植物物候遥感监测精度影响因素研究综述

基于植物物候的遥感监测对于研究植被对气候变化的响应具有重要的科学价值。本文在阐述植物物候遥感监测原理及其通用技术流程的基础上,分别从植被类型及其所处的地理条件、遥感数据源及其预处理、植物物候遥感识别方法和植物物候遥感监测结果评价4个方面分析了影响植物物候遥感监测精度的因素,并针对当前研究中存在的不足,探讨了提高植物物候遥感监测精度的可行性途径,即建立高分辨率的近地面遥感定点观测及数据共享网络,发展普适性更强的卫星遥感时序数据去噪及植被指数曲线重建方法,寻求稳定性更高的植物物候期遥感识别方法,探索综合运用地面观测、遥感监测与模型模拟实现物候观测空间尺度拓展的可能性。     

基于客流特征的北京地铁站点类型识别

地铁站点是城市各种社会经济活动的关键节点,不同类型的地铁站点在城市中的区域条件、交通功能、土地利用类型等方面均存在差异,科学的站点分类有助于了解城市功能分区及评价轨道交通基础设施建设状况。本文基于2013年3月份14天工作日地铁刷卡客流量数据,运用引入客流特征的时间序列聚类方法,对北京市195个地铁站点进行分类。研究表明：①地铁站点客流量存在时空差异,也是城市功能分区时空差异的表现之一。②通过引入客流特征的时间序列方法,将地铁站点分为居住导向型、就业导向型、职住错位型、错位偏居住型、错位偏就业型、混合型、综合型及其他型8种不同类型。③利用地铁站点客流量数据,是将空间行为和实体空间进行关联比较的有效途径。     

中国半城市化地区乡村聚落空间格局演化机制探索——以西安市南郊大学城康杜村为例

半城市化地区因其在社会、经济、景观等方面的过渡性、多样性和动态性,从而得到地理学、城乡规划学、生态学及社会学等多个学科学者的关注。本文重点研究城市化近域推进过程中半城市化地区城乡聚落的消长规律,探讨保留村落的空间格局演化特征及其动力机制。在综述半城市化地区和乡村聚落研究进展的基础上,以西安市南郊大学城康杜村为例,综合运用遥感影像解译、野外调查和统计分析等方法,对其近15年来的聚落空间格局及其演化机制进行研究。结果表明：康杜村在2001-2015年间共经历了4次建房高峰和2次显著的就业变迁,绝大多数原住民的房屋租赁始于2006年;原住民的就业变迁时间与主要的城市化时间节点高度一致;就业变迁与建房高峰之间呈现出“刺激—反馈”的系统演化特征。城市化近域推进的外部驱动和村庄原居民的自我调适是半城市化地区乡村聚落空间格局演化的主要动力。     

Assessing artificial neural networks coupled with wavelet analysis for multi-layer soil moisture dynamics prediction

Soil moisture simulation and prediction in semi-arid regions are important for agricultural production,soil conservation and climate change.However,considerable heterogeneity in the spatial distribution of soil moisture,and poor ability of distributed hydrological models to estimate it,severely impact the use of soil moisture models in research and practical applications.In this study,a newly-developed technique of coupled(WA-ANN) wavelet analysis(WA) and artificial neural network(ANN) was applied for a multi-layer soil moisture simulation in the Pailugou catchment of the Qilian Mountains,Gansu Province, China.Datasets included seven meteorological factors:air and land surface temperatures,relative humidity,global radiation, atmospheric pressure,wind speed,precipitation,and soil water content at 20,40,60,80,120 and 160 cm.To investigate the effectiveness of WA-ANN,ANN was applied by itself to conduct a comparison.Three main findings of this study were:(1) ANN and WA-ANN provided a statistically reliable and robust prediction of soil moisture in both the root zone and deepest soil layer studied(NSE >0.85,NSE means Nash-Sutcliffe Efficiency coefficient);(2) when input meteorological factors were transformed using maximum signal to noise ratio(SNR) and one-dimensional auto de-noising algorithm(heursure) in WA, the coupling technique improved the performance of ANN especially for soil moisture at 160 cm depth;(3) the results of multi-layer soil moisture prediction indicated that there may be different sources of water at different soil layers,and this can be used as an indicator of the maximum impact depth of meteorological factors on the soil water content at this study site.We conclude that our results show that appropriate simulation methodology can provide optimal simulation with a minimum distortion of the raw-time series;the new method used here is applicable to soil sciences and management applications.     

