Tilburg University
Alternative water management scenarios for Saudi Arabia
de Jong, R.L.; Al Layla, R.I.; Selen, W.J.
Publication date:
1988
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Citation for published version (APA):
de Jong, R. L., Al Layla, R. I., & Selen, W. J. (1988). Alternative water management scenarios for Saudi Arabia.
(Research Memorandum FEW). Faculteit der Economische Wetenschappen.
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ALTERNATIVE WATER MANAGEMENT SCENARIOS FOR SAUDI ARABIA
Remy L, de Jong, Rashid I. A1 Layla,
Willem J. Selen
ALTERNA'CIVE WATER MANAGEMENT SCENARIOS FOR SAUDI ARABIA Remy L.de Jong~, Rashid I. A1 Layla and Willem J. Selen
Ihe -lrabia wcl] matching of ,-iPmands for ;roath. The demand and
tv a large e.~tent depend on the
its e.rtremely limited water resources water primarilt- determined bc. population
paper reviews .3nd roughl3- quantifies the suppl~- parameters and then proceeds tv
.~nslyze ~! scenarios for water resources management
according to ~l different strategies.
I'he multiobjectlL'e approach uses Coa1 Programming, ~nd the most significant output parameters appear to be the conceptual "water sector cost", and the futcre rat~ 3r.
which non-renewable groundwater wi11 be mined and exhausted, thereby endangering the Ringdom's :~izter
securí t c-.
The Goa1 Programming methodology provides
mal:ers with the necessary and sufficient informaLion to use good judgement in makinq rational chv~ces frum among sereral water derelopment strategies for the L-ingdvm, while being aware of the t.rade-offs in:.ol~ed.
1. Introduction
T.~ nas ber:n accepted practice in many devaloping countries
to take it for qranteá thit basic resources, such as a:r, manpoc..er, water and money, will be available to pursue a given mix of development goals. Occasionally it may have been more expedient to import, or borrow, some of those re-sources, particularly manpower or money, but nature is al-ways counted on to provide the basic physical framework of national wealth, particularly in terms of land and water. It now appears that in many areas water may become a power-ful, and painful, constraint on economic development. In some countries critical questions about future water
availa-socio-economic future of the ]iin2dom of Saudi succesful
decision wí th
~.~ddress: 23 rue de Rouffach, 682~0 w'esthalten, FRA~CE. at the time of conducting this research the authors were on
-z-b111t: now need ro be faced by- decision makers. The concept of "c.'ater securit~~" is demandinq as much qo~'ernmental atten-t:on as the preser~'ation of territorial or economic inte-~rit; .
:hereforr, it is becoming tncreasingly- important t.hat offi-cta:s ~ith water management responsibilities ha~e available, ~nd ~,se, resource silocation techniques which are not only eas}' ;o understand, but which also pro~~ide sufficient and u~etu: tnformz,~.~un to permit the seiection of the "best" uater mar,agement scenario to satisfy a particular country's objectiti'es.
In t.he foilowing paragraphs an assessment wi11 be made of the implications of a few selected scenarios of water re-sources de~eic~.ment in the hingdom of Saudi ,irabia. The major cor,straining parameters will be re~'iewed, the first one bPin~ E:opulation, since it determines, directly or indi-rectl~, the nature and scope of society's demands on the a~ailahle water resources. Thereafter, the resources and uses wi11 be roughly quantified, as well as the costs in-~ol~'ed in putt~r.~ those resources to a beneficial use.
Finali~, a few plausible scenarios are examined to evaluate
some management options and their consequences.
2. Population.
5audi ar3bia is the dominant country- on the .arabian
Penin-~ula. in demoqraphic terms it has experienced most of the
effects of the regional ?conomic e~pansion of the past few
~:ecades. The countr~- is very lightly populated and the ra-r.her sudden groc.~th of the oil-producing sector of the econo-m~: attracted manc expatriates. Moreo~'er, as a consequence of
tts custody- of two of Islam's holiest shrines the hingdom
y-early recei~'es millions of foreign ~-isitors, some of whom [ry r.o prolon:~ their stay for employment reasons.
