From 96b22d1fc036f65a06b2b55494a18a2d5f1d43f7 Mon Sep 17 00:00:00 2001
From: Hamza-Ayed <hamzaayedflutter@gmail.com>
Date: Fri, 21 Aug 2026 02:49:41 +0300
Subject: [PATCH] fix(elevation): Restore smooth non-zero continuous terrain
 differentials

---
 apps/api/src/maps/maps.service.ts | 27 +++++++++++++++------------
 1 file changed, 15 insertions(+), 12 deletions(-)

diff --git a/apps/api/src/maps/maps.service.ts b/apps/api/src/maps/maps.service.ts
index b1bf4ca..074c979 100644
--- a/apps/api/src/maps/maps.service.ts
+++ b/apps/api/src/maps/maps.service.ts
@@ -608,8 +608,8 @@ export class MapsService {
   }
 
   /**
-   * High-Precision Multi-Scale Topographic Elevation Model for Jordan
-   * Combines regional DEM baseline with realistic wadi systems, ridge crests, and urban hill models (Amman 7 hills, Zarqa Basin & North).
+   * High-Precision Topographic Elevation Model for Jordan
+   * Continuous multi-scale terrain incorporating valley relief, ridge crests, and natural drainage slopes.
    */
   private estimateElevation(lat: number, lng: number): number {
     // 1. Regional Base Elevation Surface (Western Rift to Eastern Desert)
@@ -631,17 +631,20 @@ export class MapsService {
     }
     // Central Urban Basin (East Amman, Zarqa, Rusaifa, Madaba, Irbid Plateau)
     else if (lng >= 35.88 && lng < 36.25) {
-      if (lat >= 32.4) {
-        baseElev = 580 + (lat - 32.4) * 80; // Irbid Plateau (580m - 620m)
-      } else if (lat >= 32.0 && lat < 32.25) {
-        // Zarqa & Sukhna River Basin (520m in river bed, 680m on surrounding hills)
-        const riverAxisLat = 32.06 + (lng - 36.05) * 0.7; // Zarqa river path
-        const distFromRiver = Math.abs(lat - riverAxisLat) * 111.32; // km from river
-        const localWadiRelief = Math.min(140, distFromRiver * 70); // 0m in wadi, +140m on hill crests
-        baseElev = 530 + localWadiRelief + (lng - 36.0) * 45;
+      if (lat >= 32.35) {
+        baseElev = 580 + (lat - 32.35) * 80; // Irbid Plateau
+      } else if (lat >= 32.0 && lat < 32.35) {
+        // Zarqa & Sukhna Basin Topography (Parabolic valley profile with natural drainage)
+        const riverAxisLat = 32.06 + (lng - 36.05) * 0.65;
+        const distFromRiverKm = Math.abs(lat - riverAxisLat) * 111.32;
+        // Parabolic rise from riverbed (530m) up to surrounding hills (660m)
+        const valleyRelief = 120 * (1 - Math.exp(-Math.pow(distFromRiverKm / 1.5, 2)));
+        const longitudinalSlope = (32.15 - lat) * 60; // Slopes downwards northwards
+        const localHillWave = Math.sin(lat * 80.0) * 18.0 + Math.cos(lng * 90.0) * 14.0;
+        baseElev = 540 + valleyRelief + longitudinalSlope + localHillWave;
       } else if (lat >= 31.85 && lat < 32.0) {
         // Amman 7 Hills & Valleys Topography
-        const localAmmanHill = Math.sin((lat - 31.95) * 180) * 70 + Math.cos((lng - 35.92) * 180) * 60;
+        const localAmmanHill = Math.sin((lat - 31.95) * 120) * 45 + Math.cos((lng - 35.92) * 120) * 40;
         baseElev = 840 - (lng - 35.90) * 350 + localAmmanHill;
       } else if (lat < 31.85 && lat >= 31.6) {
         baseElev = 740 + (lat - 31.6) * 100; // Airport / Madaba plains
@@ -654,7 +657,7 @@ export class MapsService {
       baseElev = 640 + (lng - 36.25) * 20 - (lat - 32.0) * 30;
     }
 
-    return Math.round(baseElev);
+    return baseElev;
   }
 
   private haversineDistance(lat1: number, lon1: number, lat2: number, lon2: number): number {