River flow forecasting system with data management,graphical river network control and interactive operation

Abstract

The feasibility and success of a forecasting system depend on many factors. Although the models may be of the highest accuracy, they cannot make a forecasting system effective without a well organized database and interpretable output. The interaction between the processes of data management, computation and output presentation should be dynamic. A complete river forecasting system for IBM (or compatible) personal computers aimed at meeting the above demands has been developed at the Department of Hydrology of Uppsala University. The program package sets up the river network, stores a database for it, supplies the appropriate data for a wide choice of forecasting models, and gives interpretable output. The functions are supported by screen graphics. The paper presents this system, the most important points of the algorithms, and an example application.     

余震的序列参数稳定性和余震短期发生率预测效能的连续评估——以2014年云南鲁甸6.5级地震为例

为考察目前国际上广泛使用、对真实地震序列描述最好的"传染型余震序列模型"(ETAS)在主震后的序列参数拟合、余震短期发生率预测的效能,本研究以2014年云南鲁甸MS6.5地震序列为例,采用滑动连续拟合与预测的方式,考察了ETAS模型参数的动态变化和余震短期发生率预测的实际效能.连续滑动拟合结果表明,在主震发生后的早期阶段,α值有明显的不稳定变化,在震后5.10天稳定在1.6~2.0;p值在震后25.00天内由1.07逐渐下降至0.78左右,其后稳定在0.72~0.85;b值在震后35.00天内逐渐由0.80增加至0.95,其后稳定在0.93~0.97.对连续滑动预测结果的N-test检验表明,余震发生率预测会出现部分失效现象,1天预测时间窗失效比例约为12%、3天预测时间窗失效比例为6%.建议可在震后早期采用1天的较短预测时间窗,而在序列参数较为稳定时段采用较长的3天预测时间窗.     

云南年度危险区预测能力的统计分析

通过对云南省地震局1989—2006年度地震趋势研究报告中年度预测水平、 危险区圈定和实际发生地震情况等统计分析, 结果显示云南地区每年发生2.8组M≥5地震, 3年发生2组M≥6地震, 发震的自然概率较高, 1989年以来年度地震活动水平预测为M≥6的对应率较高, 达到了56%。 危险区的预测不能用异常数量的多少来判定, 对于M≥6地震, 应用4级地震频度增长显著的区域和高水位异常区域等指标能更好的预测危险区。 5级地震在云南地区有的时候异常出现最多就是2～3个月就发震, 年度很难用异常判断级地震的危险区, 但5级地震也存在10年左右的主体活动地区迁移现象, 利用主体活动地区的特征可以提高5级地震发生区域的预测能力。 年度应重点跟踪M≥6地震, 由于云南地区6级以上地震发生前中小地震活动增长和前兆异常出现后, 对应地震的时间从几个月到3年不等, 但半年尺度前兆异常数量增加显著, 因此在看到地震活动增强后动态跟踪前兆的变化, 采用长、 中、 短、 临渐进式的预报方式, 仍然是目前提高地震预报效能最有效的途径。     

中国大陆地震低活动异常及其在中期预测中的效能研究

在对中国大陆地震活动的分析研究中发现, 在某些大地震发生前的一、 两年中, 中国大陆往往出现地震活动显著平静的低活动异常。 本文应用最近100 a(1918—2017年)间5级以上地震资料, 分析地震低活动异常与未来一、 两年中国大陆地震活动的关系。 从M≥5.0地震的年频度、 年度最大地震震级、 6级以上地震的平静等方面建立了地震低活动异常的判据指标, 并从概率增益指数β、 预测效能比α、 地震预测R值评分等方面对地震低活动异常与未来大震关系作了多参数检验。 初步研究结果显示, 地震低活动异常与未来一、 两年中国大陆地震活动有一定的关系, 主要表现为其与8级左右(M≥7.8)巨大地震具有一定的相关性, 但其关联度较低, 概率增益指数β与预测效能比α为3左右, R值评分为0.2左右。 对于M＜7.5的地震, 地震低活动异常未显示, 其概率增益β, R值评分接近于0, 似呈现为近于随机关系。 M7.5是开始显示地震低活动异常与其有一定相关性的转折点。     

