Research Progress of Relative Humidity and Its Changing Annual Cycle

Studies on the characteristics of relative humidity annual cycle change include the frequency, phase, and amplitude of the time series and their changes. The effective diagnosis of the relative humidity annual cycle can provide important help in the monitoring and regulation of seasonal haze, the spatial distribution of epidemic outbreaks and their prevention and control, and the real-time forecasting and decision-making of monsoon precipitation. Different from studies on the trend of the relative humidity, the diagnosis in the annual cycle is scarce. This paper summarized the research status of relative humidity and its annual cycle, introduced several current methods for extracting common signals, and evaluated the feasibility of these methods for extracting annual cycle signals. Due to the time-varying characteristics of the annual cycle of relative humidity and complex structures such as asymmetric triangular waves, square-like waves, and state transients, harmonic-based extraction methods are difficult to succeed. The nonlinear signal extraction method with high noise immunity will solve this problem. At present, the relative humidity annual cycle studies urgently need to be improved and improve the quality of relative humidity observation data, accurately extract and quantify the time-varying characteristics and complex structure of the annual cycle. Moreover, combining the dynamic process and statistical analysis, we also need to study the physical mechanism of the change of relative humidity annual cycle (frequency, phase, amplitude, etc.) in China.     

Recent Sea Level and Sea Surface Temperature Changes Along the Maldives Coast

Maldives, a South Asian small island nation in the northern part of the Indian Ocean is extremely vulnerable to the impacts of Sea Level Rise (SLR) due to its low altitude from the mean sea level. This artricle attempts to estimate the recent rates of SLR in Maldives during different seasons of the year with the help of existing tidal data recorded in the Maldives coast. Corresponding Sea Surface Temperature (SST) trends, utilizing reliable satellite climatology, have also been obtained. The relationships between the SST and mean sea level have been comprehensively investigated. Results show that recent sea level trends in the Maldives coast are very high. At Male, the capital of the Republic of Maldives, the rising rates of Mean Tidal Level (MTL) are: 8.5, 7.6, and 5.8 mm/year during the postmonsoon (October-December), Premonsoon (March-May) and southwest monsoon (June-September) seasons respectively. At Gan, a station very close to the equator, the increasing rate of MTL is maximum during the period from June to September (which is 6.2 mm/year). These rising trends in MTL along the Maldives coast are certainly alarming for this small developing island nation, which is hardly one meter above the mean sea level. Thus there is a need for careful monitoring of future sea level changes in the Maldives coast. The trends presented are based on the available time-series of MTL for the Maldives coast, which are rather short. These trends need not necessarily reflect the long-term scenario. SST in the Maldives coast has also registered significant increasing trend during the period from June to September. There are large seasonal variations in the SST trends at Gan but SST and MTL trends at Male are consistently increasing during all the seasons and the rising rates are very high. The interannual mode of variation is prominent both in SST as well as MTL. Annual profile of MTL along the Maldives coast is bimodal, having two maxima during April and July. The April Mode is by far the dominant one. The SST appears to be the main factor governing the sea level variations along the Maldives coast. The influence of SST and sea level is more near the equatorial region (i.e., at Gan). There is lag of about two months for the maximum influence of SST on the sea level. The correlation coefficient between the smoothed SST and mean tidal level at Gan with lag of two months is as high as ~ +0.8, which is highly significant. The corresponding correlation coefficients at Male with the lags of one and two months are +0.5 and +0.3, respectively. Thus, the important finding of the present work for the Maldives coast is the dominance of SST factor in sea level variation, especially near the region close to the equator.     

秦岭主脊区年降水量空间插值最优方法研究

利用ARCGIS软件,以研究区多年平均年降水量为数据源,开展以下研究：（1）采用反距离权重法、普通（泛）克里金法、样条函数法和趋势面法进行直接内插。（2）利用降水量随海拔递增率,再次利用以上方法进行插值。（3）分析站点数量的变化对插值精度的影响。（4）分析插值空间尺度变化对插值精度的影响。针对插值结果,使用交叉验证法来评估插值方法的优劣,旨在找出研究区年降水量空间插值的最优方法。结果表明：（1）研究区多年降水量与纬度呈现出很好的负相关,与其他各地理环境因子相关性很差或无相关性。（2）考虑降水随海拔的递增率后,研究区南坡西段和研究区海拔<600 m和>800 m的大部分观测站的空间内插精度得到有效提高,其它区域以及其它海拔区间的插值精度反而降低,因此使用单一线性数据作为整个研究区降水随海拔的变化率不够科学和严谨。（3）在缺少研究区不同剖面降水观测资料的情况下,权重为0.001 的正规则样条函数法是最优插值方法。（4）像元尺度在50～1 000 m间的变化对降水插值的不确定影响甚微;插值精度与选取的插值点个数无明显相关性,当站点个数为20个时,插值精度最高。     

