Causes and effects of spatial and temporal variations of cold period in Chinese oases between 1960 and 2014

Based on daily average temperatures and observation data from 74 meteorological stations in Chinese oases, we calculate five-day (pentad) average temperature ≤0°C for the start and end pentad as well as pentads of cold period using linear regression analysis, nonparametric Mann-Kendall tests, the Morlet wavelet power spectrum, and correlation analysis. We also analyze spatial and temporal variations and their effects on the start and end pentad as well as pentads of cold period in Chinese oases. Results show that over the last 55 years, the start pentad of cold period has been postponed while the end pentad has been advanced. Overall, the pentads have gradually shortened over time at trend rates that are 0.3 p/10a,–0.27 p/10a, and–0.58 p/10a, respectively. Spatial differences are significant, especially for the Qaidam Basin oasis where the start pentad is the earliest, the end pentad is the latest, and the trend of change is most obvious. Mutation points for the start and end pentad as well as pentads of cold period were observed in 1990, 1998, and 1994, respectively. Of these, the start pentad and pentads of cold period show a periodic cycle, related to atmospheric circulation and El Nino events, while the end pentad exhibits a periodic cycle, related to solar activity. The Tibetan Plateau index (TPI), the Asian polar vortex area index (APVAI), and carbon dioxide emissions (CDE) are the main factors affecting cold period in the study area, whereas the South Asian summer monsoon (SASM) index exerts the greatest effect on the Qaidam Basin oasis. The start and end pentad as well as pentads of cold period increase in concert with latitude, longitude, and altitude; in response to these changes, the start pentad is advanced, the end pentad is postponed, and pentads of cold period are gradually extended. Results show that change in latitude is most significant. Overall, the start and end pentad as well as pentads of cold period show clear responses to regional warming, but there are different effects on each.     

D-InSAR-based landslide location and monitoring at Wudongde hydropower reservoir in China

Differential synthetic aperture radar interferometry (D-InSAR) has become a useful technique for monitoring ground movement. The technique enables the analysis of very small ground movements in continuous, large areas and has the advantages of high accuracy, high resolution, all-weather adaptability, low cost, and inaccessible area coverage. Thus, D-InSAR has been widely used in the investigation of geologic hazards, such as subsidence, landslide, earthquake, and volcanic activity. In this paper, D-InSAR is used to locate and monitor landslide movement in the wide area of Wudongde Hydropower Reservoir in Jinsha River, China. Five SAR acquisitions are obtained by using the phased array-type L-band synthetic aperture radar sensor of the Advanced Land Observing Satellite. Detailed moving displacement maps in two time periods are derived by using the D-InSAR technique, and potentially moving landslide areas, as well as landslide hazard areas, are then located. The L1R-6 landslide, which is in active state, is investigated in detail. The deforming tendency obtained via D-InSAR is consistent with that obtained via global positioning system (GPS) monitoring. Error analysis of the D-InSAR results is also conducted. Finally, the grid function interpolation method of error reduction, which combines D-InSAR and GPS, is proposed to reduce the single-point error in D-InSAR monitoring and is further verified by the considerable improvement in the accuracy of L1R-6 landslide monitoring.     

Correlation between incompetent beds and slope deformation at Badong town in the Three Gorges reservoir, China

Badong town is a new immigration area in the Three Gorges reservoir, China, which is built on many giant deep-seated landslides. In this region, the slope deformation is very severe and it is strongly correlated with the incompetent beds, which are distributed widely in the rock mass. In this paper, two giant deep-seated translational rock landslides used as study cases are Huangtupo landslide and Zhaoshuling landslide. Firstly, the composition materials, structures and deformation characteristics of the two landslides are analyzed. Then, the position, structure, mineral composition and the formation mechanism of the incompetent beds are studied in detail. Finally, based on the comparison of the position, mineral and structure between incompetent beds and sliding zones of the landslides, the correlations between incompetent beds and giant landslide are discussed. The results indicate that 13 large incompetent beds exist in the middle Triassic Badong Formation strata, which can be divided into three types as weak interlayers, crushed beds and groundwater corrosion zones. The dominant minerals in the incompetent beds are illite, chlorite, quartz and calcite. The contents of the clay minerals in different positions are quite distinct, and the maximum difference of clay content exceeds 70 %. In addition, it is found that the contents of minerals in incompetent beds are similar to the slide zones of the landslides. The initial deformation of slopes normally developed along the incompetent beds, which induced subsequent shear displacement easily. Under the effect of gravity, the deep slip zones were generated mainly along the incompetent beds and the failure mode evolved from creep to integral slide gradually. The results can provide an important reference for the mechanism analysis and prevention of landslides in Badong town.     

