SOI和El Nino与湘潭汛期洪涝的关系

本文研究了湘潭汛期（4～9月）洪涝与南方涛动指数（SOI）和厄尔尼诺（ElNino）事件的遥相关联系。结果表明，南方涛动指数异常偏负（弱）以及厄尔尼诺事件的滞后影响对湘潭汛期洪涝的短期气候预报有很好的指示性。在统计分析的基础上，我们建立了日常业务应用的湘潭汛期洪涝预报物理模型。     

Applicability evaluation of the SWIM at river basins of the black soil region in Northeast China: A case study of the upper and middle Wuyuer River basin

In this paper, we selected the middle and upper reaches of the Wuyuer River basin in the black soil region of Northeast China as the study area. We adopted the soil and water integrated model (SWIM) and evaluated the parameter sensitivity using partial correlation coefficient. We calibrated and validated our simulation results based on the daily runoff data from Yi’an hydrological station at the outlet of the river basin and the evaporation data recorded by various weather stations from 1961 to 1997. Following evaluation of the modeling data against the observed data, we present the applicability of SWIM in the river basin of the black soil region, and discuss the resulting errors and their probable causes. Results show that in the periods of calibration and validation, the Nash-Sutcliffe efficiency (NSE) coefficients of the monthly and daily runoffs were not less than 0.71 and 0.55, and the relative errors were less than 6.0%. Compared to daily runoffs, the simulation result of monthly runoffs was better. Additionally, the NSE coefficients of the potential monthly evaporation were not less than 0.81. Together, the results suggest that the calibrated SWIM can be utilized in various simulation analyses of runoffs on a monthly scale in the black soil region of Northeast China. On the contrary, the model had some limitations in simulating runoffs from snowmelt and frozen soil. Meanwhile, the stimulation data deviated from the measured data largely when applied to the years with spring and summer floods. The simulated annual runoffs were considerably higher than the measured data in the years with abrupt increases in annual precipitation. However, the model is capable of reproducing the changes in runoffs during flood seasons. In summary, this model can provide fundamental hydrological information for comprehensive management of the Wuyuer River basin water environment, and its application can be potentially extended to other river basins in the black soil region.     

Characteristics of permafrost degradation in Northeast China and its ecological effects: A review

Latitudinal permafrost in Northern Northeast(NNE)China is located in the southern margin of the Eurasian continent,and is very sensitive to climatic and environmental change.Numerical simulations indicate that air temperature in the permafrost regions of Northeast China has been on the rise since the 1950s,and will keep rising in the 21st century,leading to extensive degradation of permafrost.Permafrost degradation in NNE China has its own characteristics,such as northward shifts in the shape of aWfor the permafrost southern boundary(SLP),discontinuous permafrost degradation into islandlike frozen soil,and gradually disappearing island permafrost.Permafrost degradation leads to deterioration of the ecological environment in cold regions.As a result,the belt of larch forests dominated by Larix gmelinii has shifted northwards and wetland areas with symbiotic relationships with permafrost have decreased significantly.With rapid retreat and thinning of permafrost and vegetation change,the CO2 and CH4 flux increases with mean air temperature from continuous to sporadic permafrost areas as a result of activity of methanogen enhancement,positively feeding back to climate warming.This paper reviews the features of permafrost degradation,the effects of permafrost degradation on wetland and forest ecosystem structure and function,and greenhouse gas emissions on latitudinal permafrost in NNE China.We also put forward critical questions about the aforementioned effects,including:(1)establish long-term permafrost observation systems to evaluate the distribution of permafrost and SLP change,in order to study the feedback of permafrost to climate change;(2)carry out research about the effects of permafrost degradation on the wetland ecosystem and the response of Xing'an larch to global change,and predict ecosystem dynamics in permafrost degradation based on long-term field observation;(3)focus intensively on the dynamics of greenhouse gas flux in permafrost degradation of Northeast China and the feedback of greenhouse gas emissions to climate change;(4)quantitative studies on the permafrost carbon feedback and vegetation carbon feedback due to permafrost change to climate multi-impact and estimate the balance of C in permafrost regions in the future.     

大兴安岭博乌勒山一带早白垩世侵入岩地质特征

大兴安岭博乌勒山地区早白垩世侵入岩发育,可分为两个岩石系列:闪长岩类,有石英闪长岩、石英二长闪长岩;花岗岩系列,有花岗闪长岩、正长花岗岩、花岗斑岩。岩石学、岩石化学、岩石地球化学特征表明,岩石类型由中性向酸性演化,以成份演化为特征;属碱钙性-钙碱性系列,成因类型为同熔型(I型),并具有同源岩浆演化特点。成矿专属性,闪长岩类对Au、Ag、Pb、Zn金属成矿有利,花岗岩类对Cu、Pb、W、Mo金属成矿有利。     

1996年8月5日—1997年5月15日Hale—Bopp彗星的照相观测

在1996年8月5日——1997年5月15日对Hale-Bopp彗星进行了照相观测,多次观测到Hale-Bopp彗星彗核的小规模分裂,喷流,壳层结构及彗发的膨胀现象。     

基于改进熵值模型的城市土地集约利用动态评价——以广州市为例

从社会、经济和生态3个方面构建了城市土地集约利用评价指标体系,借助改进熵值模型和综合评价方法对2003—2007年的广州市城市土地集约利用水平进行了综合评价。结果表明:(1)经济状况是影响城市土地集约利用水平的最重要因素,其次为社会状况和生态环境状况。(2)近年来,广州城市土地集约利用水平稳步提升,经济、社会和环境各子系统基本朝有序方向发展,而2004—2006年广州市城市土地利用出现了短暂无序化发展征兆,主要是由于其经济增长放缓、环保投入降低所致。(3)通过对广州市与广东省的纵向和横向对比发现,近年来,广州市的空气质量和珠江广州段水质并未明显改善,环保投入和城市绿化建设更是仅相当于或低于全省的平均水平,这意味着广州市在推进节约集约用地试点示范工作中必须加大环境保护投入,注重人口、土地、环境与经济发展的协调关系。     

昆仑山口西8.1级大震前后重力场动态变化

2001年11月14日17时26分,在新疆、青海交界处的昆仑山(36.2°N,90.9°E)发生8.1级地震.震后又相继发生5次5级以上的强烈余震.其主震和余震基本上都在东昆仑断裂带的两侧或断裂带上.这次地震虽然没有人员伤亡的报道,但研究大震前后震中周围地区局部重力场动态变化情况,研究大地震与局部重力场动态变化之间的相关性,对捕捉地震前兆减轻未来地震的灾害,却具有极高的科学研究价值.     

华北板块东缘晚古生代火山活动及其大地构造含义

在华北板块东缘,从皖北,鲁西到冀中,辽东,分布着一条长达千余ｋｍ的晚古生代北北东向火山活动带,已发现的火山岩主要为正常火山碎屑岩和沉积火山碎屑岩,岩石化学分析表明为钙碱系列中（酸）性火山岩,在华北晚古生代煤系中记录了这种强烈的火山活动,包含有丰富的火山碎屑以及由火山灰堆积蚀变而成的煤矸层（ｔｏｎｓｔｅｉｎ）。作者认为,在晚古生代,华北板块东缘可能存在一火山弧链,即华北板块东缘为一主支大陆边缘。