Review of Landuse and Land
Degradation Status in Myanmar
Maung Maung Than, Assistant Director,
Remote Sensing and GIS Section, Planning and Statistics Division, Forest
Department
1. BACKGROUND
1.1
The Land and Climate
The
Union of Myanmar lies in Southeast Asia between latitudes 10° and 28° North and longitudes 92° and 101° East. The country is roughly in the
form of a diamond 920 km. across from east to west and 1450 km. from north to
south. The Tanintharyi coastal strip extends from the south eastern side of the
diamond some 690 km. further south into the Malay Peninsula.
The
country is bordered by Bangladesh and India on the north-west, China on the
north-east, Laos and Thailand on the south-east and the Bay of Bengal on the
south and west.
The
mountain ranges on the west, north and east serve as natural barriers. The
Rakhine Yoma separates the Ayeyarwady River valley from the sea, the Bago Yoma
separates the Ayeyarwady and Sittaung river valleys while the Shan escarpment
rises to the east of the Sittaung River. The Tanintharyi Yoma runs down the
coastal strip of the same name. The highest peak Khakaborazi is in the far
north and is 5788.8 meters high. The famous extinct volcano, Mt. Popa, is in
central Myanmar at the northern end of the Bago Yoma and is 1350 meters high.
Most
of Myanmar lies within the tropics, the Tropic of Cancer passing through the
country about a hundred and fifty kilometres north of Mandalay. There are three
seasons: the wet, the cold and the dry.
The
wet season is from mid-May to October end. During this period the south-west
monsoon brings rain from the Bay of Bengal. The coastal regions receive about
500 centimetres of rain, the Ayeyarwady delta about 250 centimetres and the
hilly regions about 200. Central Myanmar which lies within the rain shadow of
the Rakhine Yoma receives about 50 to 75 centimetres of rain.
The
cold season is from early November to late February when temperatures in the
south of the country may drop to15.5°.C. In other areas the cold is more
intense.
The
hot season comes before the rains. Temperatures in the south are around 37.75° C but those in the central Myanmar may be as
high as 43°.C.
2.
FOREST COVER OF
MYANMAR
2.1 Forest Resource Assessments using Remote Sensing data
Definitions
Following
definitions are essential to understand the forest cover conditions of Myanmar.
Forest: Land with tree crown cover (or equivalent
stocking level) of more than 10 percent and area of more than 0.5 hectares
(ha). The trees should be able to reach a minimum height of 5 meters (m) at
maturity in situ. May consist either
of closed forest formations where trees of various storeys and undergrowth cover
a high proportion of the ground; or open forest formations with a
continuous vegetation cover in which tree crown cover exceeds 10 percent.
Closed Forests (Actual Forest): Formations where trees in the various storeys and the
undergrowth cover a high proportion (> 40 percent) of the ground and do not
have a continuous dense grass layer. It has the same meaning with "Actual
Forest " in "Forest Cover of Myanmar, the 1989 Appraisal, by Kyaw
Tint and Tun Hla, and has been in continuous use by the Forest Department for
change analysis.
Open Forests: Formations
with discontinuous tree layer but with a coverage of at least 10 percent and
less than 40 percent. Generally there is a continuous grass layer allowing
grazing and spreading of fires. This can be loosely called degraded forest.
Other Wooded Land: Land either with a crown cover (or equivalent
stocking level) of 5-10 percent of trees able to reach a height of 5 m at
maturity in situ; or a crown cover
(or equivalent stocking level) of more than 10 percent of trees not able to
reach a height of 5 m at maturity in situ
(e.g. dwarf or stunted trees); or with shrub or bush cover of more than 10
percent.
Other Land: Land
not classified as forest or other wooded land as defined above. Includes agricultural land, meadows and
pastures, built-on areas, barren land, etc.
Shrubs: Refer
to vegetation types where the dominant woody elements are shrubs i.e. woody perennial plants, generally of more than
0.5 m and less than 5 m in height on maturity and without a definite crown. The height limits for trees and shrubs should
be interpreted with flexibility, particularly the minimum tree and maximum
shrub height, which may vary between 5 and 7 meters approximately.
Forest Fallow System: Refers to all complexes of woody vegetation
deriving from the clearing of natural forest for shifting agriculture. It
consists of a mosaic of various reconstitution phases and includes patches of
uncleared forests and agriculture fields, which cannot be realistically
segregated and accounted for area‑wise, especially from satellite imagery.
Forest fallow system is an intermediate class between forest and non‑forest
land uses. Part of the area may have the appearance of a secondary forest. Even
the part currently under cultivation sometimes has appearance of forest, due to
presence of tree cover. Accurate separation between forest and forest fallow
may not always be possible. (However latest digital image classifications used
can differentiate between forests and forest fallows much more than in previous
manual interpretations.)
2.1.1 First
Appraisal (1955)
The first forest cover assessment of the whole country was done in 1957
using the aerial photography of 1953-1957. Reports of that assessment have been
lost but the result of 57% forest cover has been accepted as an official
feature for a long time. U Aung Myint, retired Director of Forest Department
who had taken charge of that assessment has explained that interpretation has
been done on each of the photos map-sheet by map-sheet. The term forest has
been given not only to forested area but also to shifting cultivation area,
which are sure of covering by forests again. This is in the same concept with
the definitions above. (In 1950s real cultivators following strict fallow
periods perform shifting cultivation or clearings in the forests. Now a day the
clearings are either for permanent agriculture encroachment or heavy illegal
timber extractions) Aerial photographs of those periods show well covered
forests and this 57% can be assuredly counted as actual forest cover (over 40%
crown density). Other land (43%) will include many forms of degraded forests
and other wooded lands beside agriculture. However no records have been found
at present except that forest cover is 57%.