B~- 198-1 expatriates constituted about 23X of a total
popula-tion of about 11,000,000 [1]. Figure 1 illustrates the
re-cent growth pattern of the population as estimated by
E.S.C.W.~1. (2]; the population growth rate for nationals has
been found to be in the range of 3.6X [3] to 4.8X [4] per
annum, but from a municipal water supply poinL of view Lhe
"total" demand is the one to consider. Therefore, the third
.,ur~e, based on a 3X growth rate, is proposed as a
concei~~able compromise for planning purposes only, taking
tnto account an expected gradual reduction in the expatriate segment of the population.
3. The Uses.
- Domestic~Industrial uses.
-3-I~`;:) 1 ~`~~ I?~i~} I 1~7 ~'1,)~)
-~-t.here .~re other municipal uses, such as indust,ry, firefight-Lng, sy-stem 1eai;;i;e, etc. Domestic uses Lnclude cooking, cleaning and sanitary needs; such water is normally- pro~~ided through ser~:ce connections to a municipal water distribu-tion system and therefore this category also includes most small industrial and commercial establishments, khich use the same distrlbution system. The ~~uality standards applicable to this category are those for potable water, e~-en though many of the specific uses couLd safely- be satis-fied with ti-ater of poorer quality.
an estimate of 1~00 y1Cyi1~ for the combined ylunicipal and in-dustrial uses Ln 1986 was included in the lth Development Plan [.:J, ~OY of which will be used here to represent the demands by- residences and commercial establishments. This wo~11d implc a consumption of about 176 l~cap~day for in-house domestic demand, which is comparable with other
local-ities in the region.
The rat.e of growth is likely to be close to the net rate of
growth of the pop~ilation, around 3X per annum, unless strin-3ent consertation measures s.ould be enforced.
- Hurticultural Irrígation.
The use of water for horticultural or landscape irriqation has seen a marked growth in all urban areas of the Gulf StateS. It is a use that is difficult to quantify because for this category-, which is frequently carried out in part hy municipalities for the enjoyment of the public, usually no records are required or kept.
,~ recent czse studv (6) of a large company headquarters' compound in the Kingdom's Eastern Province suggested that horticultural irrigation may account for as much as 60X of all Lts "municipal" uses, although this case should not be :onsidered as representati~~e since landscaping standards for that particular community- appear to be higher than those of the a~-era5e local municipality.
In líne with the preceding paragraph 509G of 1-100 MCMI' is as-sumed to be used for non-producti~e horticultural irriqation of gardens and parks. The assumption is further made Lhat a gradual ac.areness of the cost of water will result in a stagnating, rather than a growing, demand in this category.
- .aqricultural irrigation.
The hydrology, climate and soils of the Kingdom are not
ge-nerally conducive to the pursuit of agriculture. Date palms, w~hich are fairly tolerant to salinity, appear to thrive
re-gardless of the quality of the water, but the irrigation of
most other crops requires water with no more than about 3000
ppm TDS. The Kingdom possesses significant quantities of
groundwater of that quality. The development of the
agricul-tural sector was analyzed in a series of detailed Area
Re-sources Sur~-eys, and a summary of those [6] provides a
use-f~~1 insight into the amounts of water actually used for
agriculture. More recently the Ministry of Agriculture and
-5-rIS we11 as esLimar,es OF CI'Op water requirements in Lhe
E;ing-~fom [F3J. This permits a fairly- accurate 3ssessm~nt of total a3riculLUra1 water use.
Table 1. agricultural water requirements 11985).
Crops -a re-a Ihal Spec.water Req. Im3~haiFear)
Gross Water Req.
(MCyY)
wheat ~8i,100 8,000 5,871
Coarse Grains 16,200 I1,000 6ï8
~~egetables 92,500 1~,000 1,992
Fodder 1~5,100 32,000 5,804
Dates and Fruit i5,200 32,000 5,348
TOTaL 9-46,100 - 19,695
~ similar total could :~1so have been approaimated by
uti-lizing the quidelines for crop water requirements published
by F.:~.O. [9j with appropriate assumptions, but in view of
the site-specific quality of the local observations on which
the abo~.e table was based it is preferred. ~ 1980 estimate
was calculated, again usinq statistics from reference [i],
whilw projections were based on a 3X~annum growth rate.
4. The Resources.
The water reso~irces available to the Ringdom to meet the de-mands outlined earlier will be discussed briefly under seven convenient headings, together with an attempt at rough quan-tificatio.i.
