Hydrological consequences of converting forested land to coffee plantations and other agriculture crops in sumber jaya watershed, west lampung, indonesia

C at chm ent C at chm ent 0.5 0.25 0.2 Observed 0.15 Predicted 0.1 0.05 Water discharge (m3/s) Water discharge (m3/s) 0.3 0.4 0.3 0.2 0.1 23 45 67 89 111 133 155 177 Tim e ( m in) 26 51 76 101 126 151 176 201 226 251 Tim e ( m in) Observed Predicted C at chm ent C atchm ent WB 1.4 Water discharge (m3/s) Water discharge (m3/s) 1.6 1.2 0.8 0.6 0.4 0.2 2.5 1.5 0.5 21 41 61 81 101 121 141 161 181 201 Tim e ( m in) Observed Predicted 254 507 760 1013 1266 1519 1772 2025 Tim e ( m in) Observed Predicted 265 C at chment C at chment 0.6 Water discharge (m3/s) Water discharge (m3/s) 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0.5 0.4 0.3 0.2 0.1 45 89 133 177 221 265 309 353 397 441 Tim e ( m in) 26 51 76 101 126 151 176 201 226 Observed Tim e ( m in) Predicted Predicted C at chm ent C atchm ent WB 1.6 1.4 Water discharge (m3/s) Water discharge (m3/s) Observed 1.2 0.8 0.6 0.4 0.2 2.5 1.5 0.5 34 67 100 133 166 199 232 265 298 331 Tim e ( m in) Observed Predicted 247 493 739 985 1231 1477 1723 1969 Tim e ( 2m in) Observed Predicted Figure A.17 Water discharge predicted by IHACRES for the December event, catchment treated as nested 266 C at chment 1.2 1.2 Output rate Output rate C at chm ent 0.8 0.6 0.4 0.2 0.8 0.6 0.4 0.2 10 13 16 19 22 25 28 31 Tim e (m in) Predicted 10 13 16 19 22 25 28 31 Tim e (m in) Observed Observed C at chment C at chment 1.2 1.2 Output rate Output rate Predicted 0.8 0.6 0.4 0.8 0.6 0.4 0.2 0.2 10 13 16 19 22 25 28 31 Tim e (m in) Predicted Observed 10 13 16 19 22 25 28 31 Time (m in) Predicted Observed 267 C at chment 1.2 1.2 Output rate Output rate C atchm ent W B 0.8 0.6 0.4 0.8 0.6 0.4 0.2 0.2 10 13 16 19 22 25 28 31 21 31 41 51 61 71 81 91 101 Tim e (m in) Predicted Tim e (m in) 11 Predicted Observed Observed C atchment C atchment 1.2 1.2 O u ut rate Output rate 0.8 0.6 0.4 0.8 0.6 0.4 0.2 0.2 11 21 31 41 51 61 Tim e (m in) 71 81 91 101 Predicted Observed 11 21 31 41 51 61 71 81 91 101 Tim e (m in) Predicted Observed 268 C atchment C at chment WB 1.2 1.2 Output rate Output rate 0.8 0.6 0.4 0.2 0.8 0.6 0.4 0.2 11 21 31 41 51 61 71 81 91 101 Tim e (min) Predicted Observed 11 21 31 41 51 61 71 81 91 101 Time (min) Predicted Observed Figure A.18 Water discharge rate estimated by linear distribution for August and December events 269 Catchment Catchment 0.045 0.04 0.007 0.006 0.005 18-Jul 0.004 02-Aug 0.003 21-Aug 0.002 18-Aug 0.001 22-Aug 07-Dec 21 41 61 81 101 Tim e (m in) Water discharge (m3/s) Water discharge (m3/s) 0.008 0.035 02-Aug 0.03 02-Nov 0.025 25-Oct 0.02 19-Nov 0.015 0.01 23-Oct 0.005 07-Dec 25 Oct b Dec b 17 33 49 Average 65 81 97 113 129 145 Tim e (m in) Catchment Dec b Average Catchment 0.07 02-Aug 0.035 19-Nov 0.03 18-Nov 0.025 0.02 14-Nov 02-Nov 0.015 26-Oct 0.01 0.005 25-Oct 23-Oct 16 31 46 61 76 91 106 121 136 Tim e (m in) 25 Oct b Average Water discharge (m3/s) Water discharge (m3/s) 0.05 0.045 0.04 02-Aug 0.06 19-Nov 0.05 02-Nov 0.04 26-Oct 0.03 25-Oct 0.02 23-Oct 0.01 07-Dec 25 Oct b 17 33 49 65 81 97 