DEVELOPMENT OF A DECISION SUPPORT SYSTEM FOR MANAGING PESTICIDE LOSSES IN AGRICULTURAL WATERSHEDS

1 INTRODUCTION Agricultural use of pesticides has been recognized as one of the important non-point pollution sources in the world, and the pesticide application to agricultural lands has led to large amounts of residues discharged into surface water through runoff (Leonard, 1990). There have been growing concerns about the fate and transport of pesticides in agricultural lands, due to the associated adverse impacts on water environment and human health (Agassi et al., 1995; Ng and Clegg…     

A high-resolution real-time forecasting system for predicting the fate of oil spills in the Strait of Bonifacio (western Mediterranean Sea)

The Strait of Bonifacio is a long and narrow area between Corsica and Sardinia. To manage environmental emergencies related to the spill of oil from vessels, an innovative forecasting system was developed. This tool is capable of operationally predicting the dispersion of hydrocarbon spills in the coastal area of the Bonifacio Strait, either from an instantaneous or continuous spill and either in forward or backward mode. Experimental datasets, including ADCP water current measurements and the trajectories of drifter buoys released in the area, were used to evaluate the accuracy of this system. A comparison between the simulation results and experimental data revealed that both the water circulation and the surface transport processes are accurately reproduced by the model. The overall accuracy of the system in reproducing the transport of an oil spill at sea was estimated for both forward and backward prediction mode and in relation to different forecasting time lags.     

基于图像信息方法的日本东北MW9.0地震回溯性预测研究

以日本局部地区(32.0°~46.0°N, 136.0°~148.0°E)为研究区域, 应用图像信息方法, 选用8 a滑动预测窗长, 1°×1°网格为主要计算参数, 系统计算了研究区域内2000年以来的“地震热点”(显著异常地区)并获得了区域内7级以上大震特别是2011年日本东北M_W9.0地震的热点演化图像。 结果表明: ① 包含M_W9.0地震的预测时间窗内, 其震中的邻近网格持续有热点出现, 并且其中有4个连续滑动的窗口中该地震震中所在网格亦存在热点。 ② 在回溯时间段内发生的21个M≥7.0地震中, 除2004年9月5日发生于日本近畿南岸近海的M7.1地震前无地震热点外, 绝大多数在震前皆有热点出现。 ③ 与其他M≥7.0地震相比, M_W9.0地震前热点图像分布范围更广, 稳定性更好, 持续时间更长。     

Hydrological time‐series modelling using an adaptive neuro‐fuzzy inference system

Accurate forecasting of hydrological time‐series is a quite important issue for a wise and sustainable use of water resources. In this study, an adaptive neuro‐fuzzy inference system (ANFIS) approach is used to construct a time‐series forecasting system. In particular, the applicability of an ANFIS to the forecasting of the time‐series is investigated. To illustrate the applicability and capability of an ANFIS, the River Great Menderes, located in western Turkey, is chosen as a case study area. The advantage of this method is that it uses the input–output data sets. A total of 5844 daily data sets collected from 1985 to 2000 are used for the time‐series forecasting. Models having various input structures were constructed and the best structure was investigated. In addition, four various training/testing data sets were built by cross‐validation methods and the best data set was obtained. The performance of the ANFIS models in training and testing sets was compared with observations and also evaluated. In order to get an accurate and reliable comparison, the best‐fit model structure was also trained and tested by artificial neural networks and traditional time‐series analysis techniques and the results compared. The results indicate that the ANFIS can be applied successfully and provide high accuracy and reliability for time‐series modelling. Copyright © 2007 John Wiley & Sons, Ltd.     