Actual Forest
|
385635.2
|
57.0%
|
Others
|
290917.8
|
43.0%
|
The first introduction of Landsat imagery to Myanmar was in 1980. Under
a FAO / UNEP project (Tropical Resources Assessment Project) a quick appraisal
of the forest cover of the whole country was carried out using 1 : 1,000,000
scale Landsat imagery of the year 1972-1979. This appraisal can be termed 1975
appraisal because of the reference year of the satellite imageries. The result
is actual forests covered 47.8% of total land area.
Actual
Forest
|
323216
|
47.8%
|
Forest
Fallow
|
177520
|
26.2%
|
Others
|
175817
|
26.0%
|
2.1.3
Third Appraisal (1989)
The project (MYA/85/003) National Forest Management and Inventory
purchased a set of Landsat TM imagery for the period 1989-90 at 1:500,000 scale
and a countrywide landuse map was produced by visual interpretation. Official
third appraisal of Myanmar forests was done by this project. The classification
is adjusted to attain consistency with 1975 appraisal. The result is actual
forests covered 43.2 % of total land area in 1989.
Actual
Forest
|
292579
|
43.2%
|
Forest
Fallow
|
206047
|
30.5%
|
Others
|
177927
|
26.3%
|
Japan Forest Technical Association and Forest Department performed
Information System Development Project for the Management of Tropical Forest.
This project covers 68% of the country. The working scale is the resampled
50-meter resolution of the Landsat TM images. Field reconnaissance surveys,
field verification surveys are included and digital classification is first
used on Myanmar Forest area. The classification legend is the same as the
official Forest Department’s legends used in aerial photographic surveys.
In 1999 Total Oil Company donated 5 landsat TM scenes to perform land
use mappings in the Tanintharyi Division, southern area of Myanmar. Integrated
use of Remote Sensing and GIS is applied. Digital Landsat TM data is
downloaded, enhanced and plotted out in 1:250,000 scale. 1989 1:250,000 scale
aerialphotography is used as ancillary data. Administrative, Forest and infrastructure
data is derived from 1:250,000 scale topographic maps. All data are overlaid
and maps and analysis data produced.
National Space Development Agency of Japan assisted with ADEOS data,
which covered Mon State for field testing. The by product of this field test is
the Landuse data of the said area.
All these data (ISDP, Tanintharyi and Mon mappings) are used in FRA2000
data assessment of Myanmar. Actual Forest Cover is now 37.4% (252939 hectares)
of total country.
Actual
Forest
|
252939
|
37.4%
|
Open
Forest
|
100808
|
14.9%
|
Other
Wooded Land
|
119193
|
17.6%
|
Others
|
203613
|
30.1%
|
2.2 Change Assessments or calculating Deforestation Rates
As
can be seen in Table ( 1 ) forest cover appraisals used different remote
sensing data, different technologies and also performed by different persons.
Therefore the deforestation rates can be sometime misleading. Scientifically
actual change assessments have to be done by the same personal using uniform
data types with the same techniques and classification systems. This is an
ideal situation possible only after 1990s when Landsat series satellite data
becomes available. However most countries especially developing countries like
Myanmar have to do with what they have and different forest cover assessments
have to be used in calculating deforestation rates of the said periods. FRA2000
has suggested what it calls comparability tables. In Table ( 2 ) the
comparability table used to convert 1989 third appraisal data into FRA2000
classification is shown as an example.
Table 1. Results of four successive forest cover
assessments of Myanmar
Total
land area (676553 sq.km)
1
|
2
|
3
|
4
|
5
|
Assessment
Year
|
1955
|
1975
|
1989
|
1997
|
Percent
|
57.0
|
47.8
|
43.2
|
37.4
|
Total
Land Area
|
||||
Actual
forest area
|
385635.2
|
323392.3
|
292270.9
|
252939
|
(>40%
c.c.)sq.km
|
||||
Lost
in forest cover sq.km
|
62242.9
|
31121.4
|
39331.9
|
|
Interval
|
20.0
|
14.0
|
8.0
|
|
Deforestation
rate
|
311214.38
|
222295.99
|
491648.75
|
|
(Hectare/year)
|
||||
Deforestation
rate
|
0.5
|
0.3
|
0.7
|
|
Percent
of total land area
|
||||
Interpretation
level
|
1:24000
|
1:1,000,000
|
1:
500,000
|
Landsat TM
|
1:20,000
|
Landsat
MSS
|
Landsat
TM
|
Digital
Image Process
|
|
1:50,000
|
Diapositives
|
hardcopies
|
1:250,000
hardcopy
|
|
Airphoto
|
1:50,000
scale ADEOS
|
|||
Hardcopy
|
||||
Over
all 1955-1997 changes
|
132696.2
|
sq.km
|
||
Interval
|
42
|
years
|
||
Deforestation
rate
|
315940
|
|||
(hectare/year)
|
||||
Deforestation
rate
|
0.467
|
|||
(percent
of total land area)
|
However
as the open forest types (crown density between 10% to 40%) and other wooded
land types (< 10%) are subject to controversy only actual forest area(over
40% crown density) has been used in comparing second appraisal (1975) and third
appraisal (1989) by Forest Department. (Kyaw Tint and Tun Hla, 1991). The same
concept has been taken in comparing third appraisal data with FRA2000 data
(Fourth Appraisal) in 2000.
