共查询到20条相似文献,搜索用时 15 毫秒
1.
S. Kundu A. K. Saha D. C. Sharma C. C. Pant 《Journal of the Indian Society of Remote Sensing》2013,41(3):697-709
A comprehensive Landslide Susceptibility Zonation (LSZ) map is sought for adopting any landslide preventive and mitigation measures. In the present study, LSZ map of landslide prone Ganeshganga watershed (known for Patalganga Landslide) has been generated using a binary logistic regression (BLR) model. Relevant thematic layers pertaining to the causative factors for landslide occurrences, such as slope, aspect, relative relief, lithology, tectonic structures, lineaments, land use and land cover, distance to drainage, drainage density and anthropogenic factors like distance to road, have been generated using remote sensing images, field survey, ancillary data and GIS techniques. The coefficients of the causative factors retained by the BLR model along with the constant have been used to construct the landslide susceptibility map of the study area, which has further been categorized into four landslide susceptibility zones from high to very low. The resultant landslide susceptibility map was validated using receiver operator characteristic (ROC) curve analysis showing an accuracy of 95.2 % for an independent set of test samples. The result also showed a strong agreement between distribution of existing landslides and predicted landslide susceptibility zones. 相似文献
2.
以广州市为例,将Landsat-8-OLS数据与NPP-VIIRS夜间灯光数据相结合提取城镇建筑用地,在常规的NDBI指数、ULI指数方法的基础上进行改进,以获得更加精确的城镇建筑用地信息。首先,利用NPP-VIIRS夜间灯光数据得到城镇建筑用地的大致分布范围,基于Landsat-8-OLS数据提取NDBI、NDVI指数;然后通过分析夜间灯光建筑用地范围、NDVI指数,NDBI指数三者的特性,分别对三者图像进行二值化、求交运算来提取城镇建筑用地;最后将提取结果与传统的NDBI指数、ULI指数方法的提取结果进行对比,利用Google Earth高空间分辨率影像数据进行精度验证。结果表明,结合NPP-VIIRS数据和Landsat-8-OLS数据的多指数提取相交运算,可有效剔除提取结果中包含的裸土信息,与NDBI等指数方法相比,能得到更高的精度。 相似文献
3.
Radiant temperature images from thermal remote sensing sensors are used to delineate surface coal fires, by deriving a cut-off temperature to separate coal-fire from non-fire pixels. Temperature contrast of coal fire and background elements (rocks and vegetation etc.) controls this cut-off temperature. This contrast varies across the coal field, as it is influenced by variability of associated rock types, proportion of vegetation cover and intensity of coal fires etc. We have delineated coal fires from background, based on separation in data clusters in maximum v/s mean radiant temperature (13th band of ASTER and 10th band of Landsat-8) scatter-plot, derived using randomly distributed homogeneous pixel-blocks (9 × 9 pixels for ASTER and 27 × 27 pixels for Landsat-8), covering the entire coal bearing geological formation. It is seen that, for both the datasets, overall temperature variability of background and fires can be addressed using this regional cut-off. However, the summer time ASTER data could not delineate fire pixels for one specific mine (Bhulanbararee) as opposed to the winter time Landsat-8 data. The contrast of radiant temperature of fire and background terrain elements, specific to this mine, is different from the regional contrast of fire and background, during summer. This is due to the higher solar heating of background rocky outcrops, thus, reducing their temperature contrast with fire. The specific cut-off temperature determined for this mine, to extract this fire, differs from the regional cut-off. This is derived by reducing the pixel-block size of the temperature data. It is seen that, summer-time ASTER image is useful for fire detection but required additional processing to determine a local threshold, along with the regional threshold to capture all the fires. However, the winter Landsat-8 data was better for fire detection with a regional threshold. 相似文献
4.
空间可达性是评价医疗资源分布合理性的重要指标之一,借助GIS强大的空间分析功能,可以对医疗资源可达性进行科学的分析与评价。本文尝试基于白城市的行政区划、交通数据以及医疗资源相关资料,使用GIS技术、空间可达性指标和改进的潜能模型对医疗资源可达性进行综合分析,为医疗资源的规划及分配提供决策参考。 相似文献
5.