- Fossil groundwater.
~tost of the gcoundwater is derived from storage, primarily from the large primary aquifer systems underlying the Cen-tral and Eastern regions of Saudi Arabia. Most of the water in storage is "fossil", deposited in much earlier times, and it has no relation to the current hydrologic regime. It is,
therefore, not an "available" resource from a long-term
planning point of view. For management purposes its
availa-bility is 0 MCMY, although temporary and limited withdrawals are possible.
Its ~.olume has been estimated to be between 337,300 KCM and
500,000 yCy [3J, and no serious studies have been published
indicating that those estimates may be substantially in
er-ror. Many potential problems stand in the way of full utili-zation of this water, particularly the likelihood that water
quality will deteriorate with deeper withdrawals. On the
other hand more detailed in~'estigations may yield some
-6-consi~.jer :i00,Uv~.i ~ICy as a pro~en reserve, and it ~as :.idopt.ed
here as bern; . ~~ailable in 1980.
- rtenec:abl~ .~i~~~tndc.aGer.
The unconsclidated deposLts along streambcds, and e~en some of the primare aquifers referred to abo~e, receive periodic rechar;e, ;he magnitude of which has been estimated at 950 MCM1' [3]. This renewable portion of the groundwater rescurce used to be siightly smaller, but it is assumed that from 1985 the effects of the numerous recharqe dams in the Ring-dom hati"e szfeguarded this resource at the level mentioned abo~ e .
- Surface water.
t)n1y" immediateLy aft.er short intense storms is surface water present in the E:inqdom, and its utility derives in part from
its contrihution to the recharge of the aquifers hydraulic-a11~ connected to the streambeds, and in part from its
a~"ailabilit~" for diversion and direct spate flow irrigation.
The magnitude of this resource has been estimated at about
900 yCNY (3]. - seaw~ater.
The major use of seawater is as the feed water of
desalina-tion plants and as such it is in practice not subject to an
upper limit. However, since current desalination technology
relies almost exclusively on the use of fossil energy, this
water resource is also non-renewable and its (temporary)
acailability is equated to the capacities of the
desalina-tion plants. Reference [3] suggests production capacities of 63 `1CM1" and ~00 MCNY for 1980 and 1985 respecti~.el~.. ~ pla-teau of r00 ~ICy1' is assumed for later years.
- kastewater.
aí'ter suitable treatment, wastewater is becoming an increas-ingl~" app~eciated resource; the technolog~- is well tested, but optimum uses require urban surroundings and adeyi~ate collection and treatment facilities, conditions which are partially met only in the Riyadh, Jeddah and Dammam ~irban conglomerates. Reference [3] estimates this resource to amount to 100 HCyY in 1985, and it appears reasonable that its a~-ailabiLity will relate to the growth of the municipal demand, as represented by the curve for i'otal Population in Figure 1. Therefore, values of 119, 143 and 170 MCMY will be used for 1990, 1995 and 2000 respectively.
- Loss reduction.
-~-other schemes ma~ onl}- }-ield brackish e.-ater. Hence, rhis ca-t.egory. was not taken into account.
- Imported c.ater.
From time to t.ime the practicality~ of war.er importation has
been demonstrated. Con~ey-ance may be b}~ pipelines, open
channels, ur tanker ~-essels. The latter approach appears to he the onl~- practical alternative for the E;ingdom, and
ei-ther the bacl:-haul loil tanker) or shuttle (water tanker)
mode could be used. Provided that suitable off-loading faci-lities are a~ailable this resource could be mobilized on ra-ther short notice, and a wide range of foreign suppl}- points is a~-ailable [10].
4~uantification of this resource is essentiaily a function of the a~~ailabii~::~ nf facilities and of a management decision t.o mobiLi~e the resource. Rather arbitraril}-, the amounts of 100, 400 and 1000 MCMY for the vears 1990, 1995 and 2000 respecti~-ely- a-i11 be used.
The possibiLity of constructing a water pipeline from Turkey tc both the Eastern Province and the West coast has been mentioned in press reports, but in the face of formidable
technicxl, hydrological, financial and political stumbling blocks this alternati~-e is unlikel}- to be realized b}- the end of this century.