Table 2. Comparability
Table of 1989 Third Appraisal data to FRA2000
Section 2: Table 4_89 - Comparability
between country classification and FRA 2000 classification
Country: Reference
year: 1989
Geographic Unit: Myanmar
Title of the inventory/survey: Forest Cover Appraisal of
Myanmar 1989 using 1:500,000 scale Landsat TM
Forest and other woody vegetation types
(country classification)
|
Corresponding FRA 2000 classes
|
1. 1, Closed
Forest
2. 2A, Closed
Forest affected by 25% shifting cultivation
3. 2B, Closed
Forest affected by 50% shifting cultivation
4. 2C, Closed
Forest affected by 75% shifting cultivation
|
Closed Forest
Closed Forest, 25% go to forest fallow
Closed Forest, 50% go to forest fallow
Closed Forest, 75% go to forest fallow
|
1. 3, Degraded
Forest
2. 4A, Degraded
Forest affected by 25% shifting cultivation
3. 4B, Degraded
Forest affected by 50% shifting cultivation
4. 4C, Degraded
Forest affected by 75% shifting cultivation
|
Open Forest
Open Forest, 25% go to forest fallow
Open Forest, 50% go to forest fallow
Open Forest, 75% go to forest fallow
|
1. Not Accessible
|
Shrub
|
1. Shifting Cultivation
|
Forest fallow system
|
Note: Open and closed forest make up
“natural forest”; shrub and forest fallow make up “other wooded land”
Comments:
2.3 Conclusion on Deforestation Rate
Technically
speaking remote sensing data directly compatible is between 1957 (air photos)
and 1997 (digital classification of Landsat data). Therefore final calculation
of 0.467 % (316049 hectares annually) of total land area for 1955 to 1997 (42
years) is an acceptable figure for actual forest cover changes.
However if one wants to know by different periods following short table
can be compiled.
Table 3 Different Deforestation Rates of Actual
Forests of Myanmar
Serial
|
Period
|
Interval
|
Actual Forest Cover
Lost During the Period (sq.Km)
|
Lost of Actual
Forest Cover per year (hectares/year)
|
Deforestation Rate
of Actual Forests
Percent of Total
Land area
|
1
|
1955 to 1975
|
20
|
62242.9
|
311214.38
|
0.5
|
2
|
1975 to 1989
|
14
|
31121.4
|
222295.99
|
0.3
|
3
|
1989 to 1997
|
8
|
39331.9
|
491648.75
|
0.7
|
Overall
|
1955 to 1997
|
42
|
132696.2
|
315940
|
0.467
|
3.
DRYZONE OF
MYANMAR
Dryzone
area is about 700 Kilometre north of the capital city of Myanmar. This area is
about 400 Kilometre long from north to south and about 192 Kilometre wide from
east to west, situated between east longitudes 93° 40´ and 96° 36´ and north
latitudes 19° 20´ and 22° 50´. Bounded by Kachin State in north, Shan State in
east, Bago Division in south and Chin State and Rakhine State in west.
Topography is
mostly flat in Mu, Sittaung and Ayeyarwady valleys with a significant flat area
of about 4144 sq.km from Singu to Tatkon. Isolated mountain ridge and hills
with Mt. Popa (is an extinct volcano, with an altitude of 1,509 meters and the
highest in this area), Sagaing hill 254 meters, Mandalay hill 235 meters,
Shinmadaung hill 522 meters, Kyaynitaung 320 meters. Ayeyarwady basin with
rolling hills on both side of bank with about 10,360 sq.km from Mandalay to
Thayet.
Rain
shadow effect is created by the high mountain range of Rakhine in the western
part. The Mt. Popa is centrally situated with a peak of 1509 meters, attracts
heavy clouds and creates the Oasis of central Myanmar with 1,000-mm rainfall.
Rainfall varies between 500 mm to 1,000 mm with very high variation and
fluctuation. The first rain started in last week of June with two distinctive
periods. Getting 3.2 % of total rainfall of Myanmar. Average annual rainfall is
about 718 mm. Monthly highest is in September with a record rainfall of 227 mm.
There
exists severe temperature during summer time, and maximum temperature is during
March and April rising up to 43°C. Average maximum temperature is 32°C. The coldest month is January with 7°C with a wide
range of temperature difference about 15°C. Average relative humidity is 63%.
March and April are driest months with the relative humidity of 42 %. September
is highest with 80%.
Northeast monsoon during October and March carries no
cloud hence any rain. Thunder storms and whirlwind occurs during March and
April, which carries dust storm causing loss of soil fertility. Southwest
monsoon enters in first week of June and leaves in first week of October.
4.
CURRENT LAND USE
OF DRYZONE
When the
Dryzone Greening Department has been established Remote Sensing and GIS Section
of Forest Department has performed landuse mapping, erosion susceptibility
mapping and regeneration plan mapping for the new department. Methodology and
results of these activities will be discussed in the following sections.
4.1 Background
Remote Sensing and GIS
Section of Planning and Statistics Division has been assigned to produce Land
Use and Land Cover Maps and associated databases of 12 Districts of Dryzone by
Director General of Forest Department. Official mandate is given by Meeting
Minutes on April 30th 1997 meeting at the meeting room of DG’s
office. The area is comprised of 3 Divisions, 12 Administrative Districts and
altogether 53 townships covering a total area of 20.12 million acres. Output
data will be used in drawing of a 20 years master plan. Time allowed to finish
the assignment or project is if possible 2 months starting from May and if not
a maximum target of 3 months. Later Gangaw District has been added to the list.
