Equilibrium erosion of soft rock shores with a shallow or absent beach under increased sea level rise   总被引：1，自引：0，他引：1  

Mike Walkden  Mark Dickson   《Marine Geology》2008,251(1-2):75-84

A process-based numerical model was used to explore the response of soft rock shores with low volume beaches to variable rates of sea level rise. Equilibrium recession rates were simulated for ranges of wave height and period, tidal amplitude, rock strength, beach volume and rate of sea level rise. Equilibrium shore profiles were found to be steeper with higher rates of sea level rise. Beaches were represented as protective surfaces yet were found to cause no significant reduction in equilibrium recession rate when their volumes were below a critical threshold. Reduced equilibrium recession rates were found with beaches that extended sufficiently far below low tide level. The model results imply that, given several constraints, a very simple relationship exists between increased rates of sea level rise and the response of eroding composite soft rock/low volume beach shores.  相似文献   

Wavelet analysis and nonparametric test for climate change in Tarim River Basin of Xinjiang during 1959–2006     

Jianhua Xu  Yaning Chen  Weihong Li  Minhe Ji  Shan Dong  Yulian Hong 《中国地理科学(英文版)》2009,19(4):306-313

Using wavelet analysis, regression analysis and the Mann-Kendall test, this paper analyzed time-series (1959–2006) weather data from 23 meteorological stations in an attempt to characterize the climate change in the Tarim River Basin of Xinjiang Uygur Autonomous Region, China. Major findings are as follows: 1) In the 48-year study period, average annual temperature, annual precipitation and average annual relative humidity all presented nonlinear trends. 2) At the 16-year time scale, all three climate indices unanimously showed a rather flat before 1964 and a detectable pickup thereafter. At the 8-year time scale, an S-shaped nonlinear and uprising trend was revealed with slight fluctuations in the entire process for all three indices. Incidentally, they all showed similar pattern of a slight increase before 1980 and a noticeable up-swing afterwards. The 4-year time scale provided a highly fluctuating pattern of periodical oscillations and spiral increases. 3) Average annual relative humidity presented a negative correlation with average annual temperature and a positive correlation with annual precipitation at each time scale, which revealed a close dynamic relationship among them at the confidence level of 0.001. 4) The Mann-Kendall test at the 0.05 confidence level demonstrated that the climate warming trend, as represented by the rising average annual temperature, was remarkable, but the climate wetting trend, as indicated by the rising annual precipitation and average annual relative humidity, was not obvious.  相似文献   

1998-2002年中国地表太阳辐射的时空变化分析   总被引：2，自引：0，他引：2  

吕宁  刘荣高  刘纪远 《地球信息科学学报》2009,11(5):623-630

地表太阳辐射是陆气能量交换过程中重要的物理参数和生态参数,利用卫星数据反演地表太阳辐射对于全面认识地表太阳辐射空间差异性和年际变化特征具有重要的意义。本文利用GMS-5静止气象卫星数据反演了中国区域1998-2002年地表太阳辐射值,在此基础上分析了我国地表太阳辐射的时空分布特征。结果表明:(1)青藏高原的地表太阳辐射最大,川黔地区最小,都位于北纬22^~35°这一带除川黔地区外,地表太阳辐射从东向西增强,西部随纬度升高而减小,东部以长江流域最小,向南北增加,西南最大,北部次之,至东北地区随纬度升高而减小(2)各月地表太阳辐射量分布复杂,最小值都出现在12月,但最大值出现时间受雨季影响很大,珠江、长江一带主要在雨季过后的7月,华北、东北和青藏高原主要出现在雨季前的6月及5月,西南地区则在季风雨季前的4-5月(3)5年来东部沿海地区地表太阳辐射增加了13.71%(+4.37W/m²·a),西藏高原地区地表太阳辐射减少了9.31%(-3.47W/m²·a),全国地表太阳辐射平均减少了0.84%(-0.27W/m²·a)。  相似文献   

����̶ˮ����ˮ�Գ�����׼վ���������仯��Ӱ��     

王晓兵  张为民  钟敏 《大地测量与地球动力学》2009,29(5):72-75

??FG5??112?????????????й?????????????硱????????? ??JZ06????????4?ξ?????????????????????????????????????????????????????????????????????1??2001??2008??3?ι?????????????????20??10^-8ms^-2???????????????????????????????????????????15.4??10^-8ms^-2??????6.7??10^-8??ms^-2????2?????????仯??????????????????????????????????仯?????0.61??10^-8ms????^-2??/a???????????λ???????-0.18cm/a??????????????????仯??????????????????????????????????????????????????????  相似文献   

Global sea level change and thermal contribution   总被引：4，自引：0，他引：4  

Juncheng Zuo  Jianli Zhang  Ling Du  Peiliang Li  Lei Li 《中国海洋大学学报(英文版)》2009,8(1):1-8

