fix manning parameterization

benchmarks/wetting-drying/volcano/volcano.geo

@@ -2,8 +2,8 @@ L = 12000;
 lc = 1000;
 Point(1) = {-L/2,-L/2,0,lc}; 
 Point(2) = {-L/2,L/2,0,lc}; 
-Point(3) = {L/2,L/2,0,lc}; 
-Point(4) = {L/2,-L/2,0,lc}; 
+Point(3) = {L/2+L,L/2,0,lc}; 
+Point(4) = {L/2+L,-L/2,0,lc}; 
 
 Line(1) = {1,2};
 Line(2) = {2,3};

benchmarks/wetting-drying/volcano/volcano.py

@@ -21,7 +21,7 @@ def bathf(x,y) :
     return 0
 
 hlimt = 1
-hlimd = 0.5
+hlimd = 1
 linDrag = 0.05
 
 ###################

modules/shallowWater/dgConservationLawShallowWater2dC.cpp

@@ -4,7 +4,7 @@
 static double tdrag(double g, double H, double U, double V, double HLIM, double linDrag) {
   const double Hc = std::max(HLIM, H);
   const double a = std::max(0., (HLIM-std::max(0.,H))/HLIM);
-  return 0.0004*g*(hypot(U,V))*pow(Hc, -4./3)+a*linDrag;
+  return 0.0004*g*(hypot(U,V))*pow(Hc, -7./3)+a*linDrag;
 }
 
 static void tflux(double g, double H, double U, double V, double &fluxU, double &fluxV, double &c, double &ct, double _HLIM) {