测井技术在泰安姚庄油页岩勘探中的识别应用

油页岩是一种很有前景的油气资源,测井技术是油页岩矿勘探开发的关键技术。该文依托姚庄地区油页岩矿钻孔的测井工作,通过对典型钻孔zk002的测井资料进行分析对比,得出测井曲线的变化与岩层有机质含量的关系,识别出地层岩性,并定出含油页岩层厚度,其结果与地质岩心钻探结果基本一致,因此,测井技术能较好地识别含油页岩层。     

涟源富硒土壤研究与湖南省富硒土壤分布初探

在部省合作"湖南省娄邵盆地多目标地球化学调查"项目的资助下,系统地采集测试了涟源市耕地和园地的表层土壤样品。调查发现该地区发育了大量的富硒土壤,富硒土壤的来源主要与震旦系上统—寒武系下统和二叠系中上统的黑色岩系有关。上述黑色岩系分布区域的表层土壤具有全区最高的硒含量,均大于1 mg/kg,部分甚至达到硒过量的水平。经文献研究和综合评价,推断黑色岩系风化物质扩散堆积形成的山间盆地是湖南省快速高效的寻找富硒土壤的理想靶区。     

Cretaceous amber inclusions of Spain and Myanmar demonstrate early diversification and wide dispersal of Cephenniitae (Coleoptera: Staphylinidae: Scydmaeninae)

The taxonomic status of previously misplaced species of an ant-like stone beetle from Spanish amber (Albian) is clarified. Specimens of Kachinus magnificus (originally placed as incertae sedis within Scydmaenitae) were re-examined and their characters were found different from those of the type species of Kachinus from Myanmar amber. Consequently, Archeutheia gen. nov. is proposed to accommodate the Spanish species, resulting in Archeutheia magnifica comb. nov. Moreover, in a comprehensive phylogenetic analysis Archeutheia was placed as a sister group to extant Eutheia, within the tribe Eutheiini of Cephenniitae. A specimen of an undetermined genus from Myanmar amber clearly belonging in Cephenniini is also recorded. Both taxa represent the first definite Cretaceous Cephenniitae, a supertribe whose recent members are distributed on all continents but are especially diverse in the Oriental and East Palaearctic regions. This finding demonstrates a diversification of two presently most species-rich tribes of Cephenniitae already in Early Cretaceous. Archeutheia is strikingly similar to the extant species of Eutheia and Veraphis, showing male dimorphic characters (modified protrochanters) and antennal cavities characteristic of Palaearctic Eutheiini. This fact suggests a long morphological stability in the supertribe. A previously proposed hypothesis of an early presence of the Cephenniitae in the Northern Hemisphere is for the first time supported by the fossil record, and the palaeolocalities (western Europe and Southeast Asia) demonstrate a wide distribution of Cephenniitae in the Cretaceous and an early split of its ancestral lineage.     

夏玉米生长过程曲线重建研究——以鹤壁市为例

增强型植被指数(EVI)时间序列数据(即植被生长曲线)是整个生育期内植被各种生物学特征的综合反映。由于太阳位置、大气、地表和传感器位置与性能等的影响,根据遥感数据计算的EVI值往往比实际值偏低(存在大量噪声),并不能反映植被生长的真实情况,应用前需进行去噪重建工作。针对目前生长曲线重建研究大多是针对MODIS等国外遥感数据的情况,在综合分析重建方法的基础上,利用风云3号卫星的MERSI中分辨率遥感卫星数据构建鹤壁市夏玉米的EVI生长过程曲线。首先,用最大值合成法(MVC)对原始EVI时间序列数据进行初步的去云处理。接着,利用基于时间域的Savitzky-Golay滤波(简称SG滤波)对该EVI序列进行进一步的平滑去噪处理,结果发现,在噪声点EVI数值提高了,但同时在其他不是噪声点的地方EVI的值降低了。针对这种不合理的情况,利用基于SG迭代滤波取上包络线的改进方法进行处理,很好地克服了上述缺陷,在非噪声点EVI数值适当提高,且曲线平滑,达到了生长曲线重建的目的。然后,采用基于频率域的小波变换方法进行实验对比,结果发现,小波变换存在着与经典SG滤波类似的缺陷,而且在曲线末端存在突变情况。经过比较分析发现,针对研究区的实际情况,改进SG迭代滤波是较优的去噪方法。     

