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Optimizing Adjustments to Transboundary Water Sharing Plans: A Multi-Basin Approach

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Abstract

Afghanistan contributes water supplies to Iran, Pakistan, Tajikistan, Turkmenistan, and Uzbekistan. However, with the exception of the Helmand Basin, Afghanistan has negotiated transboundary water sharing agreements with no downstream country. This paper describes a constrained optimization framework to minimize economic costs within each of nine Afghan transboundary basins of adapting to potential water sharing agreements. Model results show impacts of water agreements on farm income and food security for each Afghan basin. Our results show that unrestricted trading reduces the economic costs of adapting to water sharing treaties by two to 6 % compared to the conventional water sharing system. A higher scale of reservoir storage capacity as well as market trading of water among regions moderates costs of water shortages, both with and without water agreements in place.

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References

  1. Adams RM, Fleming RA, Chang C-C, McCarl BA, Rosenzweig C (1995) A reassessment of the economic effects of global climate change on US agriculture. Clim Chang 30(2):147–167

  2. Ahmad S (2010) Towards Kabul Water Treaty: Managing Shared Water Resources–Policy Issues and Options Karachi, Pakistan 15

  3. Al-Faraj FA, Tigkas D (2016) Impacts of Multi-year Droughts and Upstream Human-Induced Activities on the Development of a Semi-arid Transboundary Basin. Water Resour Manag 30(14):5131–5143

  4. Dinar A, Wolf A (1994) International markets for water and the potential for regional cooperation: economic and political perspectives in the western Middle East. Econ Dev Cult Chang 43(1):43–66

  5. Doppler W, Salman AZ, Al-Karablieh EK, Wolff H-P (2002) The impact of water price strategies on the allocation of irrigation water: the case of the Jordan Valley. Agric Water Manag 55(3):171–182

  6. Emadi H (1995) Exporting Iran's revolution: the radicalization of the Shiite movement in Afghanistan. Middle Eastern Stud 31(1):1–12

  7. Food And Agricultural Organization (2012) Coping with Scarcity: An action framework for agriculture and food security. FAO

  8. Giordano MA, Wolf AT (2003) Sharing waters: Post-Rio international water management vol 27. Wiley Online Library

  9. Goes B, Howarth S, Wardlaw R, Hancock I, Parajuli U (2016) Integrated water resources management in an insecure river basin: a case study of Helmand River Basin, Afghanistan. Intl J Water Resour Dev 32(1):3–25

  10. Gohar AA, Ward FA, Amer SA (2013) Economic performance of water storage capacity expansion for food security. J Hydrol 484:16–25. doi:10.1016/j.jhydrol.2013.01.005

  11. Gohar AA, Amer SA, Ward FA (2015) Irrigation infrastructure and water appropriation rules for food security. J Hydrol 520:85–100. doi:10.1016/j.jhydrol.2014.11.036

  12. Government of Islamic Republic of Afghanistan Ministry of Agriculture, I.a.L. (2016) National Comprehensive Agriculture Development Priority Program 2016–2020: A Strategic Framework for Agricultural Sector Development and Reform

  13. Government of the Islamic Republic of Afghanistan (2007) Appendix to the Trans-boundary Water Policy of Afghanistan: Trans-boundary water issues. 1–10. https://kakalibchakrabarti.files.wordpress.com/2017/04/pak-af-water-7.pdf

  14. Grey D, Sadoff C (2003) Beyond the river: the benefits of cooperation on international rivers. Water Sci Technol 47(6):91–96

  15. Hanasz P (2012) The politics of water security between Afghanistan and Iran Strategic Analyses Paper, Future Directions International Pty Ltd, Australia

  16. Heckelei T, Britz W, Zhang Y (2012) Positive mathematical programming approaches–recent developments in literature and applied modelling. Bio-based Appl Econ 1(1):109–124

  17. Horsman S (2005) Afghanistan and transboundary water management on Amu Darya: a political history. Central Asian Waters-Part 2: Research Papers 63–75

  18. Howitt RE (1995) Positive mathematical programming. Am J Agric Econ 77(2):329–342

  19. Hung M-F, Shaw D (2005) A trading-ratio system for trading water pollution discharge permits. J Environ Econ Manag 49(1):83–102

  20. Hurd BH, Callaway M, Smith J, Kirshen P (2004) Climatic change and US water resources: from modeled watershed impacts to national estimates. J Am Water Resour Assoc (JAWRA) 40(1):129–148