The global long-term sea level trend is obtained from the analysis of tide gauge data and TOPEX/Poseidon data. The linear trend of global mean sea level is highly non-umiform spatially, with an average rate of 2.2 mm year-1 in T/P sea-level rise from October 1992 to September 2002. Sea level change duc to temperature vanation (the thermosteric sea level) is discussed. The results are compared with TOPEX/Poseidon altimeter data in the same temporal span at different spatial scales. It is indicated that the ther-mal effect accounts for 86% and 73% of the observed seasonal variability in the northern and southern hemispheres, respectively. The TOPEX/Poseidon observed sea level lags behind the TSI, by 2 months in the zonal band of 40°-60° in both the northern and southern hemispheres. Systematic differences of about 1-2cm between TOPEX/Poseidon observations and thermosteric sea level data are obtained. The potential causes for these differences include water exchange among the atmosphere, land, and oceans, and some pos-sible deviations in thermosteric contribution estimates and geophysical corrections to the TOPEX/Poseidon data.  相似文献   

普通Kriging插值算法研究     

陈宝政  蔡德利 《测绘与空间地理信息》2009,32(3):7-9

地统计学是进行空间变异分析的有力工具.文章说明了地统计学的基本原理及其实现算法,并应用该算法对研究区域的草句白浆土有效磷的空间变异特征进行了分析,通过计算得出的地统计学参数说明了土壤有效磷具有中等空间相关性,并生成了该养分的空间分布图.  相似文献   

流沙湾的底栖大型海藻调查   总被引：1，自引：0，他引：1  

谢恩义  申玉春  叶宁  吴灶和 《广东海洋大学学报》2009,29(4):30-35

2008年3月～2009年1月调查了流沙湾潮间带及湾内(109°55'～109°59'E,20?22'～20°28'N)底栖大型海藻资源,定性、定量分析该海湾底栖大型海藻种类、生态分布、区系性质、群落结构及生物量的季节变化规律。共采集底栖大型海藻3门10目17科19属32种,其中红藻门4目9科9属15种,绿藻门4目6科7属14种,褐藻门2目2科3属3种,以亚热带藻种占绝对优势,达59.4%,温带成分21.9%,热带成分18.7%。采样海藻具印度-西太平洋海洋植物区系中国-日本亚热带海洋植物亚区特点。调查区域内底栖大型海藻群落组成的季节变化明显。  相似文献   

中国夏季气候对植被覆盖的影响:1982～2001(英文)     

HABIB Aziz Salim  陈晓玲  龚健雅  张力 《地球空间信息科学学报》2009,(1)

In this paper, we apply lagged correlation analysis to study the effects of vegetation cover on the summer climate in different zones of China, using NOAA/AVHRR normalized difference vegetation index (NDVI) data during the time period from 1982 to 2001 and climate data of 365 meteorological stations across China (precipitation from 1982 to 2001 and temperature from 1982 to 1998). The results show that there are positive correlations between spring NDVI and summer climate (temperature and precipitation) in m...  相似文献   

斑尾复鰕虎鱼群体的形态学比较   总被引：3，自引：0，他引：3  

高天翔  孙希福  宋娜 《中国海洋大学学报(自然科学版)》2009,39(1)

对采自丹东、大连、东营、青岛、赣榆、舟山、厦门7个斑尾复鰕虎鱼群体的可量性状和可数性状进行了主成分分析、聚类分析、判别分析和单因子方差分析.主成分分析和聚类分析结果显示东营和赣榆群体为一组,而其它群体为另一组.2组差异极为显著.主成分分析构建了4个主成分,其贡献率分别为41.30%,8.92%,8.08%和7.31%,累计贡献率为65.60%.第一主成分主要受尾柄长/尾柄高、体高/体长、头长/体长和吻至背鳍起点/体长的影响.判别分析也可将两组群体分开,东营和赣榆组与另一组没有误判,对于样本所属海域的判别,其中东营为100%,最低为青岛群体66.7%,综合判别率为85.5%;选取贡献较大的14个特征值建立判别公式,利用判别公式计算各群体的差别准确率为62.1%～100%.对形态特征参数进行单因子方差分析,计算差异系数,根据Mayr等提出的75%规则,认为两组群体已达到亚种水平,而两组群体内的形态差异为种内不同群体间的差异.  相似文献   

源地黑潮及其上下游流量的变化特征   总被引：3，自引：1，他引：2  

蔡榕硕  张启龙  齐庆华 《台湾海峡》2009,28(3):299-307

本文基于长时间序列的海流和温盐资料（最新版SODA高分辩率再分析资料和137°E断面的观测资料），计算了黑潮流系四个主要断面的流量，并分析了它们的变化特征．结果表明，黑潮流系各主要断面流量具有显著的季节性差异，其年际、年代际变化明显．相关分析表明，源地黑潮及其上下游流量变化具有较强的独立性，变化不尽一致，其中，短期气候变化特征可能与热带太平洋的年际变化有明显关联，而年代际变化则可能与发生于北太平洋的年代际变化以及其它副热带中尺度涡旋等变化有一定联系．  相似文献