Urban models are evolving to require more and more detailed data that in many cases have to be spatially disaggregated from larger zones. This paper deals with the disaggregation of statistical data in an urban context in which land use data are available at a less detailed level. With the availability of land use data, the traditional approach of areal weighting is improved with an areal and land use weighted approach. This weighted approach is further elaborated to include homogeneous weight zones (HWZ) so as to reflect general geographical variations among the same land use type. A case study in Wuhan, China has demonstrated the effectiveness of the doubly weighted approach within the specified context. 相似文献
6.
为更加深入地了解村镇尺度城镇建设用地发展适宜性情况,提高土地利用综合效益,本文以常州市金坛区遥感影像数据和土地利用现状数据为基础,采用层次分析法和GIS空间分析技术,选择自然、区位、生态和土地转换适宜度四大类10个指标,建立了适用于平原地区的具有区域代表性的城镇建设用地发展适宜性评价指标体系,分析了金坛区城镇发展适宜区分布与空间自相关特征。研究结果能为城市规划、土地规划等提供依据,尤其在城镇建设用地发展布局上具有重要的现实意义。 相似文献
7.
G. P. Obi Reddy M. S. S. Nagaraju I. K. Ramteke Dipak Sarkar 《Journal of the Indian Society of Remote Sensing》2013,41(2):331-343
In the present study, landforms and soils have been characterized in Borgaon Manju watershed of basaltic terrain located in Akola district, Maharashtra, Central India. Terrain characterization using Shuttle Radar Topography Mission (SRTM) elevation data (90 m) and IRS-P6 LISS IV data in conjunction with adequate field surveys shows nine distinct landforms. Soil resource inventory shows fourteen soil series in the study area. Soils formed on gently sloping (3–8 %) subdued plateau are very shallow (23 cm), moderately well drained, moderate (15–40 %) surface stoniness, severely eroded, clayey and slightly alkaline in reaction, whereas, the soils formed on level to nearly level (0–1 %) slope in the main valley are very deep (>150 cm), well drained, very slight (<3 %) surface stoniness, moderately eroded with clayey surface and moderately alkaline in reaction. Soils in the watershed are grouped into Lithic Ustorthents, Vertic Haplustepts, Calcic Haplustepts, Typic Haplustepts, Typic Haplusterts and Sodic Calciusterts. The study demonstrates that the analysis of SRTM elevation data and IRS P6–IV data in Geographic Information System (GIS) with adequate field surveys helps in characterization of landforms and soils in analysis of landscape-soil relationship. 相似文献
8.
In India the last 30 years had witnessed a radical transformation of urban scene. In particular, during this period, the one
lakh cities and million plus cities began to grow rapidly. In the present study, urban growth of Jaipur city in the last 31 years
(1975–2006) was assessed. Jaipur ranks 11th in India with a total population of 2.3 million and has shown a consistent increase
in the past 50 years. It is one of the fastest growing mega cities of the country with an annual average growth rate of 4.5%
which is quite high from the national urban growth rate. Remote sensing and GIS have been used to extract the information
related to urban growth-built up area and its spatial and temporal variation. The Shannon’s entropy at two levels (city as
a whole and ward wise) is computed in order to quantify the form and patterns of urban growth using built up area as spatial
phenomena. Further, multivariate statistical techniques have been used to establish the relationship between the urban growth
and its causative and determining factors. Results of this study reveal that the growth rate of built up in Jaipur has outstripped
the rate of population growth. Shannon’s entropy quantifies as dispersed form of urban growth till 2000 and after it, there
is relative compactness in 2006. 相似文献
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10.
