Atmospheric correction of HJ-1 A/B CCD over land: Land surface reflectance calculation for geographical information product

This paper proposed a method to retrieve the land surface reflectance from the HJ-1A/B CCD data. The aerosol optical depth（AOD）, the most important factor affecting the atmospheric correction of CCD images at all bands, is proposed to retrieve from the CCD imagery by the approach of dense dark vegetation（DDV） method. A look-up table in terms of the transmittances, the path radiances and the atmospheric spherical albedo as functions of the AOD was established for a variety of sun-sensor geometry and aerosol loadings. The atmospheric correction is then achieved with the look-up table and the MODIS surface reflectance output（MOD09） as the priori datasets. Based on the retrieved AOD and the look-up table of atmospheric correction coefficients, the land surface reflectance was retrieved for the HJ-1A/B data according to the atmospheric radiative transfer equation. Some in-situ measurement Data for Yanzhou of Shandong province in East China and MODIS land surface reflectance products MOD09 are used to preliminarily validate the proposed method. The results show that the proposed method can remove effectively the atmospheric contributions, and the overall accuracy of the retrieval land surface reflectance can be improved substantially.     

福建松溪后洋矿区钼矿地质特征

松溪后洋矿区钼矿埋藏浅、品位富、易于开采等特点,在闽北地区具有一定的代表性。通过对矿区钼矿成矿地质条件的分析,阐述了钼矿的控矿因素为晚侏罗世正长花岗岩和近东西向断裂构造,矿床属岩浆期后热液型。     

Analysis of groundwater-level fluctuation in a coastal confined aquifer induced by sea-level variation

Groundwater responses to tide fluctuations in different hydrogeological situations have been investigated for many years. Various solutions have been derived using the assumption that tides are composed of sinusoidal components, neglecting non-periodic variables. This approach has resulted in the introduction of some inaccuracy in predictions of groundwater responses to sea-level variation. To resolve this problem, this study used the Fourier sine transform method to derive an analytical solution based on the measured sea-level boundary. Compared with an analytical solution based on a sinusoidal assumption and a numerical solution generated by MODFLOW, this solution provided better performance in groundwater-level prediction in a coastal confined aquifer in Zhuhai City, China. The hydrogeological parameters estimated by the three aforementioned methods fitted well with those estimated by field surveys and pumping tests. The introduced analytical solution not only reflects the physical mechanisms of tide-induced groundwater-level fluctuation, but also reveals the non-periodic fluctuation of groundwater level caused by sea-level variation. This solution may also be used to evaluate groundwater responses to random mechanical stresses.     

稀性泥石流对排导槽的冲磨破坏机理

针对稀性泥石流特点，从垂直于排导槽边壁方向和平行于排导槽边壁方向对排导槽的受力情况进行比较深入的分析，导出了多个公式，为设计排导槽提供了理论依据。     

瀑河市强对流天气综合分析及预报预警

分析了漯河市强对流性天气的产生机制和形势场,并应用V-3θ图的分布特征、能量特征值、卫星云图云顶亮温和闪电数据,做出对流性天气的预报预警。     

永安地震台钻孔体应变地震响应能力评估

本文从永安地震台现状、观测手段布设、科普宣传工作和应急经验体会等方面就2018年明溪3.9级地震与2018年11月26日台湾海峡6.2级地震震后应急工作进行思考。为台站工作者提供应对突发事件时应该采取的具体工作流程和应对措施,具有一定的实践意义,对其他台站具有一定参考作用。     

条分法中土条周边水压力与渗透力之间的关系

目前在边坡稳定分析中,常常存在土条周边水压力与渗透力同时考虑的现象,导致水压力的重复考虑。针对这个问题,以瑞典条分法为例,通过用流网性质来确定土条周边水压力的方法,研究了条分法中土条周边水压力与渗透力之间的关系,得出了渗透力与土条中的水重和周边静水压力是一对平衡力的结论,澄清了模糊认识,纠正了计算方法。     

为生态建设服务的吉林省西部景观类型研究*

在GIS技术支持下,依据有关原则,对吉林省西部景观类型进行了划分;选取地形和地貌、人类对景观的利用水平以及沙碱化程度三个指标对景观类型进行了稳定性评价。在此基础上,结合景观生态学的有关理论,采用类型重要值、嵌块体密度和平均内缘比率分析了吉林省西部各小区(东部区,中部区和西部区)内不同稳定类型的景观空间结构,提出了重建不稳定类型应以西部区为重点并要注意其内部结构的协调性、防止亚稳定类型向不稳定类型过渡也应以西部为重点、东部区的景观生态建设应注意增加其异质性等建议。     

Surface water deficiency zoning of China based on surface water deficit index (SWDI)

China’s economic and social development is severely restricted by regional water deficiency, and the determination of water deficiency level in different regions is an important basis of water resource management. In this study, we zoned 32 provinces of China into five surface water deficiency levels based on surface water deficit index derived from the Chinese meteorological satellite FY-2C images. The result shows that China is facing serious water shortage crisis with only 15.44% of total area without water deficiency, which is located in the south and southeast coast. More than 60% of total area of China suffered from severe or extremely water deficiency, which are mainly distributed in western and northern regions. Jingjinji area (namely Beijing, Tianjin and Hebei province), which is a special region with high amount of gross domestic product and relative abundant water resources, is suffering from severe water deficiency. It revealed that water resources were interacted with regional development and water management should consider local conditions. To Jingjinji area, water management should focus on adjustment of industrial structure, urban expansion control and scientific water resources allocation. In general, the surface water deficit index based water deficiency zoning will be of significant value to be applied in water resources management at regional scales.     

长春市及周围邻近地区的地震记录特征

对长春市地震速测速报中心遥测台网近年来记录到的长春市及周围邻近地区不同方位的地震在仔细分析与对比的基础上,总结出一些规律性的认识。这些认识将有助于对该区域的地震更加快速准确地进行测报。