Impacts of climate change and human activities on surface runoff in the Dongjiang River basin of China     

Dedi Liu  Xiaohong Chen  Yanqing Lian  Zhanghua Lou 《水文研究》2010,24(11):1487-1495

Observed rainfall and flow data from the Dongjiang River basin in humid southern China were used to investigate runoff changes during low‐flow and flooding periods and in annual flows over the past 45 years. We first applied the non‐parametric Mann–Kendall rank statistic method to analyze the change trend in precipitation, surface runoff and pan evaporation in those three periods. Findings showed that only the surface runoff in the low‐flow period increased significantly, which was due to a combination of increased precipitation and decreased pan evaporation. The Pettitt–Mann–Whitney statistical test results showed that 1973 and 1978 were the change points for the low‐flow period runoff in the Boluo sub‐catchment and in the Qilinzui sub‐catchment, respectively. Most importantly, we have developed a framework to separate the effects of climate change and human activities on the changes in surface runoff based on the back‐propagation artificial neural network (BP‐ANN) method from this research. Analyses from this study indicated that climate variabilities such as changes in precipitation and evaporation, and human activities such as reservoir operations, each accounted for about 50% of the runoff change in the low‐flow period in the study basin. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

Evaluation of temperature trends over India / Evaluation de tendances de température en Inde     

《水文科学杂志》2013,58(1)

Abstract

Abstract The impact of climate change is projected to have different effects within and between countries. Information about such change is required at global, regional and basin scales for a variety of purposes. An investigation was carried out to identify trends in temperature time series of 125 stations distributed over the whole of India. The non-parametric Mann-Kendall test was applied to detect monotonic trends in annual average and seasonal temperatures. Three variables related to temperature, viz. mean, mean maximum and mean minimum, were considered for analysis on both an annual and a seasonal basis. Each year was divided into four principal seasons, viz. winter, pre-monsoon, monsoon and post-monsoon. The percentages of significant trends obtained for each parameter in the different seasons are presented. Temperature anomalies are plotted, and it is observed that annual mean temperature, mean maximum temperature and mean minimum temperature have increased at the rate of 0.42, 0.92 and 0.09°C (100 year)^-1, respectively. On a regional basis, stations of southern and western India show a rising trend of 1.06 and 0.36°C (100 year)^-1, respectively, while stations of the north Indian plains show a falling trend of –0.38°C (100 year)^-1. The seasonal mean temperature has increased by 0.94°C (100 year)^-1 for the post-monsoon season and by 1.1°C (100 year)^-1 for the winter season.  相似文献   

Climatic Trend of Cloud Amount Related to the Aerosol Characteristics in Beijing During 1950-2005     

WANG Jizhi  YANG Yuanqin  ZHANG Guangzhi  YU Shuqi 《Acta Meteorologica Sinica》2010,24(6):762-775

This paper analyzes the correlation between variations of total and low cloud amounts and the varying features of aerosols related to urban development of Beijing by using the cubic spline fitting method based on the monthly meteorological data of temperature,humidity,precipitation,clouds,and aerosol optical depth (AOD) during 1950-2005.The statistics on the development of the city of Beijing in this period,including the total industrial output,population,residential housing development,highway construct...  相似文献   

基于PSR模型的贵州矿山地质环境变化趋势分析     

杨涛毅  陈静  冷洋洋 《贵州地质》2012,29(3):204-209

矿产资源开发必然影响矿山地质环境。研究矿山地质环境的变化趋势,有利于预防矿山地质环境的恶化和矿山地质环境问题恢复治理。采集贵州矿山地质环境现状、对矿山恢复的有利因素和不利因素,用基于PRS模型分析了全省矿山地质环境未来变化趋势,得出在未来较长时期矿山地质环境会有较大变化,且是向好的方向转化的结论,但变化速度不会太快,矿山地质环境恢复治理工作仍很艰巨。  相似文献   

低渗透变形介质渗透率时变效应规律及对油田开发的影响     

高永利  张志国 《地质科技情报》2012,31(3):70-72

针对低渗透油田开发过程中存在的时变效应,以室内实验为基础,结合数值模拟方法研究了低渗透油藏渗透率时变效应规律及其对油田开发效果的影响.结果表明,上覆压力越大,渗透率时变伤害率越大,上覆压力增大至一定值之后,上覆压力的变化对渗透率伤害率的影响不大.渗透率越小,渗透率时变伤害率越大.当渗透率小于0.1×10-3 μm2时,渗透率时变伤害明显增大,同时难以恢复到原渗透率条件,裂缝性岩心时变伤害大且伤害后恢复更加困难.时变效应对渗透率的伤害主要集中在井筒附近,无因次半径越小,渗透率伤害越大;在相同的生产压差下,时变效应系数越大,油井产量越低.  相似文献   

