary-Layer Meteorology》2001,99(3):465-488
Measurements carried out in Northern Finland on radiation and turbulent fluxes over a sparse, sub-arctic boreal forest with snow covered ground were analysed. The measurements represent late winter conditions characterised by low solar elevation angles. During the experiment (12–24 March 1997) day and night were about equally long. At low solar elevation angles the forest shades most of the snow surface. Therefore an important part of the radiation never reaches the snow surface but is absorbed by the forest. The sensible heat flux above the forest was fairly large, reaching more than 100 W m-2. The measurements of sensible heat flux within and above the forest revealed that the sensible heat flux from the snow surface is negligible and the sensible heat flux above the forest stems from warming of the trees. A simple model for the surface energy balance of a sparse forest is presented. The model treats the diffuse and direct shortwave (solar) radiation separately. It introduces a factor that accounts for the shading of the ground at low solar elevation angles, and a parameter that deals with the partial transparency of the forest.Input to the model are the direct and diffuse incoming shortwave radiation.Measurements of the global radiation (direct plus diffuse incoming shortwaveradiation) above the forest revealed a considerable attenuation of the globalradiation at low solar elevation. A relation for the atmospheric turbidity asfunction of the solar elevation angle is suggested. The global radiation wassimulated for a three month period. For conditions with a cloud cover of lessthan 7 oktas good agreement between model predictions and measurementswere found. For cloud cover 7 and 8 oktas a considerable spread can beobserved. To apply the proposed energy balance model, the global radiationmust be separated into its diffuse and direct components. We propose a simpleempirical relationship between diffuse shortwave and global radiation asfunction of cloud cover. 相似文献
154.
The responses of sea surface temperature (SST) in the western equatorial Pacific warm pool to the west erly wind bursts (WWBs) play an important role in the relationship between WWB and ENSO. By using da ta collected from eight buoys of TOGA (Tropical Ocean-Global Atmosphere)-COARE (Coupled Ocean-Atmosphere Response Experiment), the heat balances of the upper ocean in the western equatorial Pacific around 0°. 156°E during two WWB events were calculated according to Stevenson and Niiler's (1983) method. In both events, SST increased before and after the WWBs, while decreased within the WWBs. The SST amplitudes approximated to l℃. Although sometimes the horizontal heat advections may become the biggest term in the heat balance, the variation of SST was dominated by the surface heat flux. On the other aspect, some different features of the two events are also revealed. The two cases have different variation of mixed layer depth. The depth of mixed layer is almost double in the first case (35 m to 70 m), which is caused by Ekman convergence, while only 10m increments due to entrainment in the second one. There are also differences in the currents structure. The different variations of thermal and currents struc ture in the mixing layers accounted for the different variation of the heat balance during the two events, es pecially the advection and residue terms. The seasonal variation of SST in this area is also investigated sim ply. The first WWB event happened just during the seasonal transition. So we considered that it is a normal season transition rather than a so-called anomaly. That also suggested that the seasonal distinction of the WWB is worthy of more attention in the researches of its relationship to ENSO. 相似文献
155.
生态经济战略是江西21世纪发展的必然抉择 总被引:1,自引:8,他引:1
根据生态经济战略的核心问题和江西省的实际情况,分析了江西实施生态经济战略的必要性与可行性,指出了江西开展生态经济建设的几个切入点。 相似文献
156.
157.
森林采伐向来是甘孜州经济的重大支柱,对地方财政收入的贡献率达58.63%(1997年)。天然林禁伐影响巨大而广泛,既使经济产出与财政收入锐减,又导致一系列相关 产业萎缩,劳动就业压力增大,研究指出,选择新经济增长点与生长点产业大力加以培育发展迫在眉睫。其中,以加大财政转移支付力度加强基础设施建设、加强绿色产品与绿色食品发展以及天然药物开发,大力发展旅游业和流通产业等应是正确选择。 相似文献
158.
159.
质量平衡法——定量恢复新生代青藏高原造山作用 总被引:2,自引:0,他引:2
青藏高原的形成演化及其对东亚地形,水文分布,季风起源,全球气候变化,海洋化学组分改变等的影响,一直是全球地质学家关注的热点,然而由于定量研究方法的缺乏,一些关键性的问题一直悬而未决,质量平衡法的提出为解决这一困境提供了新思路,阐述了质量平衡法的原理,并以Metivier等对西藏高原地区,东亚,印度支那和印度板块地区的研究为例,介绍了质量平衡法的应用,同时对存在的问题进行了较为详细的讨论,为进一步研究指明了重点。 相似文献
160.
The circulation of the Southern Ocean is studied in the eddy-resolving model POP (Parallel Ocean Program) by an analysis
of zonally integrated balances. The TEM formalism (Transformed Eulerian Mean) is extended to include topography and continental
boundaries, thus deviations from a zonally integrated state involve transient and standing eddies. The meridional circulation
is presented in terms of the Eulerian, eddy-induced, and residual streamfunctions. It is shown that the splitting of the meridional
circulation into Ekman and geostrophic transports and the component induced by subgrid and Reynolds stresses is identical
to a particular form of the zonally integrated balance of zonal momentum. In this balance, the eddy-induced streamfunctions
represent the interfacial form stresses by transient and standing eddies and the residual streamfunction represents the acceleration
of the zonal current by density fluxes in a zonally integrated frame. The latter acceleration term is directly related to
the surface flux of density and interior fluxes due to the resolved and unresolved eddies. The eddy-induced circulation is
extremely vigorous in POP. In the upper ocean a shallow circulation, reversed in comparison to the Deacon cell and mainly
due to standing eddies, appears to the north of Drake Passage latitudes, and in the Drake Passage belt of latitudes a deep-reaching
cell is induced by transient eddies. In the resulting residual circulation the Deacon cell is largely cancelled and the residual
advection of the zonal mean potential density is balanced by diapycnal eddy and subgrid fluxes which are strong in the upper
few hundred meters but small in the ocean interior. The balance of zonal momentum is consistent with other eddy-resolving
models; a new aspect is the clear identification of density effects in the zonally integrated balance. We show that the wind
stress and the stress induced by the residual circulation drive the eastward current, whereas both eddy species result in
a braking. Finally, we extend the Johnson–Bryden model of zonal transport to incorporate all relevant terms from the zonal
momentum balance. It is shown that wind stress and induction by the residual circulation carry an eastward transport while
bottom form stress and the stress induced by standing eddies yield westward components of transport.
Received: 26 June 2001 / Accepted: 2 November 2001 相似文献