SPOT-5图像在西藏亚东县康布曲流域综合治理中的应用

以西藏亚东县为例,借助ERDASimagine、PCIGeomatic、Arc／INFO、MiCrostation等软件,研究了SPOT-5遥感数据在康布曲流域综合治理中的应用,运用了数字图像融合方法和图像增强技术,制作该区1：1万假彩色图像,并在此基础上对康布曲流域地形地貌、土地利用、植被类型、水土流失和地质灾害等进行了遥感调查,取得了良好的效果。为该区综合治理提供基础资料。     

神经递质多巴胺(DA)和5-羟色胺(5-HT)对三种主要养殖对虾争胜行为的影响

本文采用肌肉注射和行为分析的方法,进行了注射多巴胺(DA)和5-羟色胺(5-HT)对对虾争胜行为的研究,比较分析了注射多巴胺(DA)和5-羟色胺(5-HT)对日本囊对虾(Penaeus japonicus)、凡纳滨对虾(Litopenaeus vannamei)和中国明对虾(Fenneropenaeus chinensis)争胜行为的影响。多巴胺注射浓度为2×10~(-3)mol/L、2×10~(-4)mol/L,5-羟色胺注射浓度为2×10~(–5)mol/L、2×10~(–6)mol/L,以生理盐水为对照,各设3个平行组。检测注射1h后对虾体内的DA、5-HT含量,分析比较注射DA、5-HT前后及不同对虾种类争胜行为的差异。结果表明,注射多巴胺后三种对虾间的争斗显著增加,HDA比LDA更易激发对虾间的争斗,同种对虾在注射不同浓度多巴胺后与对照组差异均显著(P0.05);相较于对照组,南美白对虾、日本囊对虾、中国明对虾在注射低浓度多巴胺后,对虾平均争斗次数分别增加13.8%、11.1%、21.8%,高浓度多巴胺组分别增加91.0%、64.0%、68.5%;对虾平均争斗次数随着DA浓度的升高而增加;平均优势指数总体呈下降趋势。随着5-HT浓度的增加,对虾的平均争斗次数随之减少,相较于对照组,低浓度5-羟色胺组降幅超过50%,高浓度5-羟色胺组降幅超过270%以上。争斗次数表现为中国明对虾凡纳滨对虾日本囊对虾。平均优势指数随注射5-HT浓度的增加而小幅度上升。     

New Relationship for Estimation of Wave Overtopping on Vertical Walls

Soft computing tools in the form of combination of multiple nonlinear regression and M5'' model tree were used for estimation of overtopping rate at the vertical coastal structures. For reliable and precise estimation of overtopping rate, the experimental data available in the database CLASH were used. The dimensionless overtopping rate was estimated in terms of conventional dimensionless parameters including the relative crest freeboard R_c/H_s, seabed slope tanθ, deep water wave steepness S_om, surf similarity ξ_om and local relative water depth h_t/H_s. The accuracy of the new model was compared with other existing models and also evaluated with some field measurements. The results indicated that the model presented in this paper is more accurate than other existing models. With statistical parameters, it is shown that the accuracy of predictions in the new model is better than that of other models.     

Characteristics and Nonlinear Growth of the Singular Vector Related to a Heavy Rainfall Case over the Korean Peninsula

In this study,singular vectors related to a heavy rainfall case over the Korean Peninsula were calculated using the fifth-generation Pennsylvania State University-National Center for Atmospheric Research Mesoscale Model (MM5) adjoint modeling system.Tangent linear and adjoint models include moist physical processes,and a moist basic state and a moist total energy norm were used for the singular-vector calculations.The characteristics and nonlinear growth of the first singular vector were analyzed,focusing on the relationship between the basic state and the singular vector.The horizontal distribution of the initial singular vector was closely related to the baroclinicity index and the moisture availability of the basic state.The temperature-component energy at a lower level was dominant at the initial time,and the kinetic energy at upper levels became dominant at the final time in the energy profile of the singular vector.The nonlinear growth of the singular vector appropriately reflects the temporal variations in the basic state.The moisture-component energy at lower levels was dominant at earlier times,indicating continuous moisture transport in the basic state.There were a large amount of precipitation and corresponding latent heat release after that period because the continuous moisture transport created favorable conditions for both convective and nonconvective precipitation.The vertical propagation of the singular-vector energy was caused by precipitation and the corresponding latent heating in the basic state.     

MM5模式及CALMET模型对甘肃酒泉地区风能资源的数值模拟

利用NCEP 1°×1°再分析资料,采用中尺度模式MM5及诊断风场模型CALMET,对2009年6月—2010年5月甘肃省酒泉地区风能资源进行了数值模拟研究。结果表明,远离山体且地势平坦的地区,模拟的风速与实测风速的误差较小,地形复杂的地区误差偏大。用于对比的10座风塔中有7座在70m高度处的相对误差基本在10%以内,3座相对误差稍大但都在20%以内。风速和风功率密度的季节变化在春季最大,冬、秋季次之,夏季最小。这种季节变化与地形地势及所受的天气系统有密切联系。在酒泉地区随着高度的增加,风速逐渐加大;在河西走廊西端和酒泉北部等海拔较低的地区风速随高度增加的趋势尤为明显。通过对模拟年度风速误差的分析,得到模拟年度在酒泉地区属于大风年,若分析酒泉地区多年平均风况,还需要对模拟结果进行订正。     