Investigation of NDVI in relation to the growth phases of beech leaves in forest

The main objective of the science of phenology is to identify the time of the occurrence of conspicuous periodic phenomena in plants under the impact of climatic factors. The study of phonologic phenomena through visual observations and terrestrial studies and temperature registration using a thermo hydrometer in different altitudinal levels and using the satellite data of IRS1C/1D LISSIII in twelve 1-ha plots in pure beech stands in the altitudinal range of 500 to 1,200 m above the sea level from April to December was carried out in such a way that for each month, one image of sensor was allocated. The produced vegetation indices were matched with terrestrial observations of the phenology periods in each month in the beech plots. The results show that the increase of the altitude above the sea level functions like latitude and its most remarkable impact is the decreasing of the temperature and the shortening of growing season. The terrestrial observations carried out in the plots show that a sudden increase in the temperature leads to the faster growth and emergence of the leaves. The produced correlation coefficient between the temperature and the emergence of the leaves was (p?=?0.01) r?=?0.87. Moreover, the end of fall in the studied region has a direct and significant relation with temperature. The amount of correlation coefficient between the temperature and end of fall in the studied region is equal to (p?=?0.01) r?=?0.91. Normalized difference vegetation index (NDVI) is more related to the growth and nurturing of the leaves. The amount of NDVI during the growth of the leaves, completion of the leaves, and fall of the leaves is equal to 0.35, 0.6, and 0.25, respectively.     

CINRAD/SB雷达回波强度定标调校方法

回波强度定标和调校方法是保障CINRAD/SB回波强度测量精度的关键技术,方法不当会导致回波强度测量误差增大,直接影响雷达定量估测降水产品的可靠性。为了满足回波强度测量误差在±1 dBZ范围内的技术要求,根据雷达气象方程,通过对CINRAD/SB接收机测试通道、主通道、天馈系统相关影响回波强度测量误差的因素进行分析,提出了从接收机动态范围和雷达参数调整、线性通道增益定标目标常数定标,到测试通道参数调整的回波强度定标工作流程。总结出以线性通道增益定标目标常数定标为基准,采用测试通道参数测量法或基准法调校,以保证发射功率和接收机动态范围变化导致的回波强度测量误差得到在线实时校正,提高了CINRAD/SB回波强度测量精度。从接收机测试通道、主通道、天馈系统及发射功率4个方面,给出了回波异常的分析和诊断流程。并提出在接收机保护器前端增加机外信号注入口和定标信号功率检测功能,以利于机内外回波强度定标对比校准和消除测试通道参数变化导致回波强度测量误差的建议。     

Geochemistry,Zircon U–Pb Analysis,and Biotite 40Ar/39Ar Geochronology of the Maoling Gold Deposit,Liaodong Rift,NE China

The Maoling gold deposit is located in the southwestern part of the Liaodong rift, NE China, and has estimated reserves of 25 t. In this paper we present the results of an investigation into the geochronology and geodynamic mechanisms of igneous activity and metallogenesis within the Maoling gold deposit. New zircon U–Pb age data, biotite ⁴⁰Ar/³⁹Ar age data, whole‐rock geochemistry, and Hf isotopic analyses are presented in order to constrain the petrogenesis and mineralization of the deposit. Zircon U–Pb dating of the Wolongquan biotite monzogranite and Maoling biotite granite yielded mean ages of 194.0 ± 1.1 Ma and 196.1 ± 1.1 Ma, respectively. All the granites are characteristically high‐K calc‐alkaline, enriched in light rare earth elements and large ion lithophile elements, and depleted in high field strength elements, which is consistent with the geochemical characteristics of arc‐type magmas. The Hf isotope characteristics indicate that the granites formed by partial melting of early Paleoproterozoic crustal material. In addition, biotite ⁴⁰Ar/³⁹Ar dating indicates that the Maoling gold deposit formed at 188.9 ± 1.2 Ma, implying that the mineralization was related to both the granite intrusions. Taking into account previous data on S–Pb–O–H isotopes and our new age data, the Maoling deposit can be classified as an intrusion‐related gold deposit. Taking into account the geology of the study area and adjacent regions, we propose that the Maoling gold deposit and its associated granitic intrusions formed in a geodynamic setting that was dominated by subduction of the Paleo‐Pacific Plate beneath the Eurasian continent.     