准噶尔盆地侏罗纪含铀岩系的层序划分与对比

为对比分析准噶尔盆地侏罗纪含铀岩系的特征,在盆地北部、东部、南部筛选了3个钻透中下侏罗统西山窑组(J_2x)和八道湾组(J_1b)的钻孔,以岩性组合、沉积特征和测井曲线为基础,结合层序地层学原理和前人研究成果,对其含铀岩系进行了划分与对比。选择12个铀矿化异常孔编制了层序沉积连井模式图,讨论了层序充填及演化特征。结果表明:盆地不同位置地层层序差异较大,北缘从侏罗系下统三工河组到侏罗系上统齐古组(J_1s—J_3q)发育了3个三级层序和7个体系域。盆地东缘从侏罗系下统八道湾组到上统齐古组(J_1b—J_3q),发育了5个三级层序和12个体系域,整体经历了一个较为完整的湖侵过程,4个次级的湖侵湖退使湖平面达到最高位。南缘从侏罗系中统西山窑组到上统齐古组(J_2x—J_3q)发育了3个三级层序和7个体系域,经历一次构造隆升作用造成了大规模湖退事件和一次完整的湖侵事件。八道湾期至齐古期至少经历了两次完整的湖退、湖侵事件,整体上经历了一个先退积、后进积、再退积的过程。头屯河期湖退过程中形成的扇三角洲、辫状河砂体是主要的铀储层,也标志着一次重要的构造隆升事件。研究区岩相主要有辫状河、辫状河三角洲、湖泊、湖泊三角洲和扇三角洲5种沉积相类型和10种沉积亚相,含铀岩系亚相主要有辫状河道、扇三角洲平原、湖泊三角洲平原。西山窑组(J_2x)含煤建造上下发育2个区域性平行不整合面,界面之下发育大规模湖泊三角洲相的粘土层圈闭了上下两侧的砂体,是寻找砂岩型铀富集的有利区带。这些认识,不仅提高了准噶尔盆地侏罗系层序地层的对比划分的精度,而且对盆地控铀要素和形成环境研究及全面开展铀矿找矿工作意义重大。     

Secondary Ion Mass Spectrometry Bias on Isotope Ratios in Dolomite–Ankerite,Part II: δ13C Matrix Effects

This study is Part II of a series that documents the development of a suite of calibration reference materials for in situ SIMS analysis of stable isotope ratios in Ca‐Mg‐Fe carbonates. Part I explored the effects of Fe²⁺ substitution on SIMS δ¹⁸O bias measured from the dolomite–ankerite solid solution series [CaMg(CO₃)₂–CaFe(CO₃)₂], whereas this complementary work explores the compositional dependence of SIMS δ¹³C bias (calibrated range: Fe# = 0.004–0.789, where Fe# = molar Fe/(Mg+Fe)). Under routine operating conditions for carbonate δ¹³C analysis at WiscSIMS (CAMECA IMS 1280), the magnitude of instrumental bias increased exponentially by 2.5–5.5‰ (session‐specific) with increasing Fe‐content in the dolomite structure, but appeared insensitive to minor Mn substitution [< 2.6 mole % Mn/(Ca+Mg+Fe+Mn)]. The compositional dependence of bias (i.e., the matrix effect) was expressed using the Hill equation, yielding calibration residual values ≤ 0.3‰ relative to CRM NBS‐19 for eleven carbonate reference materials (6‐μm‐diameter spot size measurements). Based on the spot‐to‐spot repeatability of a drift monitor material that ‘bracketed’ each set of ten sample‐spot analyses, the analytical precision was ± 0.6–1.2‰ (2s, standard deviations). The analytical uncertainty for individual sample analyses was approximated by combining the precision and calibration residual values (propagated in quadrature), suggesting an uncertainty of ± 1.0–1.5‰ (2s).