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

This dataset is the Tully 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 subcatchments 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 Tully 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生成的塔利河附属汇水区，溪流提取阈值设为5000个栅格单元。莫斯曼河集水区位于澳大利亚昆士兰州东北部的湿热带地区。溪流提取基于由30米数字高程模型（digital elevation model, DEM）生成的流量累积栅格完成（S. R. Januchowski、R. L. Pressey、J. VanDerWal与A. Edwards，2010年。《Characterizing errors in digital elevation models and estimating the financial costs of accuracy》，《International Journal of Geographical Information Science》，待刊）。

### 数据集用途
本数据集专为支撑淡水生态系统相关的保护、管理规划与决策工作而构建。本次提取的子汇水区均基于30米数字高程模型完成勾绘，因此可适用于区域尺度下的集水区管理相关研究与问题解答。

### 数据集编制历史
本数据集为采用ArcHydro 1.3生成的塔利河附属汇水区，溪流提取阈值设为5000个栅格单元。溪流提取基于由30米数字高程模型生成的流量累积栅格完成。附属汇水区指从“集水区”要素类中聚合得到的上游汇水区；针对每个非源头集水区，将构建一个表征其汇入口点上游完整汇水范围的多边形，并存储于要素类中。
本次使用的数字高程模型结合了数字地形等高线与来自SRTM高分辨率数字地形数据库（http://www2.jpl.nasa.gov/srtm/）的点数据生成。该模型的规格与精度信息详见S. R. Januchowski、R. L. Pressey、J. VanDerWal与A. Edwards 2010年发表于《International Journal of Geographical Information Science》的待刊论文《Characterizing errors in digital elevation models and estimating the financial costs of accuracy》。其中，地形等高线数据的位置精度（涵盖垂直与水平方向）为20米；数字高程模型在高地形起伏区域的垂直精度为17.53米，低地形起伏区域为6.31米。