The following methodology has been drawn up to meet the Director General’s
directives.
4.2 Methodology
Main methodology is
integrated use of Remote Sensing and GIS. Land Use information derived from
Landsat5 TM satellite imageries will be superimposed on administrative and
forest boundary information taken from 1:63,360 topographic maps. Input scale
of Landsat imagery will also be in 1:50,000 scale. These large scales on both
imagery and base maps have been chosen for future updates of detailed District
and Township Plans. Streams and main roads will be taken for the present from
1: 500,000 scale digital database of Forest Department. Data analysis will be
made using Microsoft Excel software. Data level will be down to township levels
in administrative boundary and Forest Reserve level in Forest Administrative
boundary.
4.3 Data
Data sources are:
1)
Landsat5 TM digital imageries
2)
Landsat5 TM hardcopies
3)
Aerialphotography
4)
Topographic Base Maps
5)
1:500,000 scale GIS database of Myanmar
4.4 Land Use and Land Cover
Manual eyeball
interpretation is mainly used. Only in some areas some type of special
stretches are made. Even this can be done only on new plot outs as time is very
short. Following 25 keys have been developed using previous experiences of Dry
Zone land use mapping and also Watershed Management mappings. Priority
consideration has been given on human land use, agricultural practices, soil
erosion, fuel wood situation etc. other than Forest Management or Forest Type
classification.
1.
Moist Forest (M)
This includes MUMD,
Evergreen and some High Indaing of Pakokku District will be included. Dark red
on the TM bands 4,5,3 (R,G,B) colour composites. For planning purposes no
danger zone.
2.
Semi Indaing
Forest (Id)
This is only for Mount Poppa
area light gold colour. They are Thitya, Ingyin mixed with DUMD species.
Definitely no Than and Dahat. The forest is just above the horse path at the
western side and lower area is completely covered by banana plantation. At the
east side it extends are the moist line at 3000 ft and dry type below.
3.
High Indaing (In)
This is for High Indaing
forests of Monywa. Saturated with red, fine texture. Some forests around them
have been interpreted as Moist Forest but they can also be High Indaing. Only
field check can distinguish them. But for present mapping objectives this pose
no problem. Also field checking in the western part of Ayeyarwady has not
feasible of time restraint.
4.
Hill Forest (H)
Hill forests at the borders
of Shan State. Red colour. Must check with elevation. But these areas have been
mapped under the Watershed Management Project and that experience has been
used.
5.
Mixed Deciduous
Forest (MDF)
This includes both MUMD and
DUMD. Under 3000 ft line. Some are red and some are purple mixing with Dry Hill
Forest types of Kinda Watershed. If for Forest Management Planning detail
differentiation will be needed. But not now. Some hill forests are found to be
just scrub land by field check.
6.
Dry Forest (DF)
Emerald green when free from
forest fire in March. Poppa Extension Reserve areas are sort of military green
patches, the result of forest fires in 1995 scene 133/46 (March). Now we use
the 134/46 (January) 1996 scene data to correct this and found to be light
yellowish red at that time. Comprise of mainly Than and Dahat forest. Also
cutch, Kandarasein and other real dry zone species show only green or greenish
colour in this 4-5-3 band combination. Best examples are in Odaung Reserve.
This fact calls for multi season or at least in the leafless and with leaf
acquisitions of TM data for accurate interpretation. Even than some good grass
covered hills are also reflecting green by ground truth data and has to be
corrected from DF into Scrub and Grass (Sc/Gr). e.g. Taungtha Range.
N.B
Above
six classes are no problem areas.
7. Scrub Land, Scrub Forest (Sc)
The term scrub poses a
problem when describing land cover. Scrub land means open land with scattered
trees of coppice types whereas scrub forest will be degraded forest land
comprised of small trees. Time does not permit us to further distinguish this
two types. So in the forested areas Sc will be scrub forest and in dry zone
open areas this will be scrub land with scattered tree growth. Both are
important areas for management.
N.B. Right now most of the
scrub forest interpreted in Thayet district are found to be Low Indaing Hills.
We are not changing the codes again because the meanings are the same.
8. Scrub Land and Grass Land (Sc/Gr)
These are really denuded
grass hills of dry zone. Mostly bluish green on the imagery and that means very
little grass cover. Some areas are brown hill shapes which means some grass
cover still exist. Detailed plans will need to differentiate between the two.
Important areas for site selection of forestry and woodlot plantations. When covered
by good grass they come out dense green as in the case of Taungtha Taung and
some hill tops of Poppa.
9.
Grass land (Gr)
Grass lands of Dry Zone are
results of repeated shifting cultivation or forest cuttings. These are green
and sometimes brown in March. Some tall grasses (Imperata) in the moist forests
are orange. Existence of grass is very important from soil conservation point
of view.
10.
Shifting Cultivation (Sh)
Shifting cultivation has
been described as “Taungya” in Myanmar. But in our latest land use mappings
need arises to distinguish two types of shifting cultivation. Shifting cultivation in the forested area (real
Taungya) and agricultural shifting cultivation where definitely no forested
area is around in the vicinity. Shifting cultivation now used means real
shifting cultivation in the forested areas. Agricultural shifting cultivation
has been given a new class under agriculture “Ya (Y)”. Taungyas are
distinguished by their irregular patterns in the forest. Some very big areas in
the Yomas have been mapped directly. But mostly they are mosaics with
surrounding forest or vegetation. If shifting cultivation practices should be
banned completely awareness must be taken of the actual shifting cultivation
and Ya as described here. Ya can be controlled only by sound land use methods
as contour bunds, vegetative bunds etc., definitely not by complete banning of
the practices. Most of the Ya have become now ("g:rOD:cs)
hierarchical
belongings. Some even are now officially listed in local SLRD offices. A
detailed mapping operation by both FD and SLRD will be essential for clear-cut
legal proceedings later. SLRD has offered to supply cadsatral maps (uGif:a]ryHk)
to
us in one inch scale and they will be invaluable to solve conflicts.
