1960～2017年华北地区气候生长季变化特征及成因分析

基于华北地区1960~2017年逐日气温数据,运用Mann-Kendall非参数检验、Morlet小波分析和R/S分析等方法,分析了华北地区气候生长季指标生长季开始（GSS）、生长季结束（GSE）、生长季长度（GSL）、生长季内≥10℃活动积温（AT10）及其对应的天数（DT10）的时空变化特征及其影响因素。结果表明:① 华北地区GSS呈显著的提前趋势,变化速率为-2.43 d/10a,GSL呈现出明显延长,AT10和DT10表现为显著增加趋势,变化速率分别为2.95 d/10 a、67.14℃/10a和2.31 d/10a,GSE变化趋势不明显。近60 a来华北地区GSL的延长主要归因于GSS的明显提前。② 生长季指标变化趋势在空间上存在明显差异,其中GSS与GSL,AT10与DT10变化趋势的空间分布格局较为相似。③ 生长季指标普遍在20世纪90年代中后期发生了明显的突变,GSS、GSE和GSL的突变年份为1994~1995年,AT10和DT10的突变年份为1997~1998年。④ 近60 a来华北地区生长季指标变化存在着2~3 a、5~6 a的主周期。生长季指标Hurst指数都大于0.7,表现为较强的持续性,其过去变化趋势将在未来继续延续。⑤ 北大西洋年代际振荡指数（AMO）是影响近60 a来华北地区生长季指标（GSS、GSE与AT10）变化的主要大气环流因子。     

Changes in concentration–discharge regression parameters due to coal mining and reclamation activities / Changements dans les paramètres de régression entre concentration et débit,causés par l’exploitation minière de charbon et des activités de reconversion

Abstract

Abstract Assessment of the impacts of mining and reclamation, and design of management practices to reduce chemical loads in stream channels, require knowledge of changing hydrological conditions and of changing sources and rates of release of chemicals into stream waters. One simple method for evaluating these impacts is to combine flow duration curves with regression relations between surface-water chemical concentrations (C) and instantaneous discharge (Q). However, little is known regarding the drainage basin-scale effects of mining and reclaiming drainage basins on regression relations. These effects were assessed on three small experimental drainage basins in Ohio subjected to surface mining for coal. Comparisons were made between regression parameter changes for natural/undisturbed conditions, land disturbances caused by mining and reclamation, incomplete reclamation, and the final condition of the reclaimed drainage basins. Regression analysis used a total of 5047 laboratory analyses of 36 constituents. Of 429 regressions, 153 (36%) were statistically significant. Knowledge of changes in regression parameters is important because regressions supply information on the rate of release and supply of chemical constituents in mined and reclaimed drainage basins. Duration curves of concentration and loads can be constructed using these regressions with flow–duration curves to give estimates of the percentage of time that concentrations and loads are exceeded during different phases of disturbance. This study assessed the changes in regression relations due to mining coal seams and reclamation activities for 36 chemical constituents, two mining methods, three reclamation practices and three distinct geologic settings.     

Seasonal and ontogenetic patterns of habitat use in coral reef fish juveniles

We investigated the diversity of patterns of habitat use by juveniles of coral reef fishes according to seasons and at two spatial scales (10–100 m and 1–10 km). We conducted underwater visual censuses in New Caledonia's Lagoon between 1986 and 2001. Co-inertia analyses highlighted the importance of mid-shelf habitats at large spatial scale (1–10 km) and of sandy and vegetated habitats at small spatial scale (10–100 m) for most juveniles. Among all juvenile species, 53% used different habitats across seasons (e.g. Lutjanus fulviflamma and Siganus argenteus) and 39% used different habitats as they grow (e.g. Lethrinus atkinsoni and Scarus ghobban). During their ontogeny, at large and small scales, respectively, 21% and 33% of the species studied showed an increase in the number of habitats used (e.g. L. fulviflamma, L. atkinsoni), 10% and 3% showed a decrease in the number of habitats used (e.g. Amphiprion melanopus, Siganus fuscescens), 23% and 3% showed a drastic change of habitat used (e.g. S. ghobban, Scarus sp.) whereas 46% and 61% showed no change of habitat used (e.g. Lethrinus genivittatus, Ctenochaetus striatus). Changes in habitat use at both small and large spatial scales occurred during the ontogeny of several species (e.g. S. ghobban, Scarus sp.). Results pointed out the different spatial and temporal scales of juvenile habitat use to account for in conservation decisions regarding both assemblage and species-specific levels.     