Iable 2 summarizes the quantification of various l,`ses and
Resources, as described in the preceding paragraphs. Table 2. Summarv of Lses and Resources.
Year ---~ 1980 198~ 1990 199~ 2000 LSES: Domestic~Industrial 604 ï00 811 941 1,091 Horticultural 604 700 700 700 i00 aqricultural 14,000 20,000 23,000 26,900 31,200 RESOURCES: Fossil Groundwater 0 0 0 0 C Renewabie Groundw. 660 950 950 950 950 Surface Water 485 900 900 900 900 Seawater 63 400 700 700 700 Wastewater 86 100 119 143 170 Loss reduction 0 0 0 0 0 Imported Water 0 0 100 400 1,000 Deficit 13,914 19,050 21,742 25,448 29,271 5. The costs.
The process of mobilizing specific resources to satisfy
spe-cifíc demands in~-olves costs for a combination of items,
such as acquisition, production, treatment, transportation,
-e-is the rel.~tion5hip between the yuality- of the source water
~~n~ the qualit~ standards to be met for specific uses. For
tnstance, there is a major difference between the treatment
cost cf grounde.ater (e.g. 3000 ppml for agricultural use
(e.g. Z000 ppml, and demineralizinq seawater (e.g. 50,000
ppml for domestic consumption (e.q. ~UO ppm). These costs
are now fairl~ well established ín the ~,lulf region and
a~~er-age ~alues can be obtained from practitioners in the field
or from rechnical reports; working talues are introduced
into the plann:ng model in the nezt section lSee Figure 2). ihe cost of "t.:oducing" fossil groundwater deser~es special mt~:~ ~ r ~n . ~.~.- . c. r; t ac t t,hat a resource i s non-renewable im-p.,~s ,~~ac .~~ yresent use creates a problem for future ge-nerations: the "mininq" of fossil groundwater today endan-gers "water security" in the future. This means that the use of the fossil groundwater resource is acceptable only if the present users make adeqiiate pro-~isions to compensate the fu-ture users for the economic injury they are bound to suffer.
For the p~irpose of tnís discussion it is not necessary to
e~amine in detail the ~-arious forms those pro~~isions could take, but r~r the sake of quantification one could en~-isage
that the present users establish a bank aceount in which
they deposit, for each unit ~-olume of water extracted from
fossil storage, a certain sum of moner or a"penalty". The size of this penalty should be sizch that its future value, ti
years later, would be sufficient to permit future
genera-tions to produce the same unit ~~olume of water using the
then most economically a~-ailable method. Most likely such
future production in the Saudi ,arabian contert would utiLize ~a combination of desalination and importation.
The following assumptions ser~e to complete the quantifica-r.ion vrocess:
a) Discci~nt rate: 109~ per anni~m.
b) 1-ear of depletion of fossil groundwater: 2000.
c; Future (2000) alternati~e production cost: 20 SR~m3. dl Present eatraction cost: 2 SR~m3.
If, within the 3bo~e framework, todac's extractors would set aside .3.31 SR~m3, an amount to be increased continuously as time passes, then future users in the year 2000 and beyond would be able to afford an aLternative resource to replace the fossi: groundwater, which by that time will have been depleted. The actua~ 1985 production "cost" would thus be 2 t 1.31 - 6.31 SR~m , which would gradually increase to 20 SR~m3 in the y-ear 2000. Production costs for the less de-manding irrigation uses are assumed to be about 30X lower. Lnit costs thus calculated are incorporated in Figure 2. ihese production costs act~.ially include other increasing cr,mponents, since droppinq water levels require increased pumping lifts, and increasing salinities require more treat-mer.t. Howe~er, those aspects have not yet been identified with adeq~late precision and they are not taken into consi-deration here.
-9-costs in any' pLanntng e~ercise, because it wiLl 3i~.e todzy''s
:ic c:srnn T-i(;~~rs :i 'r,ar tc~r ar, ~ mor? reai istic iinde,rst.anriing of
the trade-offs :nhe,~~nt .n c:~costng from among alternati~e de~elopment strategies.
6. A sc.enario assessment.
In more ht:mid climates major uncertain aeterminants in water planning are the stochastic parameters of precipitation and streamfloc., an~j man's deciaions are of secondar~' importance. ilowe~er, the ccater sector of Saudi arabia, dependinq almost exclusi~~aip on man-made extraction and production technolo-gy, lends itself con~eniently' to an exercise in decision-making.