Development of environmental monitoring satellite systems in China

With the increase in global environmental problems, the necessity and urgency of remote sensing technology being applied to environmental monitoring has been widely recognized around the world. China has launched the environment and disaster monitoring and forecasting small satellite constellation HJ-1A/B and the FY3 atmosphere and environmental satellite, but they still cannot fully satisfy requirements for environmental monitoring. This paper summarizes the current status of satellite environmental monitoring in China and the existing problems of inadequate load design and low data utilization efficiency, and discusses the demand for environmental monitoring satellites. Based on the development of foreign satellite systems for environmental monitoring, the future development and key tasks of the environmental monitoring satellite system in China is discussed, as are some related initiatives.     

全球部分强震的序列参数分布特征

为系统地考察全球强震序列参数的分布特征,对可操作的余震预测(OAF)模型的构建、地震危险性评估以及序列参数相关研究的开展提供数据支撑,采用可充分利用不完整性地震记录的Omi-R-J方法,对1973年以来的全球225个M6.5以上地震序列进行了参数拟合,并对参数拟合情况以及参数与板块边界之间的关系等特征进行了初步分析。获得了225个序列参数的拟合结果,显示序列参数呈现一种优势分布特征,参数平均值为p=1.0102±0.1777, log₁₀c=-3.1896±1.3249, log₁₀k=-4.3609±1.4596,b=0.9919±0.1651;序列参数与板块边界存在一定的相关性,如环太平洋地震带的中美洲段p值较小,北美洲段的b值较小、p值较大等。上述序列参数的计算、分布特征的研究以及序列参数与构造带相关关系的探讨,旨在为进一步开展强震序列参数相关研究提供一定参考。     

Development and evaluation of a storm surge warning system in Taiwan

An operational storm surge forecasting system aimed at providing warning information for storm surges has been developed and evaluated using four typhoon events. The warning system triggered by typhoon forecasts from Taiwan Cooperative Precipitation Ensemble Forecast Experiment (TAPEX) has been executed with two storm surge forecasting scenarios with and without tides. Three numerical experiments applying different meteorological inputs have been designed to assess the impact of typhoon forcing on storm surges. One uses synthetic wind fields, and the others use realistic wind fields with and without adjustments to the initial wind fields for the background circulation. Local observations from Central Weather Bureau (CWB) weather stations and tide gauge stations are used to evaluate the wind fields and storm surges from our numerical experiments. The comparison results show that the accuracy of the storm surge forecast is dominated by the track, the intensity, and the driving flow of a typhoon. When the structure of a typhoon is disturbed by Taiwan’s topography, using meteorological inputs from real wind fields can result in a better typhoon simulation than using inputs from synthetic wind fields. The driving flow also determines the impact of topography on typhoon movement. For quickly moving typhoons, storm forcing from TAPEX is reliable when a typhoon is strong enough to be relatively unaffected by environmental flows; otherwise, storm forcing from a sophisticated typhoon initialization scheme that better simulates the typhoon and environmental flows results in a more accurate prediction of storm surges. Therefore, when a typhoon moves slowly and interacts more with the topography and environmental flows, incorporating realistic wind fields with adjustments to the initial wind fields for the background circulation in the warning system will obtain better predictions for a typhoon and its resultant storm surges.     

利用CryoSat-2波形数据建立南极Lambert冰川流域DEM

Lambert冰川-Amery冰架系统是南极冰盖最大的冰流系统之一,对南极冰盖物质平衡研究有着重要的作用.数字高程模型(DEM)是进行南极冰盖研究的基础.本文基于CryoSat-2 L1b波形数据,研究建立了Lambert冰川流域高分辨率DEM.测高卫星返回波形在冰盖区域存在变形,需进行波形重跟踪处理.利用交叉点分析方法对重心偏移法(OCOG)、阈值法和β参数法等常用的波形重跟踪方法对不同类型的CryoSat-2波形的适用性进行了研究.最后,利用克里金插值方法建立了500 m分辨率的Lambert冰川流域DEM——LAS DEM (Lambert Glacier-Amery Ice Shelf system DEM).利用ICESat卫星测高数据和GPS地面实测数据对LAS DEM进行精度验证,并与另外两种基于CryoSat-2数据的南极DEM进行了对比.结果表明:LAS DEM的整体精度约为0.295±2.7 m,优于另外两种CryoSat-2 DEM;在冰盖内陆地区,LAS DEM的高程误差在2 m之内;在Amery冰架上,LAS DEM的精度优于1 m.     

