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1.
农业气候资源是农业资源的重要组成部分,地形是影响农业气候资源的重要因素之一。为了使离散的高程点插值成为连续的高程点,从而得到整个研究区的高程点数据,本文采用地理信息系统软件ARC/INFO对1:10万比例尺的国家基本地形图进行矢量化,获取石河子垦区高程点数据,利用ArcGIS的地统计分析模块功能,以反距离权重插值、径向基函数插值、普通克里格插值等空间插值方法对以上高程点进行插值,创建了石河子垦区高程表面图,通过交叉验证并进行对比研究,结果表明:OK插值法效果最佳,其中MAE为21.916,RMSE为50.61,RMSS为0.9584;在检验标准上占有明显优势,IDW相对较差,其中MAE为27.726,RMSE为61.43。将各种插值法制成了相应的高程表面图,使离散的点插值成为连续的点,为农业气候资源的空间分布差异的研究等奠定了基础,从而更进一步的服务于农业。  相似文献   

2.
高程拟合方法的基本思路是:在GPS网中联测一些水准点(要求这些点分布均匀、密度充分),再利用这些点上的正常高和大地拟合高求出它们的高程异常值,再据这些点上的高程异常值与坐标的关系,用最小二乘方法拟合测区的似大地水准面,利用拟合的似大地水准面内插入其它GPS点的高程异常,从而求出各个未知点的正常高。  相似文献   

3.
以广东省番禹区沙洲和石楼镇岛地区的1 657个高程点为样本点,把其分为A、B、C组各200个高程点,A+B组400个高程点,A+B+C组600个高程点作为训练数据集,在Matlab 7.1和ArcGIS 9.2平台上分别应用广义回归神经网络(GRNN)、普通克里格(O-Kriging)、广义回归神经网络残余Kriging方法(GRNNRK)进行高程估值和成图,最后计算出三种方法的均方根误差.结果表明,如果插值样本数据量不变,样本的空间分布格局对GRNNRK插值精度的影响不大,且其插值精度要优于GRNN和O-Kriging方法的插值精度.随着插值样本数据量的增加,三种方法的插值精度都有显著提高,但GRNNRK方法的插值精度仍优于另两种方法.这表明GRNNRK方法在地形高程预测中的应用是可行的.  相似文献   

4.
基于DEM的广东省平均气温空间插值Ⅰ——研究方法   总被引:1,自引:0,他引:1  
以广东省为研究区域.利用地理信息系统软件ArcGIS9.3,分别运用样条函数法、反距离权重法、普通克里格法对广东省及周边的60个气象站点2003—20|2年的月平均气温进行空间插值,并根据气温垂直变化规律利用数字高程模型对插值结果进行了修正.采用平均绝对误差和均方根误差对插值结果进行精度评估。试图探索最适合广东省气温空间插值的方法.并通过引入数字高程模型提高插值精度。  相似文献   

5.
GIS数字地形模型的建立及应用研究   总被引:8,自引:0,他引:8  
介绍了GIS数字地形模型(DTM)的构造原理和方法,用离散点移动拟合距离加权平衡插值方法生成了GIS数字高程模型(DEM),以DEM为基础,用离散点插值数值拟合方法构造了DTM的数学模型,用该模型从DEM中提取地面单元的平均高程、相对高程、高差、高程变形、坡度、坡向、地面粗糙度、坡面形态、谷脊特征线、沟谷密度、沟谷深度等各种地形结构线,由EDM产生了三维地形立体模型和各种地形剖面,以及地面幅照度的计算和地形阴阳坡的划分等,用该方法对晋西离石羊道沟流域的土壤侵蚀进行了试验研究。  相似文献   

6.
以已知的离散数据点坐标和高程异常为研究对象,讨论了基于双线性内插模型的高程异常值获取的方法,通过内插模型建立高精度、高分辨率的区域高程异常数字模型,从而内插出该区域内任何一点或一小片区域的高程异常值,有助于解决各种与大地水准面相关的测绘工程问题,对推动“数字区域”、“数字城市”、“数字中国”的信息化建设具有重要作用.  相似文献   

7.
降雨空间插值方法的比较与改进   总被引:36,自引:0,他引:36  
对几种常用的降雨空间插值方法,如泰森多边形法、距离平方倒数法、克里金方法的优缺点进行了分析和比较.考虑到高程对降雨量影响较大,在协克里金方法的基础上将高程作为第2类影响因素引入降雨量的空间插值方法中,并提出了引入高程信息的协克里金方法.将3种方法(距离平方倒数法、普通克里金方法、引入高程信息的协克里金方法)用于沿渡河流域降雨量的插值计算,结果表明,考虑高程信息的协克里金方法的插值效果明显优于其他2种方法.  相似文献   

8.
一种免棱镜三角高程测量的方法   总被引:1,自引:0,他引:1  
在测量高差较大的点位高程时,通常利用光电测距采用三角高程测量的方法或全站仪自带的悬高测量法,但这种方法需要将棱镜准确安置在高程待求点上(如光电测距三角高程测量)或安置在通过高程待求点的铅垂线下方(如悬高测量)。但有些时候高程待求点不易到达或铅垂线下难以准确安置棱镜,给上述方法的实施带来了很大的困难。本文介绍了特殊情况下免棱镜采用三角高程测量法测定点位高程的原理、计算步骤、施测方法和应用范围。  相似文献   

9.
严磊 《科技资讯》2013,(35):36-38
从地表高程插值的研究现状出发,将多重分形理论引入Kriging和IDW两种常见插值方法,并对四种插值方法进行了比较分析.结果表明,在相同的样本数据条件下,多重分形插值的精度要高于IDW插值方法和Kriging插值方法.通过对局部奇异性指数的计算,多重分形插值方法合理地强化了局部区域的估值结果,可以更好地表达整个地区高程的局部奇异性.  相似文献   

10.
为简化传统方法用等高线地形图建立数字高程模型(DEM)时需先提取离散点数据、构建大量不规则三角形网(TIN)的繁琐过程,提出简便的带状区域法.首先对等高线进行完整性处理并按多边形编号存储,利用既有的等高线及其单边邻接关系将整个地形图划分为相互独立的带状区域,形成DEM模型;通过搜索查询点所在的带状区域及对应的等高线高程值,采用距离加权平均法计算查询点的高程.该方法建立的DEM模型明显减少了网格数量和存储空间,高程插值计算精度不低于TIN法,建模效率提高,适合于建立基于等高线的大型DEM.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

14.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

15.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

16.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

17.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

18.
In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.  相似文献   

19.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

20.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

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