do_cliff_collapse.cpp

Go to the documentation of this file.

 
/* ==============================================================================================================================
 
   This file is part of CoastalME, the Coastal Modelling Environment.
 
   CoastalME is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version.
 
   This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
 
   You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 
==============================================================================================================================*/
#include <assert.h>
 
#include <cmath>
 
#include <iostream>
using std::cerr;
using std::cout;
using std::endl;
using std::ios;
 
#include "cme.h"
#include "simulation.h"
#include "cliff.h"
 
//===============================================================================================================================
//===============================================================================================================================
int CSimulation::nDoAllWaveEnergyToCoastLandforms(void)
{
   if (m_nLogFileDetail >= LOG_FILE_MIDDLE_DETAIL)
      LogStream << m_ulIter << ": Calculating cliff collapse" << endl;
 
   int nRet;
 
   // First go along each coastline and update the total wave energy which it has experienced
   for (int i = 0; i < static_cast<int>(m_VCoast.size()); i++)
   {
      for (int j = 0; j < m_VCoast[i].nGetCoastlineSize(); j++)
      {
         CACoastLandform* pCoastLandform = m_VCoast[i].pGetCoastLandform(j);
 
         // First get wave energy for the coastal landform object
         double dWaveHeightAtCoast = m_VCoast[i].dGetCoastWaveHeight(j);
 
         // If the waves at this point are off-shore, then do nothing, just move to next coast point
         if (bFPIsEqual(dWaveHeightAtCoast, DBL_NODATA, TOLERANCE))
            continue;
 
         // OK we have on-shore waves so get the previously-calculated wave energy
         double dWaveEnergy = m_VCoast[i].dGetWaveEnergyAtBreaking(j);
// assert(isfinite(dWaveEnergy));
 
         // And save the accumulated value
         pCoastLandform->IncTotAccumWaveEnergy(dWaveEnergy);
 
         // Now, check the notch elevation
         int nX = m_VCoast[i].pPtiGetCellMarkedAsCoastline(j)->nGetX();
         int nY = m_VCoast[i].pPtiGetCellMarkedAsCoastline(j)->nGetY();
         int nCat = pCoastLandform->nGetLandFormCategory();
         double dTopElev = m_pRasterGrid->m_Cell[nX][nY].dGetSedimentTopElev();
         double dNotchElev = 0;
 
         if ((nCat == LF_CAT_CLIFF) || (nCat == LF_SUBCAT_CLIFF_ON_COASTLINE) || (nCat == LF_SUBCAT_CLIFF_INLAND))
         {
            CRWCliff * pCliff = reinterpret_cast<CRWCliff*>(pCoastLandform);
            dNotchElev = pCliff->dGetNotchBaseElev();
 
            // Is the notch elevation above the top surface of the sediment?
            if (dNotchElev > dTopElev)
            {
               // It is, so reduce the notch elevation, to be the same as the sediment top surface
               LogStream << m_ulIter << ": *** DDD [" << nX << "][" << nY << "} dTopElev = " << dTopElev << ", dNotchElev was " << dNotchElev << ", dNotchElev changed, is now " << dTopElev - m_dNotchBaseBelowSWL << endl;
 
               pCliff->SetNotchBaseElev(dTopElev - m_dNotchBaseBelowSWL);
            }
         }
 
         // // DEBUG CODE ==============
         // if ((j > 20) && (j <= 30))
         // {
         // string strCat;
         // if (nCat == LF_CAT_HINTERLAND)
         // strCat = "hinterland";
         // else if (nCat == LF_CAT_SEA)
         // strCat = "sea";
         // else if (nCat == LF_CAT_CLIFF)
         // strCat = "cliff";
         // else if (nCat == LF_CAT_DRIFT)
         // strCat = "drift";
         // else if (nCat == LF_CAT_INTERVENTION)
         // strCat = "intervention";
         // else if (nCat == LF_SUBCAT_CLIFF_ON_COASTLINE)
         // strCat = "cliff on coastline";
         // else if (nCat == LF_SUBCAT_CLIFF_INLAND)
         // strCat = "cliff inland";
         // else if (nCat == LF_SUBCAT_DRIFT_MIXED)
         // strCat = "drift mixed";
         // else if (nCat == LF_SUBCAT_DRIFT_TALUS)
         // strCat = "drift talus";
         // else if (nCat == LF_SUBCAT_DRIFT_BEACH)
         // strCat = "drift beach";
         // else
         // strCat = "unknown";
         //
         //    // LogStream << m_ulIter << ": [" << nX << "][" << nY << "] '" << strCat << "' dWaveEnergy = " << dWaveEnergy << " dGetTotAccumWaveEnergy() = " << pCoastLandform->dGetTotAccumWaveEnergy() << endl;
         //
         // LogStream << m_ulIter << ": [" << nX << "][" << nY << "] '" << strCat << "' dNotchElev = " << dNotchElev << " dTopElev = " << dTopElev << " m_dInitialMeanSWL = " << m_dInitialMeanSWL << " m_dThisIterMeanSWL = " << m_dThisIterMeanSWL << " m_dThisIterSWL = " << m_dThisIterSWL << endl;
         // }
         // // DEBUG CODE =============
 
         // Now simulate how the coastal landform responds to this wave energy
         int nCategory = pCoastLandform->nGetLandFormCategory();
 
         if (nCategory == LF_CAT_CLIFF)
         {
            // This is a cliff
            CRWCliff * pCliff = reinterpret_cast<CRWCliff*>(pCoastLandform);
 
            // Calculate this-timestep cliff notch erosion (is a length in external CRS units). Only consolidated sediment can have a cliff notch
            double dNotchExtension = dWaveEnergy / m_dCliffErosionResistance;
 
            // Deepen the cliff object's erosional notch as a result of wave energy during this timestep. Note that notch deepening may be constrained, since this-timestep notch extension cannot exceed the length (i.e. cellside minus notch depth) of sediment remaining on the cell
            pCliff->DeepenErosionalNotch(dNotchExtension);
 
            // OK, is the notch now extended enough to cause collapse (either because the overhang is greater than the threshold overhang, or because there is no sediment remaining)?
            if (pCliff->bReadyToCollapse(m_dNotchDepthAtCollapse))
            {
               // // DEBUG CODE ============================================================================================================================================
               // // Get total depths of sand consolidated and unconsolidated for every cell
               // if (m_ulIter == 5)
               // {
               // double dTmpSandCons = 0;
               // double dTmpSandUncons = 0;
               // for (int nX1 = 0; nX1 < m_nXGridSize; nX1++)
               // {
               // for (int nY1 = 0; nY1 < m_nYGridSize; nY1++)
               // {
               // dTmpSandCons += m_pRasterGrid->m_Cell[nX1][nY1].dGetTotConsSandThickConsiderNotch();
               //
               // dTmpSandUncons += m_pRasterGrid->m_Cell[nX1][nY1].dGetTotUnconsSand();
               // }
               // }
               //
               //    // Get the cliff cell's grid coords
               // int nXCliff = pCliff->pPtiGetCellMarkedAsLF()->nGetX();
               // int nYCliff = pCliff->pPtiGetCellMarkedAsLF()->nGetY();
               //
               //    // Get this cell's polygon
               // int nPoly = m_pRasterGrid->m_Cell[nXCliff][nYCliff].nGetPolygonID();
               //
               // LogStream << endl;
               // LogStream << "*****************************" << endl;
               // LogStream << m_ulIter << ": before cliff collapse on nPoly = " << nPoly << " total consolidated sand = " << dTmpSandCons * m_dCellArea << " total unconsolidated sand = " << dTmpSandUncons * m_dCellArea << endl;
               // }
               // // DEBUG CODE ============================================================================================================================================
 
               // It is ready to collapse
               double dCliffElevPreCollapse = 0;
               double dCliffElevPostCollapse = 0;
               double dFineCollapse = 0;
               double dSandCollapse = 0;
               double dCoarseCollapse = 0;
 
               // So do the cliff collapse
               nRet = nDoCliffCollapse(i, pCliff, dFineCollapse, dSandCollapse, dCoarseCollapse, dCliffElevPreCollapse, dCliffElevPostCollapse);
 
               if (nRet != RTN_OK)
               {
                  if (m_nLogFileDetail >= LOG_FILE_MIDDLE_DETAIL)
                     LogStream << m_ulIter << ": " << WARN << "problem with cliff collapse, continuing however" << endl;
               }
 
               // Deposit all sand and/or coarse sediment derived from this cliff collapse as unconsolidated sediment (talus)
               nRet = nDoCliffCollapseDeposition(i, pCliff, dSandCollapse, dCoarseCollapse, dCliffElevPreCollapse, dCliffElevPostCollapse);
 
               if (nRet != RTN_OK)
                  return nRet;
 
