diff --git a/backend/gn_module_zh/geometry.py b/backend/gn_module_zh/geometry.py
index 0d40b92d..49e383a0 100644
--- a/backend/gn_module_zh/geometry.py
+++ b/backend/gn_module_zh/geometry.py
@@ -63,12 +63,12 @@ def get_main_rb(query: list) -> int:
     area = 0
     for q_ in query:
         zh_polygon = (
-            DB.session.scalars(select(TZH.geom).where(TZH.id_zh == getattr(q_, "id_zh")))
+            DB.session.execute(select(TZH.geom).where(TZH.id_zh == getattr(q_, "id_zh")))
             .first()
             .geom
         )
         rb_polygon = (
-            DB.session.scalar(
+            DB.session.execute(
                 select(CorZhRb, TRiverBasin)
                 .join(TRiverBasin, TRiverBasin.id_rb == CorZhRb.id_rb)
                 .where(TRiverBasin.id_rb == getattr(q_, "id_rb"))
diff --git a/backend/gn_module_zh/model/cards.py b/backend/gn_module_zh/model/cards.py
index b174c7d7..c2f6b142 100644
--- a/backend/gn_module_zh/model/cards.py
+++ b/backend/gn_module_zh/model/cards.py
@@ -1216,7 +1216,7 @@ def __set_statuses(self):
         return self.status.__str__()
 
     def __set_hierarchy(self):
-        return self.hierarchy.__str__() if self.hierarchy is not None else None
+        return self.hierarchy.as_dict() if self.hierarchy is not None else None
 
     def __set_evaluation(self):
         self.__set_main_functions()
diff --git a/backend/gn_module_zh/model/zh_schema.py b/backend/gn_module_zh/model/zh_schema.py
index 714c360d..80abdd8a 100644
--- a/backend/gn_module_zh/model/zh_schema.py
+++ b/backend/gn_module_zh/model/zh_schema.py
@@ -378,7 +378,7 @@ def get_id_types_ref_geo(id_zh, ref_geo_config):
     @staticmethod
     def get_ref_geo_info(id_zh, id_types):
         return [
-            DB.session.scalars(
+            DB.session.execute(
                 select(CorZhArea, LAreas, TZH)
                 .join(LAreas)
                 .where(CorZhArea.id_zh == id_zh, LAreas.id_type == id_type, TZH.id_zh == id_zh)