The high ground is produced by massive limestone blocks displaying classic karst
scenery. These blocks extend southward into Phang Nga bay where they form islands
with vertical cliffs, mainly orientated in a north south direction.
Phang Nga bay slopes seaward and is filled with tidal sediments. The bay itself is
composed of large and small tidal channels which originally connected with the fluvial
system of the mainland.
The main tidal channels for instance Klong Koh Panyi, Khlong Phang Nga, Klong Bang
Toi and Klong Bo Saen all run in a north-south direction. They consist of several
tidal creeks or tidal channel distributaries. Most of the tidal channels are meandering
with well developed point bars. Mangrove forests grow around the whole area of the
Phang Nga bay, they differ in species depending on elevation and relative tidal range.
The landward boundary of Phang Nga bay is marked by a gentle erosion slope, limestone
cliffs and transition forest between mangrove and upland forest which extends beyond
the bay margin.
The climate experienced in Phang Nga Bay is tropical marine, with characteristic
high rainfall and year round high temperatures. Thirty year records of Metrological
Department of Thailand (1961-1990) collected at Takua Pa weather station shows that
rain is abundant in the south-west monsoon season from May to October. The average
annual rainfall is 3,560.5 mm. and the average total rain days are 189 days. The
temperature fluctuates between 23 deg C and 32 deg C. The average relative humidity
Plant society in the Phang Nga Bay National Park could be divided into three types
as follows :
Mangrove forest in the limestone mountain which found a lot of important plants in
mangrove forest up to 12 types such as Rhizophora mucronata, Rhizophora apiculata,
Xylocarpus granatum, etc. In addition, also found sea holly and a lot of Acrostichum
aureum which growing up in the bank area or mud soil. Sea cyad is found a little
bit in only the opened area or destroyed area.
Mangrove forest in the cell and quartzite rock mountain which found the seven important
types of plants such as Rhizophora mucronata, Rhizophora apiculata, Xylocarpus granatum,
etc. The other important low level plant found in this area is the dense growing
Phang Nga Bay or Ao Phang Nga National Park, Thailand