  21. Jalilov S-M, Amer SA, Ward FA (2013) Reducing conflict in development and allocation of transboundary rivers. Eurasian Geogr Econ 54(1):78–109

  22. King M, Sturtewagen B (2010) Making the most of Afghanistan’s river basins: Opportunities for regional cooperation. EastWest Institute, New York

  23. Libert B, Lipponen A (2012) Challenges and opportunities for transboundary water cooperation in Central Asia: findings from UNECE's regional assessment and project work. Int J Water Resour Dev 28(3):565–576

  24. Ma J, Hipel KW, De M, Cai J (2008) Transboundary water policies: assessment, comparison and enhancement. Water Resources Management 22:1069–1087

  25. Marglin SA (1963) The social rate of discount and the optimal rate of investment. Q J Econ 77:95–111

  26. McKinney DC (2011) Transboundary water challenges: case studies Center for Research in Water Resources. University of Texas, Austin

  27. Mimi ZA, Sawalhi BI (2003) A decision tool for allocating the waters of the Jordan River Basin between all riparian parties. Water Resour Manag 17(6):447–461

  28. Potts K, Ankrah N (2014) Construction cost management: learning from case studies. Routledge, New York

  29. Qureshi AS (2002) Water Resource Management in Afghanistan: The Issues and Options. IWMI

  30. Rycroft DW, Wegerich K ( 2009) The three blind spots of Afghanistan: Water flow, irrigation development, and the impact of climate change. China and Eurasia Forum Quarterly. p. 115–133

  31. Thomas V, Warner J (2015) Hydropolitics in the Harirud/Tejen River Basin: Afghanistan as hydro-hegemon? Water Int 40(4):593–613

  32. Thomas, V., Azizi, M.A. and Behzad, K., 2016. Developing transboundary water resources: What perspectives for cooperation between Afghanistan, Iran and Pakistan?

  33. UN Water (2008) Transboundary waters: sharing benefits, sharing responsibilities Thematic Paper. http://www.unwaterorg/downloads/UNW_TRANSBOUNDARY pdf

  34. United Nations Economic Commision for Europe (2015). Policy Guidance Note on the Benefits of Transboundary Water Cooperation

  35. Van der Zaag P (2007) Asymmetry and equity in water resources management; critical institutional issues for Southern Africa. Water Resour Manag 21(12):1993–2004

  36. van Pelt SC, Swart RJ (2011) Climate change risk management in transnational river basins: the Rhine. Water Resour Manag 25(14):3837

  37. Wegerich K (2008) Hydro-hegemony in the Amu Darya basin. Water Policy 10(S2):71–88

  38. Wegerich K (2010) The Afghan water law:“a legal solution foreign to reality”? 1. J Water Int 35(3):298–312

  39. Wouters P (2013) International law–facilitating transboundary water cooperation. Global Water Partnership 17:87

  40. Xiao Y, Hipel KW, Fang L (2016) Incorporating water demand management into a cooperative water allocation framework. Water Resour Manag 30(9):2997–3012

  41. Zeitoun M, Mirumachi N (2008) Transboundary water interaction I: Reconsidering conflict and cooperation. Int Environ Agreements 8(4):297–316

  42. Zeitoun M, Warner J (2006) Hydro-hegemony–a framework for analysis of trans-boundary water conflicts. Water Policy 8(5):435–460

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Acknowledgements

The authors gratefully acknowledge support by the New Mexico Agricultural Experiment Station and US Geological Survey International Division. Neither organization is responsible for errors in this document.

Author information

Correspondence to Frank A. Ward.

Appendix

Appendix

Overview.

The appendix summarizes relevant mathematical documentation of the multi-basin hydro-economic model design to inform water policy decisions in Afghanistan. It outlines the mathematical framework of the optimization model built using General Algebraic Modeling Systems to include sets, parameters, variables, equations and the objective function specification. The complete model show hydrological, economic and institutional constraints. The code for the hydro-economic model and spreadsheet results are available at the New Mexico State University web page at https://water-research.nmsu.edu/

Sets.Sets characterize the foundation of the multi-basin framework. Each set constitute elements as described below. In our model, sets and corresponding elements are defined for all studied transboundary river basins in Afghanistan.

