Land Degradation Assessment in Dry lands of Myanmar BY Kyaw Yee General Manager Land Use Division Myanma Agriculture Service Ministry of Agriculture & Irrigation

Introduction Land degradation in Myanmar is caused by Water erosion Wind erosion Soil fertility depletion Salinization Alkalinization, and Water logging

Nature of problem of land degradation Indicators of land degradation in central dry zone areas are; Rapid depletion of woody biomass Expansion of farming into marginal and steeper slopes Extensive and uncontrolled use of limited pastures in erosion prone areas, and Increasing numbers of small livestock that could adapt to the deteriorating environmental condition

Nature of problem of land degradation Erosion Susceptibility for dry zone of Myanmar

Nature of problem of land degradation Extents of water erosion Sr. Type of water erosion Extent 1 Slight rill erosion 7.2% 2 Slight to moderate rill and sheet erosion 38.2% 3 Severe sheet and gully erosion 26.2% 4 Topsoil completely removed 0.4% Note: Total water erosion affected area (approx) 72%

Nature of problem of land degradation Approximately 1.4% of the whole country is affected by both salinization and alkalinization causing land degradation. Salinization is observed in Coastal Strips, Deltaic and Arid Regions. Alkalinization is confined only to certain areas of the Arid Region.

Nature of problem of land degradation Salinization occurred in the Coastal and Delta Regions due to sea water intrusion. Although heavy rainfall and flooded rice cultivation washed of deposited salts, high tide and high evapotranspiration in the summer created the soils more saline. Salinization in central dry zone area is mainly caused by saline ground water evapotranpiration which results in salt crust of the soil surface. Using of saline irrigation water also causes salinization. Scanty rain is not enough to wash out the accumulated salts.

Practical Methodologies At the present, the extent and locations of land degradation in Myanmar are mainly derived from aerial photo interpretation and reconnaissance soil survey using topographic maps. It has not been done comprehensive studies concerning the severity and extent of various forms of land degradation. Because of no specific demand & financial deficit.

Mapping of degraded land, availability, scales and methods used Three types of major maps produced in LUD are agroecological zone map, soil map, and soil erosion map at nation level. Besides, soil maps based on land topography are produced at State/Division level. Mapping is done based on 16:1 scale used by Department of Settlement and Land Record, and 1:1, 1:2, 1:4 scales by military map. Types of water erosion and their affected areas were deduced from medium-scale soil survey maps produced by LUD, Myanma Agriculture Service (MAS), Ministry of Agriculture and Irrigation (MOAI).

Mapping of degraded land, availability, scales and methods used Geographic Information System (GIS) has been initiated recently for the production of soil maps to clearly explore soil degradation condition in central dry zone areas. The implementation is not applied well due to lack of software, deficit manpower, and financial aid.

Predicting and modeling for land degradation development Slope maps, which are essential for erosion mapping and land capability mapping have never been produced in Myanmar for so large an area. The methodology is contributed by the "Watershed Management for Three Critical Areas Project". erosion susceptibility data is formulated using the FAO procedures. Management practices that conserve soil moisture or increase the water holding capacity of the soils are being practiced by using different ways of soil conservation techniques.

Mapping of degraded land, availability, scales and methods used LUD of MAS, MOAI is conducting measurement of erosion rate as experimental basis mainly in central dry zone areas.

Conclusion To ensure conservation of the resource base, the effective programmes should be designed to address the following constraints in agriculture; Low productivity due to agro climatic conditions Low productivity due to water shortage Low productivity due to soil degradation, irrigation induced water logging and salinity in dry zone.

Conclusion A number of agricultural research stations and centres are presently carried out research on plant varieties, crop patterns, irrigation techniques, water storage techniques and soil analysis. The programmes and activities of those centres should be reviewed to ascertain their effectiveness and to assist in the formulation of new programmes that can address key productivity constraints.

Conclusion For the time being, only out-dated aerial photo interpretation and soil survey data (semi detailed and topography) are available. thus there is need improved methods to identify and collect more accurate information concerning the severity and extent of land degradation in Myanmar.

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