CHAPTER E1 OVERVIEW OF CLIMATE CHANGE IMPACTS ON

AGRICULTURE IN INDONESIA ... E1-1 E1.1 Global Climate Change Impacts on Agriculture in Indonesia ... E1-1 E1.1.1 Features on Impact of Climate Change on Agriculture Sector ... E1-1 E1.1.2 Mitigation and Adaptation Approaches to Global Climate Changes in

Agricultural Sector ... E1-1 E1.2 Global Climate Change Impacts on Food Crop Production in Indonesia ... E1-2 E1.2.1 Occurrence of El-Nino and La-Nino Events ... E1-2 E1.2.2 Drought and Flood Impacts on Rice and Maize Production ... E1-3 E1.2.3 Future Trend of Global Climate Change ... E1-5 CHAPTER E2 IRRIGATION SECTOR IN INDONESIA ... E2-1 E2.1 Functional Situation of Existing Surface Water Irrigation Schemes in Indonesia ... E2-1 E2.1.1 Regally Registered Schemes ... E2-1 E2.1.2 Functional Condition of Surface Water Irrigation Schemes ... E2-2 E2.2 Irrigation Water Requirement Estimate Methodology in Indonesia ... E2-2

E2.2.1 Comparison of Irrigation Water Requirement Calculation

Methodologies ... E2-2 E2.2.2 Input Climate Data ... E2-3 E2.3 On-farm Level Adaptation Measures against Drought ... E2-3 E2.3.1 Overview ... E2-3

E2.3.4 Improvement of Irrigation Efficiency ... E2-4 E2.3.5 Promotion of System Rice Intensification (SRI) ... E2-5 PART 2 BRANTAS RIVER BASIN

CHAPTER E3 AGRICULTURE IN BRANTAS RIVER BASIN ... E3-1 E3.1 Current Production of Food and Estate Crops in Brantas River Basin ... E3-1 E3.1.1 Food Crop Bowl in Indonesia ... E3-1 E3.1.2 Current Rice Production in Brantas River Basin ... E3-1 E3.1.3 Other Food Crops in Brantas River Basin ... E3-2 E3.1.4 Estate Crops in Brantas River Basin ... E3-3 E3.2 Future Rice Cultivation in Brantas River Basin ... E3-3 E3.2.1 Future Rice Harvesting Area in Brantas River Basin ... E3-3 E3.2.2 Future Rice Production in Brantas River Basin ... E3-4 CHAPTER E4 IRRIGATION IN BRANTAS RIVER BASIN ... E4-1 E4.1 Surface Water Irrigation Area in Brantas River Basin ... E4-1 E4.1.1 Existing Surface Water Irrigation Schemes in Brantas River Basin ... E4-1 E4.1.2 Future Surface Water Irrigation Scheme Area ... E4-2 E4.2 Irrigation Water Demand in Brantas River Basin ... E4-2 E4.2.1 Unit Irrigation Water Requirement under Observed Climate Condition ... E4-2 E4.2.2 Unit Irrigation Water Requirement for Planning Purpose ... E4-4 E4.2.3 Irrigation Water Diversion Requirement ... E4-5 PART 3 MUSI RIVER BASIN

CHAPTER E5 AGRICULTURE IN MUSI RIVER BASIN ... E5-1 E5.1 Present Situation of Major Crop Production in Musi River Basin ... E5-1 E5.1.1 Present Condition of Food Crop Cultivation in Musi River Basin ... E5-1 E5.1.2 Current Rice Cultivation Areas in South Sumatra ... E5-1 E5.1.3 Current Rice Production in South Sumatra ... E5-2 E5.1.4 Current Estate Crop Planting Areas in South Sumatra ... E5-3 E5.1.5 Current Estate Crop Production in South Sumatra ... E5-3 E5.2 Future Situation of Major Crop Production in Musi River Basin ... E5-4 E5.2.1 Future Rice Cultivation Area in Musi River Basin ... E5-4 E5.2.2 Future Rice Production in Musi River Basin ... E5-5 E5.2.3 Future Condition of Estate Crop Planting Areas in Musi River Basin ... E5-5 E5.2.4 Future Condition of Estate Crop Production in Musi River Basin ... E5-6