11.
Shifting Cultivation and Bamboo
(Sh/B)
Most of the area in Thayet
township is shifting cultivation with patches of bamboo among them. Cultivation
has been more of a permanent nature now. Yellow and blue or white mosaics. Also
adjacent scene in different time on the road to Taungtwingyi are Sh/B or Ya
with bamboo between them. Then colour is green and white mosaics. Here the area
is so big that we check again with the scenes. Final meaning is Sh/B includes
scrub trees left among the cultivation. B (bamboo) shows the characteristic
undergrowth of Mixed Forest Origin. Sh/B and Af/B are similar in spectral
reflections in some areas. Difference is Af/B (B means vegetative bunds here)
is trees are nurtured specially by farmers (arG:awm)
and
Af is permanent. In Sh/B bamboo and scrub trees are remnant of the old forest
cleared by taungyas. Sh/B will gradually and also is being transformed into Af.
12.
Scrub Forest and Shifting
Cultivation (Sc/Sh)
Shifting cultivation in the
scrub forest area. Shifting cultivation patches amidst brown scrub forest.
13. Moist Forest and Bamboo (M/B)
Either degraded Moist or
Mixed Deciduous Forests where Bamboo now mostly dominate. Trees are red
coloured among bright yellow of bamboo reflection in two infrared bands. These
still pose no problems for soil conservation. But for Forest Management they
are a critical class and show status of forest degradation.
14. Bamboo (B)
Only pure bamboo breaks of
Rakhine Yoma has been classified as Bamboo here. Mostly these occur as mosaics.
Distinctly yellow colour.
15. Scrub Forest and Bamboo
(Sc/B)
Mosaic of Scrub Forest
(Brown colour) and Bamboo (Yellow colour). Mostly on Bago Yoma areas (Thayet
District).
16. Agriculture (Af)
This is normal agriculture.
Annually cultivated. Clear ownership boundary demarcated with bunds. Not much
vegetative bunding exists. This class can be further distinguished to Af and
Af/W which means irrigated agriculture. Detailed mapping later must do that.
Irrigated fields can be clearly distinguished to the interpreter but needs ground
verification. At present the two class are combined. Normal Af in the dry zone
suffers serious threat from sheet erosion. Ground checking trip has confirmed
that Af and Af/W can be distinguished and also should be done as the Af/W areas
are well-off areas benefiting from irrigation. In Kume and Myittha just some
contour feet decide the type of agriculture and subsequently their production.
17. Agriculture with
vegetative bunds (Af/B)
On TM imageries they appear
green and white patches. We have once wrongly interpreted them to be scrub
areas. Main vegetation in the Dry Zone bunds are Sha, Toddy Palm and other dry
zone spps. When farmers grows trees here either on the bunds or also in the
farm they provide good source of local fuel wood and house posts. Most of the
fuelwood flowing into Meiktila are from such nurtured forests (arG:awm) of Ma-hlaing
township. In Nwa-hto-gyi township there are also very good examples. Local
township officer has regulated the use of such agroforestry practices and he is
trying to spread this very sound practice to all over the area. All dry zone
districts should follow this example.
18. Alluvial Island
Cultivation (Al)
In Ayeyarwady River,
Chindwin River and major streams there are alluvial islands formed after the
end of flooding season. Many crops are grown on them and this alluvial
cultivation is one of the main important agricultural practices. Some important
crops like tobacco and potato are mostly cultivated on these. Bright red
colours and fine texture in the rivers and streams is very distinct. Tomato,
beans etc. are also good cash crops.
19. Ya cultivation (Y)
This is an important class
for Dry Zone and also for some other areas. Landuse is mainly agriculture. But
almost no boundary being demarcated. These are in the state between shifting
cultivation and permanent agriculture. Most of the areas are now under
permanent cultivation already. But there are some fallow periods. Settlement
and Land Record Department may enlist them under culturable wastelands. The future
trend is either they are levelled to permanent fields or become waste lands and
abandoned as in the case of Taungphila Reserve Forest. When eroded they are
bright white. Main characteristic is drainage patterns and relief can be seen.
Very little tree cover exists here. Field check has confirmed that bright white
Ya areas are badly eroded land where even the farmers have abandoned.
Fortunately most of the areas are now proposed protection forest areas. I would
like to say that for detailed planning later we will need protection forest
boundaries from local Forest Township Offices. Right now all good or bad Yas
have been combined together.
20. Forest Plantations (Pt)
Not all forest plantations
are visible on the Landsat imageries. Plantations described here are those of
Dry Zone where fine texture green of undisturbed grass are clearly seen. In the
field check we have confirmed the signature of Eucalyptus plantations.
21. Horticulture and
Homestead Gardens (At)
These includes banana
plantations of Mt.Poppa. Other important orchards like mango may be at present
combined in Urban areas. Field check has confirmed mango plantations to be
bright red patched. e.g. Han-myint-mo and also around Kyaukse area. These have
been modified now.