Zhangyu Dong Zongming Wang Dianwei Liu Kaishan Song Lin Li Mingming Jia Zhi Ding 《Journal of the Indian Society of Remote Sensing》2014,42(3):569-576
Increasing interest in wetlands for environmental management requires an understanding of the location, spatial extent, and configuration of the resource. The National Wetlands Inventory is the most commonly used data source for this information. However, its accuracy is limited in some contexts, such as agricultural and forested wetlands. An large number of studies have mapped wetlands worldwide from the perspective of land use and land cover change. However, information on the actual wetland planting areas annually is limited, which greatly impacts ongoing research. In this case study of the West Songnen Plain, we developed a simple algorithm for the quick mapping of wetlands by utilizing their unique physical features, such as annual display of phenological land-cover change of exposed soils, shallow flooding water, and plants from multi-temporal Landsat images. Temporal variations of the Normalized Difference Vegetation Index (NDVI) and Land Surface Water Index (LSWI) derived from Landsat images in 2010 for wetlands at different growth stages were analyzed. Results show that during the ante-tillering phase, the NDVI value (above zero) is lower than the LSWI value of paddies because of flooding of shallow water; during the reproductive and ripening phases, the NDVI value is higher than the LSWI value (above zero); and during the post-harvest wetland planting phase, the NDVI value is still higher than the LSWI value, but the LSWI value is negative. Wetland areas can be detected using one or two images in the optimum time window. The algorithm based on the difference of NDVI and LSWI values derived from Landsat images was used to extract the actual wetland planting area. Validated alongside statistical data, the algorithm showed high accuracy. Therefore, this algorithm highlights the unique features of wetlands and can help in mapping the actual wetland area annually on a regional scale. Results further indicate that the new method has a classification accuracy of 92 %. In comparison, two traditional methods based on Landsat-7/ETM registered accuracy rates of only 83 % and 87 % respectively. 相似文献
11.
This article presents a methodology for designing a WebGIS framework intended for automatically analyzing spatial data and updating statistics of interest with new information inserted daily by multiple users via a Web portal. A practical example is used on vehicle accident data for assessing risk in specific road segments. Two main blocks integrated together will be described: the collaborative block and the data‐analysis block. The former gives end‐users computer‐aided tools to view, insert, modify and manage data related to accidents and traffic monitoring sensors, whereas the latter is developed to automatically analyze the accident data coming from user's collaboration. Because different agencies can survey accident sites, a collaborative environment is necessary – and a Web‐based solution is ideal – for permitting multi‐user access and data insertion. A centralized approach to process the data in real time is described in all its components. Server‐side Structured Query Language functions optimize performance by using dedicated libraries for spatial processing and re‐structuring the attributes associated with elements which are consequently re‐classified for correct color‐scaling. The end‐product is a system that provides a seamless integration of front‐end tools for user collaboration and back‐end tools to update accident risk statistics in real time and provide them to stakeholders. 相似文献
12.
AbstractThe Shahr-e-Babak region located in the Kerman metallogenic belt is one of the high potential segments of Urumieh–Dokhtar magmatic arc for porphyry copper and epithermal gold mineralization in the south of Iran. This high potential zone encompasses several porphyry copper deposits under exploitation, development and exploration stages. The aim of this study is to evaluate Landsat-8 data and comparison with the Advanced Spaceborne Thermal Emission and Reflection Radiometer data-sets for mapping hydrothermal alteration zones related to Cenozoic magmatic intrusions in Shahr-e-Babak region. Previous studies have proven the robust application of ASTER in lithological mapping and mineral exploration; nonetheless, the Landsat-8 data have high capability to map and detect hydrothermal alteration zones associated with porphyry copper and epithermal gold mineralization. In this investigation, several band combinations and multiplications, developed selective principal component analysis and image transformations were developed for discriminating hydrothermal alteration zones associated with porphyry copper mineralization using Landsat-8 data. 相似文献
13.
水库作为水利设施的重要组成部分,在蓄水、供水、防洪、泄洪等方面起着极为重要的作用。计算水库面积,对于水库的蓄水量,影响的流域范围等有着重要的参考价值。本文以石梁河水库为例,选取了较为常见的利用GIS技术和遥感技术计算水库面积的方法,并科学地比较了两种方法的优缺点,为选择水库面积计算方法提供有力依据。 相似文献
14.