               // // DEBUG CODE ============================================================================================================================================
               // // Get total depths of sand consolidated and unconsolidated for every cell
               // if (m_ulIter == 5)
               // {
               // double dTmpSandCons = 0;
               // double dTmpSandUncons = 0;
               // for (int nX1 = 0; nX1 < m_nXGridSize; nX1++)
               // {
               // for (int nY1 = 0; nY1 < m_nYGridSize; nY1++)
               // {
               // dTmpSandCons += m_pRasterGrid->m_Cell[nX1][nY1].dGetTotConsSandThickConsiderNotch();
               //
               // dTmpSandUncons += m_pRasterGrid->m_Cell[nX1][nY1].dGetTotUnconsSand();
               // }
               // }
               //
               //    // Get the cliff cell's grid coords
               // int nXCliff = pCliff->pPtiGetCellMarkedAsLF()->nGetX();
               // int nYCliff = pCliff->pPtiGetCellMarkedAsLF()->nGetY();
               //
               //    // Get this cell's polygon
               // int nPoly = m_pRasterGrid->m_Cell[nXCliff][nYCliff].nGetPolygonID();
               //
               // LogStream << endl;
               // LogStream << "*****************************" << endl;
               // LogStream << m_ulIter << ": after cliff collapse on nPoly = " << nPoly << " total consolidated sand = " << dTmpSandCons * m_dCellArea << " total unconsolidated sand = " << dTmpSandUncons * m_dCellArea << endl;
               // LogStream << m_ulIter << ": total consolidated sand lost this iteration =  " << (m_dStartIterConsSandAllCells - dTmpSandCons) * m_dCellArea << endl;
               // LogStream << m_ulIter << ": total unconsolidated sand added this iteration =  " << (dTmpSandUncons - m_dStartIterUnconsSandAllCells) * m_dCellArea << endl;
               //
               // double dTmpAllPolySandErosion = 0;
               // double dTmpAllPolySandDeposition = 0;
               // for (unsigned int n = 0; n < m_pVCoastPolygon.size(); n++)
               // {
               // double dTmpSandErosion = m_pVCoastPolygon[n]->dGetCliffCollapseErosionSand() * m_dCellArea ;
               // double dTmpSandDeposition = m_pVCoastPolygon[n]->dGetCliffCollapseUnconsSandDeposition() * m_dCellArea ;
               //
               // LogStream << m_ulIter << ": polygon = " << m_pVCoastPolygon[n]->nGetCoastID() << " sand erosion = " << dTmpSandErosion << " sand deposition = " << dTmpSandDeposition << endl;
               //
               // dTmpAllPolySandErosion += dTmpSandErosion;
               // dTmpAllPolySandDeposition += dTmpSandDeposition;
               // }
               //
               // LogStream << "-------------------------------------------" << endl;
               // LogStream << m_ulIter << ": all polygons, sand erosion = " << dTmpAllPolySandErosion << " sand deposition = " << dTmpAllPolySandDeposition << endl;
               // LogStream << "*****************************" << endl;
               // }
               // // DEBUG CODE ============================================================================================================================================
            }
         }
      }
   }
 
   if (m_nLogFileDetail >= LOG_FILE_ALL)
      LogStream << m_ulIter << ": total cliff collapse (m^3) = " << (m_dThisIterCliffCollapseErosionFineUncons + m_dThisIterCliffCollapseErosionFineCons + m_dThisIterCliffCollapseErosionSandUncons + m_dThisIterCliffCollapseErosionSandCons + m_dThisIterCliffCollapseErosionCoarseUncons + m_dThisIterCliffCollapseErosionCoarseCons) * m_dCellArea << " (fine = " << (m_dThisIterCliffCollapseErosionFineUncons + m_dThisIterCliffCollapseErosionFineCons) * m_dCellArea << ", sand = " << (m_dThisIterCliffCollapseErosionSandUncons + m_dThisIterCliffCollapseErosionSandCons) * m_dCellArea << ", coarse = " << (m_dThisIterCliffCollapseErosionCoarseUncons + m_dThisIterCliffCollapseErosionCoarseCons) * m_dCellArea << "), talus deposition (m^3) = " << (m_dThisIterUnconsSandCliffDeposition + m_dThisIterUnconsCoarseCliffDeposition) * m_dCellArea << " (sand = " << m_dThisIterUnconsSandCliffDeposition * m_dCellArea << ", coarse = " << m_dThisIterUnconsSandCliffDeposition * m_dCellArea << ")" << endl;
 
   return RTN_OK;
}
 
//===============================================================================================================================
//===============================================================================================================================
int CSimulation::nDoCliffCollapse(int const nCoast, CRWCliff * pCliff, double &dFineCollapse, double &dSandCollapse, double &dCoarseCollapse, double &dPreCollapseCliffElev, double &dPostCollapseCliffElev)
{
   // Get the cliff cell's grid coords
   int nX = pCliff->pPtiGetCellMarkedAsLF()->nGetX();
   int nY = pCliff->pPtiGetCellMarkedAsLF()->nGetY();
 
   // Get this cell's polygon
   int nPoly = m_pRasterGrid->m_Cell[nX][nY].nGetPolygonID();
 
   if (nPoly == INT_NODATA)
   {
      // This cell isn't in a polygon
      LogStream << m_ulIter << ": " << WARN << "in nDoCliffCollapse(), [" << nX << "][" << nY << "] = {" << dGridCentroidXToExtCRSX(nX) << ", " << dGridCentroidYToExtCRSY(nY) << "} is not in a polygon" << endl;
 
      return RTN_ERR_CLIFF_NOT_IN_POLYGON;
   }
 
   CGeomCoastPolygon* pPolygon = m_VCoast[nCoast].pGetPolygon(nPoly);
 
   double dOrigCliffTopElev = m_pRasterGrid->m_Cell[nX][nY].dGetSedimentTopElev();
 
   // Get the elevation of the base of the notch from the cliff object
   double dNotchElev = pCliff->dGetNotchBaseElev();
 
   // Get the index of the layer containing the notch (layer 0 being just above basement)
   int nNotchLayer = m_pRasterGrid->m_Cell[nX][nY].nGetLayerAtElev(dNotchElev);
 
   // Safety check
   if (nNotchLayer < 0)
   {
      // Notch layer is < 0
      LogStream << m_ulIter << ": " << WARN << "in nDoCliffCollapse(), [" << nX << "][" << nY << "] = {" << dGridCentroidXToExtCRSX(nX) << ", " << dGridCentroidYToExtCRSY(nY) << "} notch layer = " << nNotchLayer << ", dNotchElev = " << dNotchElev << " m_dNotchBaseBelowSWL = " << m_dNotchBaseBelowSWL << " dOrigCliffTopElev = " << dOrigCliffTopElev << endl;
 
      return RTN_ERR_CLIFFNOTCH;
   }
 
   if (nNotchLayer == ELEV_ABOVE_SEDIMENT_TOP)
   {
      LogStream << m_ulIter << ": " << WARN << "in nDoCliffCollapse(), [" << nX << "][" << nY << "] has nNotchLayer = " << nNotchLayer << ", this has elevation = " << dNotchElev << " which is above sediment top elevation (" << m_pRasterGrid->m_Cell[nX][nY].dGetSedimentTopElev() << ")" << endl;
 
      return RTN_ERR_CLIFFNOTCH;
   }
 
   // Flag the coastline cliff object as having collapsed
   pCliff->SetCliffCollapsed();
 
   int nTopLayer = m_pRasterGrid->m_Cell[nX][nY].nGetTopLayerAboveBasement();
 
   // Safety check
   if (nTopLayer == INT_NODATA)
   {
      LogStream << m_ulIter << ": " << WARN << "in nDoCliffCollapse(), [" << nX << "][" << nY << "] nTopLayer = " << nTopLayer << endl;
 
      return RTN_ERR_NO_TOP_LAYER;
   }
 
   // Set the base of the collapse (see above)
   pCliff->SetNotchBaseElev(dNotchElev);
 
   // Set flags to say that the top layer has changed
   m_bConsChangedThisIter[nTopLayer] = true;
   m_bUnconsChangedThisIter[nTopLayer] = true;
 
   // Get the pre-collapse cliff elevation
   dPreCollapseCliffElev = m_pRasterGrid->m_Cell[nX][nY].dGetSedimentTopElev();
 
   // Now calculate the vertical depth of sediment lost in this cliff collapse. In CoastalME, all depth equivalents are assumed to be a depth upon the whole of a cell i.e. upon the area of a whole cell. So to keep the depth of cliff collapse consistent with all other depth equivalents, weight it by the fraction of the cell's area which is being removed
   double dAvailable = 0;
   double dFineConsLost = 0;
   double dFineUnconsLost = 0;
   double dSandConsLost = 0;
   double dSandUnconsLost = 0;
   double dCoarseConsLost = 0;
   double dCoarseUnconsLost = 0;
 
