South Johnstone River Drainage Line - South Johnstone drainage line delineations from a 30 m digital elevation model

This dataset is the South Johnstone River drainagelines file created using ArcHydro 1.3, with a stream definition threshold of 5,000 cells. The Mossman River catchment is located in the Wet Tropics region of northeast Queensland Australia. Stream definition was determined from a flow accumulation grid which was generated from a 30 m digital elevation model (S. R. Januchowski, R. L. Pressey, J. VanDerWal and A. Edwards. 2010. Characterizing errors in digital elevation models and estimating the financial costs of accuracy. International Journal of Geographical Information Science. in press.)
Purpose:
This data set has been designed to inform conservation and management planning and decision making exercise related to freshwater ecosystems. The sub catchments have been delineated from a 30 m digital elevation model, and therefore, are suitable for addressing catchment management questions at a regional scale.
History:
This dataset is the South Johnstone River drainage lines created using ArcHydro 1.3, with a stream definition threshold of 5,000 cells. Stream definition was determined from a flow accumulation grid which was generated from a 30 m digital elevation model (DEM). The DrainageLine is the line through the centers of the Digital Elevation Model (DEM) cells on a drainage path. Drainage lines are produced when the DEM-based drainage paths are vectorized. The DEM was created using a combination of digital topographic contour lines and point data derived from the SRTM high-resolution digital topographic database (http://www2.jpl.nasa.gov/srtm/). The specifications and accuracy of this model are reported in S. R. Januchowski, R. L. Pressey, J. VanDerWal and A. Edwards. 2010. Characterizing errors in digital elevation models and estimating the financial costs of accuracy. International Journal of Geographical Information Science. in press. The topographic contour data had a 20 m positional accuracy (vertical and horizontal).The DEM had a vertical accuracy of 17.53 m in higher-relief areas and 6.31 in low-relief areas.

本数据集为采用ArcHydro 1.3工具生成的南约翰斯顿河（South Johnstone River）水系线文件，水系定义阈值设为5000个栅格单元。莫斯曼河（Mossman River）流域位于澳大利亚昆士兰州东北部的湿热带（Wet Tropics）区域。水系定义基于由30米分辨率数字高程模型（digital elevation model, DEM）生成的流量累积栅格计算得到（S. R. Januchowski、R. L. Pressey、J. VanDerWal与A. Edwards，2010年：《表征数字高程模型误差并估算精度提升的经济成本》，《国际地理信息科学期刊》，待刊）。

用途：
本数据集旨在为淡水生态系统相关的保护、管理规划与决策工作提供数据支撑。子流域由30米分辨率数字高程模型勾绘而成，适用于开展区域尺度的流域管理相关研究与决策问题分析。

历史沿革：
本数据集为采用ArcHydro 1.3工具生成的南约翰斯顿河水系线文件，水系定义阈值设为5000个栅格单元。水系定义基于由30米分辨率数字高程模型生成的流量累积栅格计算得到。水系线（DrainageLine）指沿汇水路径穿过数字高程模型栅格中心的线状要素。基于DEM的汇水路径经矢量化处理后即可生成水系线。本DEM由数字地形等高线与源自SRTM高分辨率数字地形数据库（http://www2.jpl.nasa.gov/srtm/）的点位数据融合生成。该DEM的参数与精度信息详见S. R. Januchowski、R. L. Pressey、J. VanDerWal与A. Edwards，2010年：《表征数字高程模型误差并估算精度提升的经济成本》，《国际地理信息科学期刊》，待刊。本次使用的地形等高线数据的水平与垂直位置精度均为20米。该DEM在高地形起伏区域的垂直精度为17.53米，在低地形起伏区域的垂直精度为6.31米。