2001-2002年广西冬作季气候及对农业生产的影响

阐述 2 0 0 1- 2 0 0 2年广西冬作季 (2 0 0 1年 11月 - 2 0 0 2年 3月 )的气候状况 ,并就其对农业生产的影响作出分析、评价。     

The use of geometric and gamma-related distributions for frequency analysis of water deficit

This paper presents an approach to perform statistical frequency analysis of water deficit duration and severity using respectively the geometric and exponential distributions. Monthly mean water discharges are compared to a given threshold and classified in two mutually exclusive ways. This leads to a two state random variable such that: a success represents the absence of a water deficit event (mean monthly discharge exceeds threshold), and a failure, a water deficit event (mean monthly discharge is below threshold). If we suppose that this random variable gives rise to a Markov process of order 1, then the duration of a water deficit event X (consecutive months in deficit) will have a geometric distribution. In turn, the summation of discharges in deficit will give the severity of a water deficit event which can be represented by a one-parameter exponential distribution. The threshold or base level is taken as a percentile of the observed mean discharges of a given month. This base level, which varies from month to month, can be viewed as the limit of an acceptable deficit (or energetic failure) associated to a given empirical probability of being in deficit. The second step of the approach is to estimate the value of the parameter for each distribution using the maximum likelihood method. Expressions for the estimator of a given percentile, , as well as its variance are deduced. Finally, the presented models are applied to observed data.     

洪水频率分析中PDS模型研究进展

为了从实测洪水资料中获取更多的信息,提出PDS(Partial duration series)洪水频率分析模型并得到发展。介绍了PDS模型及其导出的AMS(Annual Maximal Series)模型的基本理论,综述了两种模型之间的比较研究。总结了PDS模型应用的关键技术,包括独立性判别、阈值的选取、超定量次数概率分布的选择。描述了PDS模型在区域洪水频率分析、PDS模型与贝叶斯理论结合研究的新进展,展望了PDS模型进一步研究的前景。     

近40年中国气候生长期的变化

利用中国642个站点1961~2000年的逐日平均气温记录, 分析研究了中国1961~2000年气候生长期的变化趋势。结果表明, 在近40年中, 气候生长期在全国范围平均增加了6.6天, 北方地区平均增加10.2天, 南方地区平均增加4.2天, 青藏高原增加最多, 达到18.2天。20世纪90年代是气候生长期增加最大, 增长最明显的时期, 1998年是近40年气候生长期最长的年份。对气候生长期变化趋势空间分布特点的进一步分析表明, 华北和青藏高原北部是气候生长期增加最大, 增长最明显的地区, 尤其以河北省和青海西北部最为显著。南方各省份除了四川西北、云贵高原、安徽、江苏外, 其它地区的气候生长期变化趋势不明显。     

卫星云图和数值产品结合的讯期强降水预警系统

本文采用卫星云图分析和数值产品释用相结合的技术路线，对汛期强降水在红外云图、水汽图、可见光云图上的特征从形态学、统计学等方面进行了研究，获得了汛期强降水云团的特征结构，并结合数值预报产品，建立了汛期强降水云团预警系统。     

1961-2010年黑龙江省太阳能资源特征分析与评估

利用1961-2010年黑龙江省5个辐射站和32个地面基准站资料,分析黑龙江省太阳能资源的时空分布特征,并从太阳能资源丰富度及资源稳定性等方面进行资源评估。结果表明：黑龙江省年均太阳总辐射显著减少,1月和12月减少最明显,20世纪70年代太阳辐射最强,80年代最弱;总辐射和日照时数的空间分布呈西丰(多)东贫(少)的趋势。全省太阳能资源的稳定性较高,其中松嫩平原西部的太阳能资源最丰富、稳定性最高,适合集中建设大型太阳能电站。     

THE RELATIONSHIP BETWEEN SOUTH CHINA SEA SOUTHWEST MONSOON ANOMALIES AND IMPORTANT WEATHER IN GUANGDONG PROVINCE DURING THE RAINING SEASONS

The activity of South China Sea southwest monsoon (SCSSM) has direct impacts on the anomalies of important weather in Guangdong province during the raining seasons. So it is necessary to explore thoroughly the activity pattern of SCSSM and its relationship with important weather anomalies in the province. In this paper, the methods of composite analysis and correlation statistics are used to study the relationship between the onset date and intensity of SCSSM and the important weather, such as precipitation trends in Guangdong province during the annually first and second raining seasons, the timing of the annually first and last typhoon and the number of typhoons landing in Guangdong province. The results show that the rainfall is less than normal during the first raining season, but more than normal during the second one and there are more tropical cyclones landing in Guangdong province in the years of early SCSSM onset. The rainfall is more than normal during the second raining season and there are more tropical cyclones landing in Guangdong province in the years of strong SCSSM. The relationship between the SST of April - June, July - September and previous winter (December - February) and 500 hPa geopotential height and the onset date and intensity of SCSSM is analyzed. Some mechanisms between the onset dates and intensity of SCSSM and the important weather anomalies in Guangdong province are preliminarily explored. The results can be used for reference in short-term climate forecast.