Added example 04 - Water measuring stations

04_WaterMeasuringStationsMap/README.md

+Display all water level measuring stations in Schleswig-Holstein using the folium library with OpenStreetMap 
+Data Source: https://opendata.schleswig-holstein.de/dataset/pegel-stammdaten

04_WaterMeasuringStationsMap/example04.py

+import csv
+import folium
+from frictionless import Resource, Schema, validate
+
+# Validates the given CSV file against a frictionless schema
+def validate_csv_with_schema(file_path, schema_path):
+    schema = Schema(schema_path)
+    resource = Resource(file_path, schema=schema)
+    report = validate(resource)
+    
+    if report.valid:
+        print("CSV file validated using frictionless schema")
+    else:
+        print("Unable to validate CSV file:")
+        for error in report.flatten(["rowPosition", "fieldPosition", "code", "message"]):
+            print(f"Row {error['rowPosition']}, Column {error['fieldPosition']}: {error['message']}")
+
+# Create OpenStreetMap overlay using folium library
+def show_coordinates_on_map(file_path):
+    # Set the center to the city of Nortorf (which is the center of Schleswig-Holstein
+    # according to Google):
+    m = folium.Map(location=[54.16995, 9.85516], zoom_start=6)
+
+    # Read coordinates and description from CSV file
+    with open(file_path, newline='', encoding='utf-8') as csvfile:
+        reader = csv.DictReader(csvfile, delimiter = ";")
+        for row in reader:
+            #print(row.keys())
+            lon = float(row['geogrLaenge'])
+            lat = float(row['geogrBreite'])
+            #name = row.get('name', 'pegelName')
+            name = row['pegelName']
+            folium.Marker([lat, lon], popup=name).add_to(m)
+
+    # Save map
+    map_file = 'output.htm'
+    m.save(map_file)
+    print(f"Map has been saved as: '{map_file}'")
+
+# Main program
+csv_file = 'pegel.csv'
+schema_file = 'frictionless-description.json'
+
+# Step 1: Validate CSV against frictionless schema
+validate_csv_with_schema(csv_file, schema_file)
+
+# Step 2: Create OpenStreetMap overlay
+show_coordinates_on_map(csv_file)

04_WaterMeasuringStationsMap/frictionless-description.json

+{
+   "dialect" : {
+      "delimiter" : ";"
+   },
+   "encoding" : "utf-8",
+   "format" : "csv",
+   "name" : "pegel-stammdaten",
+   "path" : "https://opendata.schleswig-holstein.de/dataset/a78f23ef-7180-4274-96a3-b32150359035/resource/ea7a76cc-0ef5-4d01-8f63-4152f44a1556/download/pegel.csv",
+   "profile" : "tabular-data-resource",
+      "fields" : [
+         {
+            "name" : "pegelNummer",
+            "type" : "integer",
+"description": "eindeutige Nummer des Pegels"
+         },
+         {
+            "name" : "pegelName",
+            "type" : "string",
+"description": "Name des Pegels"
+         },
+         {
+            "name" : "betreiber",
+            "type" : "string",
+"description": "Name des Betreibers des Pegels"
+         },
+         {
+            "name" : "gewaesser",
+            "type" : "string",
+"description": "Name des Gewässers, an dem sich der Pegel befindet"
+         },
+         {
+            "name" : "geogrLaenge",
+            "rdfType" : "https://schema.org/longitude",
+            "type" : "number",
+"description": "Lage des Pegels (Längengrad)"
+         },
+         {
+            "name" : "geogrBreite",
+            "rdfType" : "https://schema.org/latitude",
+            "type" : "number",
+"description": "Lage des Pegels (Breitengrad)"
+         },
+         {
+            "name" : "von",
+            "type" : "date",
+"description": "Datum des ältesten Messwertes"
+         },
+         {
+            "name" : "bis",
+            "type" : "date",
+"description": "Datum des jüngsten Messwertes"
+         },
+         {
+            "constraints" : {
+               "enum" : [
+                  "Abfluss",
+                  "Wasserstand"
+               ]
+            },
+            "name" : "parameter",
+            "type" : "string",
+"description": "gemessener Parameter"
+         },
+         {
+            "name" : "stillgelegtAm",
+            "type" : "date",
+"description": "Datum der Stilllegung"
+         },
+         {
+            "name" : "isDFUE",
+            "type" : "boolean",
+"description": "gibt an, ob die Daten des Pegels kurzfristig verfügbar sind"
+         },
+         {
+            "name" : "einzugsgebiet",
+"title": "Einzugsgebiet",
+"description": "Größe des Einzugsgebiets in km²",
+            "type" : "number"
+         },
+         {
+            "name" : "pnp",
+"title": "Pegelnullpunkt",
+"description": "Höhe des Pegelnullpunkt",
+
+            "type" : "number"
+         },
+         {
+            "name" : "pnp_gueltig_ab",
+"title": "PNP gültig ab",
+"description": "Gültigkeit des Pegelnullpunkts (seit)",
+            "type" : "date"
+         },
+         {
+            "name" : "gewaesserfolge",
+"title": "Gewässerfolge",
+"description": "Gewässerfolge (nicht durchgängig vorhanden)",
+            "type" : "string"
+         }
+      ],
+      "primaryKey" : [
+         "pegelNummer",
+         "parameter"
+      ]
+}

04_WaterMeasuringStationsMap/install_packages.sh

+#!/bin/bash
+# Install necessary python packages for this example
+pip install folium
+pip install frictionless