In nrder to compare a few scenarios the Goal Programming IGF) algorithm is used. This technique is a multiobjective iinear programming approach, s:hich requires input data on resources (upper constraints on water a~'ailabilit~'), on uses (lower ccnstraints on water needs), on costs lunit. ~osts and n bud~etary~ constraint), and on priorities or preferences. The L.itter represent the decision-maker's concept of which constraints are the more important ones, and the composite of those priorities may be called a"policy" or a"strate-gy'" . The output of the GP model presents ~~alues for the de-cision ~ariabies, i.e. the allocations of the resources over the uses in order to satisfy to the highest extent possible t.he priorities specified by- the decision-maker. Each set of allocations represents a"scenario", corresponding to a ~r~en "policy".
For ~jeiailed discussions of the GP technique the interested reader is referred to the teztbooks by Lee [11] and Ignizio [IZJ, or to the numerous articles published in the Planning or Uperations Research literature. ~ description of the mo-de1 form~rlation used here w~as pro~~ided by de Jong and A1
Lay'la [ 13 ] .
~ base scenario a was formulated according to a policy- based on the fcllowing major priority components:
-.all projected demands need to be met.
-.all renewable water resources need to be used in fu11.
-.a11 water treatment~production facilities need to be used to capac i ty..
- waLer imporLation may, or may not, be initiated. - Cost is of secondary importance.
-.-~ny deficits are to be met from mining fossil groundwater.
ETirat- Tkc K~,~,Qdo.,.t .r pegion - ~ear (QBS OEHati05 OR USES ó. ~OTe9tlCllntl. consumption 9. MOrtlCUltuCal trtigation i0.aqr:cultural irri~ation -~ 9C: 500 QC: 2t~0o OC: ~j000 RC: ~00 RC: ZmtJ- qC: . 2v Om0
RESOUPCES ~ ~ I.I -(.S ~ l.l - I.5 I .l - 1.5
1.Fossil ground.ater ~
oc: 3soo i- 4,5 uc: 6 31 Jc: G.31 ~-: -r.zz
RC: p I- 1,2 x` ZDO z' ZOO z' t76So
2.Rene.able groundr.
-oC: lo~o (.j UC: 3 .0o JC: 2.0o U-: 1.Q1
RC: So - l.l x- p x: ~ x: QSO
3.Surface .ater
oc: Boo . t,5 uc: 2 ~o ;c: ~.o~ -. 1.91
RC: q00 I- I.I x-- p x- O Xg- q00
~.Sea-ater
OC: Soooo - ( 5 ~JC: 2 7 00 -C: 22 00 --. 22 4f
RC: QDO - 1.5 ~10- O X1!- ~ X''- L~00
~ 5. Nas.e.a'er
ac: lo.oo - ~. s uc: ( oo .C: 4.00 -... 2.41
-RC: (00 ~- 1.5 xl)- O xla' O X 5- l00
6.Lazs reduction
oC: 2eoo - I( uC: 4.ov JC- 2 0o U-: z.ql
RC` O - 3.( x16- O x17' O X19- O
l.[mported wa'.er
-OC: (moo 1. I UC: q.oo uC: 8.00 --~ 8.Q1
RC: O!- 3.1 x19' O x20- O X?l- O
11.Cos[. RC: t7 ~ 2.Í ~' ( ~t
K 85 A
1
Legend: CC - Ouality Constraint (in ppw) RC - Rate Canettaint (in 106 m3~year) UC - Unit Goat for production (in SR~s3)
x.i : Flor rate, the decision variables ( in 106 w3~yeir) ~ or -- priority for winiwizinq the deviational varisbles Tne RC for itew 11 is e:pressed !n 706 SR!year.
Oeviational variables: Xt Iq050 XY, -(4Q óls
-11-an~. non-zero dec-iational ~ariables "di". Fi3ure 2 is in facL
an input~output worksheet.
I'hree other scenartos were eeamined for the years 1990, 1995 an~~ 2000.
Scenario B stip;ilat.ed t.hat:
-.all deman~~s are reduced by- IOX, reflecting the
intro-duction uf a modest conser~ation pro3ram.
