oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

216 ( 1 )

2019 ( 1425 )

2018 ( 21136 )

2017 ( 21916 )

Custom range...

Search Results: 1 - 10 of 361711 matches for " 地形指数;ArcGIS9;Model Builder;单流向算法<br> Terrain Index "
All listed articles are free for downloading (OA Articles)
Page 1 /361711
Display every page Item
基于ArcGIS Model Builder的地形指数提取方法及实践研究
The Study on Terrain Index Extraction Method and Practice Based on ArcGIS Model Builder
 [PDF]

肖燕, 解鹏
Geomatics Science and Technology (GST) , 2013, DOI: 10.12677/GST.2013.13003
Abstract:
流域地形指数水文模型TOPMODEL已被应用于陆面模式(Land surface Models, LSMs)以改进陆面模式对水文过程的模拟。地形指数(ln(α/tanβ))是TOPMODEL的核心,是进行水文分析的重要指标。因此,高效的提取地形指数信息非常重要。本文将淮河流域作为案例区,以地形指数单流向算法为理论基础,利用ArcGIS9的Model Builder建模工具,建立地形指数提取模型。在模型设计过程中充分考虑到汇流面积、坡度等参数的有效性,使模型具有较高的通用性。使用者启动模型加载数据即可简单又快速地获得地形指数分布数据。
River terrain index TOPMODEL hydrological model has been applied to Land surface model (Land surface Models, LSMs), to improve Land surface of hydrological process simulation model. The core of TOPMODEL is terrain index (ln(α/tanβ)). And it is an important index on the hydrologic analysis. Therefore, effective extracting terrain index information is very important. In this paper, the huaihe river basin as a case area, the terrain index extraction process model is build, using the ArcGIS9 Model Builder tools. This model is based on a single flow algorithm for calculating process. Model has higher versatility, because of fully considering the effectiveness of the parameters such as the slope and the flow accumulation in the model design process. Using this model can be very simple and quick to get terrain exponential distribution data of terrain index.
Quantitative Error Assessment of Topographic Wetness Index Algorithms
地形湿度指数算法误差的定量评价

BAO Lili,QIN Chengzhi,ZHU Axing,
包黎莉
,秦承志,朱阿兴

地理科学进展 , 2011,
Abstract: Topographic Wetness Index (TWI) is a widely-used topographic attribute which can predict the control of terrain on spatial distribution of soil moisture. Diverse TWI algorithms might get very different results; therefore, it is necessary to assess the algorithms. Traditional error assessment method applies TWI algorithms to 'real-world' DEM, but the error from DEM quality might interfuse the error from algorithms and thus influence the accuracy of evaluation. To solve the problem, this paper proposes an assessment method of error from TWI algorithm with artificial DEMs which can avoid data source error. Four typical TWI algorithms, i.e. TWI algorithm based on a typical single flow direction algorithm (D8), TWI algorithm based on a typical multiple flow direction algorithm (FD8), TWI algorithm based on an adaptive multiple flow direction algorithm (MFD-md), and TWI algorithm using MFD-md in which the maximum downslope, instead of traditional slope gradient, is used to estimate the tanβ in equation of TWI, are evaluated by the proposed assessment method. First, four artificial surfaces are constructed to simulate typical compound terrain conditions, i.e. convex-centred slope, concave-centred slope, saddle-centred slope, and ridge-centred slope, respectively. Secondly, the artificial surfaces are converted to three sets of artificial DEM data with different cell size (1 m, 10 m, and 30 m) to apply TWI algorithms to compute TWI. Third, the theoretical TWIs for every artificial surface are calculated to quantitatively assess the error from TWI algorithms based on RMSE. Assessment result shows that TWI algorithms based on multiple flow direction algorithm (MFD) perform better than TWI algorithm based on single flow direction algorithm (SFD), i.e. D8, under terrain conditions of convex-centred slope, concave-centred slope and saddle-centred slope. Under ridge-centred slope terrain condition, the result of TWI algorithm based on SFD is just inferior to the result of TWI algorithm which combines MFD-md with maximum downslope algorithm. As the resolution becomes coarser, errors of TWI algorithms based on MFD become larger on the whole, while the trends of results of TWI algorithm based on SFD vary with different terrain conditions. The proposed quantitative assessment method for TWI algorithm can be similarly used to assess algorithms of other compound topographic attributes, such as specific catchment area, stream power index, and so on.
The Creating of Spatial Weights File in Calculating of Moran''s I Index
Moran’s I指数计算中空间权重文件的生成实现①

