民国初期河南省1∶10万地图精度分析

Accuracy Analysis of the 1∶100000 Topographic Maps of Henan Province in Early Period of the Republic of China

清末与民国初期调绘了大范围的、内容较为详尽的1∶2.5万至1∶20万比例尺地图,是研究20世纪初中国历史的宝贵资料。为高效利用这些地图资源,评估地图精度提供了基础性的图件。针对民国初期河南陆地测量局调绘的1∶10万河南省地图,应用ArcGIS软件将民国地图与当代地图作对比,对其精度进行了系统分析和初步解释。分析表明:①全省范围内地图精度分布不均匀,经线方向平均向西偏移6.28′、纬线方向平均向南移2.23′,标准差分别为3.76和2.51。②纬线方向绝对精度和相对精度总体上高于经线方向;同时,误差分布呈现空间自相关特征,经向误差Moran′s I指数为0.85(Z=57),纬向指数为0.69(Z=46)。③平原地区地图相对精度高于山区。④地图误差分布呈现三种模式:位置偏移较小,偏移较大但偏移向量保持一致,以及偏移较大且方向不一致。民国地图误差与《清史稿》记载的经纬度误差具有较强的相关性,由此提出的一个初步推论:民国地图调查作业中采用了晚清时期的经纬度成果。但有些地区利用了较新的成果,也有部分地区参照或转绘了质量较差的旧地图。本研究为民国初期河南省地图的进一步利用提供了依据,也对同期地图的利用具有借鉴价值。

Surveying and mapping were active in the period of later Qing Dynasty and early Republic of China,and numerous topographic maps（scale： 1∶25 000 to 1∶200 000） covering major areas of China were published.For efficient utilization of the old maps,this paper aims to evaluate the accuracy of the 1∶100 000 topographic maps of Henan Province in early period of the Republic of China（1915~1916）.The possible sources of map displacement were also discussed using longitude and latitude records in historical books.The map accuracy was analyzed using the displacement of sampling points.The 159 sheets of old maps were overlaid with current map layers in ArcGIS for comparison.Using ArcGIS Spatial Adjustment Extension and searching the same point in old maps and new maps,741 displacement links with original and actual coordinates were determined.The displacement map and statistics show that：（1） the longitude and latitude errors of old maps are distributed unevenly,and the average shifts are 6.28 minutes toward west and 2.23 minutes to the south,with standard deviation of 3.76 and 2.51 respectively.（2） Both the absolute and relative errors at longitude direction are higher than that at latitude direction.At the same time,the errors present an autocorrelation pattern and the Moran＇s I of longitude and latitude errors are 0.85（Z=57） and 0.69（Z=46）.（3） In general,the maps in plain area are better than those in mountain area in term of relative accuracy.（4） The errors in old maps present three patterns： higher absolute and relative accuracy,lower absolute but higher relative accuracy,and lower absolute and relative accuracy.To explore the source of absolute errors,the longitude and latitude records of the prefecture cities and county towns were collected from records in historical books.Mapping the historical records as point layers and overlaying it with old and current residential map layers in ArcGIS,the point displacements show that the shift trend of old maps is similar to those coordinate records in Draft History of Qing.Regression analysis confirms the linear and positive association between them.A hypothesis formulated from this finding is that the longitude and latitude records in later Qing Dynasty were utilized in early period of the Republic of China.It is also suggested that during the map investigation,both the newly-surveyed maps and existing older maps were also used in some areas.