SnowEx Database Preview¶

![fireworks] (https://i.gifer.com/FH7W.gif “fireworks”)

Learning Objectives:

First taste of the database!
Code snippets to extract and prep data.
Generate ideas for project pitches.

The Basics¶

How are the data contained?¶

Set Up Computing Environment¶

# standard imports
import numpy as np
import matplotlib.pyplot as plt 
import datetime
import re
import geopandas as gpd

# some mapping widgets
import ipyleaflet
from ipyleaflet import Map, GeoData, Rectangle, basemaps, LayersControl, basemap_to_tiles, TileLayer, SplitMapControl, Polygon
import ipywidgets

#database imports
from snowexsql.db import get_db
from snowexsql.data import PointData, LayerData, ImageData, SiteData
from snowexsql.conversions import query_to_geopandas, query_to_pandas

POINTER –> Notice where I import the four primary database tables. Can anyone call out what code line does this from the code block above?

# load the database
db_name = 'snow:hackweek@db.snowexdata.org/snowex'
engine, session = get_db(db_name)

print('snowexsql database successfully loaded!')

snowexsql database successfully loaded!

What’s the first thing you might like to do?¶

Find overlapping data for data analysis comparison

Grand Mesa IOP (2020)¶

Example 1: Let’s find all the pits that overlap with an airborne sensor of interest!¶

First, it would be helpful to know, which of the airborne sensors are part of the database, right?

# Query the session using .surveyors() to generate a list
qry = session.query(ImageData.surveyors)

# Locate all that are distinct
airborne_sensors_list = session.query(ImageData.surveyors).distinct().all()

print('list of airborne sensors by "surveyor" name: \n', airborne_sensors_list)

list of airborne sensors by "surveyor" name: 
 [('USGS',), ('UAVSAR team, JPL',), ('ASO Inc.',)]

1a). Unsure of the flight date, but know which sensor you’d like to overlap with, here’s how:¶

# Airborne sensor from list above
sensor = 'UAVSAR team, JPL'

# Form on the Images table that returns Raster collection dates
qry = session.query(ImageData.date)

# Filter for UAVSAR data
qry = qry.filter(ImageData.surveyors == sensor)

# Grab the unique dates
qry = qry.distinct()

# Execute the query 
dates = qry.all() 

# Clean up the dates 
dates = [d[0] for d in dates] 
dlist = [str(d) for d in dates]
dlist = ", ".join(dlist)
print('%s flight dates are: %s' %(sensor, dlist))

# Find all the snow pits done on these days
qry = session.query(SiteData.geom, SiteData.site_id, SiteData.date)
qry = qry.filter(SiteData.date.in_(dates))

# Return a geopandas df
df = query_to_geopandas(qry, engine)

# View the returned pandas dataframe!
print(df.head())

# Close your session to avoid hanging transactions
session.close()

UAVSAR team, JPL flight dates are: 2020-01-31, 2020-02-12

                             geom site_id        date
POINT (742453.000 4325752.000)    1C14  2020-01-31
POINT (744396.000 4323540.000)    8C26  2020-01-31
POINT (740652.000 4327445.000)     2C2  2020-01-31
POINT (741580.000 4326713.000)     2C9  2020-01-31
POINT (745340.000 4322754.000)    8S28  2020-01-31

1b).Want to select an exact flight date match? Here’s how:¶

# Pick a day from the list of dates
dt = dates[0] 

# Find all the snow pits done on these days 
qry = session.query(SiteData.geom, SiteData.site_id, SiteData.date)
qry = qry.filter(SiteData.date == dt)

# Return a geopandas df
df_exact = query_to_geopandas(qry, engine)

print('%s pits overlap with %s on %s' %(len(df_exact), sensor, dt))

# View snows pits that align with first UAVSAR date
df_exact.head()

17 pits overlap with UAVSAR team, JPL on 2020-01-31

	geom	site_id	date
0	POINT (742453.000 4325752.000)	1C14	2020-01-31
1	POINT (744396.000 4323540.000)	8C26	2020-01-31
2	POINT (740652.000 4327445.000)	2C2	2020-01-31
3	POINT (741580.000 4326713.000)	2C9	2020-01-31
4	POINT (745340.000 4322754.000)	8S28	2020-01-31

1c). Want to select a range of dates near the flight date? Here’s how:¶

# Form a date range to query on either side of our chosen day 
date_range = [dt + i * datetime.timedelta(days=1) for i in [-1, 0, 1]]