113 129 145 Tim e (m in) Dec b Average 270 Catchment WB Catchment 0.12 0.08 19-Nov 0.06 02-Nov 0.04 26-Oct 25-Oct 0.02 23-Oct 12 23 34 45 56 67 78 89 100 111 Water discharge (m3/s) Water discharge (m3/s) 0.09 0.1 0.08 0.07 0.06 21-Aug 0.05 0.04 19-Nov 02-Nov 0.03 26-Oct 0.02 0.01 25-Oct 23-Oct 07-Dec 32 25 Oct b Tim e (m in) 63 94 125 156 187 218 249 280 Tim e (m in) 07-Dec Average Average Catchment AF Catchment FR 0.003 0.0025 02-Aug 0.002 25-Sep 0.0015 19-Nov 0.001 02-Nov 0.0005 26-Oct 25-Oct 16 31 46 61 76 91 106 121 136 Tim e (m in) 07-Dec Average Water discharge (m3/s) Water discharge (m3/s) 0.0035 0.01 0.009 0.008 0.007 0.006 0.005 0.004 0.003 0.002 0.001 02-Aug 17 25 33 41 49 57 65 73 81 89 97 Tim e (m in) 08-Dec Average Figure A.19 Unit Hydrograph of mm rainfall for each catchment from several events 271 C at chm ent C at chment 0.005 y = 2E-05e0.0784x R2 = 0.8822 0.004 0.003 0.002 0.001 Discharge (m3/s) Discharge (m3/s) 0.006 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 y = 6E-05e0.1661x R2 = 0.9477 13 17 21 25 29 33 37 41 45 49 53 57 61 10 13 16 19 22 25 28 31 34 37 Tim e (m in) Time (min) C at chm ent C at chment Discharge (m3/s) 0.05 0.04 y = 8E-05e 0.2359x R2 = 0.9541 0.03 0.02 0.01 Discharge (m3/s) 0.07 0.06 0.06 0.05 y = 3E-05e 0.1722x R2 = 0.9546 0.04 0.03 0.02 0.01 11 13 15 17 19 21 23 25 27 10 13 16 19 22 25 28 31 34 37 40 43 Tim e (m in) Tim e (m in) 272 C at chment WB 0.06 0.07 0.05 0.06 Discharge (m3/s) Discharge (m3/s) C at chm ent 0.04 0.1335x y = 0.0002e R2 = 0.9486 0.03 0.02 0.01 0.05 y = 0.0005e 0.0322x 0.04 0.03 R2 = 0.8345 0.02 0.01 10 13 16 19 22 25 28 31 34 37 12 23 34 45 56 67 78 89 100 111 122 133 144 Tim e (m in) Tim e (m in) C at chm ent FR 0.0035 0.014 0.003 0.0025 0.012 0.01 y = 6E-06e0.1602x 0.002 0.0015 R = 0.9538 0.001 0.0005 Discharge (m3/s) Discharge (m3/s) C at chment A F 0.008 0.006 y = 3E-05e0.1714x R2 = 0.9026 0.004 0.002 10 13 16 19 22 25 28 31 34 37 Tim e (m in) 11 13 15 17 19 21 23 25 27 29 31 33 Tim e (m in) a 273 C at chm ent C at chment 0.025 0.005 0.004 y = 0.0059e-0.072x R2 = 0.8967 0.003 0.002 0.001 Discharge (m3/s) Discharge (m3/s) 0.006 0.02 0.015 y = 0.0164e-0.0716x R2 = 0.9813 0.01 0.005 13 17 21 25 29 33 37 41 45 49 53 57 Tim e (m in) C at chment 0.05 0.1 0.04 y = 0.1104e -0.1454x R2 = 0.8607 0.02 Discharge (m3/s) Discharge (m3/s) 0.12 0.06 13 17 21 25 29 33 37 41 45 49 53 57 61 65 Tim e (m in) C at chm ent 0.08 0.04 0.03 y = 0.0435e -0.1138x R2 = 0.9902 0.02 0.01 13 17 21 25 29 33 37 41 45 49 53 57 61 65 69 Tim e (m in) 11 16 21 26 31 36 41 46 51 56 61 66 71 76 Tim e (m in) 274 C at chm ent C atchm ent WB 0.1 0.06 0.05 0.04 0.03 y = 0.0712e -0.1041x R2 = 0.9653 0.02 0.01 Discharge (m3/s) Discharge (m3/s) 0.07 0.08 y = 0.0922e -0.0329x R2 = 0.897 0.06 0.04 0.02 13 17 21 25 29 33 37 41 45 49 53 57 61 65 69 12 23 34 45 56 67 78 89 100 111 122 133 144 Tim e (m in) Tim e (m in) C at chm ent FR 0.003 0.012 0.0025 0.01 0.002 y = 0.0031e 0.0015 -0.1137x R = 0.9661 0.001 0.0005 Discharge (m3/s) Discharge (m3/s) C at chment A F y = 0.0128e-0.2483x R2 = 0.9535 0.008 0.006 0.004 0.002 13 17 21 25 29 33 37 41 45 49 53 57 11 13 15 17 19 Tim e (m in) Tim e (m in) b Figure A.20 Peak response (a) and recession rate (b) of each catchment (from the unit hydrograph on Figure A.19) 275 14 - 21 Jul y 2005 Discharge (m3/s) 0.25 0.2 0.15 0.1 C1 0.05 C2 C3 1001 2001 3001 C4 4001 C5 Time Step (2 min) AF - 24 A ug 2005 0.8 Discharge (m3/s) 0.7 0.6 0.5 0.4 C1 0.3 C2 0.2 C3 0.1 C4 C5 2001 4001 6001 8001 Time Step (2 min) 10001 12001 14001 AF FR WB 276 - 30 S ept 2005 0.4 Discharge (m3/s) 0.35 0.3 0.25 0.2 0.15 C1 0.1 C3 0.05 C4 C5 2001 4001 6001 8001 10001 12001 AF 14001 FR Time Step (2 min) WB 12 - 30 O ct 2005 Discharge (m3/s) 2.5 1.5 C1 C2 C3 0.5 C4 C5 2001 4001 6001 8001 Time Step (2 min) 10001 12001 14001 AF FR WB 278 - 24 Nov 2005 Discharge (m3/s) 1.8 1.6 1.4 1.2 C1 0.8 0.6 C2 C3 0.4 0.2 C4 C5 2001 4001 6001 8001 10001 12001 14001 16001 AF FR Time step (2 min) WB Total discharges (m3/s) 12000 10000 8000 C1 6000 AF 4000 C2 FR 2000 C3 Data period 10 11 12 C4 C5 WB Figure A.21 Comparison of water discharge series from all catchments for different periods and comparison of total discharge 279 22 A ugus t 05 12 70 y = 0.0007x + 0.0826x + 0.9198 R2 = 0.9321 10 0 20 40 60 80 Total Discharge (m3/s) Total Discharge (m3/s) 19 Jul y 2005 y = 0.8654x - 6.0968 R2 = 0.9187 60 50 40 30 20 10 -10 20 25 Sept 2005 20 10 0 20 40 Area (ha) 60 80 Total Discharge (m3/s) Total Discharge (m3/s) 200 30 -10 80 60 80 26 Oct 2005 y = 0.6971x - 5.0596 R2 = 0.9542 40 60 Area (ha) Area (ha) 50 40 y = 2.442x - 9.339 R2 = 0.9647 150 100 50 0 20 40 -50 Area (ha) 280 19 Nov 2005 Total Discharge (m3/s) 250 y = 3.0047x - 14.231 R2 = 0.9628 200 150 100 50 -50 20 40 60 80 Area (ha) Figure A.22 Total discharge increasing linearly with increasing catchment size 281 [...]... fact, the profitability of coffee plantations brought many people to Sumber Jaya (Budidarsono et al, 2000) Coffee is also one of the main products of Lampung Province; 15% of Indonesian coffee production in 2001 came from Lampung (Verbist et al, 2002) However, the long-term sustainability of such forest conversion practices is indeed questionable The rapid rate of forest conversion to coffee plantations. .. initial driving force of land use changes in Lampung Province I.1.2 Forest Conversion in Sumber Jaya Sumber Jaya is a district in West Lampung, Sumatra The long mountain range in Sumatra, Bukit Barisan, runs north to south on the western side of Sumatra and Sumber Jaya is located at the end of this range Sumber Jaya (54,194 hectares) is located at the upper part of Tulang Bawang watershed, known as Way... purchasing land in the surrounding area Since no land deeds were ever issued to the immigrants, disputes over land claims occurred (Hardjono, 1977) Consequently, the transmigration project, which led to a population increase in Lampung from 2,456,000 in 1971 to 5,318,000 in 1990, and more than 6.7 million in 2001 (Pemda TK I Lampung, 1992; BPS Propinsi Lampung, 2001), was the major initial driving force of. .. regression model to related rainfall within a local area to elevation, and Wotling et al (2000) used rainfall intensity distribution and principle component analysis (PCA) to assess the complexity of the