   // Now update the cell's sediment. If there are sediment layers above the notched layer, we must remove sediment from the whole depth of each layer
   for (int n = nTopLayer; n > nNotchLayer; n--)
   {
      // Start with the unconsolidated sediment
      dAvailable = m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(n)->pGetUnconsolidatedSediment()->dGetFineDepth() - m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(n)->pGetUnconsolidatedSediment()->dGetNotchFineLost();
 
      if (dAvailable > 0)
      {
         dFineCollapse += dAvailable;
         dFineUnconsLost += dAvailable;
         m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(n)->pGetUnconsolidatedSediment()->SetFineDepth(0);
         m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(n)->pGetUnconsolidatedSediment()->SetNotchFineLost(0);
      }
 
      dAvailable = m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(n)->pGetUnconsolidatedSediment()->dGetSandDepth() - m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(n)->pGetUnconsolidatedSediment()->dGetNotchSandLost();
 
      if (dAvailable > 0)
      {
         dSandCollapse += dAvailable;
         dSandUnconsLost += dAvailable;
         m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(n)->pGetUnconsolidatedSediment()->SetSandDepth(0);
         m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(n)->pGetUnconsolidatedSediment()->SetNotchSandLost(0);
      }
 
      dAvailable = m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(n)->pGetUnconsolidatedSediment()->dGetCoarseDepth() - m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(n)->pGetUnconsolidatedSediment()->dGetNotchCoarseLost();
 
      if (dAvailable > 0)
      {
         dCoarseCollapse += dAvailable;
         dCoarseUnconsLost += dAvailable;
         m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(n)->pGetUnconsolidatedSediment()->SetCoarseDepth(0);
         m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(n)->pGetUnconsolidatedSediment()->SetNotchCoarseLost(0);
      }
 
      // Now get the consolidated sediment
      dAvailable = m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(n)->pGetConsolidatedSediment()->dGetFineDepth() - m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(n)->pGetConsolidatedSediment()->dGetNotchFineLost();
 
      if (dAvailable > 0)
      {
         dFineCollapse += dAvailable;
         dFineConsLost += dAvailable;
         m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(n)->pGetConsolidatedSediment()->SetFineDepth(0);
         m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(n)->pGetConsolidatedSediment()->SetNotchFineLost(0);
      }
 
      dAvailable = m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(n)->pGetConsolidatedSediment()->dGetSandDepth() - m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(n)->pGetConsolidatedSediment()->dGetNotchSandLost();
 
      if (dAvailable > 0)
      {
         dSandCollapse += dAvailable;
         dSandConsLost += dAvailable;
         m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(n)->pGetConsolidatedSediment()->SetSandDepth(0);
         m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(n)->pGetConsolidatedSediment()->SetNotchSandLost(0);
      }
 
      dAvailable = m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(n)->pGetConsolidatedSediment()->dGetCoarseDepth() - m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(n)->pGetConsolidatedSediment()->dGetNotchCoarseLost();
 
      if (dAvailable > 0)
      {
         dCoarseCollapse += dAvailable;
         dCoarseConsLost += dAvailable;
         m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(n)->pGetConsolidatedSediment()->SetCoarseDepth(0);
         m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(n)->pGetConsolidatedSediment()->SetNotchCoarseLost(0);
      }
   }
 
   // Now sort out the sediment lost from the consolidated layer into which the erosional notch was incised
   double dNotchLayerTop = m_pRasterGrid->m_Cell[nX][nY].dCalcLayerElev(nNotchLayer);
   double dNotchLayerThickness = m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(nNotchLayer)->dGetTotalThickness();
   double dNotchLayerFracRemoved = (dNotchLayerTop - dNotchElev) / dNotchLayerThickness;
 
   // Sort out the notched layer's sediment, both consolidated and unconsolidated, for this cell. First the unconsolidated sediment
   double dFineDepth = m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(nNotchLayer)->pGetUnconsolidatedSediment()->dGetFineDepth();
   dAvailable = dFineDepth - m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(nNotchLayer)->pGetUnconsolidatedSediment()->dGetNotchFineLost();
 
   if (dAvailable > 0)
   {
      // Some unconsolidated fine sediment is available for collapse
      double dLost = dAvailable * dNotchLayerFracRemoved;
      dFineCollapse += dLost;
      dFineUnconsLost += dLost;
      m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(nNotchLayer)->pGetUnconsolidatedSediment()->SetFineDepth(dFineDepth - dLost);
      m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(nNotchLayer)->pGetUnconsolidatedSediment()->SetNotchFineLost(0);
   }
 
   double dSandDepth = m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(nNotchLayer)->pGetUnconsolidatedSediment()->dGetSandDepth();
   dAvailable = dSandDepth - m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(nNotchLayer)->pGetUnconsolidatedSediment()->dGetNotchSandLost();
 
   if (dAvailable > 0)
   {
      // Some unconsolidated sand sediment is available for collapse
      double dLost = dAvailable * dNotchLayerFracRemoved;
      dSandCollapse += dLost;
      dSandUnconsLost += dLost;
      m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(nNotchLayer)->pGetUnconsolidatedSediment()->SetSandDepth(dSandDepth - dLost);
      m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(nNotchLayer)->pGetUnconsolidatedSediment()->SetNotchSandLost(0);
   }
 
   double dCoarseDepth = m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(nNotchLayer)->pGetUnconsolidatedSediment()->dGetCoarseDepth();
   dAvailable = dCoarseDepth - m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(nNotchLayer)->pGetUnconsolidatedSediment()->dGetNotchCoarseLost();
 
   if (dAvailable > 0)
   {
      // Some unconsolidated coarse sediment is available for collapse
      double dLost = dAvailable * dNotchLayerFracRemoved;
      dCoarseCollapse += dLost;
      dCoarseUnconsLost += dLost;
      m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(nNotchLayer)->pGetUnconsolidatedSediment()->SetCoarseDepth(dCoarseDepth - dLost);
      m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(nNotchLayer)->pGetUnconsolidatedSediment()->SetNotchCoarseLost(0);
   }
 
   // Now do the consolidated sediment
   dFineDepth = m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(nNotchLayer)->pGetConsolidatedSediment()->dGetFineDepth();
   dAvailable = dFineDepth - m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(nNotchLayer)->pGetConsolidatedSediment()->dGetNotchFineLost();
 
   if (dAvailable > 0)
   {
      // Some consolidated fine sediment is available for collapse
      double dLost = dAvailable * dNotchLayerFracRemoved;
      dFineCollapse += dLost;
      dFineConsLost += dLost;
      m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(nNotchLayer)->pGetConsolidatedSediment()->SetFineDepth(dFineDepth - dLost);
      m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(nNotchLayer)->pGetConsolidatedSediment()->SetNotchFineLost(0);
   }
 
   dSandDepth = m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(nNotchLayer)->pGetConsolidatedSediment()->dGetSandDepth();
   dAvailable = dSandDepth - m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(nNotchLayer)->pGetConsolidatedSediment()->dGetNotchSandLost();
 
   if (dAvailable > 0)
   {
      // Some consolidated sand sediment is available for collapse
      double dLost = dAvailable * dNotchLayerFracRemoved;
      dSandCollapse += dLost;
      dSandConsLost += dLost;
      m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(nNotchLayer)->pGetConsolidatedSediment()->SetSandDepth(dSandDepth - dLost);
      m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(nNotchLayer)->pGetConsolidatedSediment()->SetNotchSandLost(0);
   }
 
   dCoarseDepth = m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(nNotchLayer)->pGetConsolidatedSediment()->dGetCoarseDepth();
   dAvailable = dCoarseDepth - m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(nNotchLayer)->pGetConsolidatedSediment()->dGetNotchCoarseLost();
 
   if (dAvailable > 0)
   {
      // Some consolidated coarse sediment is available for collapse
      double dLost = dAvailable * dNotchLayerFracRemoved;
      dCoarseCollapse += dLost;
      dCoarseConsLost += dLost;
      m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(nNotchLayer)->pGetConsolidatedSediment()->SetCoarseDepth(dCoarseDepth - dLost);
      m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(nNotchLayer)->pGetConsolidatedSediment()->SetNotchCoarseLost(0);
   }
 
   // Update the cell's totals for cliff collapse erosion
   m_pRasterGrid->m_Cell[nX][nY].IncrCliffCollapseErosion(dFineCollapse, dSandCollapse, dCoarseCollapse);
 
   // Update the cell's layer elevations and d50
   m_pRasterGrid->m_Cell[nX][nY].CalcAllLayerElevsAndD50();
 