# Find all the snow pits done on these days 
qry = session.query(SiteData.geom, SiteData.site_id, SiteData.date)
qry = qry.filter(SiteData.date.in_(date_range))

# Return a geopandas df
df_range = query_to_geopandas(qry, engine)

# Clean up dates (for print statement only)
dlist = [str(d) for d in date_range]
dlist = ", ".join(dlist)

print('%s pits overlap with %s on %s' %(len(df_range), sensor, dlist))

# View snow pits that are +/- 1 day of the first UAVSAR flight date
df_range.sample(10)

47 pits overlap with UAVSAR team, JPL on 2020-01-30, 2020-01-31, 2020-02-01

	geom	site_id	date
22	POINT (743884.000 4324477.000)	5C21	2020-01-30
9	POINT (744862.000 4323250.000)	4C30	2020-01-31
6	POINT (740839.000 4327345.000)	2C4	2020-01-31
26	POINT (743446.000 4324827.000)	9C19	2020-01-30
19	POINT (744913.000 4324095.000)	8N34	2020-01-30
29	POINT (744625.000 4323947.000)	6N31	2020-01-30
38	POINT (746228.000 4322671.000)	9S39	2020-02-01
20	POINT (745787.000 4322066.000)	2C33	2020-01-30
41	POINT (746546.000 4324066.000)	8N45	2020-02-01
21	POINT (743040.000 4324967.000)	9C17	2020-01-30

1d). Have a known date that you wish to select data for, here’s how:¶

# Find all the data that was collected on 2-12-2020
dt = datetime.date(2020, 2, 12)

#--------------- Point Data -----------------------------------
# Grab all Point data instruments from our date
point_instruments = session.query(PointData.instrument).filter(PointData.date == dt).distinct().all()
point_type = session.query(PointData.type).filter(PointData.date == dt).distinct().all()

# Clean up point data (i.e. remove tuple)
point_instruments = [p[0] for p in point_instruments]
point_instruments = ", ".join(point_instruments)
point_type = [p[0] for p in point_type]
point_type = ", ".join(point_type)
print('Point data on %s are: %s, with the following list of parameters: %s' %(str(dt), point_instruments, point_type))

#--------------- Layer Data -----------------------------------
# Grab all Layer data instruments from our date
layer_instruments = session.query(LayerData.instrument).filter(LayerData.date == dt).distinct().all()
layer_type = session.query(LayerData.type).filter(LayerData.date == dt).distinct().all()

# Clean up layer data 
layer_instruments = [l[0] for l in layer_instruments if l[0] is not None]
layer_instruments = ", ".join(layer_instruments)
layer_type = [l[0] for l in layer_type]
layer_type = ", ".join(layer_type)
print('\nLayer Data on %s are: %s, with the following list of parameters: %s' %(str(dt), layer_instruments, layer_type))

#--------------- Image Data -----------------------------------
# Grab all Image data instruments from our date
image_instruments = session.query(ImageData.instrument).filter(ImageData.date == dt).distinct().all()
image_type = session.query(ImageData.type).filter(ImageData.date == dt).distinct().all()

# Clean up image data (i.e. remove tuple)
image_instruments = [i[0] for i in image_instruments]
image_instruments = ", ".join(image_instruments)
image_type = [i[0] for i in image_type]
image_type = ", ".join(image_type)
print('\nImage Data on %s are: %s, with the following list of parameters: %s' %(str(dt), image_instruments, image_type))

Point data on 2020-02-12 are: camera, magnaprobe, pit ruler, with the following list of parameters: depth

Layer Data on 2020-02-12 are: snowmicropen, with the following list of parameters: force, grain_size, density, permittivity, lwc_vol, manual_wetness, grain_type, temperature, hand_hardness

Image Data on 2020-02-12 are: UAVSAR, L-band InSAR, with the following list of parameters: insar correlation, insar interferogram real, insar interferogram imaginary, insar amplitude

Time Series (2020)¶

# Set up database
from snowexsql.db import get_db
from snowexsql.data import PointData, LayerData, ImageData, SiteData
from snowexsql.conversions import query_to_geopandas

# Query temp profiles from 2 sites: Banner Forest, Banner Snotel

# Plot full timeseries of temp profile vs depth in side by side plot

Explore the Spatial Extent of Field Campaign Data¶

bbox = [-125, 49, -102, 31]
west, north, east, south = bbox
bbox_ctr = [0.5*(north+south), 0.5*(west+east)]

m = Map(basemap=basemaps.CartoDB.Positron, center=bbox_ctr, zoom=4)
rectangle = Rectangle(bounds=((south, west), (north, east))) #SW and NE corners of the rectangle (lat, lon)
m.add_layer(rectangle)
m

