Integrating remote sensing and GIS techniques for monitoring and modeling shoreline evolution to support coastal risk management     

Luca Cenci  Leonardo Disperati  Maria Giuseppina Persichillo  Eduardo R Oliveira  Fátima L Alves  Michael Phillips 《地理信息系统科学与遥感》2018,55(3):355-375

The precise delineation of coastal areas subject to past, present, and future erosive processes plays a fundamental role in coastal risk management. Within this framework, satellite data represent a valuable synoptic and multi-temporal information source. Therefore, this research integrated remote sensing and GIS techniques for mapping and modeling shoreline evolution through time. Long-term shoreline’s proxy rates of advance and retreat were determined using Landsat data from the mid-1980s to 2011 and subsequently, a short-term scenario (3 years) was predicted and validated. Two different coastal environments, Oceanic and Mediterranean, were investigated. In the first, different proxies were analyzed, thereby enabling a multi-proxy analysis. Findings showed that the method provided more accurate results in higher energy environments (Oceanic) and where the coastline is not urbanized. Results also highlighted the importance of performing multi-proxy analyses in given study areas, to more reliably define shoreline modeling. Importantly, during the analyses, particular attention was given to assessing uncertainty, which is crucial when outcomes of scientific research are considered for management.  相似文献   

Mapping crop phenology using NDVI time-series derived from HJ-1 A/B data     

《International Journal of Applied Earth Observation and Geoinformation》2015

With the availability of high frequent satellite data, crop phenology could be accurately mapped using time-series remote sensing data. Vegetation index time-series data derived from AVHRR, MODIS, and SPOT-VEGETATION images usually have coarse spatial resolution. Mapping crop phenology parameters using higher spatial resolution images (e.g., Landsat TM-like) is unprecedented. Recently launched HJ-1 A/B CCD sensors boarded on China Environment Satellite provided a feasible and ideal data source for the construction of high spatio-temporal resolution vegetation index time-series. This paper presented a comprehensive method to construct NDVI time-series dataset derived from HJ-1 A/B CCD and demonstrated its application in cropland areas. The procedures of time-series data construction included image preprocessing, signal filtering, and interpolation for daily NDVI images then the NDVI time-series could present a smooth and complete phenological cycle. To demonstrate its application, TIMESAT program was employed to extract phenology parameters of crop lands located in Guanzhong Plain, China. The small-scale test showed that the crop season start/end derived from HJ-1 A/B NDVI time-series was comparable with local agro-metrological observation. The methodology for reconstructing time-series remote sensing data had been proved feasible, though forgoing researches will improve this a lot in mapping crop phenology. Last but not least, further studies should be focused on field-data collection, smoothing method and phenology definitions using time-series remote sensing data.  相似文献   

西北地区一次人工消雨试验效果分析     

尹宪志  付双喜  李宝梓  张丰伟  丁瑞津  陈祺 《干旱区地理》2015,38(3)

通过利用人工消雨作业目标区和对比区降水量资料,研究了作业前后降水量的时间变化和空间变化。开展作业后作业区出现了显著的降水低值区,作业影响区出现了延迟降水。说明集中过量播撒作业对抑制云团的发展起到了积极的作用,消雨作业实施后1~3 h内有一定的作业效果。消雨作业实施后,目标区(影响区)的降水量要明显小于对比区的降水量。  相似文献   

A TIME SERIES ANALYSIS OF STATE GASOLINE DEMAND, 1975–1980 *     

David L. Greene  Chih-Kang Chen 《The Professional geographer》1983,35(1):40-51

ARIMA time series model building techniques are used to construct fifty-one state gasoline demand models based on monthly data for the period of January, 1975 to July, 1960. Statistically satisfactory models are obtained for all states. Price elasticity estimates are >0 for all states. All but four are statistically significant at the 0.05 level. The significant price elasticity estimates range from ?0.138 to ?0.377, with most clustering about ?0.2. Estimates of state gasoline supply shortages for May, June, and July, 1979 are also presented which range from 0 to 8 percent of normal consumption for the three-month-period.  相似文献   

基于卡尔曼滤波重建的GPS点位修正     

徐爱功  吴探诗  隋心  张建龙 《测绘工程》2014,23(10):1-3

由于单点定位的结果受卫星星历误差、卫星钟误差以及卫星信号传播过程中大气延迟误差的影响较为显著,因此解算出的定位结果在真值附近上下浮动。文中采用ARMA模型建立卡尔曼滤波的观测方程和状态方程,并对定位结果进行滤波;采用一次滤波后的坐标值作为初值,建立ARMA模型并二次滤波。实验表明,滤波有效防止了定位结果偏差过大情况的发生,使滤波收敛值与准确值最大偏差不超过3cm,表明采用一次滤波后的坐标值建立的模型更为合理,从而为单点定位结果的时间序列模型的建立提供一种新方法。  相似文献   