聂芹,李连运
计算机系统应用 , 2009,
Abstract: Moran’s I指数是空间自相关分析常用的指标。ArcGIS9.0加强了空间统计分析功能,在Moran’s I指数计算中,他提供了6种空间关系的定义方法。但在基于空间权重文件的方法中,ArcGIS9.0没有提供相应的空间权重文件生成的运算工具,需编程实现。基于MapBasic实现了基于二进制权重的空间权重文件的生成,并给出了详细的实现过程和具体的应用实例。
Computation Method of Topogr aphic Wetness Index in Low Relief Ar ea
平缓地区地形湿度指数的计算方法

QIN Chengzhi,YANG Lin,ZHU AXing,LI Baolin,PEI Tao,ZHOU Chenghu,
秦承志
,杨琳,朱阿兴,李宝林,裴韬,周成虎

地理科学进展 , 2006,
Abstract: Topographic wetness index, which is designed for modeling the status ("dry" or "wet") of the soil moisture quantitatively, is an important index for both predictive soil mapping and distributed hydrological modeling in a catchment. Current methods for calculating topographic wetness index have evident problems when applied in low relief area. Outside the positions of narrow accumulation line with high topographic wetness index, the topographic wetness index dramatically jumps down in other parts of wide valley area. This is unreasonable because the soil moisture should be comparatively average and high in the wide and flat valley, and the value of topographic wetness index should be high. This problem is caused by both the flow accumulation algorithm and the slope gradient used during computing the topographic wetness index. A new method for computing topographic wetness index is proposed in this paper to address this problem. Firstly, flow accumulation is calculated by a multiple flow direction algorithm(MFD-fg). Topographic wetness index is then computed by the flow accumulation and maximum downslope. The maximum downslope used in the computation of topographic wetness index is matched with the idea of both MFD-fg and topographic wetness index. Furthermore, a post-processing method is also proposed to compute the topographic wetness index in valley area. The topographic wetness index in the valley area is interpolated by a Gaussian function based on the value of the topographic wetness index on the nearest position on extracted flow accumulation line. The application in a small watershed shows that the method proposed in this paper can get a comparatively reasonable distribution of topographic wetness index for not only the hillslope but also the wide valley area. The value of topographic wetness index in valley area is averagely high and with a smooth transition, which reflects the natural status of the soil moisture in application area. In the future research, the method proposed in this paper will be evaluated by both artificial surfaces and the real applications.
A new algorithm of the topographic index ln(α/tanβ) in TOPMODEL and its resultant analysis
TOPMODEL中地形指数ln(α/tanβ)的新算法

YONG Bin,ZHANG Wan-chang,CHEN Yan-hua,
雍斌
,张万昌,陈艳华

地理研究 , 2007,
Abstract: TOPMODEL中地形指数ln(α/tanβ)被用来近似表征流域径流源面积和地下水水位的空间分布特征,目前广泛使用的计算地形指数的方法为多流向算法(FD8算法)。本文首先介绍了多流向算法的基本原理,并基于此对流动累积分配中的有效等高线长度精确计算提出了几何锥面内切圆算法,同时改进了传统的地形指数中单位等高线汇流面积α的计算方法,增强了多流向算法对DEM中异常栅格的处理能力。改进后的地形指数新算法在两个不同流域和不同分辨率DEM上与传统多流向算法进行了对比分析。结果表明新算法在原理上更符合地形指数物理意义,实际应用中其计算结果更准确。这种地形指数新算法的提出对于流域水文过程机理分析及陆面过程定量化研究具有一定的现实意义。
Land use change characteristics along the terrain gradient and the spatial expanding analysis: A case study of Haidian District and Yanqing County, Beijing
土地利用变化的地形梯度特征与空间扩展——以北京市海淀区和延庆县为例