22. Urban Areas, Towns,
Villages etc. (Ui)
These are main towns and
villages. Some become sort of long chain of villages as in Semikhone. These are
classified by their patterns. Villages in the Dry Zone are distinct by brown
colour blocks, result of good coverage of Tamarind trees.
23. Water in Main Rivers,
Streams, Main Irrigation Systems, Lakes, and Ponds (W)
All has been classified into
water. The usual black colour on imagery. Some natural lakes and ponds are
covered by water plants resulting red at the rims. Not all irrigation dams of
dry zone are visible in the scene as they are out of water at the time of
imagery. Myakan reservoir has been under dry spell for about 4 years.
Kyetmauktaung dam at present field checking time, you can see even cattle
grazing in the dam water area. There are some cultivation also.
24. Swamp (Um)
Swamp areas.
25.
Sands (S)
Sand banks in the rivers and
streams. White colour.
Table (4) shows the result
of Land Use mapping for the whole 13 districts.
Table 4 Overall
Landuse of Dryzone
Area/acres
|
||
Serial
|
Forest
Type
|
Overall
Total
|
1
|
Moist
Forests
|
1614760.2
|
2
|
Hill
Forests
|
87380.9
|
3
|
Dry
Forests
|
46428.5
|
4
|
Mixed
Deciduous Forests
|
2042203.7
|
5
|
High
Indaing Forests
|
223906.6
|
6
|
Semi-Indaing
Forests
|
4036.6
|
7
|
Bamboo
|
483.5
|
8
|
Moist
Forests/Bamboo
|
182507.8
|
9
|
Scrub
Forests/Land
|
1143782.5
|
10
|
Scrub
Land/Grass
|
551244.5
|
11
|
Scrub
Land/Bamboo
|
70034.9
|
12
|
Scrub
Land/Shifting Cultivation
|
745098.1
|
13
|
Shifting
Cultivation
|
994308.0
|
14
|
Shifting
Cultivation/Bamboo
|
1064768.2
|
15
|
Grass
Lands
|
50780.6
|
16
|
Forest
Plantation
|
48888.1
|
17
|
Permanent
Agriculture
|
9177364.7
|
18
|
Agriculture/Vegetative
Bunds
|
416513.2
|
19
|
Ya
(Upland farming)
|
1924351.0
|
20
|
Alluvial
Island Cultivation
|
430081.4
|
21
|
Horticulture
|
14084.8
|
22
|
Water
Bodies
|
302177.8
|
23
|
Swamps
|
11984.5
|
24
|
Urban
Areas
|
172083.3
|
25
|
Sand
|
238205.6
|
26
|
Total
|
21557459.2
|
Data generated for Dryzone
Greening Department (DGD) contains detailed land use and land cover information
derived from satellite data and aerial photographs as explained above. Thereby
an attempt has been made to modify the data into simple format and analysed. In
addition, detailed mapping has been carried out for all townships in the
districts so that Forest Department can also use the maps for their Forest
Management Plans. Here only those townships, which fall under the DRD, have
been analysed.
Modified Classes
Six major classes are
defined combining the detailed classification as follows.
1.
Good Forest: This includes Moist Forest (M),
Semi-Indaing (Id), Dry Forest (DF), Hill Forest (H), High Indaing (In), Mixed
Deciduous Forest (MDF), Moist Forest with Bamboo (M/B), Bamboo Breaks of
Rakhine Yoma and Forest Plantations (Pt). Good means good vegetation cover for
dry zone management. Some areas may not be good for Forest Management (timber
production).
2.
Degraded Forest: This includes Scrub Forest (Sc), Scrub with
Grassland (Sc/Gr), Scrub with Bamboo (Sc/B) and Grass land (Gr). Some area
needs only natural regeneration methods. If need arise please look at the
detailed data sheets already supplied.
3.
Shifting
Cultivation: This includes
Shifting Cultivation (Sh), Shifting cultivation with Bamboo (Sh/B), and Scrub
land affected with Shifting Cultivation (Sc/Sh).
4.
Agriculture: This includes Permanent Agriculture
(Af), Agriculture with vegetative bunds (Af/B), Ya cultivation (Y), Alluvial
Island Cultivation (Al) and Homestead Gardens (At).
5.
Water: This includes open water, lakes and major
irrigation systems. Same as in detailed classes. Some dams though calculated do
not have any water at all. (e.g. Myakan of Nyaung U District).
6.
Others: This includes Swamp areas (Um), Sand (S)
and Settlements (Ui).
Summarised data is presented in the Table (5).
Table 5. Summary Landuse types of Dryzone
Serial
|
Land Use Type
|
Area (acres)
|
Area (sq.miles)
|
% of Total
|
1
|
Closed Forest
|
4,250,596
|
6,641.55
|
19.7%
|
2
|
Degraded Forest
|
1,815,843
|
2,837.25
|
8.4%
|
3
|
Shifting Cultivation
|
2,804,174
|
4,381.52
|
13.0%
|
4
|
Agriculture
|
11,962,395
|
18,691.24
|
55.5%
|
5
|
Other Landuse
|
422,273
|
659.80
|
2.0%
|
6
|
Water bodies
|
302,178
|
472.15
|
1.4%
|
Total
|
21,557,459
|
33,683.53
|
100%
|
One can quickly assumed that the dryzone area is under agriculture.
Actually shifting cultivation in the area is more permanent in nature totalling
68.5% of total area under agricultural use.