B) Organisations internationales     

《水文科学杂志》2013,58(1):130-161

Abstract

A modification of Svanidze's fragments method was applied to generate synthetic samples of monthly inflows to the La Angostura and Malpaso dams, located on the Grijalva River, in the state of Chiapas, Mexico. This modification allows generation of the monthly runoff of several dams in a series and preservation of their cross-correlations. Comparing statistics of generated and historical series, a good agreement between them was observed, especially for the autocorrelations between consecutive months and for cross-correlations between both dams, except for slight differences in the standard deviation and the skewness during the dry period.  相似文献   

Stream water geochemistry from selected catchments on the Kola Peninsula (NW Russia) and in neighbouring areas of Finland and Norway: 2. Time-series     

Patrice de Caritat  Clemens Reimann  Matti Äyräs  Heikki Niskavaara  Viktor A. Chekushin  Vladimir A. Pavlov 《Aquatic Geochemistry》1996,2(2):169-184

Stream water composition, measured weekly for 8–9 months in 1994 in three arctic catchments on and around the Kola Peninsula (Russia, Finland and Norway), is presented in the form of time-series. In all three catchments, snowmelt causes a major dilution of the stream water, as reflected by marked dips in electrical conductance. In the most polluted catchment (C2), the snowmelt flood (the major hydrological event at these latitudes) is reflected in the stream water by a pH dip and a pulse in technogenic heavy metals (Cu, Ni, etc.), Al and S. This results from melting of the snow laden with heavy metals and sulphate, and from leaching of the topsoil layer. In the most pristine catchment (C8), snowmelt causes no heavy metal pulse (remote location) but yields an increase in stream water Al (acidic lithology/overburden). In the intermediate catchment (C5), very subdued heavy metal and S increases are noticeable in the stream water, whilst its pH increases steadily until summer (basic lithology). Some elements (Cl, S) may be mobilised out of the snowpack before its complete thawing and reach the stream 1–2 weeks ahead of the heavy metals. The substrate (soil, overburden and bedrock) of a catchment controls to a large extent its ability to buffer acid inputs.  相似文献   

基于时序数据库的空间数据处理     

林荫峰  林俊仁  杨俞平 《测绘与空间地理信息》2017,40(Z1)

分析了空间数据和时间序列数据的基本概念,提出了引入时序数据库技术来解决传统数据库在处理海量数据时遇到的存储容量和访问效率方面的问题.使用时序数据库可以很好地解决目前时序数据所遇到的一些问题.最后介绍了一种特殊的时间序列数据库的技术架构和使用该架构时间序列数据库处理空间数据的相关案例.该种架构的时间序列数据库可以更好地处理时序数据和空间数据相结合的问题.  相似文献   

基于客源地的聚类-ARIMA模型的短期旅游需求预测--以天津欢乐谷主题公园为例     

段莉琼  宫辉力  刘少俊  刘泽华  李勇永  葛军莲 《地域研究与开发》2017,36(3)

大多数旅游需求预测研究是基于目的地游客总数或消费总量开展的,尚未按不同的旅游目的或客源地细分进行预测.以天津欢乐谷主题公园为案例地,选择2014年第40周到2015年第26周为研究时段,利用通信大数据,提出了一种面向客源地的聚类-ARIMA组合预测模型.通过对不同客源地的时序数据进行聚类,选取各类别中的代表性客源地分别构建ARIMA预测模型.结果表明:对欢乐谷主题公园各客源地分别建模与聚类后通过6个代表客源地建模得到的结果一致;后者可以降低80%的预测成本.该方法具有较高的预测精度和较低的计算成本,适合面向客源地的短期旅游需求预测,可为旅游目的地提供更具针对性的旅游需求管理、分析与决策支撑.  相似文献   

Comparative analysis of Calanus finmarchicus demography at locations around the Northeast Atlantic   总被引：1，自引：0，他引：1  

Heath  M. R.; Astthorsson  O. S.; Dunn  J.; Ellertsen  B.; Gaard  E.; Gislason  A.; Gurney  W. S. C.; Hind  A. T.; Irigoien  X.; Melle  W.; Niehoff  B.; Olsen  K.; Skreslet  S.; Tande  K. S. 《ICES Journal of Marine Science》2000,57(6):1562-1580

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