Albedo Surface Temperature Energy Balance

IV. RESULTS AND DISCUSSION

4.1. Energy Balance

The component is analyzed from Landsat-7 and climate data. Landsat-7 ETM+ image data used is from 2003 to 2006. Mosaic process is applied only to data 2006 to see land cover condition. The data actually was invalid since 2003 and a lot of striping data cannot be analyzed. Climate data are obtained from BMG air temperature and wind velocity data acquisition 1995 to 2002 and from PJT-II Jatiluhur rainfall data acquisition 2004 to 2006. 4.1.1. Existing Land Use The exiting land use map is obtained by interpreting Landsat-7 ETM+ image in October 2006. The land use map consists of paddy field, industrial area, residential area, fish pond, vegetation cover, unirrigated land and water body. Table 5 shows Karawang district where 22 of the total area is paddy field area and 1.8 industrial area. Because in October 2006 usually start of the rainy season, but there was no rainfall observed. Based on data form BPS Karawang total area paddy field at 2006 is 82,285 ha. So existing paddy field detected is low and partly detected is unirrigated land. Data used is Landsat-7 ETM+ after mosaic process. Table 5. The existing land use of Karawang district No Land Use Area ha Area 1 Paddy Field 42,424 22 2 Industry 3,476 2 3 Residential 10,282 5 4 Fish Pond 14,777 8 5 Vegetation 51,889 27 6 Unirrigated Land 69,891 36 7 Water 357 Total 193,097 100

4.1.2. Albedo

The albedo of an object is the extent to which it reflects light, defined as ratio of reflected to incident electromagnetic radiation. Its value depends on the frequency of radiation unqualified, it usually refers to same appropriate average across the spectrum of visible light. In general, the albedo depends on the 31 direction and direction distribution of incoming radiation. Around 20,000-30,000 ha area cannot be analyzed due to a striping data since 2003. Acquisition: 632003 Acquisition: 4182004 Acquisition: 652004 Acquisition: 7232004 Acquisition: 4212005 Acquisition: 7102005 Acquisition: 8112005 Acquisition: 1012006 Legend Figure 6. Distribution of albedo in Karawang district 32 Table 6. Albedo from Karawang district 632003 4182004 652004 7232004 4212005 7102005 8112005 1012006 0-0.1 22,364 19,029 39,652 28,152 25,128 46,825 15,435 12,972 0.1-0.2 149,146 149,049 110,634 135,556 115,995 116,127 150,699 156,612 0.2-0.3 583 1,035 6,623 6,341 13,220 1,137 1,711 2,581 0.3-0.4 74 287 3,150 337 4,958 320 357 49 0.4-0.5 49 262 3,826 47 4,198 164 312 6 0.5-0.6 3 48 2,811 1,255 29 171 0.6-0.7 519 16 0.7-0.8 0.8-0.9 0.9-1 No Data 21,022 23,533 26,026 22,808 28,486 28,639 24,540 21,022 Total 193,241 193,241 193,241 193,241 193,241 193,241 193,241 193,241 Albedo Date Area ha Table 6 shows area of albedo range in Karawang district, and the distribution of albedo. The dominant albedo is 0.1-0.2, the indicator area are vegetation, residential, industrial, and unirrigated lands. Albedo with range of 0- 0.1 is dominant in water body and fish pond areas. It indicaties that a lot of radiant reflected from surface is low and radiation absorbed is high.

4.1.3. Surface Temperature

Land surface temperature is one of the key parameters of land surface process, combining surface-atmosphere interaction and energy fluxes between the atmosphere and the ground. Table 7 shows the distribution of surface temperature at Karawang district. The value of land surface temperature ranges from 24-34 o C detected from thermal sensor of Landsat-7 ETM+ satellite. Based on Figure 7 the surface temperature value of October 01, 2006 is high. Table 7. Surface temperature in Karawang district. 632003 4182004 652004 7232004 4212005 7102005 8112005 1012006 24-25 102 4,782 24,432 10,941 1,135 289 2 25-26 10 317 5,443 11,181 8,533 4,587 515 7 26-27 205 1,885 6,325 17,096 36,622 16,748 1,086 32 27-28 44,197 64,421 42,995 46,838 102,035 125,211 83,370 2,539 28-29 94,448 85,636 92,316 52,874 6,255 14,563 67,609 25,529 29-30 32,642 16,389 15,119 16,530 360 2,328 15,516 42,425 30-31 715 923 235 1,464 9 30 316 40,766 31-32 2 25 1 19 1 1 40,497 32-33 12, 33-34 8, No Data 21,022 23,543 26,026 22,808 28,486 28,639 24,540 21,022 Total 193,241 193,231 193,241 193,241 193,241 193,241 193,241 193,241 TS Date Area ha 406 016 33 Acquisition: 632003 Acquisition: 4182004 Acquisition: 652004 Acquisition: 7232004 Acquisition: 4212005 Acquisition: 7102005 Acquisition: 8112005 Acquisition: 1012006 Legend o C Figure 7. Distribution of surface temperature in Karawang district Distribution pattern of surface temperature shows higher surface temperature in residential and industrial areas than other areas, for example Landsat data of August 11, 2005. Surface temperatures in residential and industrial areas range between 29-31 o C, while the other land cover classifications are lower. Very significant condition is shown in October 1, 2006, where the land 34 surface is relatively dry because there was no rain for a successive time and limited distribution of water from Jatiluhur dam, consequently the surface temperature of non-vegetation is higher 29-34 o C , while for vegetation area it is less than 29 o C. 4.1.4. NDVI Based on Figure 8 the vegetation index number in April 2004 is higher than in June-July 2004, while the condition in 2005 showed that for the wet season it is lower than dry season July-August. Furthermore, in 2003 the vegetation index is moderate especially in paddy field areas, while in 2006 the distribution is different with low vegetation index or mostly negative. Vegetation index area Normalized Different Vegetation Index is dominant at moderate level 0-0.6 except in October 2006 where the dominance is at low level -0.6-0. Table 8. NDVI in Karawang district. 632003 4182004 652004 7232004 4212005 7102005 8112005 1012006 -1--0.8 5 1 33 12 -0.8--0.6 123 131 93 60 57 56 4 119 -0.6--0.4 9,545 6,881 8,884 10,385 6,716 7,044 5,215 5,208 -0.4--0.2 41,670 31,168 48,430 59,101 53,720 44,969 36,733 52,157 -0.2-0 42,765 38,734 46,870 40,907 59,219 37,240 48,599 70,431 0-0.2 32,341 37,598 41,678 34,672 29,609 30,227 45,068 30,470 0.2-0.4 42,600 53,387 19,602 24,113 14,692 39,125 32,745 13,427 0.4-0.6 2,730 1,591 1,149 924 190 5,478 1 393 0.6-0.8 0.8-1 214 508 269 518 452 336 11 No Data 21,467 23,533 26,026 22,808 28,486 28,639 24,540 21,022 Total 193,241 193,241 193,241 193,241 193,241 193,241 193,241 193,241 NDVI Date Area ha 1 3 Acquisition: 632003 Acquisition: 4182004 Acquisition: 652004 35 Acquisition: 7232004 Acquisition: 4212005 Acquisition: 7102005 Acquisition: 8112005 Acquisition: 1012006 Legend Figure 8. Distribution of NDVI in Karawang district.

4.1.5. Wind Velocity