5. GENERATION
OF SLOPE MAPS, EROSION SUSCEPTIBILITY MAPS, AND REGENERATION PLAN MAPS
After finishing the land use maps in
time the data is given to the Dryzone Greening Department Officials. However
analysis of the map data and for planning Remote Sensing and GIS Section has
been given another task, erosion mapping and regeneration plan mapping. Slope
maps, which are essential for erosion mapping and land capability mapping have
never been produced in Myanmar for so large an area. However the task cannot be
avoided and immediate action taken. The methodology is contributed by the
"Watershed Management for Three Critical Areas Project". Manual
interpretation of contour lines into slope polygons plus digital
computerisation of those polygons into GIS format is the key in producing GIS
slope maps for so large an area.
After the slope maps have been produced
for entire project area in 1:633600 scale algorithm to produce erosion
susceptibility data is formulated using the FAO procedures. The result is
presented in detail in Table (6 ).
Table 6. Erosion
Susceptibility Data (Area/acres)
(acres)
Slight
|
Moderate
|
Critical
|
Grand Total
|
|
Sagaing District
|
826914.7195
|
13187.64
|
1355.562
|
841457.92
|
Shwebo District
|
2938869.91
|
90136.4
|
372.2522
|
3029378.56
|
Monywa District
|
1526572.646
|
123038.3
|
1706.794
|
1651317.76
|
Sagaing Division
|
5292357.275
|
226362.4
|
3434.608
|
5522154.24
|
Magway District
|
2192503.568
|
159528.1
|
27679.71
|
2379711.36
|
Minbu District
|
1388493.647
|
212070.7
|
7751.84
|
1608316.16
|
Thayet District
|
1612105.093
|
1228891
|
123099.7
|
2964095.36
|
Pakokku District
|
1824441.362
|
208863.1
|
18161.79
|
2051466.24
|
Gangaw District
|
822068.4977
|
448500.2
|
107964.5
|
1378533.12
|
Magway Division
|
7839612.168
|
2257853
|
284657.5
|
10382122.24
|
Kyaukse District
|
682541.9126
|
192773
|
41099.77
|
916414.72
|
Myingyan District
|
1319003.236
|
29503.74
|
8958.626
|
1357465.6
|
Nyaung_U District
|
362969.3825
|
178.4165
|
3415.401
|
366563.2
|
Yamethin District
|
1304962.688
|
257781.7
|
19434.84
|
1582179.2
|
Meiktila District
|
1299399.439
|
75377.22
|
55783.34
|
1430560
|
Mandalay Division
|
4968876.658
|
555614.1
|
128692
|
5653182.72
|
Dryzone Total
|
18100846.1
|
3039829
|
416784.1
|
21557459.2
|
Following Pie Chart shows the overall
conditions for dryzone.
Modelling can be explained simply that
steepness of slope degree and presence of land cover are determining factors
for erosion. From the combination of this two factors in GIS three groups can
be classified as slight, moderate and critical conditions of erosion
susceptibility.
We can conclude here that regionally
speaking erosion hazard is not much in dryzone. In fact the area is mostly flat
ground. However moderate areas can pose problems and these figures gave
foundation for formulating regenerating plan.
6. REGENERATION MAPPING
This is based on the following factors:
1)
Good forest covered areas do
not need to be regenerated. In addition, well established agricultural areas
cannot be reclaimed for afforestation. If these areas are below 27% slope there
is no erosion danger. These areas are grouped in Class 1 "Areas not
feasible or unnecessary for regeneration".
2)
Areas not well covered by
forest vegetation and also having slope of well over 36% need to be reforested.
Plantations established here cannot be harvested for human use. These areas are
suitable for watershed plantations and natural regeneration and termed "Class
2".
3)
Areas not well covered by
forest vegetation but the slope is between 26% and 36% are selected for
establishing forest plantations, which can be utilised or harvested under
scientific management. Community forestry sites, which will be using clearfelling
practices, can be selected from such areas.
4)
Established or permanent
agriculture areas are difficult to reclaim under forestland. If they are on
areas over 26% slope there exists erosion danger. These are put under
"Class 4" which is suitable for agroforestry practices.
This plan concept is a combination of
FAO Land Capability Mapping and Mekong Commission's Watershed Mapping. With the
help of GIS systems data is easily calculated as presented in Table ( 7 ).
Table 7. Data
on Regeneration Plan of Dryzone Greening Department
Area/acres
Class 1
|
Class 2
|
Class 3
|
Class 4
|
Grand Total
|
|
Sagaing District
|
818256.447
|
6544.022732
|
12676.51037
|
3980.939936
|
841457.92
|
Shwebo District
|
2645311.371
|
300667.862
|
82665.00863
|
734.3184901
|
3029378.56
|
Monywa District
|
1520210.982
|
61776.58629
|
66576.55179
|
2753.640118
|
1651317.76
|
Sagaing Division
|
4983778.8
|
368988.471
|
161918.0708
|
7468.898544
|
5522154.24
|
Magway District
|
1752883.199
|
230403.897
|
362475.1021
|
33949.16213
|
2379711.36
|
Minbu District
|
1089460.394
|
202696.1812
|
314178.0246
|
1981.560521
|
1608316.16
|
Thayet District
|
1588104.201
|
91964.27008
|
1273579.089
|
10447.80015
|
2964095.36
|
Pakokku District
|
1519838.979
|
168100.3434
|
362667.5609
|
859.3564242
|
2051466.24
|
Gangaw District
|
985819.0002
|
19481.74332
|
355740.5377
|
17491.83883
|
1378533.12
|
Magway Division
|
6936105.773
|
712646.435
|
2668640.314
|
64729.71806
|
10382122.24
|
Kyaukse District
|
831489.824
|
32392.58714
|
43758.41527
|
8773.893571
|
916414.72
|
Myingyan District
|
1219914.616
|
76379.04778
|
56467.59051
|
4704.345544
|
1357465.6
|
Nyaung_U District
|
323518.1413
|
23355.19643
|
18957.67934
|
732.1829387
|
366563.2
|
Yamethin District
|
1229112.293
|
13136.44125
|
323047.3932
|
16883.07215
|
1582179.2
|
Meiktila District
|
1302426.392
|
36884.23903
|
83408.83556
|
7840.532924
|
1430560
|
Mandalay Division
|
4906461.267
|
182147.5116
|
525639.9138
|
38934.02713
|
5653182.72
|
Class 1
|
Class 2
|
Class 3
|
Class 4
|
Grand Total
|
|
DRYZONE TOTAL
|
16826345.84
|
1263782.418
|
3356198.299
|
111132.6437
|
21557459.2
|
Following Pie Chart shows the overall
Dryzone situation.
