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以扎龙湿地龙泡子为研究对象,利用58个实测水深数据和季相最接近的Quick Bird数据,建立湖泊水深的反演模型。探索性地建立了单波段和多波段组合的线性(多元)回归模型、指数模型、二次多项式模型、微分模型和对数模型等;通过对比模型的决定系数R2,比较模型精度;线性模型、对数模型、指数模型和幂指数模型的R2小于0.5,而二次多项式模型和多元线性回归模型的R2大于0.5,精度相对较高;筛选出拟合度较高的模型,用20个实测验证样本,采用相对误差和均方根误差进行模型精度评价;最后,利用精度较高的模型,进行龙泡子水深反演计算。水深反演结果表明,用选出的模型反演得到的龙泡子水深基本一致,为170~200 cm,即使有稀疏的水草覆盖,依然可以表现出水深渐变的趋势。以蓝、绿、红和近红外波段多光谱遥感反射率为自变量,建立的线性湖泡水深反演模型y=123.990-3.332B1+183.859B2-237.133B3-37.143B4(y为水深;B1、B2、B3和B4分别为蓝、绿、红和近红外波段的水体反射率),能较好地反演扎龙湿地湖泡的水深。 相似文献
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Guofeng Zhu Dahe Qin Huali Tong Yuanfeng Liu Jiafang Li Dongdong Chen Kai Wang Pengfei Hu 《中国地理科学(英文版)》2016,26(5):687-702
The Thornthwaite moisture index, an index of the supply of water(precipitation) in an area relative to the climatic demand for water(potential evapotranspiration), was used to examine the spatial and temporal variation of drought and to verify the influence of environmental factors on the drought in the Hengduan Mountains, China. Results indicate that the Thornthwaite moisture index in the Hengduan Mountains had been increasing since 1960 with a rate of 0.1938/yr. Annual Thornthwaite moisture index in Hengduan Mountains was between –97.47 and 67.43 and the spatial heterogeneity was obvious in different seasons. Thornthwaite moisture index was high in the north and low in the south, and the monsoon rainfall had a significant impact on its spatial distribution. The tendency rate of Thornthwaite moisture index variation varied in different seasons, and the increasing trends in spring were greater than that in summer and autumn. However, the Thornthwaite moisture index decreased in winter. Thornthwaite moisture index increased greatly in the north and there was a small growth in the south of Hengduan Mountains. The increase of precipitation and decrease of evaporation lead to the increase of Thornthwaite moisture index. Thornthwaite moisture index has strong correlation with vegetation coverage. It can be seen that the correlation between Normalized Difference Vegetation Index(NDVI) and Thornthwaite moisture index was positive in spring and summer, but negative in autumn and winter. Correlation between Thornthwaite moisture index and relative soil relative moisture content was positive in spring, summer and autumn, but negative in winter. The typical mountainous terrain affect the distribution of temperature, precipitation, wind speed and other meteorological factors in this region, and then affect the spatial distribution of Thornthwaite moisture index. The unique ridge-gorge terrain caused the continuity of water-heat distribution from the north to south, and the water-heat was stronger than that from the east to west part, and thus determined the spatial distribution of Thornthwaite moisture index. The drought in the Hengduan Mountains area is mainly due to the unstable South Asian monsoon rainfall time. 相似文献
