Level of Implementation of Seasonal Malaria Chemoprevention in Children Aged between 3 to 59 Months in Koza, Far North Region of Cameroon

Background: Seasonal Malaria Chemoprevention (SMC) is a strategy put in place by World Health Organisation (WHO) to fight against malaria in zones of high seasonal malaria transmission since the year 2012. This strategy has been implemented in the Far North and North regions of Cameroon since the year 2016. Despite the implementation of this program the number of cases and deaths from seasonal malaria among the under 5 seems to be rising in Koza health area. Objective: To determine the level of implementation of the SMC Program and its impact on the mortality of children aged 03 to 59 months during the season of high transmission. Methods: This was a community-based cross-sectional and 7-years retrospective study. Data was surveyed for 3 months in 3 health areas of Koza health area. Data were collected and typed in Kobo collect, cleaned in MS Excel and analyzed in SPSS version 25 to come out with descriptive statistics. Results: Among the 172 households, female children were mostly represented 99 (57%) The age group mostly represented was 2 years. The population knowledge on SMC’s overall score was above average. The overall coverage rate (4 cycles) was 84% from interviewed parents and 67.5% from SMC cards. More than 23% of children experienced at least one side effect with the most common being vomiting (72%). The population’s overall impression of the program was good at 85%. The trends SMC coverage showed a sinusoidal fluctuation from 2015 to 2021, 2016 to 2019 and 2020 to 2021. Conclusion: The coverage rate of SMC was high thus the program is well implemented.

Characteristics and possible causes of the seasonal sea level anomaly along the South China Sea coast

Based on sea level, air temperature, sea surface temperature（SST）, air pressure and wind data during 1980–2014,this paper uses Morlet wavelet transform, Estuarine Coastal Ocean Model（ECOM） and so on to investigate the characteristics and possible causes of seasonal sea level anomalies along the South China Sea（SCS） coast. The research results show that：（1） Seasonal sea level anomalies often occur from January to February and from June to October. The frequency of sea level anomalies is the most in August, showing a growing trend in recent years. In addition, the occurring frequency of negative sea level anomaly accounts for 50% of the total abnormal number.（2） The seasonal sea level anomalies are closely related to ENSO events. The negative anomalies always occurred during the El Ni？o events, while the positive anomalies occurred during the La Ni？a（late El Ni？o） events. In addition, the seasonal sea level oscillation periods of 4–7 a associated with ENSO are the strongest in winter, with the amplitude over 2 cm.（3） Abnormal wind is an important factor to affect the seasonal sea level anomalies in the coastal region of the SCS. Wind-driven sea level height（SSH） is basically consistent with the seasonal sea level anomalies. Moreover, the influence of the tropical cyclone in the coastal region of the SCS is concentrated in summer and autumn, contributing to the seasonal sea level anomalies.（4） Seasonal variations of sea level, SST and air temperature are basically consistent along the coast of the SCS, but the seasonal sea level anomalies have no much correlation with the SST and air temperature.

Water Security-based Hydrological Regime Assessment Method for Lakes with Extreme Seasonal Water Level Fluctuations：A Case Study of Poyang Lake,China

Extreme seasonal water level fluctuations characterize natural floodplain lakes in monsoon regions, which are crucial for ensuring lake water security, including flood prevention water supply and health of aquatic ecosystem. In order to achieve this goal, we established a hydrological regime assessment method based on a set of hydrological indicators for lakes with heavy seasonal water level fluctuations. The results suggest that time-sensitive hydrological indicators and specific time scales for various water security aspects must be considered. We discovered that it is more practical and meaningful to combine the water level classification derived from statistical analyses with characteristic hydrological values linked to water security. The case study of Poyang Lake results show that there are no discernable trends of Poyang Lake water regime status over the last 35 years, and the two periods of poor status are in accordance with climate variation in the lake basin area. Scholars and policy makers should focus on both floods and droughts, which are the main water security problems for Poyang Lake. It is hoped that this multi-scale and multi-element hydrological regime assessment method will provide new guidelines and methods for other international scholars of river and lake water assessment.