sets set name description set elements
k crop Crop selection is an important choice variable for farm income, food security, and policy assessment that influences both. / Alfalfa, Cotton, Melon, Potato, Pulses, Rice, Tomato, Wheat/
t Year Year reflect a 20-year horizon /year1 * year 20/
i Region by basin Each basin divided into 3 regions /upper, middle, lower/
j Water right priority Priority among regions inside each basin /j1, j2, j3/
r Water allocation rule Water right systems for sharing water shortages when they occur /Upstream priority, free market/
s Storage reservoir capacity scale Scale at which new reservoirs could be built. None reflects base condition and has no storage. /none, small, medium, large/
b River Basin Lists of all river basins studied in the country /Balkh, Patika, Helmand, Farah, Kabul, Kokcha Kunduz, Murghab, Upper_Harirud
y Treaty Treaty agreement on transboundary river basins. /Without treaty, With treaty/
rji(r,j,i) Mapping set Assigns priorities to regions in a basin to vary water right regime us_priority.j1.upper,us_priority.j2.middle,us_priority.j3.lower
free_mkt.j1.upper,free_mkt.j1.middle,free_mkt.j1.lower
rwa(r) Upstream priority Upstream users receive priority when shortages occur upstream priority
rfm(r) free_market No restrictions on water reallocations from baseline free market

Parameters.

Terms ending in _p refer to parameters, data read by the model. They are:

Parameter sets Label units
Nat_supp_p (b) Natural runoff inflow to basin MCM / year
Nat_suppl_p (b,t) Stochastic water supply by year with set mean and standard deviation MCM / Year
Nat_supply_p (b,t,y) Natural water supply adjusted by downstream delivery treaty requirement MCM / Year
Pop_p (b,t) Forecast population by basin and years thousands
Popratio_p (b,t) Ratio of given year population to base year 1 and above
Rho_p   Discount rate (1%) unitless
Capacity_p (b,s) Maximum reservoir storage capacity MCM
Com_cost_mcm (b,s) Construction cost per million cubic meters storage capacity $US/MCM
Prop_right_p (b,i) Proportion of right to water compared by region within basin 0–1
Right_p (b,i) Customary absolute right to water supply by region MCM / year
Shortage_p (b,r,i,t,s,y) Water storage relative to full supply right 0–1
Basin_use_p (b,r, t,s,y) Total water use in the basin MCM / year
Change_store_p (b,r, t,s,y) Total change in storage MCM / year
Bc_p (b,i,k) Water use per unit land (irrigation depth) M / year
Land_p (b,i,k) Observed land in production Ha / year
Price_p (k,b) Observed crop prices $US per metric ton
Price_elast_p (k,b) Price elasticity of demand unitless
Yield_p (b,i,k) Observed crop yield Metric tons/ha
Cost_p (b,i,k) Production costs $US per ha
A0_p (b,k,t) Intercept in price-dependent demand function $US per metric ton
A1_p (b,k,t) Slope of price-dependent demand function $US per metric ton
B0_p (b,k,t) Intercept in crop water production function (PMP) Metric tons/ha
B1_p (b,k,t) Slope in crop water production function (PMP) Metric tons/ha

Variables.

As characterized in the multi-basin model, variables are endogenous (unknown) and end in _v to distinguish the unknown data from parameters. These variables are optimized by the model, while respecting all important bounds. The most important variables are:

Variables sets label units
Hectares_v (b,r,i,k,t,s,y) Land use 1000 ha
T_hectares_v (b,r,i, t,s,y) Total land use 1000 ha
Uses_v (b,r,i, t,s,y) Water use MCM/year
Sum_uses_v (b,r, t,s,y) Summed water use MCM/year
Production_v (b,r,i,k,t,s,y) Land in production details 1000 ha
Yield_v (b,r,i,k,t,s,y) Crop yields Tons/ha
Crop_price_v (b,r, k,t,s,y) Crop price $US/ton
Netrev_v (b,r,i,k,t,s,y) Net revenue per unit land $US/ha
Con_surp_v (b,r, k,t,s,y) Consumer surplus (willingness to pay in excess of price) $US 1000 / year
Tgrossrev_v (b,r,i,k,t,s,y) Total gross revenue over all lands $US 1000 / year
Ag_ben_j_v (b,r,i,k,t,s,y) Discounted ag benefits with details $US 1000 / year
Tot_wel_v (b,r, t,s,y) Discounted total welfare $US 1000 / year
Wel_wo_cd_v (b,r, s,y) Discounted total welfare without reservoir capacity expansion $US 1000 / year
Ttot_wel_v (b,r, s,y) Discounted total welfare with reservoir capacity expansion $US 1000 / year

Equations

Mathematical expressions connecting the relationship between variables and parameters used in the optimization frame to characterize the most important indicators such as hydrology, land in production, crop production, and economic policy choices.

