基于ArcEngine的土地利用规划修编系统的设计与实现

探讨了基于ArcEngine的土地利用规划修编系统的架构和功能模块,分析了系统实现中地类转换、面积重算、自动出图等关键技术,对土地利用规划的信息化建设具有一定参考价值和借鉴意义。     

菲律宾及其邻近地区的地磁场模型研究

根据2001～2007年期间在菲律宾境内测量的74个点的地磁场数据,利用球冠谐和、泰勒多项式两种方法建立了2005.0菲律宾及周边地区地磁基本场模型,得到了菲律宾地区X、y、Z、D、I、H、F七个分量的分布.两种模型反映的同一地区的地磁场分布形态基本类似,只在拐点的舒缓度、等值线平滑度等方面存在区别.在8°N左右,X、...     

Distribution Survey of Soils in the Hainan Island and Their Physico-mechanical Properties

This paper from the point of regional, based on the statistics and analyses on a great number of geotechnical test, deals with the geneses and composition of Hainan soils and the distribution law of various soils in the Hainan Island, the physico-mechanical properties of the soils are also discussed in the paper. All this is the summary on the work during the past three decades. The research results listed in the paper can be used to a certain extent as a reference for the development of the Hainan Island.     

基于历史相似案例空间推演的地震伤亡人口评估方法研究

地震是对人类生存构成最大威胁的自然灾害之一,往往导致巨大的损失。本研究选取中国2000—2013年震级为4.0级以上且有人员伤亡的地震灾害统计数据作为历史案例,以基于历史案例的灾情加权综合评估模型（Assessment Method of Natural Disaster Based on Similarly Historical Cases,SHC）为基础,考虑历史案例与当前灾害的空间相关程度,获得改进的基于历史相似案例空间推演的地震伤亡人口评估（Assessment Method of Earthquake Casualties Based on Spatial Reasoning of Similarly Historical Cases,SRSHC）;并选取2010年青海玉树地震、2013年四川芦山地震及2014年云南鲁甸地震作为验证案例,进行精度验证。结果表明:① 对于3个验证案例,SRSHC模型的最佳评估精度均在95%以上,表明该方法在地震伤亡人口评估方面具有一定的可行性及适用性;② SRSHC模型相较于SHC模型,参评案例的个数少且精度更高,以2010年四川芦山地震为例,当参评案例个数为3个时,SRSHC模型评估结果达到最佳（97.92%）;而SHC模型参评案例个数需6个达到评估结果最佳（35.49%）,这表明历史案例与当前灾害发生地区的空间相关程度对评估结果有较大影响;③ 灾情评估的精度与参评案例的个数有关,当参评案例在2个以上时,模型评估的精度随着参评案例个数的增加呈平稳下降趋势;当参评案例的个数为3~4个时,SRSHC模型的评估精度最佳。基于历史案例的灾情评估方法成本低、效率高、时效性强,且方法简单、约束条件较少、容易实现, 在灾情评估方面具有一定的实用价值。     

Quantitative evaluation of the effect of prohibiting grazing policy on grassland desertification reversal in northern China

In northern China, the recent eco-environment protective policies played a very important role in the ecological environment protection and rehabilitation. To better understand the quantitative effect of the prohibiting grazing policy on grassland desertification reversal process, in this paper, Yanchi County was selected as a case study to conduct a quantitative research on the effect of prohibiting grazing policy. System dynamics research method was used in this study, also both natural factors and human factors which importantly related to desertification had been considered in the index system of the system dynamics method. According to the different grazing prohibition degree from 0 to 100 %, model was set up to simulate the grassland desertification degree. The results showed that grassland desertification degree decreased with the increase of the grazing prohibition degree. When the grazing prohibition degree was 30 %, grassland desertification began to reverse, and when the grazing prohibition degree was 40 %, the trend of grassland desertification reversal was steady, and the speed of desertification reversal was the same when the grazing prohibition degree changes from 40 to 100 %. Therefore, the full prohibiting grazing policy in Yanchi County currently is not necessary at all. These results could be very useful for the applying of prohibiting grazing policy in Yanchi County and other regions with the similar eco-environment protective policies.     

Energy Flow of Macrozoobenthos Community in an Algal Lake, Houhu Lake（Wuhan, China）

INTRODUCTIONMacrozoobenthos ,amajorgroupofaquaticfauna ,playsanimportantroleinthematerialcycleandenergyflowinawaterecosystem .Inrecentdecades ,interestinthebioenergeticsofthisgrouphasgrownrapidly .Aspectsofthebioenergeticsofmanybenthicfreshwaterspecieshavebeenpub lished .Owingtodifficultyinsamplecollectionandspecimenprocessing ,studiesofthebenthiccom munityhavereceivedlessattention .Withfisherydevelopmentandthelakeeutrophicationproblem ,investigationsontheecologicalfunctionofthelakecommun…     