E5.3.2 Survey Items and Method ... E5-7 E5.3.3 Survey Area ... E5-8 E5.3.4 Survey Results ... E5-8 E5.3.5 Findings ... E5-9 CHAPTER E6 IRRIGATION IN MUSI RIVER BASIN ... E6-1 E6.1 Present Condition of Irrigation and Drainage Schemes in South Sumatra ... E6-1 E6.1.1 Registered Surface Water Irrigation and Swamp Drainage Schemes ... E6-1 E6.1.2 Recent Development of Surface Water Irrigation Schemes ... E6-2 E6.1.3 Specific Features of Surface Water Irrigation Scheme in Musi River

Basin ... E6-2 E6.2 Future Surface Water Irrigation and Swamp Drainage Areas in Musi River Basin .... E6-3 E6.2.1 Proposed Development Area in BBWS Sumatra VIII RENCANA 2017 ... E6-3 E6.2.2 Prediction of Future Irrigation Area ... E6-3 E6.3 Estimate of Irrigation Water Requirement for Selection of Representative GCMs .... E6-4 E6.3.1 Purpose ... E6-4 E6.3.2 Irrigation Water Demand Calculation Methodology and Input Data ... E6-4 E6.3.3 Cropping Calendar ... E6-5 E6.3.4 Unit Irrigation Water Requirement ... E6-5 E6.3.5 Irrigation Water Diversion Requirement ... E6-7 E6.4 Irrigation Water Demand with Adaptation Measures against Droughts ... E6-10

E6.4.1 Adaptation Measures for Irrigation Water Demand Management against

Drought ... E6-10 E6.4.2 Optimization of Cropping Calendar ... E6-11 E6.4.3 Setting-up of Cropping Intensity ... E6-12 E6.4.4 Unit Irrigation Water Requirement with Adaptation Measures against

Drought ... E6-12 E6.4.5 Irrigation Water Diversion Requirement with Adaptation Measures

against Drought ... E6-13 E6.5 Swamp Drainage Scheme ... E6-14 E6.5.1 Prevailing Rice Farming Practicies in Swamp Drainage Scheme Areas ... E6-14 E6.5.2 On-farm Level Supplemental Irrigation Water Requiremnt in Tidal

Swamp Area ... E6-14

Table E1.1.1 Features on GHG Emissions and Impacts of Agriculture Sector in Indonesia .... E1-1 Table E1.1.2 Mitigation and Adaptation Measures against Climate Change in Indonesia ... E1-2 Table E1.2.1 Proportion of Paddy and Maize Areas Damaged by Climate Hazards ... E1-3 Table E2.1.1 Distribution of Registered Schemes by Management Body in Indonesia ... E2-1 Table E2.1.2 Functional Condition of Surface Water irrigation Schemes in Indonesia ... E2-2 Table E2.2.1 Comparison of Irrigation Water Requirement Calculation Methodologies ... E2-3 Table E3.1.1 Contribution of Brantas River Basin as Food Crop Supply Source ... E3-1 Table E3.1.2 Decreasing Tendency of Rice Production Base in Brantas River Basin ... E3-1 Table E3.1.3 Rice Production Trend in Brantas River Basin ... E3-2 Table E3.1.4 Other Food Crop Production in Brantas River Basin for 2015 ... E3-2 Table E3.1.5 Estate Crop Production in Brantas River Basin for 2015 ... E3-3 Table E3.2.1 Prediction of Future Rice Harvesting Areas in Brantas River Basin ... E3-3 Table E3.2.2 Prediction of Future Rice Production in Brantas River Basin ... E3-4 Table E4.1.1 Existing Surface Water Irrigation Areas in Brantas River Basin ... E4-1 Table E4.1.2 List of BBWS-BS Managed Irrigation Schemes by Water Source River ... E4-1 Table E4.1.3 Prediction of Future Irrigation Areas in Brantas River Basin... E4-2 Table E4.2.1 Seasonal Average of Unit Irrigation Water Requirement by Major Scheme ... E4-3 Table E4.2.2 Seasonal Average of Unit Irrigation Water Requirement by Regency/ City... E4-4 Table E4.2.3 Unit Irrigation Water Requirement for Planning Purposes ... E4-4 Table E4.2.4 Average Irrigation Water Demand for Regulated Flow-based Irrigation