Hydrology Block

$$ \mathrm{X}\left(\mathrm{t}\right)\sim \mathrm{N}\left(\upmu, {\upsigma}^2\right). $$
(1)

Basin headwater supply for the year t, X(t)

$$ \mathrm{X}\_\mathrm{v}\left(\mathrm{b},\mathrm{r},\mathrm{i},\mathrm{k},\mathrm{t},\mathrm{s},\mathrm{y}\right)\kern0.5em =\kern1em \mathrm{Bc}\_\mathrm{p}{\left(\mathrm{b},\mathrm{i},\mathrm{k}\right)}^{\ast }\ \mathrm{hectares}\_\mathrm{v}\left(\mathrm{b},\mathrm{r},\mathrm{i},\mathrm{k},\mathrm{t},\mathrm{s},\mathrm{y}\right) $$
(2)

Crop water use equation calculated based on land in production

$$ \mathrm{Uses}\_\mathrm{v}\left(\mathrm{b},\mathrm{r},\mathrm{i},\mathrm{t},\mathrm{s},\mathrm{y}\right)\kern0.5em =\mathrm{sum}\left(\mathrm{k},\mathrm{X}\_\mathrm{v}\left(\mathrm{b},\mathrm{r},\mathrm{i},\mathrm{k},\mathrm{t},\mathrm{s},\mathrm{y}\right)\right) $$
(3)

Water use summed over crops

$$ \mathrm{sum}\_\mathrm{uses}\_\mathrm{v}\left(\mathrm{b},\mathrm{r},\mathrm{t},\mathrm{s},\mathrm{y}\right)=\mathrm{sum}\left(\mathrm{i},\mathrm{Uses}\_\mathrm{v}\left(\mathrm{b},\mathrm{r},\mathrm{i},\mathrm{t},\mathrm{s},\mathrm{y}\right)\right) $$
(4)

It calculates water use summed over canals

Agronomy Block

$$ \mathrm{T}\_\mathrm{hectares}\_\mathrm{v}\left(\mathrm{b},\mathrm{r},\mathrm{i},\mathrm{t},\mathrm{s},\mathrm{y}\right)=\mathrm{sum}\left(\mathrm{k},\mathrm{hectares}\_\mathrm{v}\left(\mathrm{b},\mathrm{r},\mathrm{i},\mathrm{k},\mathrm{t},\mathrm{s},\mathrm{y}\right)\right) $$
(5)

Land in production summed over crops

$$ \mathrm{Yield}\_\mathrm{v}\ \left(\mathrm{b},\mathrm{r},\mathrm{i},\mathrm{k},\mathrm{t},\mathrm{s},\mathrm{y}\right)=\mathrm{B}0\_\mathrm{p}\left(\mathrm{b},\mathrm{i},\mathrm{k}\right)+\kern0.5em \mathrm{B}1\_\mathrm{p}{\left(\mathrm{b},\mathrm{i},\mathrm{k}\right)}^{\ast }\ \mathrm{hectares}\_\mathrm{v}\ \left(\mathrm{b},\mathrm{r},\mathrm{i},\mathrm{k},\mathrm{t},\mathrm{s},\mathrm{y}\right) $$
(6)

Crop yields declines as acreage in production increases

$$ \mathrm{Production}\_\mathrm{v}\ \left(\mathrm{b},\mathrm{r},\mathrm{i},\mathrm{k},\mathrm{t},\mathrm{s},\mathrm{y}\right)=\mathrm{Yield}\_\mathrm{v}\ {\left(\mathrm{b},\mathrm{r},\mathrm{i},\mathrm{k},\mathrm{t},\mathrm{s},\mathrm{y}\right)}^{\ast }\ \mathrm{hectares}\_\mathrm{v}\ \left(\mathrm{b},\mathrm{r},\mathrm{i},\mathrm{k},\mathrm{t},\mathrm{s},\mathrm{y}\right) $$
(7)

It calculates crop production based on crop yield and acreage in production.

$$ \mathrm{Tot}\_\mathrm{prod}\_\mathrm{v}\left(\mathrm{b},\mathrm{r},\mathrm{k},\mathrm{t},\mathrm{s},\mathrm{y}\right)=\mathrm{sum}\left(\mathrm{i},\mathrm{production}\_\mathrm{v}\ \left(\mathrm{b},\mathrm{r},\mathrm{i},\mathrm{k},\mathrm{t},\mathrm{s},\mathrm{y}\right)\right) $$
(8)

Total crop production summed over regions.

