长江中下游湖泊群不同生活型水生植物分布的时空变化(1986—2020年)     

刘兆敏  张玉超  关保华  曹振  来莱  杨启铎 《湖泊科学》2023,35(6):2022-2035

不同生活型水生植物对水环境的影响和碳固持能力不同,开展大尺度范围内不同生活型水生植物的时空分布和动态变化研究,是全面掌握湖泊水生态环境变化趋势、准确核算水生生态系统碳源/碳汇的前提。以长江中下游10 km²以上(共131个)的湖泊为研究对象,基于野外调查和先验知识,通过光谱分析,研发了不同生活型水生植物遥感高精度机器学习识别算法,解析了长江中下游湖泊群不同生活型水生植物的时空变化规律。研究表明,长江中下游湖泊群不同生活型水生植物遥感监测精度为0.81,Kappa系数为0.74;1986—2020年长江中下游湖泊群水生植物面积为2541.58~4571.42 km²,占湖泊总面积的15.99%~28.77%,沉水植物是优势类型(Max_1995年=2649.21 km²,Min_2005年=921.38 km²),其次是挺水植物(Max_2005年=1779.44 km²,Min_2020年=569.05 km²)和浮叶植物(Max_2015年=685.68 km²,Min_2000年=293.04 km²);水生植物主要分布在长江干流流域湖泊群,其次是鄱阳湖流域、洞庭湖流域、太湖流域和汉江流域;变化趋势上,1986—2020年长江中下游湖泊群水生植物面积呈现先增长(1986—1995年)、后下降(1995—2010年)、再增加(2010年后)的趋势。本研究可为长江中下游湖泊群生态环境调查及水环境管理提供重要参考。  相似文献   

基于网络控制板的地震台站远程电源监控系统     

李惠玲  高云峰  胡玉良  程冬焱  李颖  王鹏伟  穆慧敏 《地震地磁观测与研究》2019,40(6):152-159

针对无人值守地震台站逐年增加,运行维护模式不佳的现状,设计一种远程电源监控系统,采用远程电源控制模块,设计软件通过TCP/IP协议,在仪器出现死机时,远程实现设备的断电重启。本文对该系统的设计思路、硬件构成进行描述,并简要介绍软件功能设计、监控告警以及该系统在无人值守台站的应用。实践证明,该系统可有效解决因仪器死机造成的观测数据缺记,为地震专业设备的可靠运行和及时维护提供依据与保障,为今后地震台站,特别是无人值守台站的维护提供借鉴。  相似文献   

Increasingly important role of numerical modeling in oceanic observation design strategy: A review     

Zhang  Kun  Mu  Mu  Wang  Qiang 《中国科学:地球科学(英文版)》2020,63(11):1678-1690

Science China Earth Sciences - Oceanic observation design is of considerable significance and has made remarkable progress during the past several decades. This study addresses the critical role of...  相似文献   

宁夏区域精细化温度预报业务平台   总被引：7，自引：2，他引：5  

丁建军胡文东  丁永红陈晓娟 穆建华 《气象科技》2005,33(3):283-288

介绍以宁夏中尺度数值模式温度预报为基础,以宁夏精细化预报系统温度预报产品为核心,结合自动气象站等多种资料,以图形方式显示、修改和制作宁夏各站逐时温度预报业务平台。该平台以宁夏各地区代表站与该地区其它站之间的回归方程的计算量为依据,在温度预报物理过程不变的情况下,通过修改曲线的方式,完成对大数据量温度预报值的订正。该平台的建成,为制作高时间密度的预报提供了技术支撑。  相似文献   

