非常规气象要素在紫外线预报中的应用

利用吉林省业务运行的WRF模式,计算了与紫外线指数相关的气温、湿度、云量、风速等常规气象要素和地表向下的短波辐射通量、地面热通量、反照率等非常规气象要素,利用长春市紫外线观测资料,分析了紫外线辐射与常规和非常规气象要素的相关性。基于长春市紫外线观测实况,以常规气象要素、非常规气象要素、混合气象要素为因子,利用相同的统计建模方法,分别建立紫外线预报模型。结果表明:大气短波辐射等非常规气象要素与紫外线指数的相关性,明显高于气温、云量、比湿、风速等常规气象要素;应用非常规气象要素和混合气象要素的紫外线预报方程,显著优于常规气象要素;基于混合气象要素的紫外线预报方程,与基于非常规气象要素的预报方程比较,预报性能差异不大。此外,应用常规气象要素建立的分季节紫外线预报方程,其预报效果明显优于全年预报方程。应用非常规气象要素建立的分季节紫外线预报方程,与全年预报方程相比,预报效果差异不大。     

2007年12月至2008年2月T213、ECMWF及日本模式中期预报性能检验

为了解中期数值预报模式性能,提高中期预报水平,针对2007年12月至2008年2月T213模式96小时预报产品进行天气学检验,并与ECMWF、日本模式96小时预报性能进行了对比分析.结果表明,三个模式的96小时预报对亚洲中高纬地区大尺度环流形势演变和重大调整有较强的预报能力,对于转折性天气的预报有较强的指示意义.综合分析来看,ECMWF模式对西风指数、850hPa温度变化、500hPa环流形势及南支槽的预报误差最小,日本模式次之.     

Using value engineering to optimize flood forecasting and flood warning systems: Golestan and Golabdare watersheds in Iran as case studies

Flood occurrence has always been one of the most important natural phenomena, which is often associated with disaster. Consequently, flood forecasting (FF) and flood warning (FW) systems, as the most efficient non-structural measures in reducing flood loss and damage, are of prime importance. These systems are low cost and the time required for their implementation is relatively short. It is emphasized that for designing the components of these systems for various rivers, climatic conditions and geographical settings different methods are required. One of the major difficulties during implementing these systems in different projects is the fact that sometimes the main functions of these systems are ignored. Based on a systematic and practical approach and considering the components of these systems, it would be possible to extract the most essential key functions of the system and save time, effort and money by this way. For instance, in a small watershed with low concentration and small lead time, the main emphasis should be on predicting and monitoring weather conditions. In this article, different components of flood forecasting and flood warning systems have been introduced. Then analysis of the FF and FW system functions has been undertaken based on the value engineering (VE) technique. Utilizing a functional view based on function analysis system technique (FAST), the total trend of FF and FW functions has been identified. The systematic trend and holistic view of this technique have been used in optimizing FF and FW systems of the Golestan province and Golabdare watersheds in Iran as the case studies.     

新疆天山地区 PP回归综合预报模型研究及预报效能评价

运用基于 PP回归理论的数值型地震综合预报软件系统, 对新疆天山地区进行了 PP回归建模研究。 通过回顾性 PP回归动态建模预测检验,对其预报效能进行了评价。 结果认为,该模型作为时序性数值预报模型具有较好的中短期预报效能。 尤其对地震样本量大、震级分布完备的地区,其预报效能更好。     

初夏暴雨综合物理诊断预报自动化系统

简要介绍了一个与ＳＴＹＳ接口的省－市－县配套的市级暴雨综合物理诊断预报自动化系统,即市台根据省台的指导预报信息,启动市台预报系统作出响应,再结合县站单站预报指标,综合判断作出全区预报。     

The use of predictive analysis in spatiotemporal crime forecasting: Building and testing a model in an urban context

Police databases hold a large amount of crime data that could be used to inform us about current and future crime trends and patterns. Predictive analysis aims to optimize the use of these data to anticipate criminal events. It utilizes specific statistical methods to predict the likelihood of new crime events at small spatiotemporal units of analysis. The aim of this study is to investigate the potential of applying predictive analysis in an urban context. To this end, the available crime data for three types of crime (home burglary, street robbery, and battery) are spatially aggregated to grids of 200 by 200 m and retrospectively analyzed. An ensemble model is applied, synthesizing the results of a logistic regression and neural network model, resulting in bi-weekly predictions for 2014, based on crime data from the previous three years. Temporally disaggregated (day versus night predictions) monthly predictions are also made. The quality of the predictions is evaluated based on the following criteria: direct hit rate (proportion of incidents correctly predicted), precision (proportion of correct predictions versus the total number of predictions), and prediction index (ratio of direct hit rate versus proportion of total area predicted as high risk). Results indicate that it is possible to attain functional predictions by applying predictive analysis to grid-level crime data. The monthly predictions with a distinction between day and night produce better results overall than the bi-weekly predictions, indicating that the temporal resolution can have an important impact on the prediction performance.     

构造叠加晕法是危机金矿山寻找接替资源的有效新方法

构造叠加晕是在发展了原生晕分带理论基础上而开创的一种盲矿预测新方法、新技术.运用该方法在金矿区深部及其外围进行盲矿预测,取得了显著效果.     

基于自动站观测的北京夏季降水特征

应用2007~2011年北京地区237个自动气象站资料,分析了北京夏季降水的精细化时空分布特征及城郊差异,结果表明:(1)北京大部分地区夏季平均有效降水时数约120~160 h,降水时数高值区主要位于北部怀柔、密云山前迎风坡一带。城、郊区间有效降水时数差异并不明显,城市化对局地降水强度有较明显影响。(2)北京夏季降水主要出现在傍晚到前半夜,凌晨到正午降水较少出现。夏季平均降水量极大值出现在17:00(北京时间),为3.2 mm/h。降水量存在较明显的周期变化特征,其中7 d左右的周期是主周期。(3)夏季城区平均降水量多于郊区,城、郊雨量差异主要来自较强降水过程。城市效应会导致城区弱降水事件的减少,亦会导致较强降水事件的增多。(4)城、郊区间降水持续时长的差异主要由较强降水过程决定,多数情况下城区降水持续时长大于郊区,午后到前半夜发生的降水尤甚。     

祁连山夏季地形云结构和云微物理过程的模拟研究(II):云微物理过程和地形影响

本文是祁连山夏季地形云结构和微物理过程模拟的第II部分。文中利用第I部分中祁连山夏季两个地形云降水个例的模拟结果,详细分析了地形云及其降水发展期间云微物理过程的特征及变化,并通过与平坦地面条件下模拟结果的对比,研究了云发展过程中的地形影响。研究表明,地形云中微物理过程的发展受地形影响很大,冰相微物理过程明显增强;地形影响下云的主要降水机制也受到影响甚至被改变。     

湖北省空中水资源分析

利用湖北省77站地面大气水汽压资料,计算了湖北省整层大气可降水量,分析了湖北省整层大气年、季平均可降水量的时空分布特征以及湖北省整层大气可降水量与地面降水的关系,发现夏季是湖北省整层大气可降水量最高的一个季节,而从时间分布上看,湖北省自然致雨的概率以春季为最高;从空间分布上看,湖北省自然致雨的概率以鄂西南为最高。通过多雨年与少雨年比较,认为少雨年与多雨年的差异,空中水汽含量偏少是一个方面,但不是主要方面,主要是由于成雨的概率不高。多雨年降雨系统较强,且非常稳定,容易出现连续性降水,系统之间配合较好,利于水汽辐合成雨,少雨年与之相反,但仍有可开发的降雨时段,仍具有开发前景。