Economics Block

$$ \mathrm{crop}\_\mathrm{p}\mathrm{rice}\_\mathrm{v}\ \left(\mathrm{b},\mathrm{r},\mathrm{k},\mathrm{t},\mathrm{s},\mathrm{y}\right)=\mathrm{BB}0\_\mathrm{p}\ \left(\mathrm{b},\mathrm{k},\mathrm{t}\right)+\left[\mathrm{BB}1\_\mathrm{p}{\left(\mathrm{b},\mathrm{k},\mathrm{t}\right)}^{\ast }\ \mathrm{Tot}\_\mathrm{p}\mathrm{rod}\_\mathrm{v}\left(\mathrm{b},\mathrm{r},\mathrm{k},\mathrm{t},\mathrm{s},\mathrm{y}\right)\right] $$
(9)

Linear demand function of crop price for each basin as influence by water right systems, region, time, storage capacity and treaty

$$ \mathrm{con}\_\mathrm{surp}\_\mathrm{v}\ \left(\mathrm{b},\mathrm{r},\mathrm{k},\mathrm{t},\mathrm{s},\mathrm{y}\right)={0.5}^{\ast }\ \left[{\left[\mathrm{BB}0\_\mathrm{p}\left(\mathrm{b}\mathrm{b},\mathrm{k},\mathrm{t}\right)-\mathrm{crop}\_\mathrm{p}\mathrm{rice}\_\mathrm{v}\ \left(\mathrm{b},\mathrm{r},\mathrm{k},\mathrm{t},\mathrm{s},\mathrm{y}\right)\right]}^{\ast }\ \mathrm{Tot}\_\mathrm{p}\mathrm{rod}\_\mathrm{v}\ \left(\mathrm{b},\mathrm{r},\mathrm{k},\mathrm{t},\mathrm{s},\mathrm{y}\right)\right] $$
(10)

Consumer surplus representing gains in economic benefits to the Afghan people as water right systems, treaty agreement and storage capacities are varied.

$$ \mathrm{Netrev}\_\mathrm{v}\ \left(\mathrm{b},\mathrm{r},\mathrm{i},\mathrm{k},\mathrm{t},\mathrm{s},\mathrm{y}\right)=\mathrm{crop}\_\mathrm{p}\mathrm{rice}\_\mathrm{v}{\left(\mathrm{b},\mathrm{r},\mathrm{k},\mathrm{t},\mathrm{s},\mathrm{y}\right)}^{\ast }\ \mathrm{Yield}\_\mathrm{v}\left(\mathrm{b},\mathrm{r},\mathrm{i},\mathrm{k},\mathrm{t},\mathrm{s},\mathrm{y}\right)-\mathrm{Cost}\_\mathrm{p}\left(\mathrm{b},\mathrm{i},\mathrm{k}\right) $$
(11)

Net revenue per unit land is price times yield minus costs per unit land

$$ \mathrm{Ag}\_\mathrm{Ben}\_\mathrm{j}\_\mathrm{v}\ \left(\mathrm{b},\mathrm{r},\mathrm{i},\mathrm{k},\mathrm{t},\mathrm{s},\mathrm{y}\right)=\mathrm{Netrev}\_\mathrm{v}{\left(\mathrm{b},\mathrm{r},\mathrm{i},\mathrm{k},\mathrm{t},\mathrm{s},\mathrm{y}\right)}^{\ast }\ \mathrm{hectares}\_\mathrm{v}\left(\mathrm{b},\mathrm{r},\mathrm{i},\mathrm{k},\mathrm{t},\mathrm{s},\mathrm{y}\right) $$
(12)

Agricultural benefits by river basin, water right systems, agricultural region, crop, time period, storage capacity and treaty.

