LADA Group Sri Lanka Natural Resources Management Centre Department of Agriculture Sri Lanka
Lies in the between longitudes 79.5-81.8 E latitudes 5.9-9.8 N Land Area 64,453.6 Km 2 Inland Water 1,156.2 Km 2 Maximum length 435 Km maximum width 225 Km Extensive faulting and erosion over time have produced a wide range of topographic features
CLIMATE Annual rainfall varies between 900 mm to over 5500 millimeters Average Rainfall Dry zone < 1,750 mm Intermediate zone 1,750-2,500 mm Wet zone > 2,500 mm Very high spatial variability of rainfall 46 Agro-ecological regions
Agro ecological map of Sri Lanka
Soils of Sri Lanka Nine out of the ten major soil orders based on the USDA soil taxonomic system are distributed through out the country in a mosaic pattern (Panabokke, 1978)
Series level soil map of Sri Lanka soil series level spatial distribution in wet, intermediate and dry zone respectively
Land degradation processes in Sri Lanka 1. Soil erosion: loss of surface soil by water and wind. The productivity of 50 % of land in the agricultural sector is significantly affected due to soil erosion 2. Fertility decline: Net decrease in available nutrients and organic matter in the soil. The productivity of 30 % of land in the agricultural sector is significantly affected due to declining soil fertility. 3. Dystrification: Lowering of soil ph by increasing acidic compounds in soil. The productivity of agricultural lands particularly cultivated with tea, potato and vegetable in the up country wet zone are significantly affected due to acceleration of the dystrification process.
Land degradation processes in Sri Lanka. 4. Sealing and crusting: Clogging of pores in soil surface with fine soil material and development of a thin impermeable layer. It has been very common in lands exploited for seasonal agriculture in the Alfisols region in Sri Lanka. 5. Compaction: Deterioration of soil structure and formation of a dense layer by trampling or frequent use of machinery. It has been very common in rice lands on Alfisols where shallow farm implements such as rotary tillers are frequently used for land preparation. In this situation, a compacted soil horizon has been developed over the plow pan in rice lands causing a reduction in the effective depth of Ap horizon. 6. Salinization/alkalization: Net increase in salt content/sodium content of soil leading to significant decline in crop productivity. The productivity of low lands particularly in the low country dry zone are affected due to acceleration of salinization/alkalization processes
Land degradation processes in Sri Lanka.. 7. Water logging: Net increase in soil voids filled with water and it causes a significant decline in crop productivity. This situation is created temporally or permanently in soil due to increasing up of ground water table or lowering down of water infiltration as a result of human activities. It has been very common in lowland. Fortunately, as rice is grown well under waterlogged conditions, such lands are productively used in agriculture in Sri Lanka. 8. Subsidence: Lowering of soil surface particularly in organic soil. It has been reported from lands filled for non agricultural purposes in the Histosol region of Sri Lanka. 9. Aridification: A net decrease in average soil moisture content due to human activities. It has been reported from uplands particularly in the dry zone where greater fraction of precipitation goes as runoff. Therefore, it causes a decline in soil profile storage. 10. Pollution: Addition of materials to soil which causes toxic effects in soil. It has been reported in areas where industrial and urban waste is disposed over the land.
1.Assess Land Degradation at national and sub-national levels 2.Identify the Intensity and Trends of Land Degradation 3.Identify the priority areas / high risk areas 4.Identify the areas where the degradation has been slowed or reversed through conducive policies and actions 5.Build national and regional assessment capacities 6.Building a national / regional database of degradation status in aid of monitoring status / trends
Development of Administration unit Development of LUS maps Combining LUS and ADMIN Preparation of QM software for data processing Collection of degradation related data Entering data in LADA-QM Degradation map development
Data Description Source of data 1 Landuse data Extracted from digital map layers of land use, water and built-up area from 1:50000 scale topographic map sheets Survey department of Sri Lanka 2 Admin boundary map Admin boundaries for province, District, DSD and GN division has been used for LADA QM mapping unit development Digital Admin map available at NRMC was used 3 Forest and wildlife reserve The digital map of forest and reservation areas of has been used Department of Forest 4 Elevation and Slope Slope map was developed using GIS analysis with 30m Digital Elevation Model 30m data downloaded from ASTGTM website
Data Description Source of data 5 Paddy area map Paddy land map updated by Forecasting project of NRMC for Ampara, Polonnaruwa and Batticaloa Natural Resources Management Centre, DOA. has been used 6 Climate data Rainfall and other climate data Met database, 7 Agro-ecological map Digital map has been Used for LUS boundary adjustments NRMC Natural Resources Management Centre, DOA. 8 Expert knowledge on land degradation Expert knowledge and local experiences were included in the LADA-QM approach Data gathered through guided discussions held in national workshops and informal small group meetings.