   // Get the post-collapse cliff elevation
   dPostCollapseCliffElev = m_pRasterGrid->m_Cell[nX][nY].dGetSedimentTopElev();
 
   if (m_nLogFileDetail >= LOG_FILE_MIDDLE_DETAIL)
      LogStream << m_ulIter << ": cliff collapse at [" << nX << "][" << nY << "], original cliff elevation = " << dOrigCliffTopElev << ", new cliff elevation = " << dPostCollapseCliffElev << ", change in elevation = " << dOrigCliffTopElev - dPostCollapseCliffElev << endl;
 
   // And update the cell's sea depth
   m_pRasterGrid->m_Cell[nX][nY].SetSeaDepth();
 
   // LogStream << m_ulIter << ": cell [" << nX << "][" << nY << "] after removing sediment, dGetVolEquivSedTopElev() = " << m_pRasterGrid->m_Cell[nX][nY].dGetVolEquivSedTopElev() << ", dGetSedimentTopElev() = " << m_pRasterGrid->m_Cell[nX][nY].dGetSedimentTopElev() << endl << endl;
 
   // Update this-polygon totals: add to the depths of cliff collapse erosion for this polygon
   pPolygon->AddCliffCollapseErosionFine(dFineCollapse);
   pPolygon->AddCliffCollapseToSuspensionFine(dFineCollapse);
   pPolygon->AddCliffCollapseErosionSand(dSandCollapse);
   pPolygon->AddCliffCollapseErosionCoarse(dCoarseCollapse);
 
   // And update the this-timestep totals and the grand totals for collapse
   // m_nNThisIterCliffCollapse++;
   // m_nNTotCliffCollapse++;
 
   // Add to this-iteration totals
   m_dThisIterCliffCollapseErosionFineUncons += dFineUnconsLost;
   m_dThisIterCliffCollapseErosionFineCons += dFineConsLost;
 
   // Also add to the total suspended load. Note that this addition to the suspended load has not yet been added to all cells, this happens in nUpdateGrid()
   m_dThisIterFineSedimentToSuspension += (dFineConsLost + dFineUnconsLost);
 
   m_dThisIterCliffCollapseErosionSandUncons += dSandUnconsLost;
   m_dThisIterCliffCollapseErosionSandCons += dSandConsLost;
   m_dThisIterCliffCollapseErosionCoarseUncons += dCoarseUnconsLost;
   m_dThisIterCliffCollapseErosionCoarseCons += dCoarseConsLost;
 
   return RTN_OK;
}
 
//===============================================================================================================================
//===============================================================================================================================
int CSimulation::nDoCliffCollapseDeposition(int const nCoast, CRWCliff const* pCliff, double const dSandFromCollapse, double const dCoarseFromCollapse, double const dPreCollapseCliffElev, double const dPostCollapseCliffElev)
{
   // Check: is there some sand- or coarse-sized sediment to deposit?
   if ((dSandFromCollapse + dCoarseFromCollapse) < SEDIMENT_ELEV_TOLERANCE)
      return RTN_OK;
 
   // LogStream << "\tdSandFromCollapse = " << dSandFromCollapse << " dCoarseFromCollapse = " << dCoarseFromCollapse << endl;
 
   // OK, we have some sand- and/or coarse-sized sediment to deposit
   int nStartPoint = pCliff->nGetPointOnCoast();
   int nCoastSize = m_VCoast[nCoast].nGetCoastlineSize();
 
   // Get the cliff cell's grid coords
   int nXCliff = pCliff->pPtiGetCellMarkedAsLF()->nGetX();
   int nYCliff = pCliff->pPtiGetCellMarkedAsLF()->nGetY();
 
   // Get this cell's polygon
   int nPoly = m_pRasterGrid->m_Cell[nXCliff][nYCliff].nGetPolygonID();
 
   if (nPoly == INT_NODATA)
   {
      // This cell isn't in a polygon
      LogStream << m_ulIter << " : in nDoCliffCollapse(), [" << nXCliff << "][" << nYCliff << "] = {" << dGridCentroidXToExtCRSX(nXCliff) << ", " << dGridCentroidYToExtCRSY(nYCliff) << "} is not in a polygon" << endl;
 
      return RTN_ERR_CLIFF_NOT_IN_POLYGON;
   }
 
   CGeomCoastPolygon* pPolygon = m_VCoast[nCoast].pGetPolygon(nPoly);
 
   // OK, now set up the planview sequence talus deposition. First we deposit to create a Dean profile starting from the cliff collapse cell. Then we deposit along two profiles which start from the coast cells on either side of the cliff collapse cell, and then on two profiles starting on the next two "outside" coast cells, etc. However, we do have a "preferred" talus width
   int nTalusWidthInCells = nConvertMetresToNumCells(m_dCliffDepositionPlanviewWidth);
 
   // The default talus collapse width must be an odd number of cells in width i.e. centred on the cliff collapse cell (but only if we are not at the end of the coast)
   if ((nTalusWidthInCells % 2) == 0)
      nTalusWidthInCells++;
 
   // This holds the valid coast start points for each cliff collapse Dean profile
   vector<int> VnTalusProfileCoastStartPoint(nCoastSize);
 
   // This is the coast start point for the first Dean profile
   VnTalusProfileCoastStartPoint[0] = nStartPoint;
   int nn = 1;
   int nSigned = 1;
   int nCount = 1;
 
   do
   {
      int nTmpPoint;
 
      if ((nCount % 2) != 0)
         nTmpPoint = nStartPoint + nSigned;
 
      else
      {
         nTmpPoint = nStartPoint - nSigned;
         nSigned++;
      }
 
      // Is this start point valid?
      if ((nTmpPoint < 0) || (nTmpPoint > (nCoastSize - 1)))
      {
         // No, it is outside the grid, so find another
         nCount++;
         continue;
      }
 
      else
      {
         // It is valid
         VnTalusProfileCoastStartPoint[nn] = nTmpPoint;
         nn++;
         nCount++;
      }
   } while (nn < nCoastSize);
 
   bool bHitFirstCoastPoint = false;
   bool bHitLastCoastPoint = false;
 
   double dTotSandToDepositAllProfiles = dSandFromCollapse;          // Note that this can increase, if we get erosion because Dean profile is lower than profile at that point
   double dTotCoarseToDepositAllProfiles = dCoarseFromCollapse;      // Note that this can increase, if we get erosion because Dean profile is lower than profile at that point
   double dTotSandDepositedAllProfiles = 0;
   double dTotCoarseDepositedAllProfiles = 0;
 
   // Process each deposition profile
   for (int nAcross = 0; nAcross < nCoastSize; nAcross++)
   {
      bool bDoSandDepositionOnThisProfile = false;
      bool bSandDepositionCompletedOnThisProfile = false;
      bool bDoCoarseDepositionOnThisProfile = false;
      bool bCoarseDepositionCompletedOnThisProfile = false;
 
      // int nRemaining = tMax(1, nTalusWidthInCells - nAcross);
 
      // This is the minimum planview length (in cells) of the Dean profile. The initial length will be increased later if we can't deposit sufficient talus
      int nTalusProfileLenInCells = nConvertMetresToNumCells(m_dCliffTalusMinDepositionLength);
 
      // Calculate the target amount to be deposited on each talus profile, assuming the "preferred" talus width
      double dTargetSandToDepositOnThisProfile = dTotSandToDepositAllProfiles / nTalusWidthInCells;
      double dTargetCoarseToDepositOnThisProfile = dTotCoarseToDepositAllProfiles / nTalusWidthInCells;
      // double dTargetSandToDepositOnThisProfile = (dTotSandToDepositAllProfiles - dTotSandDepositedAllProfiles) / nRemaining;
      // double dTargetCoarseToDepositOnThisProfile = (dTotCoarseToDepositAllProfiles - dTotCoarseDepositedAllProfiles) / nRemaining;
 