Evaluation of the RPC Model for Ziyuan-3 Three-line Array Imagery

Ziyuan-3 (ZY-3) satellite is the first civilian stereo mapping satellite in China and was designed to achieve the 1: 50,000 scale mapping for land and ocean. Rigorous sensor model (RSM) is required to build the relationship between the three-dimensional (3D) object space and two-dimensional (2D) image space of ZY-3 satellite imagery. However, each satellite sensor has its own imaging system with different physical sensor models, which increase the difficulty of geometric integration of multi-source images with different sensor models. Therefore, it is critical to generate generic model, especially rational polynomial coefficients (RPCs) of optical imagery. Recently, relatively a few researches have been conducted on RPCs generation to ZY-3 satellite. This paper proposes an approach to evaluate the performance of RPCs generation from RSM of ZY-3 imagery. Three scenario experiments with different terrain features (such as ocean, hill, city and grassland) are designed and conducted to comprehensively evaluate the replacement accuracies of this approach and analyze the RPCs fitting error. All the experimental results demonstrate that the proposed method achieved the encouraging accuracy of better than 1.946E?04 pixel in both x-axis direction and y-axis direction, and it indicates that the RPCs are suitable for ZY-3 imagery and can be used as a replacement for the RSM of ZY-3 imagery.     

气候变暖背景下我国南方旱涝灾害时空格局变化

我国南方地区各季节降水异常主要包含三种优势模态：长江及其以南地区降水呈整体偏多或偏少的一致型,长江中下游流域与华南呈反相变化的南北反相型以及东南与西南呈反相变化的东西反相型。其中一致型是南方地区各季节降水变率的第一优势模态。总体而言,在1961—2013年南方地区平均降水存在明显的年代际和长期趋势变化。其中,夏季和冬季南方区域平均降水具有相似的年代际变化特征,而秋季降水的年代际演变几乎与上述两个季节的相反。不过,在近30年南方各季降水量发生年代际转折的时间不尽相同：春季和秋季降水分别在21世纪初期和20世纪80年代中后期之后进入干位相,冬季和夏季降水则分别在80年代中期和90年代初期之后进入湿位相。自21世纪初期以来,南方夏季和冬季降水逐渐转入中性位相。此外,南方春季和秋季降水均呈减少趋势;而夏季和冬季则相反,均呈增多趋势。对于西南地区,除了春季外,其他三个季节的降水均呈减少趋势,出现了季节连旱的特征,尤其是秋旱最为严重。不过,不管是季节降水量还是旱/涝日数,在我国南方大部分地区其线性变化趋势并不十分显著,这与南方降水年代际分量对降水变率存在较大贡献相关。分析还发现,我国南方区域洪涝受灾面积具有比较明显的年代际变化,而干旱受灾面积则没有明显的年代际变化特征,近十多年来西南地区干旱和洪涝受灾出现了交替互现的特点。     

Web‐based real‐time visualization of large‐scale weather radar data using 3D tiles

Weather radar data play an important role in meteorological analysis and forecasting. In particular, web‐based real‐time 3D visualization will enable and enhance various meteorological applications by avoiding the dissemination of a large amount of data over the internet. Despite that, most existing studies are either limited to 2D or small‐scale data analytics due to methodological limitations. This article proposes a new framework to enable web‐based real‐time 3D visualization of large‐scale weather radar data using 3D tiles and WebGIS technology. The 3D tiles technology is an open specification for online streaming massive heterogeneous 3D geospatial datasets, which is designed to improve rendering performance and reduce memory consumption. First, the weather radar data from multiple single‐radar sites across a large coverage area are organized into a spliced grid data (i.e., weather radar composing data, WRCD). Next, the WRCD is converted into a widely used 3D tile data structure in four steps: data preprocessing, data indexing, data transformation, and 3D tile generation. Last, to validate the feasibility of the proposed strategy, a prototype, namely Meteo3D at https://202.195.237.252:82 , is implemented to accommodate the WRCD collected from all the weather radar sites over the whole of China. The results show that near real‐time and accurate visualization for the monitoring and early warning of strong convective weather can be achieved.     

Hyper-spectrum models for monitoring water quality in Dianshan Lake,China

The correlation between water quality parameters and hyper-spectral reflectance is studied with models established for each parameter and applied in Dianshan Lake, in the upstream of the Huangpu River running through Shanghai, China. Models are for dissolved oxygen (DO in mg/L): R720/R680 = 20.362×(R720/R680)2-31.438×(R720/R680)+19.156; for turbidity (NTU): R*714.5 = 206.07× (R*714.5)2-582.5×R*714.5 + 423.24; and for total phosphorus (TP in mg/L): R*509.5 = 16.661× (R*509.5)2-32.646×R*509.5+16.116. The R2 values are 0.770 8, 0.660 4 and 0.738 7, respectively, showing strong positive relationships. The models were then applied to assess water quality of different times. Results are quite satisfactory for some samples.