漳河流域基流演变规律

为揭示漳河流域基流对河川径流的贡献及基流的变化规律,基于观台水文站的实测日径流量(1959~1990、2006~2018年),运用Eckhardt滤波法将日径流量划分为直接径流量和基流量,并通过M-K检验法判别不同时间尺度(年、季、月)基流量和基流指数(BFI)的演变规律。结果表明,1959~1990、2006~2018年基流对河川径流的贡献分别为0.63、0.64;年基流量和BFI呈下降趋势,且在1971、1966年发生突变;季节性基流量均呈显著下降趋势,且突变点出现在1970年前后;春、秋、冬三季BFI均呈显著下降趋势;月基流量和月BFI均呈下降趋势,在1970年前后发生突变。

Preliminary Study on the Relationship between the M_s8.0 Wenchuan Earthquake of 2008 and the Anomalies of Earth Resistivity Observed at Qingdao Seismic Station

Near-surface earth resistivity and underground water level anomalies were recorded at Qingdao seismic observatory of Shandong Province before and after the MS8.0 Wenchuan Earthquake of May 12,2008.The observed data of earth resistivity at the observatory revealed that the underground water level dropped and the resistivity increased.It is postulated that in the special tectonic setting at Qingdao observatory,the variation of stress and strain caused the change of water level beneath the station,thus,leading to the variation of earth resistivity.The relationship between the variation of stress field and the change of earth resistivity before earthquake is analyzed.

Verification of Parameters of Major Historical Earthquakes in the North Yellow Sea

Based on existing historical data and observations from the Dalian seismic station,this paper rechecks the parameters of the three historical earthquakes of 1916,1917 and 1944 in the North Yellow Sea,near the Yalu River region.The results show that their relocated epicenters are located at contemporarily intense seismic active zones,consistent with the results derived from the data of the Dalian seismic station.The results are valuable in both revising earthquake catalogues and understanding the local background seismicity.

Establishment of Geomagnetic Observatories in Pakistan and Repeat Station Results from Northern Part of Pakistan

A geomagnetic observatory was established at Karachi （geog coord： 24.95°N, 167.14° E）, Pakistan in 1983 which comprised of AMOS-Ⅲ （Automatic Magnetic Observatory System）. In 2006 SUPARCO （Space and Upper Atmosphere Research Commission） planned to upgrade the old observatory of Karachi in order to qualify it as an IMO （Intermagnet Magnetic Observatory）. Dr. Jean Rasson agreed to give support and assist us in the upgradation. BGS （British Geological Survey） provided a complete observatory instrument setup. Due to perturbations traceable to the increased urbanization, the observatory has been shifted to a site ＂Sonmiani＂, 80 km north-west of Karachi, where long term protection from cultural noise is offered. This site in a sparsely built research complex was selected after a magnetic survey. A new observatory has also been established at Islamabad （geog cord： 33.75° N, 72.87° E） which is mountainous region. SUPARCO purchased new equipment for the establishment of new observatories. Plan of upgradation of observatory at Quetta is also under consideration in order to improve the monitoring of geomagnetic field on the western part of Pakistan. Repeat station work has been done for the northern part of Pakistan with the collaboration of IRM, Belgium. The obtained results also compared with the global geomagnetic model （IGRF）.

Earth's Free Toroidal Oscillations Observed by the JCZ-1 Seismometer

We firstly detected the Earth's free toroidal oscillations excited by three large earthquakes in Japan,2011,Chile,2010 and Indonesia,2005 from the observed data of the JCZ-1 seismometer at Wuhan Seismic Station. The eigenperiods of basic modes (0T2 - 0T67 ) and first modes (1T2 ～ 1T50 ) were detected,and their error ratios were less than 0. 5% by comparing the observed eigenvalues with the theoretical eigenvalues in PREM. We supplemented some modes- 0T11,0T15 , 0T19 , 1T4 , 1T5 and 1T14 ,which were not mentioned in PREM,and also observed the spectral line multi-peak phenomenon from 0T2, 0T6 , 0T7 and 0T8 . These results show that the JCZ-1 seismometer is able to precisely observe the Earth's long period toroidal free oscillations.

On a Method of Climatological Observations Processing

The task of climate observation data processing is central to the quality of an assessment of future climate change impact. The current state-of-the-art is based on the long-running observation records of the meteorological stations. However, it is common for the developing states to have only relatively short and/or intermittent record histories. The issue becomes even more aggravated under an effort to assess the climatic trends for specific territories with few meteorological stations. The paper offers a simple and effective technique to handle the climate observations; the technique makes the most complete use of an available data set by counting the data provided by all meteorological stations including those with short records and omissions. The method is based on numeric differentiation of source data samples.

Shifts in water-level variation of Namco in the central Tibetan Plateau from ICESat and Cryo Sat-2 altimetry and station observations

The dynamics of high-altitude inland lakes in the Tibetan Plateau are sensitive indicators of climate change. Due to the remoteness and hard access, satellite altimetry becomes an effective approach to obtaining largescale and temporally continuous information of lake-level changes. The CryoSat-2 altimetry is expected to solve the current problem that earlier radar altimeters are only practical for monitoring large water bodies, while ICESat laser altimetry is available only for the period 2003-2009. In this study, the comparison of CryoSat-2 altimetry for Namco with in situ water-level data suggests a high cor- relation coefficient of 0.71 （P 〈 0.01）, with the mean error of -0.12 m and root-mean-square error of 0.18 m. Further, the combination of ICESat and CryoSat-2 altimetry data and in situ lake-level observations reveals a rapid water- level rise of 0.24 4- 0.04 m/year during 2003-2008 and then a slightly decreasing trend of -0.09 4- 0.04 m/year during 2009-2013. This study suggests that the CryoSat-2 altimetry has the potential of sustaining the fine observa- tions on Tibetan lakes, following the ICESat mission. Besides, the examination of four key climatic variables （temperature, precipitation, potential evapotranspiration, and relative humidity） during 1990-2013 indicates that the wetting climate over Namco Basin stagnated or even reversed around 2006, which may be tightly related to the slowing lake growth.

Construction of a Comprehensive Observation Network for Natural-Resource Elements in Heihe River Basin,NW China

The construction of a comprehensive observation platform for natural-resource elements would provide data support for studies of dynamic changes in various natural resources,and could serve the needs of natural-resource management and the construction of ecological civilization during a period of global change.As the second-largest inland river basin in NW China,the Heihe River Basin(HRB)lies in the central part of the Silk Road Economic Belt,consequently,pilot studies of resource management in the basin are urgently needed.This paper describes the construction of a comprehensive natural-resource elements observation network in the HRB to meet requirements for natural-resource management,based on natural-resource and Earth-system science.Based on current observations and research,thirteen observation stations were established in different river basins through integration with existing stations,reconstruction and upgrading,and new construction.The main types of land-surface resources in the HRB(grassland,forests,rivers,lakes,deserts,wetlands,and farmland)were included in the observation network constructed for the monitoring of natural-resource elements.Long-term,continuous,and stable observation can yield key data concerning coupling processes,trends of change,and rates of change in natural resources.This is of great significance in improving cognitive ability,scientific management,and strategic decision-making regarding natural resources in the HRB,and can provide a reference paradigm for the observation of and research into natural resources in other basins.