      // Use this to make sure that, if we have both sand and coarse to deposit, we don't drop all the sand on a cell and then be unable to deposit any coarse
      double dSandProp = 0.5;
      double dCoarseProp = 1 - dSandProp;
 
      if (dTargetSandToDepositOnThisProfile + dTargetCoarseToDepositOnThisProfile > 0)
      {
         dSandProp = dTargetSandToDepositOnThisProfile / (dTargetSandToDepositOnThisProfile + dTargetCoarseToDepositOnThisProfile);
         dCoarseProp = 1 - dSandProp;
      }
 
      double dSandDepositedOnThisProfile = 0;
      double dCoarseDepositedOnThisProfile = 0;
 
      if (dTotSandToDepositAllProfiles > 0)
      {
         bDoSandDepositionOnThisProfile = true;
 
         if (bFPIsEqual(dTotSandToDepositAllProfiles - dTotSandDepositedAllProfiles, 0.0, MASS_BALANCE_TOLERANCE))
            bSandDepositionCompletedOnThisProfile = true;
      }
 
      else
         bSandDepositionCompletedOnThisProfile = true;
 
      if (dTotCoarseToDepositAllProfiles > 0)
      {
         bDoCoarseDepositionOnThisProfile = true;
 
         if (bFPIsEqual(dTotCoarseToDepositAllProfiles - dTotCoarseDepositedAllProfiles, 0.0, MASS_BALANCE_TOLERANCE))
            bCoarseDepositionCompletedOnThisProfile = true;
      }
 
      else
         bCoarseDepositionCompletedOnThisProfile = true;
 
      if (bSandDepositionCompletedOnThisProfile && bCoarseDepositionCompletedOnThisProfile)
      {
         // LogStream << m_ulIter << ": break 2 for cliff collapse at [" << nXCliff << "][" << nYCliff << "] nStartPoint = " << nStartPoint << " nAcross = " << nAcross << endl << "\tdTargetSandToDepositOnThisProfile = " << dTargetSandToDepositOnThisProfile << " dSandDepositedOnThisProfile = " << dSandDepositedOnThisProfile << " dTotSandToDepositAllProfiles = " << dTotSandToDepositAllProfiles << " dTotSandDepositedAllProfiles = " << dTotSandDepositedAllProfiles << endl << "\tdTargetCoarseToDepositOnThisProfile = " << dTargetCoarseToDepositOnThisProfile << " dCoarseDepositedOnThisProfile = " << dCoarseDepositedOnThisProfile << " dTotCoarseToDepositAllProfiles = " <<  dTotCoarseToDepositAllProfiles << " dTotCoarseDepositedAllProfiles = " << dTotCoarseDepositedAllProfiles << endl;
 
         break;
      }
 
      // Get the start point of this cliff collapse deposition profile
      int nThisPoint = VnTalusProfileCoastStartPoint[nAcross];
 
      // Are we at the start or end of the coast?
      if (nThisPoint == 0)
         bHitFirstCoastPoint = true;
 
      if (nThisPoint == nCoastSize - 1)
         bHitLastCoastPoint = true;
 
      CGeom2DPoint PtStart;
      CGeom2DPoint PtEnd;
 
      // Make the start of the deposition profile the cliff cell that is marked as coast (not the cell under the smoothed vector coast, they may well be different)
      PtStart.SetX(dGridCentroidXToExtCRSX(m_VCoast[nCoast].pPtiGetCellMarkedAsCoastline(nThisPoint)->nGetX()));
      PtStart.SetY(dGridCentroidYToExtCRSY(m_VCoast[nCoast].pPtiGetCellMarkedAsCoastline(nThisPoint)->nGetY()));
 
      // Set the initial fraction of cliff height, this will be increased (max is one) if we can't deposit sufficient talus
      double dCliffHeightFrac = m_dMinCliffTalusHeightFrac;
 
      bool bJustDepositWhatWeCan = false;
 
      // The initial seaward offset, in cells. This will be increased if we can't deposit sufficient talus
      int nSeawardOffset = 1;
 
      // Process this profile
      do
      {
         if (bJustDepositWhatWeCan || (bSandDepositionCompletedOnThisProfile && bCoarseDepositionCompletedOnThisProfile))
         {
            // LogStream << m_ulIter << ": break 3 for cliff collapse at [" << nXCliff << "][" << nYCliff << "] nStartPoint = " << nStartPoint << " nThisPoint = " << nThisPoint << endl << "\tnSeawardOffset = " << nSeawardOffset << " dCliffHeightFrac = " << dCliffHeightFrac << " nAcross = " << nAcross << endl << "\tbJustDepositWhatWeCan = " << bJustDepositWhatWeCan << "\tdTargetSandToDepositOnThisProfile = " << dTargetSandToDepositOnThisProfile << " dSandDepositedOnThisProfile = " << dSandDepositedOnThisProfile << " dTotSandToDepositAllProfiles = " << dTotSandToDepositAllProfiles << " dTotSandDepositedAllProfiles = " << dTotSandDepositedAllProfiles << endl << "\tdTargetCoarseToDepositOnThisProfile = " << dTargetCoarseToDepositOnThisProfile << " dCoarseDepositedOnThisProfile = " << dCoarseDepositedOnThisProfile << " dTotCoarseToDepositAllProfiles = " <<  dTotCoarseToDepositAllProfiles << " dTotCoarseDepositedAllProfiles = " << dTotCoarseDepositedAllProfiles << endl;
 
            break;
         }
 
         // Need to deposit more on this profile: increase the seaward offset each time round the loop
         nSeawardOffset++;
 
         // Has the seaward offset reached the arbitrary limit?
         if (nSeawardOffset >= MAX_SEAWARD_OFFSET_FOR_CLIFF_TALUS)
         {
            // It has, so if cliff height is not at the maximum, then try again with a larger fraction of cliff height
            if (dCliffHeightFrac < 1)
            {
               dCliffHeightFrac += CLIFF_COLLAPSE_HEIGHT_INCREMENT;
 
               // Reset seaward offset
               nSeawardOffset = 1;
            }
 
            else
            {
               // Cliff height has reached the limit, is the talus length also at its arbitrary limit?
               if (nTalusProfileLenInCells >= MAX_CLIFF_TALUS_LENGTH)
               {
                  // The talus length is also at this limit, so there is nothing more we can increase on this profile. Just deposit what we can and move on to the next profile
                  bJustDepositWhatWeCan = true;
               }
 
               else
               {
                  // The talus length is not at its limit, so try again with an increased talus length
                  nTalusProfileLenInCells += CLIFF_COLLAPSE_LENGTH_INCREMENT;
 
                  // Reset seaward offset
                  nSeawardOffset = 1;
 
                  // Set cliff height to exactly one
                  dCliffHeightFrac = 1;
               }
            }
         }
 
         if (bHitFirstCoastPoint && bHitLastCoastPoint)
         {
            // Uh-oh, we've reached both ends of the coast (!) and we can't increase anything any more
            LogStream << m_ulIter << ": unable to deposit sufficient unconsolidated talus from cliff collapse at [" << nXCliff << "][" << nYCliff << "] nStartPoint = " << nStartPoint << " nThisPoint = " << nThisPoint << endl << "\tnSeawardOffset = " << nSeawardOffset << " dCliffHeightFrac = " << dCliffHeightFrac << " nAcross = " << nAcross << endl << "\tdTargetSandToDepositOnThisProfile = " << dTargetSandToDepositOnThisProfile << " dSandDepositedOnThisProfile = " << dSandDepositedOnThisProfile << " dTotSandToDepositAllProfiles = " << dTotSandToDepositAllProfiles << " dTotSandDepositedAllProfiles = " << dTotSandDepositedAllProfiles << endl << "\tdTargetCoarseToDepositOnThisProfile = " << dTargetCoarseToDepositOnThisProfile << " dCoarseDepositedOnThisProfile = " << dCoarseDepositedOnThisProfile << " dTotCoarseToDepositAllProfiles = " << dTotCoarseToDepositAllProfiles << " dTotCoarseDepositedAllProfiles = " << dTotCoarseDepositedAllProfiles << endl;
 
            return RTN_ERR_CLIFFDEPOSIT;
         }
 
         // Now construct a deposition collapse profile from the start point, it is one cell longer than the specified length because it includes the cliff point in the profile. Calculate its length in external CRS units, the way it is done here is approximate but probably OK
         double dThisProfileLength = (nTalusProfileLenInCells + nSeawardOffset + 1) * m_dCellSide;
 
         // Get the end point of this coastline-normal line
         CGeom2DIPoint PtiEnd;            // In grid CRS
         int nRtn = nGetCoastNormalEndPoint(nCoast, nThisPoint, nCoastSize, &PtStart, dThisProfileLength, &PtEnd, &PtiEnd, false);
 
         // Safety check
         if (nRtn == RTN_ERR_NO_SOLUTION_FOR_ENDPOINT)
         {
            LogStream << m_ulIter << ": unable to deposit sufficient unconsolidated talus from cliff collapse, could not find a solution for the end point of the Dean profile" << endl;
 
            return nRtn;
         }
 
         // Safety check
         if (PtStart == PtEnd)
         {
            // This would give a zero-length profile, and a zero-divide error during rasterization. So just move on to the next profile
            break;
         }
 