Textural and carbon isotopic evidence of monsoonal changes recorded in a composite-type speleothem from Korea since MIS 5a

Textural and stable isotopic records of a composite-type speleothem from Gwaneum Cave in the eastern part of the Korean peninsula show prominent paleoenvironmental changes since MIS (marine oxygen isotope stage) 5a. Based on ²³⁰Th/²³⁴U dating, the speleothem experienced growth from 90.9 ± 6.5 ka to 1.2 ± 0.5 ka with several hiatuses. Four growth phases (A, B, C and D) are recognized based on speleothem type and texture. Very irregular and laterally discontinuous growth laminae in Phases B and C indicate that the cave coralloids grew over the stalagmite (Phase A) when the supply of dripping water became limited. Variations within the δ¹³C time series of Phase A are interpreted as responses to millennial-scale fluctuations of the East Asian monsoon intensity during MIS 5a. The monsoonal interpretation is based on the idea that δ¹³C values reflect the isotopic composition of soil-derived CO₂, which, in turn, should relate to monsoon-driven changes in terrestrial productivity above the cave during the MIS 5a. Our reconstruction reveals that the significant monsoonal changes on the Korean peninsula occurred in conjunction with changes in sea level and/or oceanic circulations during the transition period from MIS 5a to MIS 4.     

Spatially variable sedimentary responses to orbitally driven pluvial climate during Marine Oxygen Isotope Stage 5.1, Dakhla Oasis region, Egypt

Pleistocene basinal sediments (PBS) in the Dakhla region of Egypt's hyperarid Western Desert comprise four facies: (A) fluvio-lacustrine, (B) mixed lacustrine/pluvio-eolian, (C) pluvio-eolian, and (D) mixed eolian/pluvio-eolian. Contiguity of basins containing each facies, and their stratigraphic position between two bajada gravel formations, P/B-II and P/B-III, confirm their equivalence. Facies A and B, with lacustrine components, are attributed to orbitally forced poleward incursion of the Intertropical Convergence Zone (ITCZ), resulting in increased summer insolation/temperature/precipitation. Facies C and D, comprising pluvio-eolian and eolian sediments, reflect geologic/topographic influences overprinted on regional 'pluvial' conditions, eliminating lacustrine response. A Th/U age of ∼ 62 ka on lacustrine marl within Facies B is minimal, and an OSL age of 110 ± 18 ka on sediments immediately below Facies B is maximal. Since bajada gravels P/B-III are the youngest Pleistocene formation, they must represent the final strong incursion of the ITCZ into the Dakhla region at MIS 5.1, ∼ 80 ka. Because PBS Facies A pass rapidly up into P/B-III bajada gravels, PBS are assigned to the rising limb of the MIS 5.1 insolation/temperature/precipitation curve, slightly younger than 80 ka.     

基于TM和SPOT5影像融合的土地利用分类及精度比较——以朝阳区为例

本文基于TM和SPOT5的影像在ERDASIMAGINE环境中进行融合,在融合前后分别对TM图像与融合后图像进行土地利用分类,对比分类精度并进行定性和定量的解释和分析。本文给出了实验的详细步骤以及完整的评价报告。研究结果表明,融合后图像分类精度有明显提高。对融合后影像进行土地利用分类,在测绘与地图更新、土地利用与城市规划、生态环境监测和政府规划决策等中,具有广阔的应用前景。     

CMIP5模式对中国东部夏季不同强度降水气候态和年代际变化的模拟能力评估

利用东亚地区逐日降水资料,评估了17个CMIP5气候模式对中国东部夏季不同强度降水的时空分布、不同强度降水对1970年代末中国东部夏季总降水量年代际转折的贡献的模拟能力。从夏季不同强度降水占总降水的比重来看,在中国东北和华北地区,小雨和中雨占主导;而在华南和江淮地区,大雨和暴雨则相对更为重要。CMIP5模式可大致模拟出中国东部小雨、大雨和暴雨占总降水比重的空间分布,但对中雨占比的空间分布模拟较差。总体说来,多数CMIP5模式高估了小雨和中雨的比重,但低估了大雨和暴雨的比重,从而导致大多数模式高估东北和华北的总降水量,而低估华南和江淮的总降水量。对1970年代末我国华北和江淮地区夏季降水量的年代际转折,观测资料表明该转折主要体现为大雨和暴雨雨量的年代际转折;仅有少数CMIP5模式能模拟出华北大雨和暴雨年代际减少的特征,使得这些模式对华北地区总降水的年代际变化也有较好的模拟能力。对于江淮区域,由于大雨和暴雨的比重被严重低估,尽管部分模式能模拟出夏季总降水量年代际增加的特征,但却多以小雨、中雨的年代际变化为主。多模式集合并不能显著提高模式对不同强度降水的空间分布的模拟能力,尤其是降水年代际变化的模拟能力。     

SPOT5单景卫星遥感影像区域网平差试验

随着相关技术的飞速发展,高分辨率卫星遥感影像越来越多地用于地理信息产品生产。本文通过生产试验,讨论在已有DEM数据的前提下,利用少量地面控制点结合卫星影像自带的轨道参数,依靠卫星影像单片区域网平差技术来生产1:50000 DOM产品,以解决地面控制点数量不足、分布不好的问题。试验结果产品精度满足规范要求。