diff --git a/external/mdal/frmts/mdal_2dm.cpp b/external/mdal/frmts/mdal_2dm.cpp
index 243cb12c403..76b162ac7d2 100644
--- a/external/mdal/frmts/mdal_2dm.cpp
+++ b/external/mdal/frmts/mdal_2dm.cpp
@@ -402,7 +402,7 @@ void MDAL::Driver2dm::save( const std::string &fileName, const std::string &, MD
     for ( size_t j = 0; j < 2; ++j )
     {
       line.append( " " );
-      line.append( MDAL::doubleToString( vertex[j], 8, true ) );
+      line.append( MDAL::doubleToString( vertex[j], 16 ) );
     }
     line.append( " " );
     line.append( MDAL::doubleToString( vertex[2] ) );
diff --git a/external/mdal/frmts/mdal_hec2d.cpp b/external/mdal/frmts/mdal_hec2d.cpp
index dfcd29e729b..eabe21d4e0b 100644
--- a/external/mdal/frmts/mdal_hec2d.cpp
+++ b/external/mdal/frmts/mdal_hec2d.cpp
@@ -122,7 +122,7 @@ static MDAL::DateTime convertToDateTime( const std::string strDateTime )
 {
   //HECRAS format date is 01JAN2000
 
-  auto data = MDAL::split( strDateTime, " " );
+  auto data = MDAL::split( strDateTime, ' ' );
   if ( data.size() < 2 )
     return MDAL::DateTime();
 
diff --git a/external/mdal/frmts/mdal_mike21.cpp b/external/mdal/frmts/mdal_mike21.cpp
index 16252160710..51991fe9058 100644
--- a/external/mdal/frmts/mdal_mike21.cpp
+++ b/external/mdal/frmts/mdal_mike21.cpp
@@ -23,13 +23,6 @@
 
 #define DRIVER_NAME "Mike21"
 
-// function to split using regex, by default split on whitespace characters
-std::vector<std::string> regex_split( const std::string &input, const std::regex &split_regex = std::regex{"\\s+"} )
-{
-  std::sregex_token_iterator iter( input.begin(), input.end(), split_regex, -1 );
-  std::sregex_token_iterator end;
-  return {iter, end};
-}
 
 static bool parse_vertex_id_gaps( std::map<size_t, size_t> &vertexIDtoIndex, size_t vertexIndex, size_t vertexID )
 {
@@ -246,7 +239,8 @@ std::unique_ptr<MDAL::Mesh> MDAL::DriverMike21::load( const std::string &meshFil
   {
     if ( 0 < lineNumber && lineNumber < mVertexCount + 1 )
     {
-      chunks = regex_split( MDAL::trim( line ) );
+      std::replace( line.begin(), line.end(), '\t', ' ' );
+      chunks = MDAL::split( MDAL::trim( line ), ' ' );
       if ( chunks.size() != 5 )
       {
         MDAL::Log::error( MDAL_Status::Err_InvalidData, name(), "vertex line in invalid format." );
@@ -283,7 +277,8 @@ std::unique_ptr<MDAL::Mesh> MDAL::DriverMike21::load( const std::string &meshFil
 
     if ( mVertexCount + 1 < lineNumber )
     {
-      chunks = regex_split( MDAL::trim( line ) );
+      std::replace( line.begin(), line.end(), '\t', ' ' );
+      chunks = MDAL::split( MDAL::trim( line ), ' ' );
       assert( faceIndex < faceCount );
 
       size_t faceVertexCount = chunks.size() - 1;
diff --git a/external/mdal/frmts/mdal_ugrid.cpp b/external/mdal/frmts/mdal_ugrid.cpp
index d4a2c7e5828..616049dc87d 100644
--- a/external/mdal/frmts/mdal_ugrid.cpp
+++ b/external/mdal/frmts/mdal_ugrid.cpp
@@ -461,7 +461,7 @@ void MDAL::DriverUgrid::ignore1DMeshVariables( const std::string &mesh, std::set
   for ( const std::string &coordinateIt : coordinateVarsToIgnore )
   {
     std::string coordinatesVar = mNcFile->getAttrStr( mesh, coordinateIt );
-    std::vector<std::string> allCoords = MDAL::split( coordinatesVar, " " );
+    std::vector<std::string> allCoords = MDAL::split( coordinatesVar, ' ' );
 
     for ( const std::string &var : allCoords )
     {
@@ -1041,7 +1041,7 @@ void MDAL::DriverUgrid::writeVariables( MDAL::Mesh *mesh, const std::string &mes
   }
   else
   {
-    std::vector<std::string> words = MDAL::split( mesh->crs(), ":" );
+    std::vector<std::string> words = MDAL::split( mesh->crs(), ':' );
 
     if ( words[0] == "EPSG" && words.size() > 1 )
     {
diff --git a/external/mdal/frmts/mdal_xdmf.cpp b/external/mdal/frmts/mdal_xdmf.cpp
index 3432b0280a2..56885d28a35 100644
--- a/external/mdal/frmts/mdal_xdmf.cpp
+++ b/external/mdal/frmts/mdal_xdmf.cpp
@@ -359,7 +359,7 @@ void MDAL::DriverXdmf::hdf5NamePath( const std::string &dataItemPath, std::strin
     path.erase( 0, startpos );
   }
 
-  std::vector<std::string> chunks = MDAL::split( path, ":" );
+  std::vector<std::string> chunks = MDAL::split( path, ':' );
   if ( chunks.size() != 2 )
   {
     throw MDAL::Error( MDAL_Status::Err_UnknownFormat, "must be in format fileName:hdfPath" );
diff --git a/external/mdal/mdal.cpp b/external/mdal/mdal.cpp
index 6faa0d42894..7e72827a231 100644
--- a/external/mdal/mdal.cpp
+++ b/external/mdal/mdal.cpp
@@ -21,7 +21,7 @@ static const char *EMPTY_STR = "";
 
 const char *MDAL_Version()
 {
-  return "1.3.0";
+  return "1.3.1";
 }
 
 MDAL_Status MDAL_LastStatus()
diff --git a/external/mdal/mdal_utils.cpp b/external/mdal/mdal_utils.cpp
index b9ee0482d41..ff46ffa33e2 100644
--- a/external/mdal/mdal_utils.cpp
+++ b/external/mdal/mdal_utils.cpp
@@ -964,7 +964,7 @@ MDAL::DateTime MDAL::parseCFReferenceTime( const std::string &timeInformation, c
   if ( strings.size() > 3 )
   {
     std::string timeString = strings[3];
-    auto timeStringsValue = MDAL::split( timeString, ":" );
+    auto timeStringsValue = MDAL::split( timeString, ':' );
     if ( timeStringsValue.size() == 3 )
     {
       hours = MDAL::toInt( timeStringsValue[0] );