$$ \mathrm{To}\_\mathrm{wel}\_\mathrm{v}\left(\mathrm{b},\mathrm{r},\mathrm{k},\mathrm{t},\mathrm{s},\mathrm{y}\right)=\mathrm{sum}\ \left[\mathrm{i},\mathrm{ag}\_\mathrm{ben}\_\mathrm{j}\_\mathrm{v}\left(\mathrm{b},\mathrm{r},\mathrm{i},\mathrm{k},\mathrm{t},\mathrm{s},\mathrm{y}\right)\right]+\mathrm{con}\_\mathrm{surp}\_\mathrm{v}\left(\mathrm{b},\mathrm{r},\mathrm{k},\mathrm{t},\mathrm{s},\mathrm{y}\right) $$
(13)

Discounted net present value of total economic welfare

$$ \mathrm{Tot}\_\mathrm{wel}\_\mathrm{v}\left(\mathrm{b},\mathrm{r},\mathrm{t},\mathrm{s},\mathrm{y}\right)=\mathrm{sum}\ \left(\mathrm{k},\mathrm{To}\_\mathrm{wel}\_\mathrm{v}\left(\mathrm{b},\mathrm{r},\mathrm{k},\mathrm{t},\mathrm{s},\mathrm{y}\right)\right) $$
(14)

Summed total welfare over crops

$$ \mathrm{Wel}\_\mathrm{wo}\_\mathrm{cd}\_\mathrm{v}\ \left(\mathrm{b},\mathrm{r},\mathrm{s},\mathrm{y}\right)=\mathrm{sum}\ \left(\mathrm{t},\mathrm{DF}{\left(\mathrm{t}\right)}^{\ast }\ \mathrm{Tot}\_\mathrm{wel}\_\mathrm{v}\left(\mathrm{b},\mathrm{r},\mathrm{t},\mathrm{s},\mathrm{y}\right)\right) $$
(15)

Net present value of farm income plus consumer surplus

$$ \mathrm{Ttot}\_\mathrm{wel}\_\mathrm{v}\ \left(\mathrm{b},\mathrm{r},\mathrm{s},\mathrm{y}\right)=\mathrm{Wel}\_\mathrm{wo}\_\mathrm{cd}\_\mathrm{v}\left(\mathrm{b},\mathrm{r},\mathrm{s},\mathrm{y}\right)-\mathrm{Tot}\_\mathrm{COM}\_\mathrm{cost}\_\mathrm{p}\left(\mathrm{b},\mathrm{s}\right) $$
(16)

Total net benefits after subtracting dam construction cost

$$ \mathrm{Tot}\_\mathrm{b}\_\mathrm{v}=\mathrm{sum}\ \left(\left(\mathrm{b},\mathrm{r},\mathrm{s},\mathrm{y}\right),\mathrm{Ttot}\_\mathrm{wel}\_\mathrm{v}\left(\mathrm{b},\mathrm{r},\mathrm{s},\mathrm{y}\right)\right) $$
(17)

Total benefits looped over all changeable indices

$$ \mathrm{shad}\_\mathrm{p}\mathrm{rice}\_\mathrm{p}\left(\mathrm{b},\mathrm{r},\mathrm{i},\mathrm{t},\mathrm{s},\mathrm{y}\right)=\mathrm{uses}\_\mathrm{v}.\mathrm{m}\ \left(\mathrm{b},\mathrm{r},\mathrm{i},\mathrm{t},\mathrm{s},\mathrm{y}\right) $$
(18)

Shadow prices for all water allocation rules except unrestricted trading

$$ \mathrm{shad}\_\mathrm{p}\mathrm{rice}\_\mathrm{p}\left(\mathrm{b},\mathrm{rfm},\mathrm{i},\mathrm{t},\mathrm{s},\mathrm{y}\right)=\mathrm{sum}\_\mathrm{uses}\_\mathrm{v}.\mathrm{m}\left(\mathrm{b},\mathrm{rfm},\mathrm{t},\mathrm{s},\mathrm{y}\right) $$
(19)

Shadow prices for unrestricted trading

$$ \mathrm{Storage}\_\mathrm{Capacity}\_\mathrm{p}=\mathrm{scale}\_{\mathrm{p}}^{\ast }\ \mathrm{natural}\_\mathrm{supply}\_\mathrm{p}. $$
(20)