Schemes ... E4-5 Table E4.2.5 Average Irrigation Water Demand for Natural Flow-based Irrigation

Schemes ... E4-6 Table E5.1.1 Features of Rice Cultivation in Musi River Basin ... E5-1 Table E5.1.2 Current Wetland Paddy Field Areas in South Sumatra ... E5-2 Table E5.1.3 Current Wetland Paddy Production in South Sumatra ... E5-2 Table E5.1.4 Current Estate Crop Planted Areas in South Sumatra ... E5-3 Table E5.1.5 Current Estate Crop Production in South Sumatra ... E5-4 Table E5.2.1 Prediction of Future Wetland Paddy Field Area in South Sumatra ... E5-4 Table E5.2.2 Future Wetland Paddy Production by Regency/ City in South Sumatra ... E5-5 Table E5.2.3 Predicted Estate Crop Planting Areas in South Sumatra for 2050 ... E5-5 Table E5.2.4 Predicted Estate Crop Production in South Sumatra for 2050 ... E5-6 Table E5.3.1 Survey Items and Methods ... E5-7 Table E5.3.2 Focal Points of Survey Results ... E5-8 Table E6.1.1 Number and Area of Registered Irrigation and Swamp Drainage Schemes ... E6-1

Table E6.1.3 Monthly Water Diversion Record at Perjaya Barrage by KIP ... E6-2 Table E6.2.1 Proposed Development Plan in BBWS Sumatra VIII RENCANA 2017 ... E6-3 Table E6.2.2 Prediction of Future Surface Water Irrigation Areas ... E6-4 Table E6.3.1 Area-wise Seasonal Average of Unit Irrigation Water Requirement for Case 1 .. E6-5 Table E6.3.2 Area-wise Seasonal Average of Unit Irrigation Water Requirement for Case 2 .. E6-5 Table E6.3.3 Area-wise Seasonal Average of Unit Irrigation Water Requirement for

Cases 3 & 4 ... E6-6 Table E6.3.4 Area-wise Average of Irrigation Water Diversion Requirement for Case 1 ... E6-7 Table E6.3.5 Area-wise Average of Irrigation Diversion Water Requirement for Case 2 ... E6-7 Table E6.3.6 Area-wise Average of Irrigation Diversion Water Requirement for Case 3 ... E6-8 Table E6.3.7 Area-wise Average of Irrigation Diversion Water Requirement for Case 4 ... E6-9 Table E6.4.1 Comparison of Irrigation Water Demand Estimate Procedures ... E6-10 Table E6.4.2 Future Cropping Intensity in Surface Water Irrigation Scheme Areas ... E6-12 Table E6.4.3 Area-wise Average of Unit Irrigation Water Requirement with Adaptation

Measures ... E6-12 Table E6.4.4 Area-wise Average of Irrigation Water Diversion Requirement with

Adaptation Measures ... E6-13 Table E6.5.1 Example of On-farm Level Supplemental Water Demand in Tidal Swamp

Areas ... E6-14

List of Figures

Page Figure E1.2.1 Variation of El-Nino-Southern Oscillation Index, 1950-2014 ... E1-2 Figure E1.2.2 Average Rice Production Loss due to Droughts in Indonesia from 1990 to

2013 ... E1-4 Figure E1.2.3 Average Rice Production Loss due to Floods in Indonesia from 1990 to

2013 ... E1-4 Figure E1.2.4 Negative Monthly Rainfall Change by Strengthening of El-Nino Event ... E1-5 Figure E2.1.1 Functional Condition of Surface Water irrigation Schemes in Indonesia ... E2-2 Figure E4.2.1 Cropping Calendar for Irrigation Schemes in Brantas River Basin ... E4-3 Figure E5.3.1 Linkage between Hydrological, Irrigation and Rice Production Models ... E5-7 Figure E5.3.2 Location of Survey Areas ... E5-8 Figure E6.3.1 Cropping Calendar for Surface Water Irrigation Schemes in Musi River

Basin ... E6-5 Figure E6.4.1 Optimized Cropping Calendar in Musi River Basin ... E6-11

PART 1 GENERAL

CHAPTER E1 OVERVIEW OF CLIMATE CHANGE IMPACTS ON