adds unit mapping functions to utilities.py

`get_spatial_data`, its helper `selector`, and `show_map`

addresses edgi-govdata-archiving/ECHO-Cross-Program#64

geographies.py

@@ -1,8 +1,60 @@
+spatial_tables = {
+    # HUC8
+    "Watershed": dict(
+        table_name="wbdhu8",
+        id_field="huc8"
+    ),
+
+    "HUC10 Watersheds": dict(
+        table_name="wbdhu10",
+        id_field="huc10"
+    ),
+
+    "HUC12 Watersheds": dict(
+        table_name="wbdhu12",
+        id_field="huc12"
+    ),
+
+    #"Ecoregions": dict(
+    #    table_name="eco_level3",
+    #    id_field="US_L3NAME" #e.g. Atlantic Coastal Pine Barrens 
+    #    
+    #),
+
+    "County": dict(
+        table_name="tl_2019_us_county",
+        id_field="GEOID" # four or five digit code corresponding to two digit state number (e.g. 55) and 2-3 digit county code! 
+    ),
+
+    "Zip Code": dict(
+        table_name="tl_2019_us_zcta510",
+        id_field="zcta5ce10" 
+
+    ),
+
+    "EPA Region": dict(
+        table_name="epa_regions",
+        id_field="eparegion" # In the form of "Region 1", "Region 2", up to "Region 10"
+    ),
+
+    "State": dict(
+        table_name = "tl_2019_us_state",
+        id_field = "STUSPS" # e.g. MS, IA, AK
+    ),
+
+    "Congressional District": dict(
+        table_name = "tl_2019_us_cd116",
+        id_field = "GEOID" # this is the combination of the state id and the CD e.g. AR-2 = 0502
+    )
+}
+
 region_field = {
     'State': { "field": 'FAC_STATE' },
     'Congressional District': { "field": 'FAC_DERIVED_CD113' },
     'County': { "field": 'FAC_COUNTY' },
     'Zip Code': { "field": 'FAC_ZIP' },
+    'Watershed': { "field": 'FAC_DERIVED_HUC'},
+    'EPA Region': { "field": 'FAC_EPA_REGION'}
 }
 # Commenting out these region types until implemented
 #     'Watershed': {"field": 'FAC_DERIVED_HUC'},