Seasonal Change of Steric Sea Level in the GIN Seas

The Greenland Sea,Iceland Sea,and Norwegian Sea (GIN seas) form the main channel connecting the Arctic Ocean with other Oceans,where significant water and energy exchange take place,and play an important role in global climate change.In this study steric sea level,associated with temperature and salinity,in the GIN seas is examined based on analysis of the monthly temperature and salinity fields from Polar science center Hydrographic Climatology (PHC3.0).A method proposed by Tabata et al.is used to calculate steric sea level,in which,steric sea level change due to thermal expansion and haline contraction is termed as the thermosteric component (TC) and the halosteric component (SC),recpectively.Total steric sea level (TSSL) change is the sum of TC and SC.The study shows that SC is making more contributions than TC to the seasonal change of TSSL in the Greenland Sea,whereas TC contributes more in the Norwegian and the Iceland Seas.Annual variation of TSSL is larger than 50 mm over most regions of the GIN Seas,and can be larger than 200 mm at some locations such as 308 mm at 76.5 N,12.5 E and 246 mm at 77.5 N,17.5 W.

Seasonal responses of monthly mean sea levels in the Bohai Sea to hydrometeorological forcing and their double screening regression models

-In this paper, the maximum entropy spectral, the cross-spectral and the frequency response analyses are madeon the basis of the data of monthly mean sea levels at coastal stations in the Bohai Sea during 1965-1986. The results show that the annual fluctuations of the monthly mean sea levels in the Bohai Sea are the results of the coupling response of seasonal variations of the marine hydrometeorological factors. Furthermore, the regression prediction equation is obtained by using the double screening stepwise regression analysis method . Through the prediction test , it is proved that the obtained results are desirable.

Modeling Seasonal Fractionally Integrated Autoregressive Moving Average-Generalized Autoregressive Conditional Heteroscedasticity Model with Seasonal Level Shift Intervention

This paper introduces the class of seasonal fractionally integrated autoregressive moving average-generalized conditional heteroskedastisticty (SARFIMA- GARCH) models, with level shift type intervention that are capable of capturing simultaneously four key features of time series: seasonality, long range dependence, volatility and level shift. The main focus is on modeling seasonal level shift (SLS) in fractionally integrated and volatile processes. A natural extension of the seasonal level shift detection test of the mean for a realization of time series satisfying SLS-SARFIMA and SLS-GARCH models was derived. Test statistics that are useful to examine if seasonal level shift in an SARFIMA-GARCH model is statistically plausible were established. Estimation of SLS-SARFIMA and SLS-GARCH parameters was also considered.

基于氡同位素示踪的洞庭湖区枯水期湖水与地下水交互作用研究

洞庭湖区水系发达,水文地质条件复杂,人类活动强烈,地表水和地下水的水力联系变化频繁,其研究的难度以及由此造成的研究不足影响了对湖区地下水赋存和运动规律的深入认识。本文以洞庭湖整体为研究对象,采用水位动态分析和氡(222 Rn)同位素示踪法,定性和定量研究枯水期洞庭湖区地表水与地下水的交互作用关系与交互通量。枯水期洞庭湖区水位和氡浓度空间分布特征指示研究区内地下水向湖水排泄,尤以东洞庭湖最为显著。氡箱模型计算结果显示枯水期地下水排泄222 Rn通量为455.09 Bq/(m^(2)·d),占总输入222 Rn通量的60.07%,地下水排泄总量为0.29×10^(8)m^(3)/d,平均排泄速率为56.27 mm/d,地下水排泄对湖水的贡献率为7.04%。敏感性分析表明:风速、地下水和湖水222 Rn浓度以及湖面面积等参数较为敏感,合理布置取样点并提高敏感参数测量准确度能提高模型计算结果的可靠度。氡同位素示踪法物理意义明确、操作过程简便,是研究复杂区域地下水补、径、排特征的有效方法。研究成果一定程度上提供了洞庭湖区水量均衡的更多认识,可为洞庭湖区地下水资源评价和管理提供参考。

基于系统协调度模型的汛限水位分期控制

为协调防洪与兴利的矛盾,提高洪水资源化利用效益,基于改进模糊集方法进行汛期分期,建立系统协调度模型并计算得到汛限水位的动态控制域。以思林水库为例,前、后汛期的汛限水位与发电效益协同贡献度成正比,与防洪风险协同贡献度成反比;为实现系统协调度最大,前、后汛期的汛限水位动态控制域应分别为[435,437]m和[435,438]m,前、后汛期可分别增发电量2169.907×10^(4)、6509.722×10^(4)kW·h,水资源利用量可分别提高0.716×10^(8)、1.079×10^(8)m^(3)。研究成果可提高洪水资源利用效率,为水库安全合理运行提供参考。

考虑生态流量约束的梯级水库分期消落水位多目标优化调度

针对如何表征枯水期季节性特征、优化分期消落水位来指导水库群消落调度的科学问题,提出了考虑生态流量约束的梯级水库分期消落水位多目标优化调度模型。以金沙江中下游6座水库与三峡水库为研究对象,综合运用多种数理统计方法划分流域枯水期;采用逐月滑动计算法推求梯级水库分期消落水位;以生态和发电效益最大为目标函数,利用NSGA-Ⅱ算法求解调度模型,得到不同来水情景下梯级水库枯水期消落调度方案。研究结果表明:不同来水情景下,相较于常规调度方案,选定的优化调度方案可增加梯级水库发电量30.20亿~52.27亿kW·h(增加2.3%~5.0%)和供水量83.15亿~87.14亿m3(增加5.8%~7.4%),并提高河道生态流量保证率2.6%~22.9%。研究成果可为协调梯级水库生态和发电调度提供技术支撑。

梯级水库运行期设计洪水及水位联合优化调控变革与启示

我国水资源时空分布不均,年际、年内变差大,洪涝和干旱并存,流域防洪与兴利需求并重。随着大规模水库群建成投运,流域下垫面条件及产汇流机制明显变异,水库及引调水工程运行等人类活动对设计洪水影响显著,梯级水库群运行管理中如何分析和应用设计洪水成为亟待解决的新问题,水库群联合优化调控、水资源高效利用的现实要求十分迫切,已列入中国科学技术协会2023年十大产业技术问题。经过多年探索实践,我国在梯级水库运行期设计洪水及水位联合优化调控方面已取得一定研究进展和成果,但仍存在对暴雨洪水季节性变化规律认识不足、梯级水库群系统中各水库运行相互影响考虑不足、现代水文气象实时预报信息运用不足等问题,亟须系统开展运行期设计洪水及水位联合优化调控体系研究,实现风险可控条件下水资源高效利用,保障防洪安全、供水安全、能源安全、生态安全,推进新阶段经济社会高质量发展。

季冻区列车轨道附近的地面振动级分析

季节性冻土区的极寒气温改变了土体的剪切波速,列车引起的地表振动特征有待揭示。将负温相关的冻土动力学参数引入列车-轨道-层状场地耦合振动模型,计算了冬季不同气温、不同轨道距、不同车速条件下的地表振动级。结果表明:入冬后当气温未降至-8.7℃的阈值温度时,地面振动未受负温影响;随着气温继续下降,地面振动的中、高频成分受到明显抑制,低频成分受到的影响不大;气温越低,中、高频成分向远离轨道方向的衰减梯度越大;车速的提高可加剧地表振动,这个特征基本不受气温的影响。研究成果有助于深入理解季节性冻土地区轨道交通振动的传播规律,为减振技术开发提供有益的参考。

大型梯级水电站枯水期多模式优化调度模型研究

针对大型梯级水电站枯水期调度面临的市场环境复杂、枯汛转换期来水形势多变等难题,提出了梯级水电站调度决策多模式自适应匹配方法,分别建立“无(消落)压力环境”模式和“有(消落)压力环境”模式下的优化调度模型,根据预报信息自动选择和灵活切换调度模式和目标,生成各电站水位动态控制和灵活调整策略。结果表明:“无(消落)压力环境”模式下可使流域发电量增加2.57%;“有(消落)压力环境”的“均匀突破”模式和“集中突破”模式下分别可增加发电量4.59%、5.32%,前者面临无法消落到位的风险更小,后者发电效益更大。该模型可有效降低枯水期消落和发电风险,提升流域整体发电效益,对于不同来水、发电等工况均表现出较好的适应能力和优化效果。

重庆市向阳水库滑坡稳定性分析与评价

为研究近坝库岸滑坡堆积体对水库建筑物及附近居民安全的影响,采用基于极限平衡理论的传递系数法,查明重庆市向阳水库工程滑坡堆积体的稳定边界条件,对自重、自重+度汛水位由386 m降至367.24 m、自重+度汛水位由386 m降至367.24 m并叠加暴雨等3种工况下滑坡体的稳定性进行分析与评价。结果表明:该滑坡在3种工况下处于基本稳定、欠稳定和不稳定状态,结果与现场实地调查情况一致,建议采取工程治理措施。

基于汛期水位动态控制的洪水资源化利用研究

洪水是一种重要的水资源,洪水资源化利用在水资源较少地区显得尤为重要。以河北刘家台水库为例,通过HEC-HMS水文模型软件,对汛期水位动态控制的防洪效果以及地下水转换效率加以评价。结果显示,采用该方法后,海河流域部分河段5天可增加地下水量约9.02×10^(6) m^(3),多拦截洪水1.58×10^(8) m^(3),表明汛期动态水位控制具有良好削峰防洪作用,研究成果可为洪水资源化利用提供参考。

Global Sea Level Change and Thermal Contribution

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-uniform 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 due to temperature variation (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 thermal 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 TSL by 2 months in the zonal band of 40?–60? in both the northern and southern hemispheres. Systematic differences of about 1–2 cm 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 possible deviations in thermosteric contribution estimates and geophysical corrections to the TOPEX/Poseidon data.

