🚀 Deploy Sudan GCN as a GEE App

Step-by-step guide to publish your Curve Number application as a public Google Earth Engine App on cloud/ee-osmangeomatics1993

Save the App Script

First, save the App-ready script to your GEE repository.

Action: Open code.earthengine.google.com

Action: In the script panel, delete all existing code

Action: Paste the entire contents of Sudan_GCN_APP.js

Action: Click Save (top menu) → Name it:
Sudan_Hydrologic_CN_App
Save to your repository (e.g., users/osmangeomatics1993/)

⚠️ Important: Use the Sudan_GCN_APP.js file (NOT the Sudan_GCN_CodeEditor.js). The APP version has print() and Export.image.toDrive() removed because they don't work in GEE Apps.

Test the Script First

Before publishing, run the script to make sure everything works.

Action: Click ▶ Run

Verify these work correctly:

Test	Expected Result
Map loads CN Average layer	Full Sudan in green-yellow-red colors
State dropdown populated	18 Sudan states listed
Select "Khartoum" → Apply State	Map zooms to Khartoum State
Click on map	Point query shows CN + State + Locality
Legend appears	Color bar with labels below layer selector
Change layer to "Land Cover"	Legend updates to categorical classes
Draw rectangle → Apply	Map clips to drawn area
Generate Download Link	Blue download URL appears

✅ If all tests pass, proceed to Step 3.

❌ If there are errors, check the Console tab for red error messages and fix before publishing.

Open the App Manager

Action: In the Code Editor, click the Apps button (top-right, near your profile icon)

Action: This opens the "Manage Apps" dialog you showed in your screenshot

You should see your existing cloud project: cloud/ee-osmangeomatics1993

Create New App

Action: Click the blue NEW APP button (top-right of the Manage Apps dialog)

A "New App" form will appear with these fields:

Field	What to Enter
App Name	`Sudan Hydrologic Curve Number Application`
Project	Select: `cloud/ee-osmangeomatics1993`
App ID (auto-generated)	Will auto-fill something like: `cloud/ee-osmangeomatics1993/sudan-hydrologic-curve-number-application` You can edit the slug if you want a shorter URL
Source Code	Should automatically point to your currently open script If not, browse to: `users/osmangeomatics1993/Sudan_Hydrologic_CN_App`

Configure App Settings

Setting	Recommended Value
Access	Select: "Anyone with the link" (for public research access) Or: "Anyone" (to appear in the GEE App Gallery)
Earth Engine App Visibility	Check "Show in Gallery" if you want public discovery

⚠️ Google Account required: Users must have a GEE account to run the app. For fully public access (no login), consider the "Anyone" option, but note GEE still requires authentication for heavy computation.

Publish the App

Action: Click PUBLISH

After publishing, you'll get your app URL:

https://ee-osmangeomatics1993.projects.earthengine.app/view/sudan-hydrologic-curve-number-application

✅ Your app is now live! Share this URL with researchers, students, and agencies.

Test the Published App

Open the URL in a new browser tab (or incognito window) and verify:

#	Test	Pass?
1	App loads and shows CN Average map	☐
2	Left panel visible with all sections	☐
3	State dropdown shows 18 states	☐
4	Selecting state → map zooms and clips	☐
5	Locality populates after state selected	☐
6	Click on map → shows query with State + Locality	☐
7	Legend updates when switching layers	☐
8	Draw tools work (rectangle/polygon/point)	☐
9	Runoff calculator produces results	☐
10	GPM rainfall fetches and displays	☐
11	Download link generates for selected product	☐
12	Reset to Full Sudan works	☐

Update the App (Future Changes)

To update your app after making code changes:

Action: Edit and save the script in Code Editor

Action: Open Apps manager → find your app → click the pencil icon ✏️ next to the App ID

Action: Click UPDATE (or PUBLISH again)

The URL stays the same — users always see the latest version.

🔧 What Changed from Code Editor Version → App Version

Feature	Code Editor (Sudan_GCN_CodeEditor.js)	App (Sudan_GCN_APP.js)
`print()`	Console messages	❌ Removed (not available in Apps). Welcome message shown in result panel instead.
`Export.image.toDrive()`	5 export tasks to Google Drive	❌ Replaced with `getDownloadURL()` — generates direct download links for GeoTIFF files. User selects product + scale.
Download	Tasks tab required	✅ Direct download link in the panel. User clicks link → browser downloads GeoTIFF.
Scale selection	Fixed 250m	✅ User can choose 250m / 500m / 1000m / 5000m (smaller scale = faster for large AOIs).
All other features	Identical: State/Locality, Draw, Asset, 12 layers, Legend, Runoff, GPM, Click query, Statistics

💡 Pro Tip: Keep both script versions. Use Sudan_GCN_CodeEditor.js for your own research (with Export to Drive), and Sudan_GCN_APP.js for the published App (with download links).