Class 1
|
Areas not feasible or unnecessary for
regeneration
|
||||
Class 2
|
Areas requiring regeneration but on steep
slopes
|
||||
(> 36%) suitable for watershed
plantations and natural regeneration
|
|||||
Class 3
|
Areas requiring regeneration but on gentle
slopes (< 36%)
|
||||
suitable for fuelwood plantations and
commercial also
|
|||||
Class 4
|
Agriculture areas over 27% slope which
require
|
||||
special treatments and endangering to
erosion
|
|||||
Source
|
GIS Overlay of Landsat Satellite Data and
Slope Maps
|
||||
Remote Sensing and GIS Section
|
|||||
Planning and Statistics Division
|
|||||
Forest Department
|
|||||
Finished on 15:45, 24-10-1997 for Dryzone
Greening Department
|
|||||
This is the basic data of Dryzone
Greening Department's Thirty Years Plan. As the data has been generated in
township level all planning concerning manpower, machinery, plantation targets
etc. are made feasible.
7. LAND DEGRADATION,
ENVIRONMENTAL CONDITIONS AND SOCIO-ECONOMIC IMPACTS
Scientific studies need to be taken in
this field. In this paper only the general background and what has been
observed in the field can be discussed.
The main impact can be said in the
following categories:
1)
The degradation of water
quality and quantity, controlling water related disasters
2)
The degradation of arable soil
3)
The fuelwood conditions
Well being of water sources and their
sustainability is life and death for agriculture sector of the country. A
survey has been carried out the status of the watersheds of important
reservoirs and dams of the country. (Billy Ne Win, 2001). Following chart shows
the status in Mandalay Division. The Watershed Management Division of Forest
Department supplies source data. Classification is done by simple ratio of
forestlands to the total area of watersheds.
Ratio of forested land to total
watershed
|
Status
|
80% and over
|
Very good condition
|
60% to 79%
|
Good condition
|
40% to 59%
|
Moderate condition
|
20% to 39%
|
Poor condition
|
Under 20%
|
Critical condition
|
Most of the critical condition watersheds fall in the dryzone area. In figure ( ) one an clearly see the conditions of water body areas of Kyetmauktaung Dam and Myakan.
Figure(
1 ) Cattle grazing in the Kyetmauktaung dam, one can see green paddy fields
near the water line
When people start talking about water
related disasters they only think about the flash floods of the sandy streams
like Dawng-Ne chaung. However in the 2001 rainy season because of high rainfall
and in the absence of forest cover on the watersheds severe floods have induced
great damage on both property and human lives in the core dryzone areas.
Water supply has been always a problem.
Present conditions have been improved a lot by the efforts of Dryzone Greening
Department and Water Resources Department. However the effect of using
Ayeyarwady River as a main source can not be access at present. Experiences in
many other countries have shown possible problems in transportation and long
term sustainability of the projects.
Figure ( 2 ) shows highly eroded bad lands. These areas can be identified from satellite images. No landuse is possible except reforestation now.
What is needing is soil conserving
agricultural practices. Mahlaing and Nwahtogyi townships have very good
examples. Fig. ( 3 ) shows well established Acacia trees nurtured in the
agriculture fields. Stocking is as high as 40 trees per acre.
These nurture forests are also solving
fuelwood problems. This type of Non-forest land fuelwood production should be
encouraged together with the community forestry drive by both Dryzone Greening
Department and Forest Department.
8. CONCLUSIONS
1)
Forest cover of Myanmar is in a
degrading trend, which needs to be checked with effective measures.
2)
Landuse and other databases
required for planning purposes have been already produced and measures being
implemented at present.
3)
Sustainability of water
resources both in quantity and quality is the major problem facing the
socio-economic structure of dryzone area.
4)
Scientific research should be
promoted to monitor and evaluate the changing conditions of dynamic activities
in the dryzone area.
References
1)
Forest Cover of Myanmar, the
1989 Appraisal. Kyaw Tint and Tun Hla, Yangon January 1991.
2)
Forest Resources Assessments
Using Remote Sensing Data in Myanmar. Remote Sensing and GIS Section, May 2000.
3)
Terminal Report of Land Use and
Land Cover Mapping of Dryzone, RS & GIS Section, August 1997.
4)
Application of GIS to
Assessment, Monitoring and Management of Yezin Dam Watershed Area, Billy Newin,
MSc. Thesis.
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