湖北省宣恩县罗家沟滑坡风险评价实例研究

近年来大比例尺单体滑坡灾害风险研究是滑坡研究领域的重点及难点,本文以湖北省宣恩县罗家沟滑坡为例,研究了不同降雨工况下（10年、20年、50年）的滑坡破坏概率,在承灾体详细现场调查的基础上,采用定性方法确定滑坡影响范围内不同区域承灾体易损性,定量计算了不同降雨工况下滑坡人员、经济总风险,并利用年超越概率方法计算了滑坡人员与经济的年风险值;最后结合遥感影像数据,以ARCGIS系统为平台制作三维数字模型直观展示了滑坡不同降雨工况下房屋、人员风险的变化情况。结果显示,滑坡风险值在10年和20年一遇暴雨工况下相近,50年一遇暴雨工况下,滑坡破坏概率增大,滑坡总风险值随之增大。     

What factors affect the decision making process when setting TACs?: The case of Chilean fisheries

Although failures and successes in fisheries management are related to decision making processes, these are rarely analyzed in detail and even less often following quantitative or semi-quantitative approaches. Herein, we study the decision making process for Chile's most important fisheries using a binary decision model. This model evaluates the probability that an annual total allowable catch (TAC) will or will not be modified by the National Fisheries Council (NFC) based on biological, economic, and social factors. We also analyze some aspects of individual voting, particularly whether the members vote against or abstain from voting on the proposed TAC and if they prioritize resource conservation objectives. Our results indicate that the risk of over exploitation for many important stocks in Chile is aggravated by failures at the decision making level: the scientifically recommended TACs for those fisheries that generate higher levels of employment and have greater economic value are normally increased. This analysis shows that the NFC has clearly prioritized short-term economic and social objectives over resource conservation goals. We discuss the need to adjust the composition and functioning of the NFC in order to ensure long-term sustainability of the fisheries.     

中国水资源年景评估方法及其应用研究

根据产水模数及水资源利用率两项指标 ,将我国水资源状况分为三类 :常年缺水区、旱年缺水区、常年不缺水区 ,确定北方地区为水资源评估业务服务的重点地区。为实现年水资源的定量评估 ,利用降水历史资料和水资源总量资料 ,根据水资源总量、产水系数与降水的关系 ,建立了全国及各省 (市、区 )年水资源总量的评估模型 ,并形成水资源年景评估业务系统。     

中国西北干旱区年降水量非线性动力模式预测试验

利用中国西北干旱区16个代表站年降水量序列,引入非线性动力模式对年降水量做了非独立样本和独立样本预测试验。对模式参数及非线性函数的选取做了一些改进和探讨。初步结果表明,模式能较好地拟合降水量变化趋势和具有一定的预测能力。预测效果优于自回归模式。     

乌塘鳢Bostrichthys sinensis（Lacépède）的年龄研究

研究乌塘鳢年龄的鉴定材料采用胸鳍支鳍骨。结果表明：胸鳍支鳍骨上骨化环的数目与年轮数目相一致，体长频率分布与各年龄组体长分布曲线基本相符。用胸鳍支鳍骨的骨化环来鉴定乌塘鳢的年龄是可信的。     

洮河径流时空变化分析

依据洮河流域红旗站1956～2005年逐月径流量资料,采用Kendall检验法、线性趋势分析法、累积距平法,分析洮河流域径流的时空变化规律,重点探讨不同时间段月径流的变化和季节性变化特征,并对径流减少的成因以及汛期各月出现不同频率洪水的可能性进行了分析,得出如下结论：洮河径流呈现年际变化大、年内分配不均匀、季节性突出和周期性明显的特点,较大以上洪水主要发生在8—9月份,出现的概率为5．4％。