Comparison of runoff characteristics of two adjacent basins in a tropical rainforest using a modified hydrologic cycle model with outflow

We propose a new runoff model including an outflow process that was applied to two adjacent basins (CL, TL) located in Lambir Hills National Park in north‐central Sarawak, Malaysia. Rainfall, runoff, topography, and soil layer thickness were observed. About 19% of annual runoff was observed in the CL basin (21.97 ha), whereas about 46% was observed in the TL basin (23.25 ha). It was inferred that the CL basin has an outflow because of low base flow, small runoff peak, and excessive water loss. By incorporating the outflow process into the HYdrological CYcle MODEL, good agreement between the data generated by the model and that observed was shown, with the exception of the data from the rainless period. Then, the fitting parameters for each basin were exchanged, except for the outflow parameter, and the characteristics of each basin were compared by calculating virtual runoff. As a result, the low base flow of the CL basin was estimated by the movement of the rainwater that escaped from the basin as deep percolation or lateral flow (11% of rainfall). The potential of the CL basin for mitigating flood and drought appeared to be higher than that of the TL basin. This is consistent with the topographic characteristics of the CL basin, which has a gentler slope than the TL basin. Copyright © 2012 John Wiley & Sons, Ltd.     

Tectono–Thermal Evolution, Hydrocarbon Filling and Accumulation Phases of the Hari Sag, in the Yingen–Ejinaqi Basin, Inner Mongolia, Northern China

This work restored the erosion thickness of the top surface of each Cretaceous formations penetrated by the typical well in the Hari sag, and simulated the subsidence burial history of this well with software BasinMod. It is firstly pointed out that the tectonic subsidence evolution of the Hari sag since the Cretaceous can be divided into four phases: initial subsidence phase, rapid subsidence phase,uplift and erosion phase, and stable slow subsidence phase. A detailed reconstruction of the tectonothermal evolution and hydrocarbon generation histories of typical well was undertaken using the EASY R_0% model, which is constrained by vitrinite reflectance(R_0) and homogenization temperatures of fluid inclusions. In the rapid subsidence phase, the peak period of hydrocarbon generation was reached at c.a.105.59 Ma with the increasing thermal evolution degree. A concomitant rapid increase in paleotemperatures occurred and reached a maximum geothermal gradient of about 43-45℃/km. The main hydrocarbon generation period ensued around 105.59-80.00 Ma and the greatest buried depth of the Hari sag was reached at c.a. 80.00 Ma, when the maximum paleo-temperature was over 180℃.Subsequently, the sag entered an uplift and erosion phase followed by a stable slow subsidence phase during which the temperature gradient, thermal evolution, and hydrocarbon generation decreased gradually. The hydrocarbon accumulation period was discussed based on homogenization temperatures of inclusions and it is believed that two periods of rapid hydrocarbon accumulation events occurred during the Cretaceous rapid subsidence phase. The first accumulation period observed in the Bayingebi Formation(K_1 b) occurred primarily around 105.59-103.50 Ma with temperatures of 125-150℃. The second accumulation period observed in the Suhongtu Formation(K_1 s) occurred primarily around84.00-80.00 Ma with temperatures of 120-130℃. The second is the major accumulation period, and the accumulation mainly occurred in the Late Cretaceous. The hydrocarbon accumulation process was comprehensively controlled by tectono-thermal evolution and hydrocarbon generation history. During the rapid subsidence phase, the paleo temperature and geothermal gradient increased rapidly and resulted in increasing thermal evolution extending into the peak period of hydrocarbon generation,which is the key reason for hydrocarbon filling and accumulation.     

