how to manage elevation values - Giswater/giswater_dbmodel GitHub Wiki

What is the elevation column used for system to calculate everything such slope among others? Both nodes and arcs uses non-editable columns, in fact columns calculated using some rules detalied below. For nodes the column is sys_elev and for arcs columns are sys_elev1 and sys_elev2.

**How are system elevation columns (sys_elev, sys_elev1 and sys_elev2) calculated?** They are calculated using two different strategies:

• Strategy 1 : Taking values from: NODES: elev column. ARCS: elev1 & elev2 columns.

• Strategy 2 : Using the formula top elevation minus depth values. NODES:top_elev - ymax ARCS: top_elev(node_1) - y1 or top_elev(node_2) - y2

WARNING: For each value for each row it is mandatory to use only one strategy. In case you fill in both, the system_elevation values may have conflict.

**What are the custom_ columns? How do they works?** The custom_ colums are columns ready to fill additional values for some data without overwriting the original. If value is present, custom columns will be used to calculated system elevation values.

Ex1: In case of fill data on elev1 as well as custom_elev1, both data custom_elev1 will be used to calculate sys_elev1.

**What is r1, z1, r2, z2?** This columns are whole calculated by system and their values means: r1: Distance from top_elevation to the highest part of the conduit (like covering depth on node_1). r2: Distance from top_elevation to the highest part of the conduit (like covering depth on node_2). z1: Distance from bottom of node to the lowest part of the conduit (some kind of step, if exists, againts node and arc) on node_1. z2: Distance from bottom of node to the lowest part of the conduit (some kind of step, if exists, againts node and arc) on node_2.

Details: