Advanced features
Land cover evolution
The land cover types in hydrobricks are defined by the user (see the hydro units section). Each hydro unit is thus internally defined by a total area and fractional land covers. These land covers can have a dynamic evolution, externally driven. One can provide the model with a timeseries of dates and new land cover areas, such as:
changes = behaviours.BehaviourLandCoverChange()
changes.load_from_csv(
'/path/to/surface_changes_glacier_debris.csv',
hydro_units, area_unit='km2', match_with='elevation'
)
model.add_behaviour(changes)
The definition of a land cover evolution does not replace the original definition of
the hydro units, which need to be also provided to the function.
The areas provided in the definition of the hydro units are the starting point of the
model, and these changes will be enforced in due time.
However, if some changes are defined for dates prior to the start of the modelling
period, these changes will also be applied.
The function changes.load_from_csv() can be called multiple times for different files.
The corresponding csv file must contain the name of the land cover to change on the
first row (for example here glacier_debris), the dates of these changes on the
second row, and then the change time series.
These changes list all hydro units that need to change; those that do not need to
change should not be listed in the file.
There are two ways to identify the hydro units: by elevation
(match_with='elevation') or by ID (match_with='id').
In the following example, these changes start with the unit elevation and contain the
time series of the area (here in km2) for every date given above.
bands,glacier_debris,glacier_debris,glacier_debris,glacier_debris,glacier_debris,glacier_debris,glacier_debris,glacier_debris,glacier_debris,glacier_debris,glacier_debris,glacier_debris,glacier_debris,glacier_debris,glacier_debris,glacier_debris,glacier_debris
,01/08/2020,01/08/2025,01/08/2030,01/08/2035,01/08/2040,01/08/2045,01/08/2050,01/08/2055,01/08/2060,01/08/2065,01/08/2070,01/08/2075,01/08/2080,01/08/2085,01/08/2090,01/08/2095,01/08/2100
4274,0.013,0.003,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
4310,0.019,0.009,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
4346,0.052,0.042,0.032,0.022,0.012,0.002,0,0,0,0,0,0,0,0,0,0,0
4382,0.072,0.062,0.052,0.042,0.032,0.022,0.012,0.002,0,0,0,0,0,0,0,0,0
4418,0.129,0.119,0.109,0.099,0.089,0.079,0.069,0.059,0.049,0.039,0.029,0.019,0.009,0,0,0,0
4454,0.252,0.242,0.232,0.222,0.212,0.202,0.192,0.182,0.172,0.162,0.152,0.142,0.132,0.122,0.112,0.102,0.092
4490,0.288,0.278,0.268,0.258,0.248,0.238,0.228,0.218,0.208,0.198,0.188,0.178,0.168,0.158,0.148,0.138,0.128
4526,0.341,0.331,0.321,0.311,0.301,0.291,0.281,0.271,0.261,0.251,0.241,0.231,0.221,0.211,0.201,0.191,0.181
4562,0.613,0.603,0.593,0.583,0.573,0.563,0.553,0.543,0.533,0.523,0.513,0.503,0.493,0.483,0.473,0.463,0.453
4598,0.648,0.638,0.628,0.618,0.608,0.598,0.588,0.578,0.568,0.558,0.548,0.538,0.528,0.518,0.508,0.498,0.488
4634,0.618,0.608,0.598,0.588,0.578,0.568,0.558,0.548,0.538,0.528,0.518,0.508,0.498,0.488,0.478,0.468,0.458
4670,0.478,0.468,0.458,0.448,0.438,0.428,0.418,0.408,0.398,0.388,0.378,0.368,0.358,0.348,0.338,0.328,0.318
4706,0.306,0.296,0.286,0.276,0.266,0.256,0.246,0.236,0.226,0.216,0.206,0.196,0.186,0.176,0.166,0.156,0.146
4742,0.338,0.328,0.318,0.308,0.298,0.288,0.278,0.268,0.258,0.248,0.238,0.228,0.218,0.208,0.198,0.188,0.178
4778,0.199,0.189,0.179,0.169,0.159,0.149,0.139,0.129,0.119,0.109,0.099,0.089,0.079,0.069,0.059,0.049,0.039
4814,0.105,0.095,0.085,0.075,0.065,0.055,0.045,0.035,0.025,0.015,0.005,0,0,0,0,0,0
4850,0.051,0.041,0.031,0.021,0.011,0.001,0,0,0,0,0,0,0,0,0,0,0
4886,0.019,0.009,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
4922,0.008,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
4958,0.003,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
There is no need to specify the corresponding changes in the generic ground land
cover as it will be automatically computed to preserve the total hydro unit area.