         // OK, both the start and end points of this deposition profile are within the grid
         // LogStream << m_ulIter << ": nWidthDistSigned = " << nWidthDistSigned << " cliff collapse profile from " << PtStart.dGetX() << ", " << PtStart.dGetY() << " to " << PtEnd.dGetX() << ", " << PtEnd.dGetY() << " with length (inc. cliff point) = " << dThisProfileLength << endl;
 
         vector<CGeom2DPoint> VTmpProfile;
         VTmpProfile.push_back(PtStart);
         VTmpProfile.push_back(PtEnd);
         vector<CGeom2DIPoint> VCellsUnderProfile;
 
         // Now get the raster cells under this profile
         RasterizeCliffCollapseProfile(&VTmpProfile, &VCellsUnderProfile);
 
         int nRasterProfileLength = static_cast<int>(VCellsUnderProfile.size());
 
         // Check now, for the case where the profile is very short
         if (nRasterProfileLength - nSeawardOffset < 3)
         {
            // Can't do anything with this very short profile, since (nRasterProfileLength - nSeawardOffset - 2) later will give zero or -ve dInc. So just move on to the next profile
            break;
         }
 
         else if (nRasterProfileLength - nSeawardOffset == 3)
         {
            // Can't increase offset any more, or get zero divide with (nRasterProfileLength - nSeawardOffset - 2) later. So just deposit what we can and then move on to the next profile
            bJustDepositWhatWeCan = true;
         }
 
         vector<double> dVProfileNow(nRasterProfileLength, 0);
         vector<bool> bVProfileValid(nRasterProfileLength, true);
 
         // LogStream << m_ulIter << ": for cliff collapse at [" << nXCliff << "][" << nYCliff << "] nStartPoint = " << nStartPoint << " nAcross = " << nAcross << endl << "\tnRasterProfileLength = " << nRasterProfileLength << " nSeawardOffset = " << nSeawardOffset << " nRasterProfileLength - nSeawardOffset - 2 = " << nRasterProfileLength - nSeawardOffset - 2 << endl;
 
         // Calculate the existing elevation for all points along the deposition profile
         for (int n = 0; n < nRasterProfileLength; n++)
         {
            int nX = VCellsUnderProfile[n].nGetX();
            int nY = VCellsUnderProfile[n].nGetY();
 
            dVProfileNow[n] = m_pRasterGrid->m_Cell[nX][nY].dGetSedimentTopElev();
 
            // Don't allow cliff collapse talus onto intervention cells TODO 078 Is this realistic? Should it change with different types on intervention?
            if (bIsInterventionCell(nX, nY))
               bVProfileValid[n] = false;
         }
 
         // Now calculate the elevation of the talus top at the shoreline
         double dCliffHeight = dPreCollapseCliffElev - dPostCollapseCliffElev;
         double dTalusTopElev = dPostCollapseCliffElev + (dCliffHeight * dCliffHeightFrac);
 
         // LogStream << "Elevations: cliff top = " << dPreCollapseCliffElev << " cliff base = " << dPostCollapseCliffElev << " talus top = " << dTalusTopElev << endl;
 
         // if (dPreCollapseCliffElev < dPostCollapseCliffElev)
         // LogStream << "*** ERROR, cliff top is lower than cliff base" << endl;
 
         // Next calculate the talus slope length in external CRS units, this is approximate but probably OK
         double dTalusSlopeLength = dThisProfileLength - ((nSeawardOffset - 1) * m_dCellSide);
 
         // If user has not supplied a value for m_dCliffDepositionA, then solve for dA so that the elevations at end of the existing profile, and at the end of the Dean equilibrium profile, are the same
         double dA = 0;
 
         if (bFPIsEqual(m_dCliffDepositionA, 0.0, TOLERANCE))
            dA = m_dCliffDepositionA;
 
         else
            dA = (dTalusTopElev - dVProfileNow[nRasterProfileLength - 1]) / pow(dTalusSlopeLength, DEAN_POWER);
 
         // assert((nRasterProfileLength - nSeawardOffset - 2) > 0);
         double dInc = dTalusSlopeLength / (nRasterProfileLength - nSeawardOffset - 2);
         vector<double> dVDeanProfile(nRasterProfileLength);
 
         // Calculate the Dean equilibrium profile of the talus h(y) = A * y^(2/3) where h(y) is the distance below the talus-top elevation (the highest point in the Dean profile) at a distance y from the cliff (the landward start of the profile)
         CalcDeanProfile(&dVDeanProfile, dInc, dTalusTopElev, dA, true, nSeawardOffset, dTalusTopElev);
 
         // Get the total difference in elevation between the two profiles (Dean profile - present profile). Since we want the Dean profile to be higher than the present profile, a good result is a +ve number
         double dTotElevDiff = dSubtractProfiles(&dVDeanProfile, &dVProfileNow, &bVProfileValid);
 
         //          // DEBUG CODE -----------------------------------------------------
         // LogStream << endl;
         // LogStream << "dTalusSlopeLength = " << dTalusSlopeLength << " dA = " << dA << endl;
         // LogStream << "dDistFromTalusStart - dInc = " << dDistFromTalusStart - dInc << " dThisProfileLength - nSeawardOffset - 2 = " << dThisProfileLength - nSeawardOffset - 2 << endl;
         // LogStream << "Profile now (inc. cliff cell) = ";
         // for (int n = 0; n < nRasterProfileLength; n++)
         // {
         // int
         // nX = VCellsUnderProfile[n].nGetX(),
         // nY = VCellsUnderProfile[n].nGetY();
         // dVProfileNow[n] = m_pRasterGrid->m_Cell[nX][nY].dGetSedimentTopElev();
         // LogStream << dVProfileNow[n] << " ";
         // }
         // LogStream << endl;
         // LogStream << "Dean equilibrium profile (inc. cliff cell) = ";
         // for (int n = 0; n < nRasterProfileLength; n++)
         // {
         // LogStream << dVDeanProfile[n] << " ";
         // }
         // LogStream << endl;
         // LogStream << "Difference (inc. cliff cell) = ";
         // for (int n = 0; n < nRasterProfileLength; n++)
         // {
         // LogStream << dVDeanProfile[n] - dVProfileNow[n] << " ";
         // }
         // LogStream << endl;
         //          // DEBUG CODE -----------------------------------------------------
 
         // If we are not in a "just deposit what we can" situation, then for this planview profile, does the Dean equilibrium profile allow us to deposit all the talus sediment which we need to get rid of?
         if (! bJustDepositWhatWeCan && (dTotElevDiff < (dTargetSandToDepositOnThisProfile + dTargetCoarseToDepositOnThisProfile)))
         {
            // No it doesn't, so try again with a larger seaward offset and/or a longer Dean profile length
            // LogStream << m_ulIter << ": bJustDepositWhatWeCan = " << bJustDepositWhatWeCan << " nSeawardOffset = " << nSeawardOffset << " dTotElevDiff = " << dTotElevDiff << endl;
 
            continue;
         }
 
         // OK, now process all cells in this profile, including the first one (which is where the cliff collapse occurred)
         for (int n = 0; n < nRasterProfileLength; n++)
         {
            // Are we depositing sand talus sediment on this profile?
            if (bDoSandDepositionOnThisProfile)
            {
               if (bFPIsEqual(dTargetSandToDepositOnThisProfile - dSandDepositedOnThisProfile, 0.0, MASS_BALANCE_TOLERANCE))
                  bSandDepositionCompletedOnThisProfile = true;
 
               else
                  bSandDepositionCompletedOnThisProfile = false;
            }
 
            // Are we depositing coarse talus sediment on this profile?
            if (bDoCoarseDepositionOnThisProfile)
            {
               if (bFPIsEqual(dTargetCoarseToDepositOnThisProfile - dCoarseDepositedOnThisProfile, 0.0, MASS_BALANCE_TOLERANCE))
                  bCoarseDepositionCompletedOnThisProfile = true;
 
               else
                  bCoarseDepositionCompletedOnThisProfile = false;
            }
 
            // If we have deposited enough, then break out of the loop
            if (bSandDepositionCompletedOnThisProfile && bCoarseDepositionCompletedOnThisProfile)
            {
               // LogStream << m_ulIter << ": break 1 for cliff collapse at [" << nXCliff << "][" << nYCliff << "] nStartPoint = " << nStartPoint << " nThisPoint = " << nThisPoint << endl << "\tbJustDepositWhatWeCan = " << bJustDepositWhatWeCan << " nSeawardOffset = " << nSeawardOffset << " dCliffHeightFrac = " << dCliffHeightFrac << " nAcross = " << nAcross << endl << "\tdTargetSandToDepositOnThisProfile = " << dTargetSandToDepositOnThisProfile << " dSandDepositedOnThisProfile = " << dSandDepositedOnThisProfile << " dTotSandToDepositAllProfiles = " << dTotSandToDepositAllProfiles << " dTotSandDepositedAllProfiles = " << dTotSandDepositedAllProfiles << endl << "\tdTargetCoarseToDepositOnThisProfile = " << dTargetCoarseToDepositOnThisProfile << " dCoarseDepositedOnThisProfile = " << dCoarseDepositedOnThisProfile << " dTotCoarseToDepositAllProfiles = " <<  dTotCoarseToDepositAllProfiles << " dTotCoarseDepositedAllProfiles = " << dTotCoarseDepositedAllProfiles << endl;
 
               break;
            }
 
            // Nope, we still have some talus left to deposit
            int nX = VCellsUnderProfile[n].nGetX();
            int nY = VCellsUnderProfile[n].nGetY();
 
