Since you're using a char array it shouldn't take too much to detect if a slope is coming:

int tilePositionX, tilePositionY;
char tileArray[mapSizeX][mapSizeY];

int nextXTile = tilePositionX+1;//+1 assuming you are moving forward
int yTileBelow = tilePositionY+1;

if ((nextXTile < mapSizeX) && (yTileBelow < mapSizeY))
{
    //where 0 is solid and 1 is hollow
    if (tileArray[nextXTile][yTileBelow]) == 1)
    {
        //the next tile is on a slope or there is a hole
    }
}

Since you're using a char array it shouldn't take too much to detect if a slope is coming:

int tilePositionX, tilePositionY;
char tileArray[mapSizeX][mapSizeY];

int nextXTile = tilePositionX+1;//+1 assuming you are moving forward
int yTileBelow = tilePositionY+1;

if ((nextXTile < mapSizeX) && (yTileBelow < mapSizeY))
{
    //where 0 is solid and 1 is hollow
    if (tileArray[nextXTile][yTileBelow]) == 1)
    {
        //the next tile is on a slope
    }
}

Since you're using a char array it shouldn't take too much to detect if a slope is coming:

int tilePositionX, tilePositionY;
char tileArray[mapSizeX][mapSizeY];

int nextXTile = tilePositionX+1;//+1 assuming you are moving forward
int yTileBelow = tilePositionY+1;

if ((nextXTile < mapSizeX) && (yTileBelow < mapSizeY))
{
    //where 0 is solid and 1 is hollow
    if (tileArray[nextXTile][yTileBelow]) == 1)
    {
        //the next tile is on a slope
    }
}

You'll need to do some bounds checking there too.