汕头市PM2.5的气象要素影响分析及预报研究

利用2014—2017年汕头市PM_2.5的日浓度资料、以及汕头市国家基准气象观测站的同期地面气象资料,重点分析了汕头市PM_2.5浓度的变化特征以及风、混合层厚度、降水等气象条件对PM_2.5浓度的影响,同时探讨了污染物浓度变化的成因。在此基础上,根据汕头市的气候特点,采用BP （Back-Propagation）人工神经网络方法针对汛期和非汛期分别建立了PM_2.5质量浓度预报模型。结果表明：与多数内陆城市不同,汕头市PM_2.5浓度日变化为单峰型,这与汕头地处沿海受海陆风影响有关;PM_2.5浓度日峰值出现在08时左右,除早高峰污染物排放增加的因素外,与早晨时段的低风速环境有关;PM_2.5日均浓度随着风速的增大呈现减小趋势,PM_2.5日均浓度与08时混合层厚度显著相关（相关系数为-0.143）;汕头市非汛期PM_2.5浓度比汛期高,这与汕头市的亚热带季风气候特征有关,汛期各量级降水（暴雨以上除外）对PM_2.5的清除效果无明显差别,而非汛期降水对PM_2.5浓度有明显清除作用;BP人工神经网络模型的预报效果表明,汛期和非汛期的PM_2.5级别命中率TS分别为100%和90.3%,准确指数分别为87.7%和89.9%,总体预报效果良好。不同时期预报模型出现正误差的数量和程度均大于负误差,汛期预报模型在有强降水发生时误差较大,而非汛期预报模型在有冷空气入侵时误差较大。     

鄂西-渝东地区热史恢复及烃源岩成烃史

根据鄂西—渝东地区镜质体反射率数据进行的热史恢复结果表明:该区在晚二叠世初期达到最高古热流(可达68~78mW/m²,地表热流),从晚二叠世初到现今古热流持续降低,在侏罗纪末期古热流平均为~54mW/m²(地表热流);鄂西—渝东地区中生界与新生界之间不整合面的剥蚀量可达1700~4000m。成烃史研究表明:鄂西—渝东地区志留系烃源岩在晚志留世—早二叠世进入生油高峰,在早-中三叠世进入生气期,中侏罗世晚期进入过成熟干气阶段,快速生烃时期是在晚志留世、二叠纪—中三叠世及早-中侏罗世;而二叠系烃源岩在早三叠世进入生油门限,于中-晚三叠世达到生油高峰,在中-晚侏罗世进入生气期,晚侏罗世晚期进入过成熟,快速生烃时期是在早-中三叠世及侏罗纪。     

新公式计算岩层真厚度的Excel算法

使用软件1,将岩层序号、导线的方位和倾角、岩层的倾向、倾角和两层面切割导线处的读数分别输入A、F、G、H、I、J、K列,先后分别沿M、N列从第2行单元格开始拖动鼠标,岩层真厚度数据和累积厚度即刻计算出来,进一步可计岩组或岩性段的真厚度;将导线的序号、方位、倾角、长度分别输入W、X、Y、Z列,先后分别沿AB、AC、AD、AE、AF、AG、AH列,从第2行单元格开始拖动鼠标,导线的水平投影长度、纵座标增量及其累积值、横座标增量及其累积值、高程增量及其累积值即刻计算出来。使用软件2,在输入原始数据的同时,结果便计算出来。     

浅地层剖面交互拾取解释技术研究

浅地层剖面探测在海洋学研究与海洋工程调查中使用愈来愈频繁,剖面资料的解释工作变得越来越繁重。因浅地层剖面实际解释工作的需要,结合浅地层剖面资料的特点,研究并实现了剖面反射层位的自动拾取、利用Event号交互拾取特征点、等Ping间隔拾取、求取海底下反射层位厚度等解释功能,这些解释功能的实现加快了剖面解释工作的进度,提高了解释结果的精度,并在实际浅地层剖面资料解释工作中取得了良好的应用效果。     

Primary investigation of statistical correlation between changes in ice volume and area of glaciers

This study makes an attempt to investigate through statistical analysis the correlation between changes in ice volume and area of glaciers. Using data from nine sample glaciers in the Tian Shan, the results show that a linear relation exists between changes in ice volume and area, with a correlation coefficient of 0.700. However, the accuracy estimation is difficult due to the limited number of samples. The correlation was not improved after adding eleven glacier samples in other mountains. Two reference glaciers are then analyzed in more detail. The linear correlation coefficient is higher than 0.800 when using the observed changes in ice volume and area during different periods on Urumqi Glacier No. 1, which suggests that the linear relation is valid for one glacier for different periods if its shape does not change noticeably and also for other glaciers of the same shape during the same period. The relation between changes in ice volume and area of Qingbingtan Glacier No. 72 is different during different periods due to change in the shape of the glacier tongue and the influence of the debris cover. Moreover, errors in glacier-change monitoring and-volume estimation have an important influence on the correlation results. Therefore, further study needs to focus not only on the distinction between glacier types and between different periods but also on the accuracy of volume estimation.     

