Murray River Adjoint Catchments - Murray adjoint catchment areas from a 30 m digital elevation model

This dataset is the Murray River adjoint catchment areas 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 Murray River adjoint catchment areas 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 Adjoint Catchments are the aggregated upstream catchments from the "Catchment" feature class. For each catchment that is not a head catchment, a polygon representing the whole upstream area draining to its inlet point is constructed and stored in a feature class. 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工具生成的墨累河伴随汇水区，其溪流定义阈值为5000个栅格单元。莫斯曼河汇水区位于澳大利亚昆士兰州东北部的湿热带区域。溪流定义基于由30米分辨率数字高程模型（digital elevation model, DEM）生成的流量累积栅格，相关研究参见S. R. Januchowski、R. L. Pressey、J. VanDerWal与A. Edwards于2010年发表于《国际地理信息科学期刊》（*International Journal of Geographical Information Science*）且即将刊出的《Characterizing errors in digital elevation models and estimating the financial costs of accuracy》一文。

### 应用目的
本数据集旨在为与淡水生态系统相关的保护与管理规划及决策制定工作提供参考依据。该次级汇水区由30米分辨率数字高程模型勾绘得到，因此适用于解答区域尺度的汇水区管理相关问题。

### 数据集编制历程
本数据集为采用ArcHydro 1.3工具生成的墨累河伴随汇水区，其溪流定义阈值为5000个栅格单元，溪流定义基于由30米分辨率数字高程模型生成的流量累积栅格。伴随汇水区指源自「汇水区」要素类（feature class）的聚合上游汇水区。针对每个非源头汇水区，将构建覆盖其汇水入口点上游全部汇水区域的多边形，并存储于要素类中。本数字高程模型结合数字地形等高线数据与源自SRTM高分辨率地形数据库（http://www2.jpl.nasa.gov/srtm/）的点位数据生成。该模型的参数规格与精度信息参见前述2010年的研究论文。地形等高线数据的平面与垂直位置精度均为20米。本数字高程模型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。