Data Description Source of data 9 Degradation related information Information on prominent degradation types and affected localities were also used during assessment Information was extracted from available literature 10 Erosion hazard maps Erosion hazard map of central highlands covering central and uva province was also used as a guide map for assess accuracy levels of LADA maps Natural Resources Management Centre, DOA.
9 Provinces
9 Provinces 25 Districts
District Codes
9 Provinces 25 Districts 331 DS Divisions
9 Provinces 25 Districts 331 DS Divisions 14,022 GN Divisions
Central Province Wide range of land use types Wide range of land degradation levels Hilly area Wide range of climatic zones Feeding area for most of the rivers and streams Most sensitive area
Implementation area of the Soil Conservation Act Extraordinary Gazette No 1550 / 9 : 2008 May 22 Legend Low Moderate High Very high Extraordinary Gazette No 1550 / 9 : 2008 May 22 Soil conservation boundary District boundary Divisional secretariat boundary
Central Province
Central Province 36 DS Divisions
9 Provinces 25 Districts 331 DS Divisions Central Province 36 DS Divisions Admin ID [Dis_ID] [DSD_ID] Admin Code [Dis_Code]-[DSD Name]
Admin ID
[Dis_ID] [DSD_ID] Admin Code [Dis_Code]-[DSD Name]
Developed by merging 92 map sheets (1;50,000) 49 classes Corrections Different names for same class Edge matching 35 landuse classes
35 Landuse classes in topo maps Areas under forest & wildlife reserves Re-classified in to 18 classes
11 Forest Protected 12 Forest - Unmanaged 13 Woody Perennial - Protected 14 Vegetated Area Protected 15 Sparsely Vegetated Area Unmanaged 16 Grasslands Protected 17 Grasslands - Unmanaged 18 Bare Area Protected 19 Bare Area Unmanaged 21 Perennial Agriculture - Coconut 22 Perennial Agriculture - Rubber 23 Perennial Agriculture - Tea 24 Woody Perennial Crops 25 Crop Lands 26 Paddy 31 Urban 32 Rock 41 Wetland - Protected 42 Wetland - Unmanaged 43 Open Water Protected 44 Open Water
Combined Admin unit & LUS Map [ADMINCODE] & [0] & [LUSCODE]
CODE Bc Bh Bl Cn Et Wg Wt Degradation Type Reduction in Vegetation Cover Loss of Habitats Loss of Soil life Fertility Decline Loss of top soil Gully Erosion Surface Erosion
Almost whole of the Central Province is suffering from land degradation No or less degraded percentages were observed in areas with thick forest cover
Human induced factors Direct Drivers & Pressures Unsystematic use of lands for continuous annual cropping Haphazard / unplanned development activities Inappropriate land reclamation Mining & other industries Unscientific solid waste management particularly in urban areas Unsystematic landuses
Human induced factors Indirect Drivers & Pressures Population pressure Poverty Inadequate and / or inappropriate policies and management Lack of Land ownership Land fragmentation
Natural factors Rainfall characteristics, topography and soils (climate change???) Surface Erosion, Gully erosion, Loss of Habitats, Fertility Decline, Loss of Soil Life, and Loss of top soil are the degradation types taking place within the Central Province at present
(Munasinghe et al, 2001)
(Senanayake, S.S. et al., 2013)
Prevention & control measures implemented at field level Introduction of policy & legal framework Awareness creation, technical assistance & training Indiscriminate land use changes without considering the land suitability and capability should be avoided farmers should be supported in the selection and choice of crops for their cultivation depending on the location, climatic forecast and impending market behavior through an extensive extension service for agriculture.
Successive governments have used land resources to provide employment to the rural population This policy of providing land in lieu of employment opportunities should be discouraged Establishment of appropriate institutional framework and their coordination There are number of government organizations dealing with land management. However under local context coordination among those institutes are minimum or not existing at all. Hence there is need to promote and strengthen coordination among different organizations dealing with land resources management.
Providing alternative income generating opportunities There are number of government organizations dealing with land management. However under local context coordination among those institutes are minimum or not existing at all. Providing alternative income generating opportunities It is widely accepted that environmental degradation and poverty are closely linked. Rural community rely on natural resources mainly on land for survival but do not have the ability to invest on improvements to improve or conserve the resource base
Information System / Database Efficient monitoring program will help to understand the present situation and would be able to understand the current trend; thus provide information for decision making. Adaptation for Climate change Technical -Promote micro-irrigation where possible, Crop recommendation based on land suitability assessments, etc. Policy reforms - Strict enforcement of Soil Conservation Act, National Environmental Act and other related Ordinances
Source: Wikipedia Encyclopedia LADA Group of Sri Lanka 55