            // Don't allow cliff collapse talus onto intervention cells TODO 078 Is this realistic? Should it change with different types on intervention?
            if (bIsInterventionCell(nX, nY))
               continue;
 
            int nTopLayer = m_pRasterGrid->m_Cell[nX][nY].nGetTopNonZeroLayerAboveBasement();
 
            // Safety check
            if (nTopLayer == INT_NODATA)
               return RTN_ERR_NO_TOP_LAYER;
 
            if (nTopLayer == NO_NONZERO_THICKNESS_LAYERS)
            {
               // TODO 021 Improve this
               cerr << "All layers have zero thickness" << endl;
               return RTN_ERR_CLIFFDEPOSIT;
            }
 
            // Only do deposition on this cell if its elevation is below the Dean elevation
            if (dVDeanProfile[n] > dVProfileNow[n])
            {
               // At this point along the profile, the Dean profile is higher than the present profile. So we can deposit some sediment on this cell
               double dSandToDeposit = 0;
 
               if (bDoSandDepositionOnThisProfile)
               {
                  dSandToDeposit = (dVDeanProfile[n] - dVProfileNow[n]) * dSandProp;
                  dSandToDeposit = tMin(dSandToDeposit, (dTargetSandToDepositOnThisProfile - dSandDepositedOnThisProfile), (dTotSandToDepositAllProfiles - dTotSandDepositedAllProfiles));
 
                  m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(nTopLayer)->pGetUnconsolidatedSediment()->AddSandDepth(dSandToDeposit);
 
                  // Set the changed-this-timestep switch
                  m_bUnconsChangedThisIter[nTopLayer] = true;
 
                  dSandDepositedOnThisProfile += dSandToDeposit;
                  dTotSandDepositedAllProfiles += dSandToDeposit;
               }
 
               double dCoarseToDeposit = 0;
 
               if (bDoCoarseDepositionOnThisProfile)
               {
                  dCoarseToDeposit = (dVDeanProfile[n] - dVProfileNow[n]) * dCoarseProp;
                  dCoarseToDeposit = tMin(dCoarseToDeposit, (dTargetCoarseToDepositOnThisProfile - dCoarseDepositedOnThisProfile), (dTotCoarseToDepositAllProfiles - dTotCoarseDepositedAllProfiles));
 
                  m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(nTopLayer)->pGetUnconsolidatedSediment()->AddCoarseDepth(dCoarseToDeposit);
 
                  // Set the changed-this-timestep switch
                  m_bUnconsChangedThisIter[nTopLayer] = true;
 
                  dCoarseDepositedOnThisProfile += dCoarseToDeposit;
                  dTotCoarseDepositedAllProfiles += dCoarseToDeposit;
               }
 
               // Now update the cell's layer elevations
               m_pRasterGrid->m_Cell[nX][nY].CalcAllLayerElevsAndD50();
 
               // Update the cell's sea depth
               m_pRasterGrid->m_Cell[nX][nY].SetSeaDepth();
 
               // Update the cell's talus deposition, and total talus deposition, values
               m_pRasterGrid->m_Cell[nX][nY].AddSandTalusDeposition(dSandToDeposit);
               m_pRasterGrid->m_Cell[nX][nY].AddCoarseTalusDeposition(dCoarseToDeposit);
 
               // And set the landform category
               CRWCellLandform* pLandform = m_pRasterGrid->m_Cell[nX][nY].pGetLandform();
               int nCat = pLandform->nGetLFCategory();
 
               if ((nCat != LF_CAT_SEDIMENT_INPUT) && (nCat != LF_CAT_SEDIMENT_INPUT_SUBMERGED) && (nCat != LF_CAT_SEDIMENT_INPUT_NOT_SUBMERGED))
                  pLandform->SetLFSubCategory(LF_SUBCAT_DRIFT_TALUS);
            }
 
            else if (dVDeanProfile[n] < dVProfileNow[n])
            {
               // Here, the Dean profile is lower than the existing profile, so we must remove some sediment from this cell  TODO 075 What if bedrock sticks above Dean profile?
               double dThisLowering = dVProfileNow[n] - dVDeanProfile[n];
 
               // Find out how much sediment we have available on this cell
               double dExistingAvailableFine = m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(nTopLayer)->pGetUnconsolidatedSediment()->dGetFineDepth();
               double dExistingAvailableSand = m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(nTopLayer)->pGetUnconsolidatedSediment()->dGetSandDepth();
               double dExistingAvailableCoarse = m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(nTopLayer)->pGetUnconsolidatedSediment()->dGetCoarseDepth();
 
               // Now partition the total lowering for this cell between the three size fractions: do this by relative erodibility
               int nFineWeight = (dExistingAvailableFine > 0 ? 1 : 0);
               int nSandWeight = (dExistingAvailableSand > 0 ? 1 : 0);
               int nCoarseWeight = (dExistingAvailableCoarse > 0 ? 1 : 0);
 
               double dTotErodibility = (nFineWeight * m_dFineErodibilityNormalized) + (nSandWeight * m_dSandErodibilityNormalized) + (nCoarseWeight * m_dCoarseErodibilityNormalized);
 
               if (nFineWeight)
               {
                  // Erode some fine-sized sediment
                  double dFineLowering = (m_dFineErodibilityNormalized * dThisLowering) / dTotErodibility;
 
                  // Make sure we don't get -ve amounts left on the cell
                  double dFine = tMin(dExistingAvailableFine, dFineLowering);
                  double dRemaining = dExistingAvailableFine - dFine;
 
                  // Set the value for this layer
                  m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(nTopLayer)->pGetUnconsolidatedSediment()->SetFineDepth(dRemaining);
 
                  // And set the changed-this-timestep switch
                  m_bUnconsChangedThisIter[nTopLayer] = true;
 
                  // And increment the per-timestep total for fine sediment eroded during cliff collapse deposition (note that this gets added in to the suspended load elsewhere, so no need to do it here)
                  m_dThisIterCliffCollapseFineErodedDuringDeposition += dFine;
 
                  // LogStream << m_ulIter << ": FINE erosion during cliff collapse talus deposition = " << dFine * m_dCellArea << endl;
 
                  // Also add to the suspended load
                  m_dThisIterFineSedimentToSuspension += dFine;
               }
 
               if (nSandWeight)
               {
                  // Erode some sand-sized sediment
                  double dSandLowering = (m_dSandErodibilityNormalized * dThisLowering) / dTotErodibility;
 
                  // Make sure we don't get -ve amounts left on the source cell
                  double dSandToErode = tMin(dExistingAvailableSand, dSandLowering);
                  double dRemaining = dExistingAvailableSand - dSandToErode;
 
                  // Set the value for this layer
                  m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(nTopLayer)->pGetUnconsolidatedSediment()->SetSandDepth(dRemaining);
 
                  // Set the changed-this-timestep switch
                  m_bUnconsChangedThisIter[nTopLayer] = true;
 
                  // And increment the per-timestep total for sand sediment eroded during cliff collapse deposition
                  m_dThisIterCliffCollapseSandErodedDuringDeposition += dSandToErode;
 
                  // Increase the all-profiles and this-profile sand deposition targets
                  dTargetSandToDepositOnThisProfile += dSandToErode;
                  dTotSandToDepositAllProfiles += dSandToErode;
 
                  // LogStream << m_ulIter << ": SAND erosion during cliff collapse talus deposition = " << dSandToErode * m_dCellArea << endl;
 
                  // Store the depth of sand sediment eroded during Dean profile deposition of sand cliff collapse talus
                  pPolygon->AddCliffCollapseSandErodedDeanProfile(dSandToErode);
               }
 
               if (nCoarseWeight)
               {
                  // Erode some coarse-sized sediment
                  double dCoarseLowering = (m_dCoarseErodibilityNormalized * dThisLowering) / dTotErodibility;
 
                  // Make sure we don't get -ve amounts left on the source cell
                  double dCoarseToErode = tMin(dExistingAvailableCoarse, dCoarseLowering);
                  double dRemaining = dExistingAvailableCoarse - dCoarseToErode;
 
                  // Set the value for this layer
                  m_pRasterGrid->m_Cell[nX][nY].pGetLayerAboveBasement(nTopLayer)->pGetUnconsolidatedSediment()->SetCoarseDepth(dRemaining);
 
