Retrieve salinity measurements on multiple heights

[veenstrajelmer]

When retrieving salinity measurements for e.g. HOEKVHLD, it is difficult to get data on all the available heights. There are dedicated HVH90/HVH45/HVH25 stations but these seem to contain only realtime information (and only nans). When downloading data for all stations for an arbitrary period, there are only two stations with data:

import ddlpy
import matplotlib.pyplot as plt
plt.close("all")

locations = ddlpy.locations()
# bool_stations = locations.index.isin(['HOEKVHLD'])
bool_stations = locations['Naam'].str.contains("olland")
# bool_stations = locations.index.isin(['HVH90','HVH45','HVH25'])
bool_grootheid = locations['Grootheid.Code'].isin(['SALNTT'])
selected = locations.loc[bool_grootheid & bool_stations]

start_data = "1988-01-01"
end_date = "1990-01-01"

print(f"downloading data for {len(selected)} stations")
fig, ax = plt.subplots()
for irow, row in selected.iterrows():
    last = ddlpy.measurements_latest(selected.iloc[0])
    station_code = row.name
    print(f"{station_code}: last measurement is {last.index[0]}")
    measurements = ddlpy.measurements(row, start_data, end_date)
    if measurements.empty:
        print("[NODATA]")
        continue
    measurements.plot(ax=ax, label=station_code, y='Meetwaarde.Waarde_Numeriek')
ax.legend()

Gives:

And prints:

downloading data for 8 stations
HVH90: last measurement is 2024-04-04 09:50:00+01:00
100%|██████████| 24/24 [00:14<00:00,  1.71it/s]
[NODATA]
HOEKVHLDMDN: last measurement is 1976-04-13 10:10:00+01:00
100%|██████████| 24/24 [00:14<00:00,  1.67it/s]
[NODATA]
HOEKVHLDNOVR: last measurement is 1976-04-13 10:20:00+01:00
100%|██████████| 24/24 [00:13<00:00,  1.72it/s]
[NODATA]
HOEKVHLZOVR: last measurement is 1976-04-13 10:00:00+01:00
100%|██████████| 24/24 [00:14<00:00,  1.66it/s]
[NODATA]
HVH45: last measurement is 2024-04-04 09:50:00+01:00
100%|██████████| 24/24 [00:13<00:00,  1.74it/s]
[NODATA]
HOEKVHLD: last measurement is 1990-12-03 08:00:00+01:00
100%|██████████| 24/24 [00:14<00:00,  1.70it/s]
HVH25: last measurement is 2024-04-04 09:50:00+01:00
100%|██████████| 24/24 [00:13<00:00,  1.74it/s]
[NODATA]
HOEKVHLBSD: last measurement is 1997-04-14 09:20:00+01:00
100%|██████████| 24/24 [00:14<00:00,  1.61it/s]

The stations with different height notations have the last month/day as last measurements so these seem to be realtime stations. How to get to the rest of the salinity measurements (historic timeseries)?

[veenstrajelmer]

There are Hoek van Holland Chlorinity measurements available, and the different heights are available via the "WaarnemingMetadata.BemonsteringshoogteLijst" property:

import ddlpy
import matplotlib.pyplot as plt
plt.close("all")

locations = ddlpy.locations()
# bool_stations = locations.index.isin(['HOEKVHLD'])
# bool_stations = locations['Naam'].str.contains("olland")

# historic
bool_stations = locations.index.isin(['HOEKVHLRTOVR']) #contains 3 depths (BemonsteringshoogteLijst)
bool_grootheid = locations['Grootheid.Code'].isin(['CONCTTE'])
bool_hoedanigheid = locations['Hoedanigheid.Code'].isin(['Cl'])
selected = locations.loc[bool_stations & bool_grootheid & bool_hoedanigheid]

# LMW/realtime
# bool_stations = locations.index.isin(['HVH90','HVH45','HVH25'])
# bool_grootheid = locations['Grootheid.Code'].isin(['SALNTT'])
# selected = locations.loc[bool_stations & bool_grootheid]

start_data = "2022-07-01"
end_date = "2022-09-01"

print(f"downloading data for {len(selected)} stations")

for irow, row in selected.iterrows():
    last = ddlpy.measurements_latest(selected.iloc[0])
    station_code = row.name
    print(f"{station_code}: last measurement is {last.index[0]}")
    # measurements_latest = ddlpy.measurements_latest(row)
    measurements = ddlpy.measurements(row, start_data, end_date, freq=None)
    if measurements.empty:
        print("[NODATA]")
        continue

fig, ax = plt.subplots()
for hoogte in measurements["WaarnemingMetadata.BemonsteringshoogteLijst"].drop_duplicates().values:
    sel_bool = measurements["WaarnemingMetadata.BemonsteringshoogteLijst"] == hoogte
    measurements_sel = measurements.loc[sel_bool]
    measurements_sel.plot(ax=ax, label=hoogte, y='Meetwaarde.Waarde_Numeriek')
ax.legend()

Gives:

[TvLoon-RWS]

See also;
https://rijkswaterstaatdata.nl/projecten/beta-waterwebservices#hef1055c5-ba3b-4658-aed0-111af96f0ca3:~:text=Filter%20op%20bemonsteringshoogte,BemonsteringshoogteLijst%22%3A%5B%22%2D250%22%5D%7D%C2%A0%20%7D