Desertification Vulnerability Assessment Model for a Resource Rich Region: A Case Study of Bellary District,Karnataka, India 总被引:1,自引:0,他引:1
G. S. Sastry K. Ganesha Raj M. A. Paul P. S. Dhinwa K. L. N. Sastry 《Journal of the Indian Society of Remote Sensing》2017,45(5):859-871
Desertification is a global challenge being experienced across countries irrespective of their levels of development. Desertification is a complex negative process involving both natural and human components in terms of their socio-economic attainments. Hence, for identification and assessment of the process, pattern, magnitude and possible impacts of desertification, a multi-disciplinary approach with inter-disciplinary framework of analysis is essential. This study has made such an attempt to develop a comprehensive desertification vulnerability assessment Model on the basis of multi-variate Principal Component Analysis along with the Geographic Information System framework by using natural and socio-economic resources data inputs from census, satellite data and other sources. Bellary district, located in a rapidly growing southern state of India, Karnataka which is afflicted with various natural and development issues such as droughts, backwardness, haphazard mining, over irrigation, and associated effects of land degradation, siltation and water pollution has been chosen for the study. The inter-disciplinary framework based desertification vulnerability assessment model has assessed that 1379.198 km2 area (15.55%) of Bellary district is prone to desertification (based on the satellite data IRS LISS III data of Dec 2005, Feb 2006, March 2006 and April 2006). In addition, 3229.337 km2 (36.40%) is under moderate vulnerability which is fragile. Hence, unless proper development intervention and conservation measures are taken well in advance, almost more than half of Bellary district (51.95%) will be vulnerable to desertification. Spatially, the talukas that are seriously affected and that require development intervention on high priority are: Sandur, Kudligi, Hospet and Bellary which are the prime talukas of the district. 相似文献
15.
Binh Thai Pham Dieu Tien Bui Ha Viet Pham Hung Quoc Le Indra Prakash M. B. Dholakia 《Journal of the Indian Society of Remote Sensing》2017,45(4):673-683
Landslide hazard assessment at the Mu Cang Chai district; Yen Bai province (Viet Nam) has been done using Random SubSpace fuzzy rules based Classifier Ensemble (RSSCE) method and probability analysis of rainfall data. RSSCE which is a novel classifier ensemble method has been applied to predict spatially landslide occurrences in the area. Prediction of temporally landslide occurrences in the present study has been done using rainfall data for the period 2008–2013. A total of fifteen landslide influencing factors namely slope, aspect, curvature, plan curvature, profile curvature, elevation, land use, lithology, rainfall, distance to faults, fault density, distance to roads, road density, distance to rivers, and river density have been utilized. The result of the analysis shows that RSSCE and probability analysis of rainfall data are promising methods for landslide hazard assessment. Finally, landslide hazard map has been generated by integrating spatial prediction and temporal probability analysis of landslides for the land use planning and landslide hazard management. 相似文献
16.
GIS和RS技术在湿地资源研究中的应用——以大庆市湿地为例 总被引:2,自引:0,他引:2
以大庆市湿地为研究对象,以地理信息系统和遥感技术为技术平台,介绍了湿地环境因子研究工作程序及湿地现状类型分布研究,分析了地理信息系统和遥感技术在湿地资源研究中的地位和作用,从而为GIS与RS技术在湿地资源应用研究中提供理论支持。 相似文献
17.
以湖南农业大学为研究区,对2005年和2010年的遥感影像进行土地利用景观分类,选取并计算具有代表性的景观指数,结合GIS的空间分析技术,从景观的总体和单元特征、空间构型和景观异质性等方面对景观变化情况进行分析。结果表明,经过五年的建设,研究区大量其他景观转变为绿地景观、道路景观、生活设施景观、娱乐场地景观及教学设施景观。尽管土地利用程度加大,但景观格局日趋合理,功能分区进一步明确,且生态环境得到较好的保护。 相似文献
18.
浙江省第二届测绘技能竞赛要求作业员利用立体测量矢量数据以及调绘资料等完成地图制图以及数据建库。现将iData数据工厂作为主要作业软件,先进行库体数据的处理,后由库体数据导出地形图。 相似文献
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传统的测绘精度控制方法中,起始数据误差与测量误差之间的比例因子要求过高,导致控制方法可靠性差。为此,以河北定州市农村土地确权为例,探讨大比例尺地籍测绘精度控制。使用GPS技术测量地形数据,完成图根控制测量,依据确权工作的具体情况,控制测量数据质量,在原有的控制网上叠加高级控制网,使用相同的比例因子,计算控制网精度,达到控制测绘精度的目的。实验结果表明:与传统方法相比,提出的精度控制方法中误差较低且绘制的地形图中未出现区域重叠问题。 相似文献