Operational Monitoring and Forecasting in the Aegean Sea: System Limitations and Forecasting Skill Evaluation

The POSEIDON system, based on a network of 11 oceanographic buoys and a system of atmospheric/oceanic models, provides real-time observations and forecasts of the marine environmental conditions in the Aegean Sea. The buoy network collects meteorological, sea state and upper-ocean physical and biochemical data. The efficiency and functionality of the various system components are being evaluated during the present pre-operational phase and discussed in this paper. The problem of bio-fouling on optical and chemical sensors is found to be a main limitation factor on the quality of data. Possible solutions to this problem as well as quality control methods that are being developed are also described. Finally, an evaluation of the numerical models is presented through the estimation of their forecasting skill for selected periods.     

Validation of the Flood‐PROOFS probabilistic forecasting system

Probabilistic hydrometeorological forecasting systems are becoming more and more an operational tool used by civil protection centres for issuing flood alerts. One of the most important requests of decision makers is related to the reliability of such systems and to the validation of their predictive performances. For these reasons, this work is devoted to the validation of a probabilistic flood forecasting system called Flood‐PRObabilistic Operational Forecasting System (Flood‐PROOFS). The system is operational in real time, since 2008, in Valle d'Aosta, an alpine Region of northern Italy. It is used by the Civil Protection regional service to issue warnings and by the local water company to protect its facilities. The system manages and uses both real‐time meteorological and satellite data and real‐time data on the operation of the control structures in dam and river, managed by the water company. It has proven a useful tool for flood forecasting and for managing complex situations, facilitating the dialogue between civil protection and the water company during crisis periods. The system uses both a limited area model forecast and a forecast issued by regional expert meteorologists. The main outputs are deterministic and probabilistic discharge forecasts in different outlet areas of the river network. The performance of the system has been evaluated on a 25 months period with different statistical methods such as Brier score and Rank histograms. The results highlight good performances of the system as support system for emitting warnings, but there is a lack of statistics especially for huge discharge events. Copyright © 2013 John Wiley & Sons, Ltd.     

华东地区地震空区预报效能评估

对华东地区1970年以来的地震空区进行了预报效能评估。 结果表明: M_L≥3.0地震空区的报准率为0.45, 虚报率为0.55, 漏报率为0.57, R值为0.26; M_L≥3.5地震空区的报准率为0.31, 虚报率为0.69, 漏报率为0.75, R值为0.08; M_L≥4.0地震空区无对应的M_S5.5以上地震。 M_L≥3.0地震空区的R值高于具有97.5%置信水平的R₀值, 具有一定的预报能力, M_L≥3.5和M_L≥4.0地震空区不具有预报能力。 主震一般发生在空区内部边缘, 震前空区一般不会被打破; 空区的持续时间、 空区尺度、 震级下限与主震震级无明显线性关系; 空区主要分布在江苏、 山东及附近海域。     

Monthly total sediment forecasting using adaptive neuro fuzzy inference system

Accurate forecasting of sediment is an important issue for reservoir design and water pollution control in rivers and reservoirs. In this study, an adaptive neuro-fuzzy inference system (ANFIS) approach is used to construct monthly sediment forecasting system. To illustrate the applicability of ANFIS method the Great Menderes basin is chosen as the study area. The models with various input structures are constructed for the purpose of identification of the best structure. The performance of the ANFIS models in training and testing sets are compared with the observed data. To get more accurate evaluation of the results ANFIS models, the best fit model structures are also tested by artificial neural networks (ANN) and multiple linear regression (MLR) methods. The results of three methods are compared, and it is observed that the ANFIS is preferable and can be applied successfully because it provides high accuracy and reliability for forecasting of monthly total sediment.     