CHEN Li-ding,YANG Shuang,FENG Xiao-ming,
陈利顶
,杨 爽,冯晓明

地理研究 , 2008,
Abstract: Studying land use change and its spatial expansion along the terrain gradient is of great significance for identifying the direction of land use change and its sustainable use.In this paper,a case study was conducted in Haidian District and Yanqing County of Beijing by comparing land use pattern in 1992,and 2002 with regard to terrain niche index using remote sensing image interpretation.It was found that:(1) A clear difference exists in land use change between Haidian District and Yanqing County.In Haidian District,the built-up area expands to both higher and lower terrain niche areas with economic development and population growth.Farmland and orchard are extruded to the higher terrain niche area due to urban expansion.Woodland in high terrain niche area is well restored,and further expands to the lower terrain niche area.The unused land,grassland and shrubberies are remarkably constricted in the middle and high terrain niche areas with the intrusion of woodland,and reduced in the low terrain niche sections due to farmland increase.In Yanqing County,the built-up area is obviously confined by the terrain niche and is mainly located in the low terrain niche area as well as the farmland.Orchard,however,is shifted to the higher terrain niche area with the economic development.Woodland is well restored in the higher terrain niche area,and the predominant distribution of the unused land,grassland and shrubberies is reduced.(2) A common point was found in both Haidian District and Yanqing County.Ecological conservation was well carried out in the both areas in recent decade,and consequently natural vegetation was restored appropriately.A difference in land use change is that land use in Haidian District is more affected by the economic development than that in Yanqing County.The built-up area spreads out faster in Haidian District,and farmland was extruded to higher terrain niche area under the pressure of urban expansion in Haidian District,while they are both constricted in the low terrain niche area in Yanqing County.
Analysis on Distribution Characteristics of Land Use Types Based on Terrain Gradient: A Case of Liuyang City in Hunan Province
基于地形梯度的土地利用类型分布特征分析——以湖南省浏阳市为例

LIANG Fachao,LIU Liming,
梁发超
,刘黎明

资源科学 , 2010,
Abstract: Terrain is not only one of the important factors affecting the spatial layout and land use change, but also a prerequisite for land evaluation and land planning. A good understanding of the relationships between land use types and terrain gradient is essential for land management. In this paper, elevation, slope, and terrain niche were conceptually divided into 13 classes, which were used to describe the terrain difference across the study area, Liuyang City in Hunan province. The nondimensional distribution index was used to examine characteristics of land use types. Using Landsat TM satellite imagery, DEM, and other materials from field survey based on the spatial analysis module in ArcGIS, the distribution pattern of land use types and their relationships with terrain factors in the study area were revealed by analyzing the nondimensional distribution index for different land use types on varying terrain gradients. Results showed that: 1) cultivated land is mainly distributed in areas ranging in elevation from 36 m to 200 m, in slope from 0o-12o, and in terrain niche from 0 to 0.39. Orchard is mainly distributed in areas ranging in elevation generally from 36 m to 200 m, in slope from 0o to 15o, and in terrain niche from 0 to 0.54. Other agricultural land and construction land are primarily distributed in areas ranging in elevation from 36 m to 200 m, in slope from 0o to 12o, and in terrain niche from 0 to 0.54. Forestland is mainly distributed in areas ranging in elevation from 200 m to 1200 m, with slope larger than 12o, and terrain niche larger than 0.39. Unused land is mainly distributed in areas with elevation larger than 1200 m, slope ranging from 0o to 6o, and terrain niche greater than 1.09. Also, the interrelationship between land use types and terrain gradient showed a significant correlation; 2) cultivated land, orchard, other agricultural land, and construction land are distributed mainly on the lower terrain gradients. The distribution index decreases with increasing terrain gradients, gradually approaching zero. The same land use types mentioned above are distributed similarly on the same terrain gradients. The forestland is distributed mainly on lands with the average or high grades of elevation, higher grades of slope and terrain niche, whereas the unused land shows an opposed trend; 3) the spatial distribution of land use types is characterized by strong area differentiation. There are different land use types associated with terrain classification. For the same land use type, the spatial distribution varies greatly in different terrain gradients; and 4) comparing the three methods, the terrain niche was found to be able to explicitly show distribution trends of land use types with variations in terrain, and the terrain niche index seems to be more effective to reflect distribution characteristics of land use types in that the terrain niche synthesizes information of both elevation and slope. This study provides a feasible qua
Evaluation of Heavy Metal Pollution in Soils from a Training Ground Based on GIS
基于GIS的某训练场土壤重金属污染评价

LIU Yu-tong,FANG Zhen-dong,YANG Qin,XIE Chao-xin,WANG Da-yong,MAO Hua-jun,
刘玉通
,方振东,杨琴,谢朝新,王大勇,毛华军