                  // Set the changed-this-timestep switch
                  m_bUnconsChangedThisIter[nTopLayer] = true;
 
                  // And increment the per-timestep total for coarse sediment eroded during cliff collapse deposition
                  m_dThisIterCliffCollapseCoarseErodedDuringDeposition += dCoarseToErode;
 
                  // Increase the all-profiles and this-profile coarse deposition targets
                  dTargetCoarseToDepositOnThisProfile += dCoarseToErode;
                  dTotCoarseToDepositAllProfiles += dCoarseToErode;
 
                  // LogStream << m_ulIter << ": COARSE erosion during cliff collapse talus deposition = " << dCoarseToErode * m_dCellArea << endl;
 
                  // Store the depth of coarse sediment eroded during Dean profile deposition of coarse cliff collapse talus
                  pPolygon->AddCliffCollapseCoarseErodedDeanProfile(dCoarseToErode);
               }
 
               // for this cell, recalculate the elevation of every layer
               m_pRasterGrid->m_Cell[nX][nY].CalcAllLayerElevsAndD50();
 
               // And update the cell's sea depth
               m_pRasterGrid->m_Cell[nX][nY].SetSeaDepth();
            }
         }     // All cells in this profile
 
         // OK we have either processed all cells in this profile, or we have deposited enough talus sediment on this profile
         break;
      } while (true);    // The seaward offset etc. loop
 
      // LogStream << m_ulIter << ": left seaward offset loop for cliff collapse at [" << nXCliff << "][" << nYCliff << "] nStartPoint = " << nStartPoint << " nThisPoint = " << nThisPoint << endl << "\tnSeawardOffset = " << nSeawardOffset << " dCliffHeightFrac = " << dCliffHeightFrac << " nAcross = " << nAcross << " bJustDepositWhatWeCan = " << bJustDepositWhatWeCan << endl << "\tdTargetSandToDepositOnThisProfile = " << dTargetSandToDepositOnThisProfile << " dSandDepositedOnThisProfile = " << dSandDepositedOnThisProfile << " dTotSandToDepositAllProfiles = " << dTotSandToDepositAllProfiles << " dTotSandDepositedAllProfiles = " << dTotSandDepositedAllProfiles << endl << "\tdTargetCoarseToDepositOnThisProfile = " << dTargetCoarseToDepositOnThisProfile << " dCoarseDepositedOnThisProfile = " << dCoarseDepositedOnThisProfile << " dTotCoarseToDepositAllProfiles = " <<  dTotCoarseToDepositAllProfiles << " dTotCoarseDepositedAllProfiles = " << dTotCoarseDepositedAllProfiles << endl;
 
      // Have we deposited enough for this cliff collapse?
      if (bDoSandDepositionOnThisProfile)
      {
         if (bFPIsEqual(dTotSandToDepositAllProfiles - dTotSandDepositedAllProfiles, 0.0, MASS_BALANCE_TOLERANCE))
            bSandDepositionCompletedOnThisProfile = true;
      }
 
      if (bDoCoarseDepositionOnThisProfile)
      {
         if (bFPIsEqual(dTotCoarseToDepositAllProfiles - dTotCoarseDepositedAllProfiles, 0.0, MASS_BALANCE_TOLERANCE))
            bCoarseDepositionCompletedOnThisProfile = true;
      }
 
      if (bSandDepositionCompletedOnThisProfile && bCoarseDepositionCompletedOnThisProfile)
      {
         // LogStream << m_ulIter << ": bSandDepositionCompletedOnThisProfile && bCoarseDepositionCompletedOnThisProfile for cliff collapse at [" << nXCliff << "][" << nYCliff << "] nStartPoint = " << nStartPoint << " nThisPoint = " << nThisPoint << endl << "\tnbJustDepositWhatWeCan = " << bJustDepositWhatWeCan << " SeawardOffset = " << nSeawardOffset << " dCliffHeightFrac = " << dCliffHeightFrac << " nAcross = " << nAcross << endl << "\tdTargetSandToDepositOnThisProfile = " << dTargetSandToDepositOnThisProfile << " dSandDepositedOnThisProfile = " << dSandDepositedOnThisProfile << " dTotSandToDepositAllProfiles = " << dTotSandToDepositAllProfiles << " dTotSandDepositedAllProfiles = " << dTotSandDepositedAllProfiles << endl << "\tdTargetCoarseToDepositOnThisProfile = " << dTargetCoarseToDepositOnThisProfile << " dCoarseDepositedOnThisProfile = " << dCoarseDepositedOnThisProfile << " dTotCoarseToDepositAllProfiles = " <<  dTotCoarseToDepositAllProfiles << " dTotCoarseDepositedAllProfiles = " << dTotCoarseDepositedAllProfiles << endl;
      }
   }     // Process each deposition profile
 
   // Safety check for sand sediment
   if (! bFPIsEqual((dTotSandToDepositAllProfiles - dTotSandDepositedAllProfiles), 0.0, MASS_BALANCE_TOLERANCE))
      LogStream << ERR << m_ulIter << ": non-zero dTotSandToDepositAllProfiles = " << dTotSandToDepositAllProfiles << endl;
 
   // Ditto for coarse sediment
   if (! bFPIsEqual((dTotCoarseToDepositAllProfiles - dTotCoarseDepositedAllProfiles), 0.0, MASS_BALANCE_TOLERANCE))
      LogStream << ERR << m_ulIter << ": non-zero dTotCoarseToDepositAllProfiles = " << dTotCoarseToDepositAllProfiles << endl;
 
   // Store the total depths of cliff collapse deposition for this polygon
   pPolygon->AddCliffCollapseUnconsSandDeposition(dTotSandDepositedAllProfiles);
   pPolygon->AddCliffCollapseUnconsCoarseDeposition(dTotCoarseDepositedAllProfiles);
 
   // Increment this-timestep totals for cliff collapse deposition
   m_dThisIterUnconsSandCliffDeposition += dTotSandDepositedAllProfiles;
   m_dThisIterUnconsCoarseCliffDeposition += dTotCoarseDepositedAllProfiles;
 
   // LogStream << endl;
   // LogStream << "\tdTotSandToDepositAllProfiles = " << dTotSandToDepositAllProfiles << " dTotSandDepositedAllProfiles = " << dTotSandDepositedAllProfiles << endl;
   // LogStream << "\tdTotCoarseToDepositAllProfiles = " << dTotCoarseToDepositAllProfiles << " dTotCoarseDepositedAllProfiles = " << dTotCoarseDepositedAllProfiles << endl;
   // LogStream << endl << "****************************************" << endl << endl;
 
   return RTN_OK;
}
 
//===============================================================================================================================
//===============================================================================================================================
void CSimulation::RasterizeCliffCollapseProfile(vector<CGeom2DPoint> const* pVPointsIn, vector<CGeom2DIPoint> *pVIPointsOut) const
{
   pVIPointsOut->clear();
 
   // The start point of the normal is the centroid of a coastline cell. Convert from the external CRS to grid CRS
   double dXStart = dExtCRSXToGridX(pVPointsIn->at(0).dGetX());
   double dYStart = dExtCRSYToGridY(pVPointsIn->at(0).dGetY());
 
   // The end point of the normal, again convert from the external CRS to grid CRS. Note too that it could be off the grid
   double dXEnd = dExtCRSXToGridX(pVPointsIn->at(1).dGetX());
   double dYEnd = dExtCRSYToGridY(pVPointsIn->at(1).dGetY());
 
   // Interpolate between cells by a simple DDA line algorithm, see http://en.wikipedia.org/wiki/Digital_differential_analyzer_(graphics_algorithm) Note that Bresenham's algorithm gave occasional gaps
   double dXInc = dXEnd - dXStart;
   double dYInc = dYEnd - dYStart;
   double dLength = tMax(tAbs(dXInc), tAbs(dYInc));
 
   dXInc /= dLength;
   dYInc /= dLength;
 
   double dX = dXStart;
   double dY = dYStart;
 
   // Process each interpolated point
   int nLength = nRound(dLength);
 
   for (int m = 0; m <= nLength; m++)
   {
      int nX = nRound(dX);
      int nY = nRound(dY);
 
      // Make sure the interpolated point is within the raster grid (can get this kind of problem due to rounding)
      if (! bIsWithinValidGrid(nX, nY))
         KeepWithinValidGrid(nRound(dXStart), nRound(dYStart), nX, nY);
 
      // This point is fine, so append it to the output vector
      pVIPointsOut->push_back(CGeom2DIPoint(nX, nY)); // In raster grid coordinates
 
      // And increment for next time
      dX += dXInc;
      dY += dYInc;
   }
}