Detailed Description

Generate precipitation phase or splitting according to the selected method.

In order to handle solid and liquid precipitation, there are two possibilities: either as total amount and phase (respectively "PSUM" and "PSUM_PH") or as solid and liquid amounts (respectively "PSUM_S" and "PSUM_L"). This generator can convert from one representation to the other one.

This generator can also generate the missing components (for example, the precipitation phase associated with a given precipitation amout based on a splitting model). For more background on the performance of splitting models based on ground-level measurements, see for example Jennings, Keith S., et al., "Machine learning shows a limit to rain-snow partitioning accuracy when using near-surface meteorology", 2025, Nature Communications, 16.1, 10.1038/s41467-025-58234-2.

The component that will be generated depends on the parameter name, so only the following parameters are supported: PSUM, PSUM_PH, PSUM_L, PSUM_S. Whenever a component is missing, a splitting model is called to compute the splitting. It is therefore recommended to configure a splitting model.

It takes the following arguments:

TYPE: the splitting method to use, any of the following:
- NONE: don't do any splitting (default). This can be usefull to overwrite an inherited generator (from an imported file)
- WET_BULB: a provided fixed wet bulb temperature threshold splits precipitation as either fully solid or fully liquid (recommended, with a threshold of 273.65K)
- THRESH: a provided fixed air temperature threshold splits precipitation as either fully solid or fully liquid
- RANGE: two air temperature thresholds provide the lower and upper range for fully solid / fully liquid precipitation. Within the provided range, a linear transition is assumed.
SNOW: when using a fixed air temperature or wet bulb temperature threshold, this gives the snow/rain threshold (in K). When using two air temperatures thresholds, this provides the temperature below which only solid precipitation is found (in K);
RAIN: when using two air temperatures thresholds, this provides the temperature above which only liquid precipitation is found (in K);

For example, to generate the precipitation phase when only the precipitation amout is available, using a simple wet bulb temperature threshold for doing the splitting followed by a fallback generator only using an air temperature threshold using :

[Generators]
PSUM_PH::generator1 = PRECSPLITTING
PSUM_PH::arg1::type = WET_BULB
PSUM_PH::arg1::snow = ${{273.15+0.5}}
 
PSUM_PH::generator2 = PRECSPLITTING
PSUM_PH::arg2::type = THRESH
PSUM_PH::arg2::snow = 274.35

To generate the liquid and solid amounts from the precipitation sum and phase, relying on a simple temperature threshold for the splitting (if the precipitation phase is available, it will be used instead of calling the splitting model):

[InputEditing]
;using the '*' station ID, this will apply to all stations
*::edit1           = CREATE
*::arg1::algorithm = PRECSPLITTING
*::arg1::param     = PSUM_L
*::arg1::type      = THRESH
*::arg1::snow      = 274.35
 
*::edit2           = CREATE
*::arg2::algorithm = PRECSPLITTING
*::arg2::param     = PSUM_S
*::arg2::type      = THRESH
*::arg2::snow      = 274.35

To generate the precipitation sum and phase from the liquid and solid amounts without any fallback algorithm for the splitting:

[Generators]
PSUM::generator1 = PRECSPLITTING
PSUM_PH::generator1 = PRECSPLITTING

Note: When generating PSUM_L / PSUM_S, you most probably also need to set their resampling to "accumulate", like for PSUM...

#include <PrecSplitting.h>

Public Member Functions
	PrecSplitting (const std::vector< std::pair< std::string, std::string > > &vecArgs, const std::string &i_algo, const std::string &i_section, const double &TZ)

bool	generate (const size_t &param, MeteoData &md, const std::vector< MeteoData > &vecMeteo) override

bool	create (const size_t &param, const size_t &ii_min, const size_t &ii_max, std::vector< MeteoData > &vecMeteo) override
	Fill one time series of MeteoData for one station.

Public Member Functions inherited from mio::GeneratorAlgorithm
virtual	~GeneratorAlgorithm ()

bool	skipStation (const std::string &station_id) const
	Should this station be skipped, based on user-provided station ID restrictions?

bool	skipTimeStep (const Date &dt) const
	Should this timestep be skipped, based on user-provided time restrictions?

bool	skipHeight (const double &height) const

std::vector< DateRange >	getTimeRestrictions () const

std::string	getAlgo () const

Additional Inherited Members
Protected Member Functions inherited from mio::GeneratorAlgorithm
	GeneratorAlgorithm (const std::vector< std::pair< std::string, std::string > > &vecArgs, const std::string &i_algo, const std::string &i_section, const double &TZ)
	protected constructor only to be called by children

void	initHeightRestrictions (const std::vector< std::pair< std::string, std::string > > vecArgs)

Static Protected Member Functions inherited from mio::GeneratorAlgorithm
static std::set< std::string >	initStationSet (const std::vector< std::pair< std::string, std::string > > &vecArgs, const std::string &keyword)

Protected Attributes inherited from mio::GeneratorAlgorithm
const std::vector< DateRange >	time_restrictions

const std::set< std::string >	excluded_stations

const std::set< std::string >	kept_stations

std::set< double >	included_heights

std::set< double >	excluded_heights

bool	all_heights

const std::string	algo

const std::string	section

Static Protected Attributes inherited from mio::GeneratorAlgorithm
static const double	default_height = IOUtils::nodata

Constructor & Destructor Documentation

◆ PrecSplitting()

mio::PrecSplitting::PrecSplitting	(	const std::vector< std::pair< std::string, std::string > > &	vecArgs,
		const std::string &	i_algo,
		const std::string &	i_section,
		const double &	TZ
	)

inline

Member Function Documentation

◆ create()

bool mio::PrecSplitting::create	(	const size_t &	param,
		const size_t &	ii_min,
		const size_t &	ii_max,
		std::vector< MeteoData > &	vecMeteo
	)

overridevirtual

Fill one time series of MeteoData for one station.

This is used by the dataCreators to create a new parameter in one go for the whole timeseries.

Parameters

[in]	param	meteo parameter to generate
[in]	ii_min	minimum index to apply it to in vecMeteo
[in]	ii_max	maximum index to apply it to in vecMeteo
[in]	vecMeteo	meteo timeseries to process

Returns: true if all missing data points for the given parameter could be generated, false otherwise

Implements mio::GeneratorAlgorithm.

◆ generate()

bool mio::PrecSplitting::generate	(	const size_t &	param,
		MeteoData &	md,
		const std::vector< MeteoData > &	vecMeteo
	)