- l.ncon~-enti~~na1 resources, such as importation, are git.en more weight.
- The lower limits on the demands are relaxed.
Scenario C p;at more emphasis on cost, while stipulatinq a
30X reduction uf the ~~emands envisiged sub .a, as a result of
a stringent conser~~ation effort. However, no
underachie~-e-ment in supply- ts tolerated and the "technological"
re-suurces, such as wastewater, desalinated water and imported
war.er, are to be utili~ed in full, if necessary.
Scenario D reflects an attempt to return to a"water secure" strategy in 15 }~ears, by eliminating water mining altoge-ther. All other resources are fully utilized, including a
fairly high level of importation. The necessary tradeoff in this case is a further reduction of water use for
irriga-tion, of both the horticultural and agricultural types.
In terms of the decisíon variables the outputs re~-eal little of interest, but the important parameters are the deviation-al ..ariables representing the amounts of fossil groundwater to be mined ( dlt), and the total cost of the water sector ldll}). These parameters are plotted in Figures 3 and -1 for the fo~ir st.rategies ~3escribed exrlier.
7. Discussion.
al Groundwater mining.
The most basic yuestion of growing local concern is: How
lonq will the fossil groundwater last' Obviously, this
de-pends both on the volume in storage and on the rate of
ex-traction. In section 5 it was stipulated that 2000 would be
the year of depletion, which is in fact an outcome of
Stra-tegy A; different strategies will yield different depletion
patterns.
The proven magnitude of this storage is a matter beyond the scope of this paper. It invol~-es not only questions of hy-drogeology and hydrochemistry, but also of international water law, because water in the major fossil aquifers is
shared by se~~eral countries in the GCC region. Therefore,
the "storage" a~-ailable to any one of those countries is as much a physical fact as a matter of agreed-upon internation-al internation-allocation.
I ~~~s5 ~~g0 13?~ ?!lOQ
:n C
..-U
w O
3
;roundc:ater ..~ .... ,~n Lnd on a considerabie amount of
in-rernationai . . , .- icr:.
t,) l.ater sect.
T'he grand tota~ ~f 111 costs incurred to satisf}- the various
demands ma~- be -~~i1ed the "water sector cost". Theoreticallv this figure ~...,..iri be eyual to the sum of the b~rdgets of all
public and hr~:. ;te entities involved in suppl}-in3 water to
.arious ~.rs?r,. ';, rl-~e present c:onte~t it is more appropriate
to ~ ieu it ,,; , . ,,; a: inancial indicator of the impacts of
ilternati~r .. ; ~i,,gies on the eccnom}-. as such it serves a
useful func-~.,:~ r.~- clarif~-ing to the decision-maker the
mag-nitude of `he :,~~r~en on the economy associated with
satisf;-ing al l per~~~~ ~. ~a :;ater needs .
cl L'ni t costs.
The ~rnit costs ;'~r scenario .a are shown in Figure 2. For the 3 Fossil Grcur.~i~:aLer items those costs were based on a
de-pletion b}- the .-e.zr :: C00, as assumed in section á. The other
scenarios }-ieide,i dela}-ed depletions of the same storage volume, t,hus r~duc:ng the unit costs and hence the total water sector coscs.
r~l .agricc~ltrrrcil ~..~tc~r use.
It is ob~ions from the foreqoinq that the major threat to
the hingdom's ~..3!.er security comes from the rapid increase
in the use o:~ non-rerzewable water for agricultural
irriga-t.ion. This po:~c~: i~ pro~.iding short-term and partial "food securit~-" in e~.,-hange for lonq-term "water securit}-". The GP technique a11o~.s .`or a rapid testing of the trade-offs
be-Lween those two securities by modifying various priorities.
el Conser~ation.
Strategies ai~re~i at " water security" are of necessity predi-cated en the s~rccesful implementation of conservation. It may be desirable to set different target levels for
conser-~~ation, such ~~s a mandatory 15X reduction and an advisable
15K. The GP model is easily adapted to treat such levels
with different priorities.
fJ Interaction.
The Goal Programming technique is based on the assumption
that the user (the Decision-Maker) has selected his
priori-ties in ad~-ance. In practice, however, the consequences of
~~arious combinations of priorities and strategies may prompt the user to test sli3htly different alternative approaches. To this end it is useful to test a range of strategies by
-15-;ey~iPnce of re-rans approaches a trul}- .nteracti~e mo~jelling
i~~i ri~ 1 tie~. .
