{
  "cells": [
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "\n# Caspian / lake\n"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "collapsed": false
      },
      "outputs": [],
      "source": [
        "from datetime import datetime, timedelta\nfrom opendrift.models.oceandrift import OceanDrift\nfrom opendrift.readers import reader_shape\nimport cartopy"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "The default GSHHG landmask reader classifies lakes\n(e.g. Caspian Sea) as land and not water.\nFor simulations in lakes, we can use a custom reader for lakes only.\n\n"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "collapsed": false
      },
      "outputs": [],
      "source": [
        "level = 'h'  # using high resolution coastline\nreader_lakes = reader_shape.Reader.from_shpfiles(\n    f'{cartopy.config['data_dir']}/shapefiles/gshhs/{level}/GSHHS_{level}_L2.shp',\n    invert=True)  # Inverting since inside of polygons is water (lake) and not land."
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "Disabling the default landmask reader, and using the above reader instead\n\n"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "collapsed": false
      },
      "outputs": [],
      "source": [
        "o = OceanDrift(loglevel=20)\no.add_reader(reader_lakes)\no.set_config('general:use_auto_landmask', False)  # To use custom landmask instead\no.set_config('environment:constant:x_sea_water_velocity', 1)\no.set_config('drift:horizontal_diffusivity', 100)\no.seed_elements(lon=48.819, lat=44.959, radius=5000, number=100, time=datetime.now())\n\no.run(steps=10)\no.plot(fast=False, buffer=2)"
      ]
    }
  ],
  "metadata": {
    "kernelspec": {
      "display_name": "Python 3",
      "language": "python",
      "name": "python3"
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      "codemirror_mode": {
        "name": "ipython",
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      },
      "file_extension": ".py",
      "mimetype": "text/x-python",
      "name": "python",
      "nbconvert_exporter": "python",
      "pygments_lexer": "ipython3",
      "version": "3.14.2"
    }
  },
  "nbformat": 4,
  "nbformat_minor": 0
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