南堡1号构造馆三段断盖配置油气渗漏部位及其控藏作用     

牟敦山  付广  陈雪晴 《吉林大学学报(地球科学版)》2018,48(4):1008-1017

为了研究南堡凹陷南堡1号馆三段火山岩盖层上下油气分布规律,在馆三段火山岩盖层及其内油气渗漏断裂发育及分布特征研究的基础上,通过对馆三段火山岩盖层断接厚度与其封油气所需最小断接厚度相对大小的比较和对油气渗漏断裂凸面脊的确定,预测了南堡1号构造馆三段断盖配置油气渗漏部位;并结合油气分布,对断盖配置油气渗漏部位对油气成藏与分布的控制作用进行了研究。结果表明,南堡1号构造馆三段断盖配置发育10处油气渗漏部位,其中：F₂及分支断裂油气渗漏部位最发育,有3处油气渗漏部位;其次是F₁、F₆断裂,有2处油气渗漏部位;F₃、F₄、F₅和F₇断裂仅各发育1处油气渗漏部位。这些油气渗漏部位及附近有利于下伏东一段油气在上覆馆三段之上聚集成藏,应是造成南堡1-1断鼻、南堡1-3断块和南堡1-5断鼻北部油区油气既可以分布在下伏东一段又可分布在馆三段之上,而南堡1-5断鼻南部油气仅分布在下伏东一段的根本原因。  相似文献   

基于GNSS浮标和验潮资料的HY-2A卫星高度计绝对定标   总被引：1，自引：0，他引：1  

杨磊  周兴华  王朝阳  梁冠辉  唐秋华  周东旭  雷宁  杨龙  穆博 《海洋学报》2017,39(1):111-120

为探测我国HY-2A卫星高度计海面高测量绝对偏差及其在轨运行状态,本文利用GNSS浮标星下点同步测量和验潮资料海面高传递方法在山东千里岩和珠海担杆岛海域开展定标研究。为验证GNSS浮标定标方法的准确性,还对国外卫星Jason-2和Saral进行了定标实验。实验表明GNSS浮标绝对海面高测量精度达2 cm,对Jason-2和Saral高度计多个周期定标得到的海面高偏差均值分别为5.7 cm和-2.3 cm,与国际专门定标场的结果符合较好。2014年9月和2015年5月HY-2A卫星高度计浮标定标结果分别是-65 cm和-91 cm,因两次结果差异显著,故又利用千里岩验潮站资料对HY-2A卫星高度计第56至73周期进行了定标分析,结果证明HY-2A卫星海面高存在约-51 cm/a的漂移,置信度为95%的回归分析表明浮标和验潮定标结果符合。本文研究结果表明在我国尚无专门定标场的情况下,可利用GNSS浮标对我国高度计实施灵活、精准的在轨绝对定标,在有高度计轨迹经过验潮站的情况下可使用验潮资料结合精密大地水准面模型进行绝对定标。  相似文献   

Effects of temperature and salinity on survival,growth and DNA methylation of juvenile Pacific abalone,Haliotis discus hannai Ino     

Kong  Ning  Liu  Xiao  Li  Junyuan  Mu  Wendan  Lian  Jianwu  Xue  Yanjie  Li  Qi 《中国海洋湖沼学报》2017,35(5):1248-1258

Temperature and salinity are two of the most potent abiotic factors infl uencing marine mollusks.In this study,we investigated the individual and combined ef fects of temperature and salinity on the survival and growth of juvenile Pacifi c abalone,Haliotis discus hannai Ino,and also examined the DNA methylation alteration that may underpin the phenotypic variation of abalone exposed to dif ferent rearing conditions.The single-factor data showed that the suitable ranges of temperature and salinity were 16–28°C at a constant salinity of 32,and 24–40 at a constant temperature of 20°C,respectively.The two-factor data indicated that both survival and growth were signifi cantly af fected by temperature,salinity and their interaction.The optimal temperature-salinity combination for juveniles was 23–25°C and 30–36.To explore environment-induced DNA methylation alteration,the methylation-sensitive amplifi ed polymorphism(MSAP)technique was used to analyze the genomic methylation profi les of abalone reared in optimal and adverse conditions.Neither temperature nor salinity induced evident changes in the global methylation level,but 67 and 63 dif ferentially methylated loci were identifi ed in temperature and salinity treatments,respectively.The between-group eigen analysis also showed that both temperature and salinity could induce epigenetic dif ferentiation in H.discus hannai Ino.The results of our study provide optimal rearing conditions for juvenile H.discus hannai Ino,and represent the fi rst step toward revealing the epigenetic regulatory mechanism of abalone in response to thermal and salt stresses.  相似文献   