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汝阳盆地是豫西地区的一个中—新生代断陷盆地,自2006年以来发现了一个以巨型蜥脚类恐龙为代表的恐龙动物群。本文描述了近期发现于汝阳盆地下白垩统郝岭组中的若干恐龙蛋蛋壳碎片。基于以下对蛋壳宏观形态和显微特征的分析,这些蛋壳碎片可以归入长形蛋科(Elongatoolithidae)的长形蛋属(Elongatoolithus):蛋壳外表面具分散瘤点状或线性脊状的纹饰;蛋壳自内而外分为锥体层和柱状层,二层之间的界线不清晰;锥体层中锥体排列紧密;柱状层中具波浪状的平行生长纹。这一发现代表了长形蛋属在早白垩世地层中的首次记录,进一步拓展了该蛋属的地史和古地理分布。由以往已知的化石关联推测,这些蛋壳可能与该层位中的窃蛋龙类如刘店洛阳龙(Luoyanggia liudianensis)等具有相关性,表明汝阳盆地在早白垩世晚期具有适宜该类恐龙生存与繁殖的环境。 相似文献
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刘家沟位于四川省阿坝州金川县,是一条狭陡型高频泥石流沟,每年雨季,降雨激发泥石流灾害链。本文在野外调查和实地勘测的基础上,分析认为,受汶川MS8.0地震扰动,刘家沟形成流通区单位面积上松散固体物质达98.11×104 m3,在409.8‰的平均纵坡降下,泥石流活动频率明显增强,泥石流沿程放大效应明显,最终形成了降雨+径流侵蚀-滑坡-堰塞体-堰塞体溃决-增大的泥石流-堵河形成堰塞湖-卡撒沟中、下游损害的灾害链。提出采用格宾石笼进行固坡护床,结合拦挡坝拦粗排细的作用,根据保护对象设置防护堤,优化排导槽与主河交汇条件的综合治理措施,可为小流域高频狭陡型泥石流灾害的治理提供参考。 相似文献
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Flood hazard assessment in the Kujukuri Plain of Chiba Prefecture,Japan, based on GIS and multicriteria decision analysis 总被引：1，自引：0，他引：1
A simple flood hazard assessment based on GIS and multicriteria decision analysis was presented, and the sensitivity analysis was applied to evaluate the uncertainty of input factors. The location chosen for the study is the Kujukuri Plain, Chiba Prefecture, Japan. The model incorporates six factors: river system, elevation, depression area, ratio of impermeable area, detention ponds, and precipitation. A hazard map for the year 2004, as an example, was obtained. The method of analytic hierarchy process was applied to calculate the weighting values of each factor. The hazard map was compared with the actual flood area, and good coincidence was found between them. The relative importance and uncertainty of the six input factors and weights were evaluated by using the global sensitivity analysis, i.e., extended FAST method, and the results showed a robust behavior of the model. The flood hazard assessment method presented here is meaningful for the flood management and environment protection in the area under the similar condition as this study. 相似文献
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山东省齐河县境内发育有矽卡岩型铁矿,近年来该区铁矿勘查和研究工作取得了较大进展。本文通过对研究区内铁矿勘查研究成果进行统计分析,旨在对其控矿特征和找矿标志进行探讨来促进该区铁矿找矿工作。研究区内铁矿控矿地层为奥陶纪碳酸盐岩和石炭纪-二叠纪碎屑岩地层,成矿地质体为燕山晚期中基性侵入岩体;铁矿体主要赋存于地层和岩体的接触带处,且在碳酸盐岩、碎屑岩地层中和侵入岩体中也赋存有部分铁矿体。区内铁矿体赋存类型多样,其中以接触带赋存式为主,且含有断裂充填式、层间充填式、裂隙贯入式、捕虏体构造式等。铁矿体形态复杂,呈层状、似层状、囊状、透镜状等;矿床典型蚀变分带特征为闪长岩带-蚀变闪长岩带-内矽卡岩带-铁矿体-外矽卡岩带-大理岩化带-灰岩带。该区成矿作用以接触扩散交代作用、接触渗滤交代作用为主,此外还有富矿热液充填作用等。研究区内铁矿找矿标志主要包括地层标志（奥陶纪碳酸盐岩和石炭纪-二叠纪碎屑岩地层）、岩体标志（中基性侵入岩体,且发育有钠长石化的蚀变闪长岩）、构造标志（地层与岩体接触带、构造交汇部位、层间滑脱部位、脆性裂隙部位等）、围岩蚀变标志（磁铁矿化、矽卡岩化、钠长石化、蛇纹石化、金云母化等与成矿关系密切）、地球物理标志（明显的高值磁异常和化极磁异常部位、重力异常梯度带和高-低电阻转换带）。在今后铁矿勘查过程中,需要在综合研究该区控矿特征的基础上,可利用多种找矿标志进行相互配合、互为补充和综合研究,以期达到预期勘查效果。 相似文献
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用编码法作降水低云预报.降水低云对飞机着陆影响很大,严重危及飞行安全.本文利用80年至89年9月、10月850hPa、700hPa、500hPa空中资料和本站的气象资料,根据多年预报经验,筛选出六个相关关系较好的因子,进行有序排列,利用六因子二八进位制关系进行编码预报降水低云. 相似文献