terrain in addition to elevation In general, difference in rainfall pattern may involve a combination of two statistical outcomes: (1) a shift in the mean and (2) a change in the scale of the distribution... rainfall and river discharge from rain and stream gauges in Sumber Jaya watershed ….172 xiii List of Figures Figure 2.1 The three climate regions according to the mean annual patterns using the DCM Indonesia is divided into Region A (solid line), Region B (short dashed line) and Region C (long dashed line) (from Aldrian and Susanto, 2003) ……………………….……… ………23 Figure 3.1 Indonesia map Lampung Province... participate in the transformation of rainfall into runoff (Singh and Birsoy, 1977) The first step in this research is to investigate the spatial and temporal variability of rainfall in Sumber Jaya Even though there are no long-term records to prove that rainfall is unevenly distributed in this area, the geographic position and landscape should predispose the area to such spatial and temporal variability 11... periods and comparison of total discharge ……………… …………….…………….………….276 Figure A.22 Total discharge increasing linearly with increasing catchment size …………………………….………………… …… .280 xvii I Introduction I.1 Research Background Land use changes have been continuous since the beginning of civilization, especially for agricultural activities (e.g., Bellot, et al., 2001) Changes in land use and resulting land cover... 1983) A variety of techniques can be employed to study the structure of storm rainfall and the dimensions and movement of convective cells, such as using rainfall radar to investigate the dimensions, velocity, and direction of movement of cells and storm systems or drawing isohyetal maps from rain gages to estimate rain cells (Shaw 1983) or calculated movement of rain from high latitude wind movements... promote sustainable and productive land use ICRAF has undertaken research on catchment management since the mid-1990s Main ICRAF research findings have been published in a number of outlets, examples include: the historical perspective of opening the forest area in Sumber Jaya (Verbist and Pasya, 2004); reasons of land cover changes and their impacts on the watershed (Verbist et 9 al.,2004; Farida and Van... Forest Conversion in Indonesia According to data presented by the NGO “Global Forest Watch” (Matthews, 2002), Indonesia is one of the five countries in the world with the richest tropical areas However, Indonesian forests also have the highest rate of area change (Table 1.1) Forest exploitation in Indonesia began in the early 1970’s due to development of the wood processing industry Today, Indonesia is . HYDROLOGICAL CONSEQUENCES OF CONVERTING FORESTLAND TO COFFEE PLANTATIONS AND OTHER AGRICULTURE CROPS ON SUMBER JAYA WATERSHED, WEST LAMPUNG, INDONESIA . KATARINA MANIK NATIONAL UNIVERSITY OF SINGAPORE 2008 2 HYDROLOGICAL CONSEQUENCES OF CONVERTING FORESTLAND TO COFFEE PLANTATIONS AND OTHER AGRICULTURE. II.5 Historical and Current Socio-Economic and Policy Influences on Land Cover and Watershed Conditions in Sumber Jaya …… ……… 58 II.5.1 Land use policy and history of Sumber Jaya 58 II.5.2