Grondwatermonitoring (GM) in samenhang

Downloading head-data using for Groundwater Monitoring Wells (All measurements within an extent (option 2: brodata.gmw.get_data_in_extent)) can require a lot of requests to the BRO-REST-service: characteristics, GrounwaterMonitoringWells and GroundwaterLevelDossiers/GroundwaterAnalysisReports. To simplify this process PDOK hosts the dataset “Grondwatermonitoring (GM) in samenhang” (available since 2024), which contains summary and characteristic information about registration objects within the groundwater monitoring domain, including the relationships between these registration objects. It provides key data such as the horizontal and vertical positions of measurement tubes, but not full well or tube metadata.

Previously (All measurements within an extent (option 1: brodata.gm.get_data_in_extent)) we demonstrated the use of this dataset to download groundwater heads within a specific area. In this notebook we will show more options to use this dataset, for example to filter the monitoring tubes before downloading actual measurements.

import matplotlib.pyplot as plt
import brodata

Download location of tubes

First we will download the location of grundwater monitoring tubes by calling brodata.gm.get_data_in_extent with the argument kind=None. This only requires a singe request to the PDOK-webservice, and resurns a GeoDataFrame. The index of this GeoDataFrame contains the bro-id of the Groundwater Monitoring Well and the tube number.

extent = [117700, 118700, 439400, 440400]
tubes = brodata.gm.get_data_in_extent(extent, kind=None)
tubes

		geometry	gm_gmw_monitoringtube_pk	gm_gmw.href	gm_gmw_fk	tube_status	tube_in_use	tube_top_diameter	screen_top_position	screen_bottom_position	electrode_top_position	electrode_bottom_position
gmw_bro_id	tube_number
GMW000000036286	1	POINT (117810.309 439763.429)	36385	https://api.pdok.nl/tno/bro-grondwatermonitori...	27655	gebruiksklaar	ja	63.0	-2.194	-3.194	None	None
GMW000000036287	1	POINT (118300.365 439767.464)	36386	https://api.pdok.nl/tno/bro-grondwatermonitori...	27656	gebruiksklaar	ja	63.0	0.142	-0.858	None	None
GMW000000036308	1	POINT (118049.119 440003.006)	36407	https://api.pdok.nl/tno/bro-grondwatermonitori...	27677	gebruiksklaar	ja	63.0	-1.289	-2.289	None	None
GMW000000036318	1	POINT (118395.903 440169.549)	36417	https://api.pdok.nl/tno/bro-grondwatermonitori...	27687	gebruiksklaar	ja	63.0	-2.029	-3.028	None	None
GMW000000036319	1	POINT (117956.994 439698.197)	36418	https://api.pdok.nl/tno/bro-grondwatermonitori...	27688	gebruiksklaar	ja	63.0	-1.721	-2.721	None	None
GMW000000036327	1	POINT (118064.181 439799.93)	36426	https://api.pdok.nl/tno/bro-grondwatermonitori...	27696	gebruiksklaar	ja	63.0	-0.833	-1.833	None	None
GMW000000036328	1	POINT (118342.321 439964.201)	36427	https://api.pdok.nl/tno/bro-grondwatermonitori...	27697	gebruiksklaar	ja	63.0	0.795	-0.205	None	None
GMW000000036339	1	POINT (118632.006 439909.352)	36438	https://api.pdok.nl/tno/bro-grondwatermonitori...	27708	gebruiksklaar	ja	63.0	-2.695	-3.695	None	None
GMW000000036354	1	POINT (117961.245 440134.173)	36453	https://api.pdok.nl/tno/bro-grondwatermonitori...	27723	gebruiksklaar	ja	63.0	-1.987	-2.987	None	None
GMW000000036365	1	POINT (118127.453 439683.098)	36464	https://api.pdok.nl/tno/bro-grondwatermonitori...	27734	gebruiksklaar	ja	63.0	-0.429	-1.428	None	None
GMW000000036371	1	POINT (117912.255 439993.558)	36470	https://api.pdok.nl/tno/bro-grondwatermonitori...	27740	gebruiksklaar	ja	63.0	-1.200	-2.200	None	None
GMW000000049567	1	POINT (117892.583 439651.861)	54849	https://api.pdok.nl/tno/bro-grondwatermonitori...	40471	onbekend	ja	NaN	-1.950	-2.950	None	None
	2	POINT (117892.583 439651.861)	54850	https://api.pdok.nl/tno/bro-grondwatermonitori...	40471	onbekend	ja	NaN	-14.000	-15.000	None	None
GMW000000088148	1	POINT (118389.168 440186.234)	101139	https://api.pdok.nl/tno/bro-grondwatermonitori...	75818	gebruiksklaar	ja	63.0	-2.829	-3.829	None	None
GMW000000088161	1	POINT (118046.785 440218.965)	101154	https://api.pdok.nl/tno/bro-grondwatermonitori...	75831	gebruiksklaar	ja	63.0	-1.364	-2.364	None	None
GMW000000088163	1	POINT (118160.656 439678.979)	101156	https://api.pdok.nl/tno/bro-grondwatermonitori...	75833	gebruiksklaar	ja	40.0	0.473	-0.527	None	None
GMW000000088164	1	POINT (118206.559 439792.296)	101157	https://api.pdok.nl/tno/bro-grondwatermonitori...	75834	gebruiksklaar	ja	40.0	0.860	-0.140	None	None
GMW000000088166	1	POINT (118157.621 439915.469)	101159	https://api.pdok.nl/tno/bro-grondwatermonitori...	75836	gebruiksklaar	ja	63.0	0.868	-0.132	None	None
GMW000000088168	1	POINT (117910.727 439993.804)	101161	https://api.pdok.nl/tno/bro-grondwatermonitori...	75838	gebruiksklaar	ja	63.0	-1.413	-2.413	None	None
GMW000000088172	1	POINT (117966.11 440143.381)	101165	https://api.pdok.nl/tno/bro-grondwatermonitori...	75842	gebruiksklaar	ja	63.0	-1.653	-2.653	None	None