环境科学 , 2012,
Abstract: In this paper, a tank shooting range in a training ground in the southwest of China was investigated, and the content of Cu, Pb, Zn, Co and Ni in the soil was monitored and analyzed. Evaluation of pollution in the sampling area was applied through the single factor index method and the composite pollution index Nemrow method, and the pollution index distribution map was worked out by Arcgis software. The evaluation result shows that: Cu, Pb, Zn, Co and Ni in the tank shooting range have different degrees of pollution respectively, the average composite pollution index Nemrow reaches 1.64.The highest single-factor pollution index of Co reaches 3.84, so Co is the priority element to be monitored in the heavy metal pollution control of soil in future. The pollution index distribution map shows that: the heavy metal pollution is particularly serious in the area of dropping bombs. The pollution distributing characters of Cu and Pb are similar, Zn, Co and Ni have similar characters. The author considers that, the migration of Ni and Pb is strong under the combined effect of various conditions in the shooting range, and the migration of Cu is weak. The sources of heavy metal pollution comprise residual cannonballs, bullets, and explosives. The residual shells and bullets in the soil could lead to a permanent soil contamination of heavy metals.
额尔古纳国家级自然保护区主要森林植被地形梯度特征定量分析
龚文峰,,,智长贵,,,范文义
南京林业大学学报(自然科学版) , 2015, DOI: 10.3969/j.issn.1000-2006.2015.01.015
Abstract: 为研究额尔古纳国家级自然保护区主要森林植被地形梯度时空演变分异特征,以RS和GIS为研究手段,辅助林相图、森林二类调查数据和野外调查数据,完成额尔古纳国家级自然保护区1992―2012年间Landsat TM遥感影像解译和植被制图,对基于DEM所构建的地形位指数进行叠加分析,在地形坡位指数分析基础上,研究主要森林植被的地形梯度空间分异特征。结果表明:针叶林、针阔混交林和阔叶林等森林植被在整个土地利用格局中占据主体地位,分别处于演替阶段的后期、中期和前期,控制着区域森林群落的发生、发展及生态过程; 针叶林面积增加和针阔混交林面积减少明显,针阔混交林?稣胍读治?森林类型转换的主要轨迹,且转换强烈。地形位梯度分析表明,地形位空间分布中低、中段区域是针叶林优势分布区,针阔混交林和阔叶林都集中于地形位指数为1~5的区域; 针阔混交林和阔叶林的地形梯度分布指数曲线变异程度要比针叶林显著,白桦林的地形梯度分布指数曲线变化明显,总体上呈递减趋势。
The spatio-temporal distribution characteristics for main forest vegetation in terrain gradient was studied by using RS and GIS based on forest auxiliary graph, forest resource management inventory data, field investigation data. Two-temporal-satellite-images based on the ERDAS IMAGE 9.3 and ArcGIS 9.3,and vegetation mapping with the supplementary of forest distribution map of Argun National Natural Reserve from the year of 1992 to 2012 were interpreted. According to the analysis of TPI(topographic position index), the spatial distribution characteristics of main forest vegetation in terrain gradient were analyzed to explore the relationship between natural environment and human activities. The results showed that: coniferous, mixed broadleaf-conifer, broad-leaved forest and other forest vegetation occupied the dominate position of the land use pattern in whole study region, they located the early, medium and latter succession periods, respectively, and controlled process for the happens, development and ecological process of mountainous forest eco-system. The increasing areas of coniferous and decreasing areas of mixed broadleaf-conifer were very obvious, the transform from broadleaf-conifer to coniferous forest was the major conversation trace and very intensive of whole forest types. Additionally, the analysis results of terrain gradient showed: during the spatial distribution in area with terrain niche, the low and medium section zone was the dominate for coniferous forest, both mixed broadleaf-conifer forest and broadleaf forest mainly occupied the low section zone with terrain niche index from 1 to 5, the various extent of distribution index curve for coniferous, mixed broadleaf-conifer on terrain gradient was more distinct than that of coniferous, the distribution index for Betula platyphylla in two periods was very similar, the curve changed very obviously in terrain gradient and taken on the decreasing trend in whole level
利用局部Morans I指数进行DEM地形简化
Terrain Simplification from Grid DEMs Based on Local Moran’s I Index

朱丹,董有福
Zhu Dan
,Dong Youfu

- , 2015,
Abstract:
Page 1 /361711
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.