From 5c89870aa83c0a1fdae9c04b9c5155183ba4e8e8 Mon Sep 17 00:00:00 2001
From: weiqi-tori <zhouwq@umich.edu>
Date: Thu, 20 Jun 2024 17:15:03 +0800
Subject: [PATCH] add ERA 5 highest temperature layer

---
 city_metrix/layers/__init__.py               |  1 +
 city_metrix/layers/era_5_high_temperature.py | 39 ++++++++++++++++++++
 tests/layers.py                              |  6 ++-
 3 files changed, 45 insertions(+), 1 deletion(-)
 create mode 100644 city_metrix/layers/era_5_high_temperature.py

diff --git a/city_metrix/layers/__init__.py b/city_metrix/layers/__init__.py
index bef56c3..307b219 100644
--- a/city_metrix/layers/__init__.py
+++ b/city_metrix/layers/__init__.py
@@ -16,3 +16,4 @@
 from .open_buildings import OpenBuildings
 from .tree_canopy_hight import TreeCanopyHeight
 from .alos_dsm import AlosDSM
+from .era_5_high_temperature import Era5HighTemperature
diff --git a/city_metrix/layers/era_5_high_temperature.py b/city_metrix/layers/era_5_high_temperature.py
new file mode 100644
index 0000000..dac8b62
--- /dev/null
+++ b/city_metrix/layers/era_5_high_temperature.py
@@ -0,0 +1,39 @@
+import ee
+
+from .layer import Layer, get_image_collection
+
+
+class Era5HighTemperature(Layer):
+    def __init__(self, start_date="2023-01-01", end_date="2024-01-01", **kwargs):
+        super().__init__(**kwargs)
+        self.start_date = start_date
+        self.end_date = end_date
+
+    def get_data(self, bbox):
+        dataset = ee.ImageCollection("ECMWF/ERA5_LAND/HOURLY")
+
+        # Function to find the maximum value - highest temperature - pixel in each image
+        def highest_temperature_image(image):
+            max_pixel = image.reduceRegion(
+                reducer=ee.Reducer.max(),
+                geometry=ee.Geometry.BBox(*bbox),
+                scale=11132,
+                bestEffort=True
+            ).values().get(0)
+
+            return image.set('highest_temperature', max_pixel)
+
+        era5 = ee.ImageCollection(dataset
+                                  .filterBounds(ee.Geometry.BBox(*bbox))
+                                  .filterDate(self.start_date, self.end_date)
+                                  .select('temperature_2m')
+                                  )
+
+        era5_highest = era5.map(highest_temperature_image)
+
+        # Sort the collection based on the highest temperature and get the first image
+        highest_temperature_day = ee.ImageCollection(era5_highest.sort('highest_temperature', False).first())
+
+        data = get_image_collection(highest_temperature_day, bbox, 11132, "ERA 5 Temperature").temperature_2m
+
+        return data
diff --git a/tests/layers.py b/tests/layers.py
index adf01ea..05b6351 100644
--- a/tests/layers.py
+++ b/tests/layers.py
@@ -1,6 +1,6 @@
 import ee
 
-from city_metrix.layers import LandsatCollection2, Albedo, LandSurfaceTemperature, EsaWorldCover, EsaWorldCoverClass, TreeCover, AverageNetBuildingHeight, OpenStreetMap, OpenStreetMapClass, UrbanLandUse, OpenBuildings, TreeCanopyHeight, AlosDSM
+from city_metrix.layers import LandsatCollection2, Albedo, LandSurfaceTemperature, EsaWorldCover, EsaWorldCoverClass, TreeCover, AverageNetBuildingHeight, OpenStreetMap, OpenStreetMapClass, UrbanLandUse, OpenBuildings, TreeCanopyHeight, AlosDSM, Era5HighTemperature
 from city_metrix.layers.layer import get_image_collection
 from .conftest import MockLayer, MockMaskLayer, ZONES, LARGE_ZONES, MockLargeLayer, MockGroupByLayer, \
     MockLargeGroupByLayer
@@ -108,3 +108,7 @@ def test_tree_canopy_hight():
 def test_AlosDSM():
     mean = AlosDSM().get_data(SAMPLE_BBOX).mean()
     assert mean
+
+def test_era_5_high_temperature():
+    mean = Era5HighTemperature().get_data(SAMPLE_BBOX).mean()
+    assert mean