Resource allocation and optimisation model RAOM October 2003

2 Resource allocation and optimisation What is the best way to allocate water in the LMB, to meet agreed planning objectives? Assessment criteria –define what is “best” (optimal) in economic, social and environmental terms

3 Many possible scenarios –combinations of external conditions and interventions RAOM is rapid appraisal to narrow down options –identify feasible and “optimal” combinations DSF provides detailed analysis of most promising options RAOM is NOT a substitute for DSF Scenario-based planning * economic, environmental, social

4 Resource Allocation and Optimisation Model Simplified hydrological model plus optimisation tool Model being developed for BDP by Halcrow –spreadsheet based (Excel plus “What’s Best”®) –fast and easy to run –“lumped” model – NOT DETAILED

5 RAOM 10 sub-basins (BDP sub-areas) Monthly time-step

6 Optimsation Values can be assigned to each water use Can optimise for different values –economic return –environmental values –combination Optimiser allows us to identify the “best” mix of uses to meet agreed objectives –within identified constraints

7 Storage Irrigation Water supply Hydropower Flow from catchment INFLOW OUTFLOW $ In-stream use

8 Storage Irrigation Water supply Hydropower Flow from catchment INFLOW OUTFLOW Z $ Z env Z fish Z flood In-stream use

Optimisation $ Economic Z Environment $+Z Combined

10 Data required - hydrology Derived from DSF –Inflow from upper basin –Inflows from each sub-area Model runs for single year –June – May Representative “wet”, “medium”, “dry” years

medium 1998 low 2000 high

12 Data required - dams Size of reservoirs Purpose –Irrigation, hydropower, mixed Water release pattern –from hydrological records, or calculated Value of power production

13 Data required - irrigation Areas irrigated –Source of water (unregulated catchment flow, mainstream river, irrigation or hydropower reservoir) Crop water requirements (by month) Crop value

14 Data required - irrigation Basin 4km2 crop 1 crop 2 crop 3 crop 4 Value ($/km2) Unregulated1000 Regulated Irrigation200 Hydropower etc20 Main river reach50

15 Data required - irrigation Crop water requirements

16 Data required - irrigation Basin 4km2 crop 1 crop 2 crop 3 crop 4 Value ($/km2) Unregulated Regulated Irrigation200 Hydropower etc20 Main river reach50

17 Baseline

18 Scenario 1: increased irrigation Sub-areaBaselineScenario 1 AreaIrrigated km

19 Dry year 1998 Medium year 1999 Wet year 2000 June1%0% July0% August0% September0% October0% November0% December3% January5% February10% March11% 10% April8% 10% May1% Flow decrease at Kratie with increased irrigation

20 RAOM Rough scenario analysis Allows user to identify resource constraints eg –minimum or maximum allocations for irrigation –minimum flows for environment Comparison of values for different uses

Not enough water 70 Not enough land Total flow = 100 I + E = 100 Irrigation limited by land availability I < Minimum flows for environment E > Base flows Water for Irrigation I Water for environmental flows E

But which allocation is optimal? Water for Irrigation I Water for environmental flows E INFEASIBLE FEASIBLE

Assume V = 2*I + E Water for Irrigation I Water for environmental flows E V=100V=170 V=160 “ Optimum ” I=70, E=30 V = 170 Objective function

24 Data inputs Hydrological data from WUP DSF –inflows –catchment flows –storage for irrigation, hydropower –extraction for irrigation, water supply –outflows

25 Data inputs Hydrological data from WUP DSF Economic data compiled by BDP –crop types and gross margins –value of hydropower production

26 Data inputs Hydrological data from WUP DSF Economic data compiled by BDP BDP and IBFMP will assess “values” of different uses –input from EP, FP, FMP, AIFP, NP –need to develop links between river flows and environment (flood extent, wetland quality, fish productivity etc) environmental indices –costs / value of environmental flows and floods

27 Data inputs Hydrological data from WUP DSF Economic data compiled by BDP BDP and IBFMP will assess “values” of different uses Hydrological modeling in RAOM is consistent with the WUP Basin Models, but much simplified

28 WUP DSF DSF analyses impacts of particular scenarios –detailed hydrological model –environmental (and social) impacts –detailed spatial and temporal analysis –complex –time-consuming

29 ISIS (below Kratie) > 800 sub-basins Hourly time-step SWAT 172 sub-basins Daily time-step DSF