中国风景名胜区交通可达性及市场潜力空间测度

基于旅游系统的区域开放性,从省内、省际两个角度出发,对国家级风景区的省内、省际交通可达性和市场潜力进行探讨。研究发现：① 风景区离散或集聚的规律性分布,使整体可达性区域差异性明显,呈现由东向西递减,由南北两侧向中间递增的分布格局。② 省内交通可达性优势区集中在东部沿海,省际交通可达性优势区集中在中原地区,与省内交通可达性相比,省际交通区域差异性更加明显,与航空可达性相比,铁路可达性对省际交通可达性的影响更大。③ 整体市场潜力呈现“带—团”状聚集式分布,基本形成了以东部沿海经济带为主的“带状”高市场潜力区,中部团状聚集式的较高市场潜力区,以及西部偏远低市场潜力区的空间分布格局。与省内市场潜力相比,省际市场潜力区域差异性更大,不同区域、种类的风景区省内、省际市场潜力优势不同。④ 旅游实际市场与市场潜力发展核心区空间错位明显,实际市场核心区主要集中在长江流域,市场潜力核心区则相对靠北,集中在中原及京津冀地区。     

Modeling the circulation in the Gulf of Tonkin, South China Sea

The circulation in the Gulf of Tonkin (Beibu Gulf) was studied using the Princeton Ocean Model, which was forced with the daily surface and lateral boundary fluxes for 2006 and 2007, as well as tidal harmonics and monthly climatological river discharges. In the southern Gulf, the vertically averaged circulation was anti-cyclonic in summer and changed to cyclonic in winter. Although it was highly correlated with the local wind, the southern gyre was driven primarily by the South China Sea (SCS) general circulation from the south. Flows in the Qiongzhou Strait that played a significant role in determining the circulation variability in the northeastern Gulf could be eastward or westward at any given day in summer or winter, but the seasonal mean current was eastward from late spring through summer and westward during the rest of the year, with an annual mean westward transport of ～0.1 Sv into the Gulf. Different water masses were distinguished at the surface with the warm and saline SCS water in the south, relatively fresh plume waters along the northern and western coasts of the Gulf, and the mixture of the two in between. At lower levels, two cold water masses were identified in the model, and each had T/S distributions qualitatively similar to the observations obtained in 2007. These two water masses were produced throughout the winter, sheltered from the surface warming by a thermocline as the season progressed, and eventually disappeared in late fall.     

一种现代不对称波痕的成因特征及类比分析——以民和盆地红古城地区下白垩统第8岩组为例

本文以黄河边上现代不对称波痕的形成为例,结合民和盆地下白垩统第８岩组沉积环境进行类比分析,一改过去传统的“浅水”认识,而把它定为三角洲平原相沉积。因而不对称波痕不能作为某一种沉积环境,它可以广泛生成于不同的环境。因此应更多强调综合分析、类比分析、层序基本单元和体系域分析,使盆地岩石地层单位的古环境解释建立在可靠的理性基础上。     

A geo-ontology-based approach to decision-making in emergency management of meteorological disasters

Ontology as a kind of method for knowledge representation is able to provide semantic integration for decision support in emergency management activities of meteorological disasters. We examine a meteorological disaster system as composed of four components: disastrous meteorological events, hazard-inducing environments, hazard-bearing bodies, and emergency management. The geospatial characteristics of these components can be represented with geographical ontology (geo-ontology). In this paper, we propose an ontology representation of domain knowledge of a meteorological disaster system descending from an adapted geospatial foundation ontology, designed to formally conceptualize the domain terms and establish relationships between those concepts. The class hierarchy and relationships of the proposed ontology are implemented finally at top level, domain level/task level, and application level. The potential application of the ontology is illustrated with a case study of prediction of secondary disasters and evacuation decision of a typhoon event. The multi-level ontology model can provide semantic support for before-, during-, after-event emergency management activities such as risk assessment, resource preparedness, and emergency response where the formed concepts and their relationships can be incorporated into reasoning sentences of these decision processes. Furthermore, the ontology model is realized with a universally used intermediate language OWL, which enables it to be used in popular environments. This work will underlie the semantic integration among human beings, between heterogeneous systems and between human beings and systems, enable spatial semantic reasoning, and will be useful in guiding advanced decision support in emergency management of meteorological disasters.