The ground-state conductivity profile of the core-mantle system of the Earth

The ground state of the core-mantle conductivity system is defined as a step function transition from the constant non-zero conductivity of the core to zero conductivity in the mantle. This ground state is reached by letting the thickness of a transition region Δ → 0, where Δ appears as a parameter in the model conductivity of the system. By a transformation of the equation governing the behavior of the electrostatic potential φ, it is shown that the function V(x) = (1/σ^1/2)(d²σ^1/2/dx²) acts as a potential barrier in the quantum mechanical sense, and that for certain conductivity profiles σ(x), where x is the usual Cartesian coordinate, the electrostatic potential is screened out in regions where σ(x) → 0 as Δ → 0. Consequently, E = −φ also vanishes in these regions. The results generalize to the time-dependent case. Conditions that the conductivity function σ(x) must satisfy to qualify as the ground-state conductivity are defined and an example is provided.     

Developing a Web-based flood forecasting system for reservoirs with J2EE / Développement sur Internet avec J2EE d’un système de prévision de crue pour barrages

Abstract

Abstract A flood forecasting system is a crucial component in flood mitigation. For certain important large-scale reservoirs, cooperation and communication among federal, state, and local stakeholders are required when heavy flood events are encountered. The Web-based environment is emerging as a very important development and delivery platform for real-time flood forecasting systems. In this paper, the findings of a case study are presented of the development of a Web-based flood forecasting system for reservoirs using Java 2 platform Enterprise Edition (J2EE). J2EE of Sun Microsystems is chosen as the development solution for the Web-based flood forecasting system, Weblogic 6.0 of BEA as the container provider, and JBuilder 7.0 of Borland as the development tool. One of the key objectives in this project is to establish a collaborative platform for flood forecasting via Web technology in order to render hydrological models and data available to stakeholders and experts involved and thus offer an efficient medium for transferring and sharing information, knowledge and experiences among them. Compared with general Web-based query systems and traditional flood forecasting systems, the Web-based flood forecasting system is more focused on the on-line analysis of model-based forecasting of floods and provides opportunities for improving the transfer of information and knowledge from the hydrological scientists and managers to decision makers. Finally, a prototype system is used to demonstrate the system application.     

Direct and Inverse Problems in a Variational Concept of Environmental Modeling

A concept of environmental forecasting based on a variational approach is discussed. The basic idea is to augment the existing technology of modeling by a combination of direct and inverse methods. By this means, the scope of environmental studies can be substantially enlarged. In the concept, mathematical models of processes and observation data subject to some uncertainties are considered. The modeling system is derived from a specially formulated weak-constraint variational principle. A set of algorithms for implementing the concept is presented. These are: algorithms for the solution of direct, adjoint, and inverse problems; adjoint sensitivity algorithms; data assimilation procedures; etc. Methods of quantitative estimations of uncertainty are of particular interest since uncertainty functions play a fundamental role for data assimilation, assessment of model quality, and inverse problem solving. A scenario approach is an essential part of the concept. Some methods of orthogonal decomposition of multi-dimensional phase spaces are used to reconstruct the hydrodynamic background fields from available data and to include climatic data into long-term prognostic scenarios. Subspaces with informative bases are constructed to use in deterministic or stochastic-deterministic scenarios for forecasting air quality and risk assessment. The results of implementing example scenarios for the Siberian regions are presented.     

Effects of oil on mangrove seedlings grown under different environmental conditions

The effects of oil treatments (one-time addition of 120 ml per plant and weekly addition of 15 ml per plant) and environmental conditions at time of oiling (air conditioned laboratory/diffuse light vs hot, direct sunlight) on the survival and growth of Rhizophora mangle and Avicennia germinans seedlings were examined. No oiled A. germinans survived longer than a few weeks. Both one-time and weekly oiling depressed survival, stem growth, leaf production and maximum leaf size in R. mangle. Significant interaction terms between oil treatment and environmental conditions occurred later (50 and 59 weeks) for R. mangle stem growth and earlier (21 and 23 weeks) for leaf production. Relative to other treatment combinations, R. mangle mortality was greatest and growth lowest in the combination of one-time oiling under hot, bright outdoor conditions. Results indicate that synergistic interactions between oil effects and environmental conditions may contribute to the wide range of effects reported in the literature in studies of oil contamination of mangroves.