Method for assessing coal-floor water-inrush risk based on the variable-weight model and unascertained measure theory   总被引：1，自引：0，他引：1  

Qiang Wu  Dekang Zhao  Yang Wang  Jianjun Shen  Wenping Mu  Honglei Liu 《Hydrogeology Journal》2017,25(7):2089-2103

Water inrush from coal-seam floors greatly threatens mining safety in North China and is a complex process controlled by multiple factors. This study presents a mathematical assessment system for coal-floor water-inrush risk based on the variable-weight model (VWM) and unascertained measure theory (UMT). In contrast to the traditional constant-weight model (CWM), which assigns a fixed weight to each factor, the VWM varies with the factor-state value. The UMT employs the confidence principle, which is more effective in ordered partition problems than the maximum membership principle adopted in the former mathematical theory. The method is applied to the Datang Tashan Coal Mine in North China. First, eight main controlling factors are selected to construct the comprehensive evaluation index system. Subsequently, an incentive-penalty variable-weight model is built to calculate the variable weights of each factor. Then, the VWM-UMT model is established using the quantitative risk-grade divide of each factor according to the UMT. On this basis, the risk of coal-floor water inrush in Tashan Mine No. 8 is divided into five grades. For comparison, the CWM is also adopted for the risk assessment, and a differences distribution map is obtained between the two methods. Finally, the verification of water-inrush points indicates that the VWM-UMT model is powerful and more feasible and reasonable. The model has great potential and practical significance in future engineering applications.  相似文献   

Comparative study of As,Cd, Cu,Cr, Mg,Mn, Ni,Pb and Zn concentrations between sediment and water from estuary and port     

I. Bejarano-Ramirez  Jose M. Jurado  R. Muñiz-Valencia  Á. Alcázar  Silvia G. Ceballos-Magaña  A. Olivos-Ortiz  O. Rangel 《International Journal of Environmental Science and Technology》2017,14(6):1333-1342

The contents of As, Cd, Cu, Cr, Mg, Mn, Ni, Pb and Zn have been determined in sediment and water samples from Valle de las Garzas estuary and Port Manzanillo (Colima, Mexico) using ICP-AES. The concentrations of these elements were used for a comparative study to determine the distribution of heavy metals and to evaluate which elements reflect natural or anthropogenic backgrounds. For this purpose, seven sampling points were selected: Four of them correspond to the lagoon, and three were situated in the port. Statistical analysis of the mineral content was assessed. Initially, data comparison was assessed by statistical tests for each variable. Principal component analysis was then applied considering the influence of all variables at the same time by obtaining the distribution of samples according to their scores in the principal component space. In this way, four studies were carried out: (1) study of sediments collected during the dry season; (2) study of sediments collected during the rainy season; (3) comparative study between sediments from rainy and dry season; and (4) study of water composition collected during rainy season. From the results of the performed analyses, it can be concluded that metals distribution pattern reflected natural and anthropogenic backgrounds (e.g., sediments from the lagoon, situated at the beginning of the rain channel, presented high contents of Zn and Cu, perhaps related to anthropogenic activities or the influence of igneous sediments).  相似文献   

利用影像纹理和阴影信息提取城市不透水面的方法——以咸阳市为例     

黄曦涛  李怀恩  张瑜  白穆 《测绘通报》2016,(5):80-83

利用2012年的咸阳市资源三号卫星影像,同时利用光谱信息和纹理信息对咸阳市的地表进行监督分类,使用阈值和开闭运算提取阴影,并通过TM影像提取NDBI等指数辅助归类,优化分类结果,提高提取不透水层信息的准确率,旨在为城市合理布局,减少城市内涝等提供基本信息。研究结果表明,利用多源遥感卫星影像,同时考虑光谱和纹理信息的分类方法进行不透水面的提取精度提高了17.2%,对阴影检测和归类处理提取精度进一步提高了2.7%,方法简便可行,结果稳定可靠;咸阳市研究区地表不透水率为30.73%,不透水率相对较低,城市生态环境较好;不透水面主要分布在渭河以北老城区。  相似文献