## Global Distributed Basin Characteristics (GDBC)

### Example

The algorithm of GDBC is demonstrated here in a tiny basin in North America.A few key variables used in the computation are described here. array (vector) variables store one-dimensional (1d ) indices that denote 1-based column-prior location of grids.

Key Variables during iterations

Variable | Description |

U | a 1d-index array of the outlet cells in the last group which are tributary cells in the current group |

D | a 1d-index array of the next downstream cells of U |

U_{U} |
the non-repeatable version of U |

B | a 1d-index array of boundary cells of U |

B_{M} |
a boundary mouth matrix of the same size as the entire map, which stores at the location of each boundary cell its basin mouth in the current group. Zero value indicates that the given cell is not located at a boundary while NaN value means out of basin. |

N_{1}-N_{4} |
matrices of the same size as BM that store a logical number at the location of each boundary cell to indicate whether a boundary cell faces outward of the basin |

#### References:

[1] Shen, Xinyi, Emmanouil N. Anagnostou, Yiwen Mei, and Yang Hong. “A global distributed basin morphometric dataset.” Scientific data 4 (2017): 160124.

[2] Shen, Xinyi, Humberto J. Vergara, Efthymios I. Nikolopoulos, Emmanouil N. Anagnostou, Yang Hong, Zengchao Hao, Ke Zhang, and Kebiao Mao. “GDBC: A tool for generating global-scale distributed basin morphometry.” Environmental modelling & software 83 (2016): 212-223.