Making a selection of tubes

Before we will download measurements, we can make a selection. For example, we can select all tubes where the top of the well screen is below -2.5 m NAP.

We can then plot the selection of this GeoDataFrame on a map using tubes.plot().

max_screen_top_position = -2.5
mask = tubes['screen_top_position'] < max_screen_top_position
print(f"{mask.sum()} of {len(tubes)} tubes selected where screen_top_position < {max_screen_top_position}")
tubes_sel = tubes[mask]

f, ax = plt.subplots()
ax.axis("scaled")
ax.axis(extent)
tubes.plot(ax=ax)
tubes_sel.plot(ax=ax, marker='o', edgecolor='red', facecolor='none');

3 of 20 tubes selected where screen_top_position < -2.5

Downloading groundwater level data

We can then download groundwater level data using brodata.gm.get_observations(). This downloads data for two of the three monitoring tubes. So the third monitoring tube does not contain any groundwater level data.

obs_df = brodata.gm.get_observations(extent=extent, tubes=tubes_sel, kind="gld", as_csv=True)
obs_df

GLD000000012845 contains 21212 duplicates (of 58834). Keeping only first values (sorted for importance).

	observation	gm_gmw_monitoringtube_fk	groundwaterMonitoringWell	tubeNumber
broId
GLD000000150449	value    qualifier     st...	54850	GMW000000049567	2
GLD000000012845	value    qualifier     st...	36438	GMW000000036339	1
GLD000000153605	value    qualifier     st...	101139	GMW000000088148	1

Combining tubes and observations

We can then add these observations to the tubes-GeoDataFrame using the method brodata.gmw.add_observations_to_tubes. If multiple Groundwater Level Dossiers are available for a single monitoring tube, they are combined.

The index of the tubes-GeoDataFrame and the measurement-dataframe both needs to be a MultiIndex, with the bro-id of the GroundwaterMonitoringWell and the tube-number as the levels. For the tubes-GeoDataFrame this is allready the case, but for the measurement-Dataframe (obs_df) we need to change the index.

THe resulting GeoDataFrame contains all the columns from the tubes-GeoDataFrame, with the added columns observation and groundwaterLevelDossier. The column observation contains one DataFrame with observations per monitoring tube. THe column groundwaterLevelDossier contains a list of GroundwaterLevelDossier-ids per monitoring tube. If we would have downloaded GroundwaterAnalysisReports (kind="gar"), these columns would have been named laboratoryAnalysis and groundwaterAnalysisReport.

obs_df = obs_df.reset_index().set_index(["groundwaterMonitoringWell", "tubeNumber"])
tubes_sel = brodata.gmw.add_observations_to_tubes(tubes_sel, obs_df, kind="gld")
tubes_sel

		geometry	gm_gmw_monitoringtube_pk	gm_gmw.href	gm_gmw_fk	tube_status	tube_in_use	tube_top_diameter	screen_top_position	screen_bottom_position	electrode_top_position	electrode_bottom_position	observation	groundwaterLevelDossier
gmw_bro_id	tube_number
GMW000000036339	1	POINT (118632.006 439909.352)	36438	https://api.pdok.nl/tno/bro-grondwatermonitori...	27708	gebruiksklaar	ja	63.0	-2.695	-3.695	None	None	value    qualifier     st...	[GLD000000012845]
GMW000000049567	2	POINT (117892.583 439651.861)	54850	https://api.pdok.nl/tno/bro-grondwatermonitori...	40471	onbekend	ja	NaN	-14.000	-15.000	None	None	value    qualifier     st...	[GLD000000150449]
GMW000000088148	1	POINT (118389.168 440186.234)	101139	https://api.pdok.nl/tno/bro-grondwatermonitori...	75818	gebruiksklaar	ja	63.0	-2.829	-3.829	None	None	value    qualifier     st...	[GLD000000153605]

f, ax = plt.subplots(ncols=2, figsize=(10, 5))
ax[0].axis("scaled")
ax[0].axis(extent)
for i, index in enumerate(tubes_sel.index):
    color = f"C{i}"
    obs = tubes_sel.at[index, "observation"]
    marker = "o"
    if obs.empty:
        marker = "x"
    else:
        obs["value"].plot(ax=ax[1], color=color, label=f"{index[0]} filter {index[1]}")
    tubes_sel.loc[[index]].plot(ax=ax[0], marker=marker, color=color)
    ax[0].annotate(
        f"{index[0]}\n filter {index[1]}",
        xy=tubes_sel.loc[index].geometry.centroid.coords[0],
        ha="center",
        xytext=(0, 5),
        textcoords="offset points",
    )

ax[1].legend();