多点地质统计学建模的发展趋势   总被引：2，自引：0，他引：2  

石书缘  尹艳树  冯文杰 《物探与化探》2012,36(4):655-660

从算法研究、训练图像处理和实际应用三个方面详细解剖了国内外多点地质统计学的发展历程,在此基础上,分析了多点地质统计学主流的几种算法的核心原理、适用范围及优缺点,以此来对储层建模的发展趋势作出展望。目前,多点地质统计学虽是随机建模的一种前沿研究热点,但由于其尚未成熟,仍需对建模算法进行研究。为此,在前人研究的基础上,重点分析了多点地质统计学的发展趋势：合理处理训练图像;合理利用软信息;选择合适的相似性方法;选择合适的标准化方法;合理利用平稳性;算法间的耦合;选择合适的过滤器;拓展缝洞型碳酸盐岩模拟。最后,提出多点地质统计学在储层建模方面,应从增加储层的模拟区域、提高模拟精度、扩大储层相的模拟范围和提高计算机模拟效率等方面进行改进。  相似文献   

分离重力区域场与局部场的Matlab趋势分析法          下载免费PDF全文

吴琼  秦丽丽 《甘肃地质》2012,(2):88-92

趋势分析法作为场分离的一种方法,当地形情况复杂、测区面积较大时,往往很难达到场分离的要求。文章通过改变多项式数学模型的阶次,选择最优的多项式数学模型进行趋势分析。通过对剖面趋势分析和曲面趋势分析的对比得知,在同一地质模型上剖面趋势分析效果较曲面趋势分析效果好,由此运用切割法将叠加异常数据直接截取,获得多个剖面进行趋势分析,再由剖面趋势分析得到曲面趋势分析。实验结果表明趋势分析效果理想,能达到场分离的要求。  相似文献   

国内外地质灾害长期变化的趋势     

杨建锋  张翠光  冯艳芳 《地质灾害与环境保护》2012,23(1):7-12

利用国际自然灾害数据库,分析全世界及典型国家地质灾害的变化规律。在此基础上,分析我国地质灾害的趋势和人类活动对地质灾害的影响,为我国地质灾害调查的宏观部署提供依据。世界范围内,地质灾害随经济社会的发展呈上升趋势,对经济社会的负面影响亦呈加大态势。国内从上世纪九十年代中期开始地质灾害进入频发状态,所导致的人员伤亡和经济损失尚未得到有效遏制。  相似文献   

我国地质找矿钻探技术装备现状及发展趋势分析          下载免费PDF全文

张林霞  李艺  周红军 《探矿工程》2012,39(2):1-8

在对我国地质找矿钻探技术装备发展经济环境分析的基础上,通过调研和统计数据,分析了我国地质找矿钻探技术和装备的现状及发展趋势,包括岩心钻机的生产、销售和使用情况,煤层气钻机的现状,施工单位对新技术、新装备的需求等。提出了我国地质找矿钻探技术及装备发展的建议。  相似文献   

基于县域单元的湖北省碳排放时空格局演变特征     

周玄德  窦文章  詹庆明  孜比布拉·司马义  邓祖涛  曾勇 《测绘通报》2022,(11):149

识别碳排放区域异质性对于制定有效的碳减排政策具有重要意义。本文运用线性回归模型、变异系数法、Hurst指数和空间自相关分析方法,开展湖北省县域碳排放空间格局演变特征研究。结果表明,1997-2017年间,湖北省碳排放总体呈显著的波动上升趋势,年均增速高达4.74%;各县域碳排放变化波动性存在显著地域差异,整体呈“中低波动居多,高波动较少”的趋势;各县域碳排放变化长期相关性特征明显,整体以中强持续性特征为主,比例达70%,分布相对较广,其中强持续性区域主要集中在武汉市内;各县域碳排放空间分布聚集效应显著,呈以武汉为核心向周围不断辐射的圈层格局。  相似文献