Chapter 5 Spatial Pattern and Environmental Conditions of Bhutan
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The Project for Formulation of Comprehensive Development Plan for Bhutan 2030 Final Report CHAPTER 5 SPATIAL PATTERN AND ENVIRONMENTAL CONDITIONS OF BHUTAN 5.1 Existing Land Cover 5.1.1 Land Cover in 2010 Collected existing land cover data from the Ministry of Agriculture and Forestry (MoAF) was generated by a supervised classification method using satellite images from ALOS AVNIR-2, acquired between 2006 and 2009. The collected land cover data can be broken down into 11 main classes and 15 sub-classes. A list and map of the land cover classes are shown below. Table 5.1.1 List of Land Cover Classes (1) Class Sub-Class Category Symbol Area (ha) % Forests Conifer Forest Fir Forest FCf 183,944 4.74 Mixed Conifer Forest FCm 614,545 15.85 Blue Pine Forest FCb 77,398 2.00 Chir Pine Forest FCc 107,353 2.77 Broadleaf Forest Broadleaf Forest FB 1,688,832 43.56 Broadleaf and Conifer Forest FBc 31,463 0.81 Shrubs - - SH 419,128 10.81 Meadows - - GP 157,238 4.06 Cultivated Chhuzhing Land - AC 31,127 0.80 Agricultural Land Kamzhing Land - AK 69,487 1.79 Horticultural Apple Orchard HA 2,039 0.05 Land Citrus Orchard HC 5,086 0.13 Areca Nut Plantation HAa 984 0.03 Cardamom Plantation HCo 3,398 0.09 Others HO 17 0.00 Built-Up Area - - BA 6,194 0.16 Non-Built Up Area - - NB 330 0.01 Snow Cover - - OS 299,339 7.72 Bare Areas Rocky Outcrops - RR 107,539 2.77 Scree - RS 23,263 0.60 Bare Soils - BS 27 0.00 Water Bodies Lakes - WL 4,751 0.12 Reservoirs - WRe 131 0.00 Rivers - WR 22,563 0.58 Marshy Areas - - MA 319 0.01 Degraded Areas Landslides - DL 6,999 0.18 Gullies - DG 7 0.00 Ravines - DR 0 0.00 Moraines - DM 13,596 0.35 Total Area 3,877,096 100.00 Source: Bhutan Land Cover Assessment 2010 (LCMP-2010), National Soil Services Centre and Policy and Planwning Division, MoAF 5-1 The Project for Formulation of Comprehensive Development Plan for Bhutan 2030 Final Report Source: Bhutan Land Cover Assessment 2010 (LCMP-2010), National Soil Services Centre and Policy and Planning Division, MoAF Figure 5.1.1 Land Cover Map Prepared in 2010 Characteristics of typical classes are described below. (1) Forests The forest class is divided into two sub-classes: Conifer Forest (FC) and Broadleaf Forest (FB). There are four categories of FC: Fir Forest (FCf), Mixed Conifer Forest (FCm), Blue Pine Forest (FCb) and Chir Pine Forest (FCc). FCm covers around 16% of the national land of Bhutan and is largely distributed between elevations of 2,500 m and 3500 m. FCf covers approximately 5% of the national land and is mostly distributed at elevations of above 3,000 m. There are two classes of FB: Broadleaf Forest (FB) and Broadleaf and Conifer Forest (FBc). FB covers about 44% of the national land and is commonly distributed at elevations of below 3,000 m. Given these circumstances, it is notable that Bhutan’s forest cover ratio is about 70% of the national land, which means that it has one of the highest forest coverage ratios in the world. (2) Shrubs Shrubs comprise the second most common land cover class, occupying approximately 11% of the national land. They are widely distributed across Northern Bhutan. (3) Meadows This class has no sub-class or category and includes any areas dominated by grass with a few or no scattered trees or shrubs. Although meadows can be found at all elevations, they tend to 5-2 The Project for Formulation of Comprehensive Development Plan for Bhutan 2030 Final Report cover higher locations. (4) Cultivated Agricultural Land This class has three sub-classes: Chhuzhing Land (AC), Kamzhing Land (AK) and Horticultural Land. In addition, there are five categories of Horticultural Land (see Table 5.1.1). AC is used for irrigated paddy fields and takes the form of terraced fields. It covers roughly 1% of the land in Bhutan, which means there are very few irrigated cultivation areas of this type in Bhutan. AK refers to cultivated rain-fed areas (dryland) and occupies approximately 2% of the national land. Horticultural land includes land for growing apples, citrus fruits, nuts and cardamom. However, these categories cover only a tiny fraction of the land (less than 0.3%) in Bhutan. (5) Built-up Areas This class contains settlements, urban areas, rural areas, airports, public facilities and industrial areas. About 0.2% of the land in Bhutan is covered by this land class. In other words, there are very few built-up areas in Bhutan because it is a mountainous country with land at extremely high elevations and steep slopes. (6) Snow Cover As described above, Bhutan is a mountainous region with certain areas located at elevations of more than 5000 m. Therefore, there are many snow-covered areas and glaciers. The total land cover ratio of this class is approximately 8%, and it is found in Northern Bhutan. (7) Bare Areas This class is divided into three sub-classes: Rocky Outcrops (RR), Scree (RS) and Bare Soils (BS). These three sub-classes cover about 3.4 % of the national land. This means that this class of land covers more area than AK, Horticultural Land and built-up areas. 