.. _hazard-common-params: Common hazard parameters ------------------------ ******* general ******* In a section conventionally called ``[general]``, the user specifies the parameters to specify the calculation type and description:: [general] description = A demo OpenQuake-engine .ini file for classical PSHA calculation_mode = classical - ``description``: a parameter that can be used to designate the model - ``calculation_mode``: used to set the kind of calculation. In this example it corresponds to ``classical``. Alternative options for the calculation_mode are described later in this manual. ******** geometry ******** A section conventionally called ``[geometry]`` is used to specify where the hazard will be computed. Two options are available. The first option is to define a polygon (usually a rectangle) and a distance (in km) to be used to discretize the polygon area. The polygon is defined by a list of longitude-latitude tuples, and the coordinates must be provided in either a clockwise or counterclockwise order. An example is provided below:: [geometry] region = 10.0 43.0, 12.0 43.0, 12.0 46.0, 10.0 46.0 region_grid_spacing = 10.0 The second option allows the definition of a number of sites where the hazardwill be computed. Each site is specified in terms of a longitude, latitude tuple. Optionally, if the user wants to consider the elevation of the sites, a value of depth [km] can also be specified, where positive values indicate below sea level, and negative values indicate above sea level (i.e. the topographic surface). If no value of depth is given for a site, it is assumed to be zero. An example is provided below:: [geometry] sites = 10.0 43.0, 12.0 43.0, 12.0 46.0, 10.0 46.0 If the list of sites is too long the user can specify the name of a CSV file as shown below:: [geometry] sites_csv = The format of the CSV file containing the list of sites is a sequence of points (one per row) specified in terms of the longitude, latitude tuple. Depth values are again optional. An example is provided below:: site_id,lon,lat 0,179.0,90.0 1,178.0,89.0 2,177.0,88.0 For reasons of backward compatibility, it is also possible to skip the header and to omit the ``site_id`` column, however we recommend to avoid that format, since it is error prone given that many users tend to use the lat,lon convention instead of the lon,lat convention that the engine honors:: 179.0,90.0 178.0,89.0 177.0,88.0 *************** site conditions *************** Such parameters are used to specify local soil conditions and are normally listed in a section of the ``job.ini`` file called ``[site_params]``. The simplest possibility is to define uniform site conditions (i.e. all the sites have the same characteristics), as in this example:: [site_params] reference_vs30_type = measured reference_vs30_value = 760.0 reference_depth_to_2pt5km_per_sec = 5.0 reference_depth_to_1pt0km_per_sec = 100.0 reference_backarc = 0 Alternatively it is possible to define spatially variable soil properties in a separate file; the engine will then assign to each investigation location the values of the closest point used to specify site conditions:: [site_params] site_model_file = site_model.csv The file containing the site model has the following structure:: lon,lat,vs30,z1pt0,z2pt5,vs30measured,backarc 10.0,40.0,800.0,19.367196734,0.588625072259,0,0 10.1,40.0,800.0,19.367196734,0.588625072259,0,0 10.2,40.0,800.0,19.367196734,0.588625072259,0,0 10.3,40.0,800.0,19.367196734,0.588625072259,0,0 10.4,40.0,800.0,19.367196734,0.588625072259,0,0 Notice that the 0 for the field ``vs30measured`` means that the ``vs30`` field is inferred, not measured. Most of the GMPEs are not sensitive to it, so you can usually skip it. For the ``backarc`` parameter 0 means false and this is the default, so you can skip such column. All columns that have defaults or are not needed by the GMPEs you are using can be skipped, while you will get an error if a relevant column is missing. If the closest available site with soil conditions is at a distance greater than 5 km from the investigation location, a warning is generated. **Note**: For backward-compatibility reasons, the site model file can also be given in XML format. That old format is deprecated but there are no plans to remove it any soon. There are a lot more site parameters than the one listed above. You can get the full list with the command `oq info`:: $ oq info site_params # full list as of engine-3.20 D50_15 F_15 Fs PHV THV T_15 T_eq ampcode amplfactor backarc bas ch_ampl03 ch_ampl06 ch_phis2s03 ch_phis2s06 ch_phiss03 ch_phiss06 cohesion_mid crit_accel cti custom_site_id dc depth dr dry_density dw dwb ec8 ec8_p18 f0 freeface_ratio friction_mid geohash geology gwd h800 hwater in_cshm kappa0 lat liq_susc_cat lon precip region relief saturation sids site_id siteclass slope soiltype tri unit vs30 vs30measured xvf yield_acceleration z1pt0 z1pt4 z2pt5 zwb Most parameters are very specific to particular GMPEs and particular calculations, so you need to study the implementation of the specific feature you are interested in to know what they mean and how they work.