海面溢油无人机高光谱遥感检测与厚度估算方法

海上溢油是海洋国家所面临的共同问题,但至今仍没有一种可靠实用的海上溢油准确识别和油量遥感监测方法。为此,本文以无人机高光谱遥感为手段,开展了海面溢油检测与厚度估算方法研究。实验中,通过搭建室外大型水槽溢油实验装置,获取了模拟真实海洋环境条件下不同溢油量的遥感和现场光谱数据,在此基础上,分析并提取了海上溢油特征光谱波段,给出了海上溢油高光谱检测模型;针对现场实验条件下水面油膜厚度难以测定的问题,设计了3种利用总体溢油量的油膜厚度估算模型。得到如下主要结论:（1）675 nm和699 nm是海上溢油检测的有效特征波段,但对极薄的油膜没有检测能力;（2）提出了归一化溢油指数模型、反比例模型和吸收基线模型等3种海上溢油油膜厚度估算模型,其中对于薄油膜（厚度≤ 5 μm）和厚油膜（厚度>50 μm）,反比例模型是溢油厚度反演的首选也是唯一选择。对于中厚度油膜,晴朗天气条件下,归一化溢油指数模型是油膜厚度反演的首选,同时反比例模型和溢油吸收基线模型也都有较好的反演能力,而在多云天气条件下,反比例模型效果最佳。     

A stochastic method for the prediction of icebreaker bow extreme stresses

It is well established that the ship-ice interaction process is quite complex and associated ice loads on the icebreaker hull is a stochastic process. Obviously, novel accurate statistical methods and models should be developed and applied to estimate extreme bow stresses.This paper studies icebreaker bow stresses based on measured distribution of ice thickness in the Arctic Ocean on the way to and from the North Pole. Since the vessel route was carefully selected searching for easier ice conditions, the Arctic Ocean crossing was not a straight linear but a meandering path. Thus, the specific ship route data was biased with respect to general ice statistics in the region, but true with respect to the route specific ice data encountered by a ship navigating in that region. Therefore the route specific ice thickness data is directly needed for ship design and navigation analysis. It is assumed that captains are competent and knowledgeable, and therefore will select a route that provides the most favourable ice conditions.This paper contributes to study of the newest Chinese self-designed polar icebreaker, serving the purpose of enhancing icebreaker operational reliability. Finite Element Method software package ANSYS/LS-DYNA has been employed to simulate bow stress pattern for a particular icebreaker operating in the Arctic Ocean. Extreme bow stresses were estimated using Naess-Gaidai method. The latter is a first application of Naess-Gaidai method to a distribution with lower bound. Thus this paper aims at introducing an efficient method of estimating route-specific icebreaker extreme bow stresses.     

赤道东印度洋和孟加拉湾障碍层厚度的季节内和准半年变化

利用2002—2015年ARGO网格化的温度、盐度数据, 结合卫星资料揭示了赤道东印度洋和孟加拉湾障碍层厚度的季节内和准半年变化特征, 探讨了其变化机制。结果表明, 障碍层厚度变化的两个高值区域出现在赤道东印度洋和孟加拉湾北部。在赤道区域, 障碍层同时受到等温层和混合层变化的影响, 5—7月和11—1月受西风驱动, Wyrtki急流携带阿拉伯海的高盐水与表层的淡水形成盐度层结, 同时西风驱动的下沉Kelvin波加深了等温层, 混合层与等温层分离, 障碍层形成。在湾内, 充沛的降雨和径流带来的大量淡水产生很强的盐度层结, 混合层全年都非常浅, 障碍层季节内变化和准半年变化主要受等温层深度变化的影响。上述两个区域障碍层变化存在关联, 季节内和准半年周期的赤道纬向风驱动的波动过程是它们存在联系的根本原因。赤道东印度洋地区的西风(东风)强迫出向东传的下沉(上升)的Kelvin波, 在苏门答腊岛西岸转变为沿岸Kelvin波向北传到孟加拉湾的东边界和北边界, 并且在缅甸的伊洛瓦底江三角洲顶部(95°E, 16°N)激发出向西的Rossby波, 造成湾内等温层深度的正(负)异常, 波动传播的速度决定了湾内的变化过程滞后于赤道区域1~2个月。