5.1.2 Land Cover in 2016 The MoAF carried out the third Land Use Land Cover assessment based on Landsat 8 satellite image data acquired from November to December in 2015.According to the collected data, there are 12 main classes and sub-classes. A list and map of the land cover classes are shown below. 5-3 The Project for Formulation of Comprehensive Development Plan for Bhutan 2030 Final Report Table 5.1.2 List of Land Cover Classes (2) Ratio Ratio Main Class Sub-class Area (ha) Main Class Sub-class Area (ha) (%) (%) Alpine Scrubs 130,097.72 3.39 Meadows 96,273.61 2.51 Forests 2,717,161.64 70.77 Built-up 7,457.03 0.19 Blue Pine 101,155.06 2.63 Non-Built Up 595.89 0.02 Chir Pine 101,537.45 2.64 Rocky Outcrops 159,455.55 4.15 Fir 230,983.99 6.02 Rocky Outcrops 119,754.16 3.12 Mixed Conifer 519,585.68 13.53 Scree 39,701.39 1.03 Broadleaf 1,763,899.46 45.94 Moraines 14,393.94 0.37 Shrubs 374,032.56 9.74 Landslides 3,730.22 0.10 Cultivated 105,682.43 2.75 Snow and Glacier 205,343.63 5.35 Agriculture Chhuzhing 31,891.87 0.83 Water Bodies 25,175.78 0.66 Kamzhing 68,260.64 1.78 Lake 6,252.58 0.16 Orchards 5,529.92 0.14 Rivers 18,923.20 0.49 Grand Total 3,839,400.00 100.00 Source: Land Use and Land of Bhutan 2016, Forest Resources Management Division, Department of Forests and Park, MoAF Source: Land Use and Land of Bhutan 2016, Forest Resources Management Division, Department of Forests and Park, MoAF Figure 5.1.2 Land Cover Map Prepared in 2016 The characteristics of typical land cover classes in 2016 are described below. (1) Forests The forest class is divided into five sub-classes: blue pine, chir pine, mixed conifer, fir and 5-4 The Project for Formulation of Comprehensive Development Plan for Bhutan 2030 Final Report broadleaf forests. Broadleaf forest is typically distributed below 3,000 m and its area ratio is around 46% of the national land of Bhutan. Regarding mixed conifer forest, this is usually found between 2,500m and 3,500m and the area ratio is approximately 14% of the national land. As the results show, the forest cover ratio in 2016 was about 71% of the national land, while, from 2010 to 2016, the forest cover ratio increased by about 1% of the national land. (2) Alpine Scrub This is a new category, which refers to a woody plant characterized by stunted growth and a height less than 5 m, due to harsh conditions. In addition, it occurs above 3,500 m and the area ratio is about 3% of the national land. (3) Shrubs In 2016, shrubs were the second most common land cover class, distributing about 10% of the national land. The area ratio decreased by 1% compared to the previous land cover analysis in 2010. They are also widely found across Northern Bhutan. (4) Meadows Meadows include any area dominated by grass with a few or no scattered trees or shrubs. Although meadows can be found at all elevations, they tend to cover higher locations. Their area ratio decreased by about 1.5% from 2010 to 2016. (5) Cultivated Agricultural Land This class has three sub-classes: Chhuzhing, Kamzhing and orchards. The area ratio of cultivated agriculture is approximately 2.8% in total, while its ratio decreased a little compared with the 2010 results. Chhuzhing land is wetland used for irrigated paddy fields and takes the form of terraced fields. On the other hand, Kamzhing land is dryland, used for vegetables. (6) Built Up Areas This class contains urban areas, rural settlements, airports, education facilities, health facilities, industrial areas and roads. The area increased by about 1,260 ha from 2010 to 2016. 5.1.3 Latest Land Cover in 2017 For the project, prepared SPOT-6/7 satellite image data was acquired from October 2016 to April 2017 by the JICA Headquarters, while a land cover classification analysis was conducted based on an unsupervised classification method to determine Bhutan’s latest land cover conditions.