# more info on available basemaps here: https://ipyleaflet.readthedocs.io/en/latest/map_and_basemaps/basemaps.html

Query the Database to add Spatial Data to Our Map¶

# # database imports
# from snowexsql.db import get_db
# from snowexsql.data import PointData, LayerData, ImageData, SiteData
# from snowexsql.conversions import query_to_geopandas, query_to_pandas

# load the database
db_name = 'snow:hackweek@db.snowexdata.org/snowex'
engine, session = get_db(db_name)

Let’s find out where we have liquid water content (LWC) data¶

Pointer –> LWC data is in the LayerData table, because data at a single location were measured as a profile on the pit wall face (i.e has a vertical dimension)

# query the LayerData for all LWC values
# qry = session.query(LayerData).filter(LayerData.type == 'lwc_vol')

# query the geometry property of PointData
# qry = session.query(LayerData.geom).distinct()

# query the LayerData for all LWC values
qry = session.query(LayerData.longitude, LayerData.latitude).filter(LayerData.type == 'lwc_vol').distinct() # 

# # query the geometry property of PointData
# qry = query(LayerData.geom).distinct()

# # limit the number of entries
# qry = qry.limit(2000)

# convert query to geopandas df
df = query_to_pandas(qry, engine)

df = gpd.GeoDataFrame(df, geometry=gpd.points_from_xy(df.longitude, df.latitude))
print(type(df))

# # convert query to geopandas df
# df = query_to_geopandas(qry, engine)

print(df.head())

# how many did we retrieve?
print(f'{len(df.index)} records returned!')

session.close()

<class 'geopandas.geodataframe.GeoDataFrame'>
    longitude   latitude                     geometry
-108.221437  39.034623  POINT (-108.22144 39.03462)
-108.220926  39.036475  POINT (-108.22093 39.03648)
-108.220239  39.064288  POINT (-108.22024 39.06429)
-108.220220  39.064180  POINT (-108.22022 39.06418)
-108.219632  39.034409  POINT (-108.21963 39.03441)
records returned!

Let’s add these points to our map!¶

m = Map(basemap=basemaps.CartoDB.Positron, center=bbox_ctr, zoom=4)

# geo_data = GeoData(geo_dataframe = df)

geo_data = GeoData(geo_dataframe = df,
    style={'color': 'black', 'radius':8, 'fillColor': '#3366cc', 'opacity':0.5, 'weight':1.9, 'dashArray':'2', 'fillOpacity':0.6},
    hover_style={'fillColor': 'red' , 'fillOpacity': 0.2},
    point_style={'radius': 5, 'color': 'red', 'fillOpacity': 0.8, 'fillColor': 'blue', 'weight': 3},
    name = 'lwc obs.')

m.add_layer(geo_data) 
m.add_control(LayersControl())
m

grab geojson from gist¶

import geopandas as gpd
import requests
url = "https://gist.githubusercontent.com/meganmason/21e6de1f7487b3e7defbe60ddde07e0e/raw/06939d8fffc0539a6014ee0d7c0c1d58938d9e8d/pits_raw.geojson"
gdf = gpd.read_file(url)
gdf.head()

	field_1	Identifier	PitID	Location	Site	Easting	Northing	Zone	Latitude	Longitude	Date	Local/Stan	geometry
0	0	CAAMCL_20191220_1300	CAAMCL	American River Basin	Caples Lake	757216	4288787	10	38.71033	-120.04187	12/20	13:00:00	POINT (-120.04187 38.71033)
1	1	CAAMCL_20200131_1215	CAAMCL	American River Basin	Caples Lake	757220	4288788	10	38.71034	-120.04182	1/31	12:15:00	POINT (-120.04182 38.71034)
2	2	CAAMCL_20200214_1200	CAAMCL	American River Basin	Caples Lake	757218	4288787	10	38.71033	-120.04185	2/14	12:00:00	POINT (-120.04185 38.71033)
3	3	CAAMCL_20200221_1200	CAAMCL	American River Basin	Caples Lake	757217	4288780	10	38.71027	-120.04186	2/21	12:00:00	POINT (-120.04186 38.71027)
4	4	CAAMCL_20200228_1130	CAAMCL	American River Basin	Caples Lake	757215	4288778	10	38.71025	-120.04188	2/28	11:30:00	POINT (-120.04188 38.71025)

SnowEx Hackweek 2022

SnowEx Database Preview

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