基于SARIMA预警模型的水位监测效果分析与研究

为了提高城市水位监测的准确性及洪涝等灾害的预警能力,提出基于季节性自回归积分滑动平均(Seasonal auto-regressive integral moving average, SARIMA)模型的水位监测预警模型。该模型综合了自回归模型、移动平均模型和季节性差分模型,适用于分析和预测具有季节性和非平稳特征的时间序列数据。结果显示,基于SARIMA预警模型的水位监测系统,对城市周边的水位监测拟合效果较好,可对城市周边水位进行有效监测,提高应对城市内涝灾害的预警效果。

2000年以来贵州最强梅汛期降水异常成因分析

【目的】为揭示2000年以来贵州最强梅汛期降水异常成因。【方法】利用天擎降水资料挑选出了2000年以来贵州最强梅汛期年份及其降水特征,再利用NCEP/NCAR再分析资料及风云FY-2G黑体亮温(TBB)资料,诊断分析最强梅汛期贵州降水异常偏多的原因及极端降水成因。【结果】(1)2020年梅汛期贵州累计降水量是1961年以来的次多年,是2000年以来的降水最异常年份;暴雨集中在6月上旬—7月上旬,6月23日和29日降水强度具有极端性。(2)2020年梅汛期贵州频繁的暴雨过程及极端暴雨与江淮梅雨的大背景密不可分。(3)2020年梅汛期影响贵州的中尺度低涡系统频繁,中尺度对流系统十分活跃。这些中尺度系统大多初生于贵州西部,在贵州省内发展加强,并产生暴雨天气,MCC是6月23日及29日极端降水的直接影响系统。(4)2020年梅汛期低空急流异常活跃,尤其是6月下旬初、下旬末及7月上旬后期出现了3段持续时间长、强度强劲的低空急流,为梅汛期的持续性暴雨过程、范围最广的3次暴雨过程及极端暴雨提供了异常充沛的水汽条件。【结论】研究结果为进一步做好梅汛期持续性暴雨、致洪暴雨和极端暴雨预报提供了依据。

Changes in quality of groundwater with seasonal fluctuations: an example from Ghor Safi area, southern Dead Sea coastal aquifers, Jordan

The demand for water resources in the area south of the Dead Sea due to continued development, especially at the Arab Potash Company （APC） for production and domestic purposes necessitates that water quality in the area be monitored and evaluated based on the local geology and hydrogeology. The objective of this paper is to monitor seasonal fluctuations of groundwater and to determine how fluctuation in the water levels will affect the groundwater quality. Groundwater levels were found to be influenced by rainfall and pumping of water from the wells for domestic and industrial use. Twenty water samples were collected from different wells and analyzed for major chemical constituents both in pre- and post-seasons to determine the quality variation. Chemical constituents are significantly increased after post-season recharge. According to the overall assessment of the area, water quality was found to be useful for drinking, irrigation and industry.

Seasonal cycle of topography in the Bohai Sea and Yellow Sea and its relationships with atmospheric forcing and oceanic adjustment based on altimetry data

Seasonal cycle is the most significant signals of topography and circulation in the Bohai Sea (BS)and Yellow Sea (YS) forced by prevailing monsoon and is still poorly understood due to lack of data in their interiors. In the present study, seasonal cycles of topography in the BS and YS and its relationship with atmospheric forcing and oceanic adjustment were examined and discussed using TOPEX/Poseidon and ERS-1/2 Sea Level Anomalies (SLA) data. Analyses revealed complicated seasonal cycles of topography composed mainly of2 REOF modes, the winter-summer mode (WIM) and spring-autumn mode (SAM). The WIM with action center in the BS displayed peak and southward pressure gradient in July, and valley and northward pressure gradient in January, which is obviously the direct response to monsoon with about 1-month response time. The SAM with action center in the western south YS displayed peak and northward pressure gradient in October and valley and southward pressure gradient in April. After the mature period of monsoon, the action center in the BS became weakened while that in the western south YS became strengthened because of regional convergence or divergence induced by seasonal variations of the Taiwan Warm Current and Yellow Sea Coastal Current. The direct response of topography to monsoon resulted in the WIM, while oceanic adjustment of topography played an important role in the forming of the SAM.