Water storage capacity is defined by natural supply at various values of the scale parameter (scale_p)

$$ \mathrm{Tot}\_\mathrm{Com}\_\mathrm{cost}\_\mathrm{p}\left(\mathrm{b},\mathrm{s}\right)=\mathrm{Cost}\_\mathrm{Per}\ \mathrm{Unit}\ \mathrm{Storage}\_{\mathrm{p}}^{\ast }\ \mathrm{Storage}\_\mathrm{Capacity}\_\mathrm{p}. $$
(21)
$$ \mathrm{Ttot}\_\mathrm{wel}\_\mathrm{v}\left(\mathrm{b},\mathrm{r},\mathrm{s},\mathrm{y}\right)=\mathrm{Wel}\_\mathrm{wo}\_\mathrm{cd}\_\mathrm{v}\left(\mathrm{b},\mathrm{r},\mathrm{s},\mathrm{y}\right)\hbox{--} \mathrm{Tot}\_\mathrm{Com}\_\mathrm{cost}\_\mathrm{p}\left(\mathrm{b},\mathrm{s}\right). $$
(22)

Total net benefits obtained after dam cost.

Bounds.

Bounds characterize constraints on institutions, technology, and water user behavior, while also producing realistic responses to future climate or policy adaptations to climate. A lower bound (.lo) on each water flows and land used assures no crop production or water supplies have negative values. An upper bound (.up) guards against a variable exceeding that set level.

$$ \mathrm{hectares}\_\mathrm{v}.\mathrm{lo}\left(\mathrm{b},\mathrm{r},\mathrm{i},\mathrm{k},\mathrm{t},\mathrm{s},\mathrm{y}\right)=0. $$
(23)

Agricultural land in production cannot be negative.

$$ \mathrm{uses}\_\mathrm{v}.\mathrm{up}\ \left(\mathrm{b},\mathrm{rwa},\mathrm{i},\mathrm{t},\mathrm{s},{}^{\hbox{'}}\mathrm{Without}\_{\mathrm{treaty}}^{'}\right)={1.0}^{\ast }\ \mathrm{wet}\_\mathrm{wat}\_\mathrm{use}\left(\mathrm{b},\mathrm{rwa},\mathrm{i},\mathrm{t},\mathrm{s},{}^{\hbox{'}}\mathrm{Without}\_{\mathrm{treaty}}^{'}\right) $$
(24)

uses_v . up (b, rwa, i, t, s, 'With_treaty) = 0.8* wet_wat_use(b, rwa, i, t, s, 'With_treaty) (25)

Bounds water use in production, with use in the face of a treaty set to 80% of without treaty level

$$ \mathrm{sum}\_\mathrm{use}\mathrm{s}\_\mathrm{v}.\mathrm{up}\left(\mathrm{b},\mathrm{rfm},\mathrm{t},\mathrm{s},{}^{\hbox{'}}\mathrm{Without}\_{\mathrm{treaty}}^{'}\right)={1.0}^{\ast }\ \mathrm{basin}\_\mathrm{use}\_\mathrm{p}\left(\mathrm{b},\mathrm{rfm},\mathrm{t},\mathrm{s},{}^{\hbox{'}}\mathrm{Without}\_{\mathrm{treaty}}^{'}\right) $$
(26)
$$ \mathrm{sum}\_\mathrm{use}\mathrm{s}\_\mathrm{v}.\mathrm{up}\left(\mathrm{b},\mathrm{rfm},\mathrm{t},\mathrm{s},{}^{\hbox{'}}\mathrm{With}\_{\mathrm{treaty}}^{'}\right)={0.8}^{\ast }\ \mathrm{basin}\_\mathrm{use}\_\mathrm{p}\left(\mathrm{b},\mathrm{rfm},\mathrm{t},\mathrm{s},{}^{\hbox{'}}\mathrm{With}\_{\mathrm{treaty}}^{'}\right) $$
(27)

When water trading is allowed among regions in each basin, only total water use is bounded.

Objective.

The objective of the model is to maximize discounted net present value subject to the hydrologic and institutional constraints described above.

The objective function Ttot_wel_v(b,r,s,y) specified above is maximized for each basin, water shortage sharing rule, treaty agreement and storage capacity level. A total of 144 model runs are optimized.

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Acquah, S., Ward, F.A. Optimizing Adjustments to Transboundary Water Sharing Plans: A Multi-Basin Approach. Water Resour Manage 31, 5019–5042 (2017). https://doi.org/10.1007/s11269-017-1794-3

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Keywords

  • Economic benefit
  • transboundary water resources
  • constrained optimization
  • water treaties