Evidence of China's sea boundary in the South China Sea

According to a series of important historical maps,i.e.,the Location Map of the South China Sea Islands,the Nansha Islands,Zhongsha Islands,Xisha Islands,Yongxing Island and Shidao Island,and Taiping Island（archived by the Territorial Administration Division of the Ministry of Interior of Republic of China in 1946）,and the Administration District Map of the Republic of China published in 1948,the dashed line surrounding the South China Sea Islands represents China＇s sea boundary in the South China Sea at that time.It was both connected with,and an extension of,the land boundary of China.At that time the dashed line was used to represent the waters boundaries while the solid line was used to represent the land boundary—a universal method used in maps that was then recognized internationally.The above observation provides historical and scientific evidence of China＇s sea boundary in the South China Sea that is useful for the international maritime delimitation over the South China Sea area.

Methodological Issues for a Landscape-Changing Analysis in Adaptive Excess Water Management

Hungary is located in the deepest part of the Pannonian Basin,which is affected by floodwaters.Lowland areas are particularly vulnerable to floods.Many natural and anthropogenic processes have contributed to the formation of these flood patches,after river regulation(decisively from the middle of 18th century)and continue to affect them.The objective of this research is to reveal the processes of landscape-change in areas of waterlogging,or areas threatened by excess water inundation in order to establish methods of adaptive excess water management.The analysis focuses on examining the previously prevalent land-use structure and linear infrastructure elements(green,blue infrastructures)of the past 200-250 years that can be identified using historical,military maps and aerial photos.Historical maps compare different periods of 50-60 years prevalence.As a result of this analysis,the role of watercourses in shaping landscapes and human intervention process can be monitored and supported with maps including data.The processing consisted of geographic information system(GIS)methods:georeference the historical maps and digitalize the well-separable land-uses of the sample area.The results confirmed the process of landscape-change and the trend of green areas:cultivated areas and the spread of settlements.In conclusion,landscape-changing analyses of landscape-changes provide valuable data onto identifying changes in land-use,which are complemented by hydrological databases,especially those related to waterlogging areas,as they adequately support adaptive excess water management methods in areas with specific characteristics.The results show which land-uses can be considered as permanent,stable land-uses in the given sample area and broach whether changes within the green and blue infrastructure network contribute to the increase or decrease of excess water formation.

Multi-frame and multi-dimensional historical digital cities: the Como example

In this article,we present the realisation of a multi-frame and multi-dimensional WebGIS that allows users to simultaneously analyse a specific portion of the Earth taking into account the historical information,too.Two graphical panels have been realised:one for the usual 2D view and one for a more realistic 3D view.Both panels display historical maps of the city,the current orthophoto and the digital topographical map.The 3D frame is based on NASA World Wind,an open source virtual globe from where 3D buildings are shown extruding the 2D shapes using their mean height.Thanks to a specifically designed graphical user interface,it is also possible to dynamically thematise the buildings on the globe according to different criteria(e.g.the construction time span)so that only the geometries fulfilling the request are turned on.Within the proposed application,a synchronisation between the two panels has been implemented,in order to maintain a constant alignment of the two viewers.The application is also open to the time dimension.In fact,assigning to each geometry two dates(e.g.‘year of construction’and‘year of demolition’),it is possible to dynamically view how buildings have changed over time,both in their shape and height.Future developments of this work will concern the possibility of implementing a city model with a higher level of detail.

近百年台湾省林地时空格局重建研究——1910-2010年

Reconstructing long-term changes of forest cover(FC)can provide reliable underlying data for carbon source/sink accounting and simulation of the effects of land use on the climate and environment.Historical maps contain a wealth of forest related information and can provide first-hand data for studying the changes in FC over a long time period.Taking the reconstruction of FC in Taiwan Province from 1910-2010 as the research object,we used map extraction and mining methods to extract forest distribution information from historical forest thematic survey maps,topographic and land cover maps,and reconstructed the spatiotemporal patterns of FC in Taiwan from 1910-2010.The results show that:first,the relative bias of the FC area extracted from the historical maps of Taiwan was below 8%,meaning the FC information contained in maps is highly accurate.Second,the FC of Taiwan has generally declined in the past 100 years.From 1910-2010,the forest area declined from 2.62×10^(6) ha to 2.47×10^(6) ha,with relatively obvious forest reduction having occurred.In stages,the forest area of Taiwan decreased by 26.39×10^(4) ha from 1910 to 1950;and increased by 10.53×10^(4) ha during the period 1950-2010.Forest reduction was obvious during the Japanese occupation period,while forest increase was remarkable during the Kuomintang period.Third,during the study period,the total area of patches maintained as forests was 2.17×10^(6) ha with little change in the overall pattern,and forests were mainly distributed in the mountain regions.The loss of forest mainly occurred in the plains,with expanding forest areas mainly in the mountain regions at high elevations and on steep slopes.Fourth,land clearing for agriculture during the Japanese occupation period has been the important driver of forest reduction in Taiwan over the past century.After retreated to Taiwan,the Kuomintang government introduced effective and remarkable reforms that led to effective restoration of forest vegetation in many areas where forests had previously disappeared.