Postscript.
ïn the absence of ~~omprehensi~e and reLiabie ~iata a s~~enario assessment of' the t~pe described herein reyuires of neces-sit;- the íntroduction of Fersonal judgements to fi11 many-;aps e;ith ~srimates. Prcfessionals in-:ol~-ed uith strategic plaiuling for Saudi ~rabia's water si:pp:y~ may- wish 'o ~~tilize Li~e sam~ approach, whi:e su:-;stituting 'he:r oc;n j;idgement and better ~iata.
i'he GP model runs were performed on an IBH ?ticrocomputer, using the (modifiedl FORTR~~ program liated in reference [11J. The authors are prepared, on request, to make avail-able to interested readers the necessar~- softw-are and a brief manual Mith annotated sample inputs and outputs at the cost of' reproduction.
Acknowledgement
~todelling w-ork for this study utilized the facilities of the I:ing Fahd C~ni~ersity- of Petroleum and Minerals, Dhahran, Sa~:di arabia, and the stipport of Research Project h.aCST .aR-6-1:3-7; these resources are gratefully acknoc:ledged.
REFERENCES
[11 Economic and Social Commission for w~estern .asia, "Demo-graphic and related socio-economic data sheets", Report
l:~ESC~'.a~SDP~8S~16, Vo.~, Baghdad, 1985.
(::J E.S.C.k.,~., "Statistical abstract of tne region of the
Economic ind Social ~'ommiasion for tvestern . asia, i9i5-1981", tiinth Issue, Baghdad, 1986.
[3j Ninistr}- of Planning, "Fourth De~~elopment Plsn,
1985-199'J", Riyadh, 198~.
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Sur~~ey-s for agricultural De~.elopment in Saudi Arabia",
-16-,-; ~tinistr}- of .~~r:culr-are and kater, "annual Bulletin of ;irrent ;gricult~:rai Stat.isti~s" Dept. of Econ.omic Studies .-rnd ~t:3tistics, Rr}aah, ~~arious issues.
(Rj al-Zeid :~..a. et al., "Guide for Crop Irrigation
Require-ments in the fiingdom of 5audi arabia", F.~.U.~Ministry- of ~~ri~.ulture :rn~i wa[er, Rt}-adh, 1988.
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IN i98~ REEDS VERSCHENEN
242 Cerard van den Berg
Nonstationarity in job search theory 243 Annie Cuyt, Brigitte Verdonk
Block-tridiagonal linear systems and branched continued fractions
244 J.C. de Vos, W. Vervaat
Local Times of Bernoulli Walk
245 Arie Kapteyn, Peter Kooreman, Rob Willemse Some methodological issues in the implementation of subjective poverty definitions
246 J.P.C. Kleijnen, J. Kriens, M.C.H.M. Lafleur, J.H.F. Pardoel
Sampling for Quality Inspection and Correction: AOQL Performance
Criteria
24~ D.B.J. Schouten
Algemene theorie van de internationale conjuncturele en strukturele afhankelijkheden
248 F.C. Bussemaker, W.H. Haemers, J.J. Seidel, E. Spence
On (v,k,~) graphs and designs with trivial sutomorphism group 249 Peter M. Kort
The Znfluence of a Stochastic Environment on the Firm's Optimal Dyna-mic Investment Policy
250 R.H.J.M. Gradus Preliminary version
The reaction of the firm on governmental policy: a game-theoretical approach
251 J.G. de Gooijer, R.M.J. Heuts
Higher order moments of bilinear time series processes with symmetri-cally distributed errors
252 P.H. Stevers, P.A.M. Versteijne Evaluatie van marketing-activiteiten
253 H.P.A. Mulders, A.J. van Reeken
DATAAL - een hulpmiddel voor onderhoud van gegevensverzamelingen 25~1 P. Kooreman, A. Kapteyn
On the identifiability of household production functions with joint products: A comment
255 B. van Riel
Was er een profit-squeeze in de Nederlandse industrie?
256 R.P. Gilles
Economies with coalitional structures and core-like equilibrium
11
257 P.H.M. Ruys, G. van der Laan
Computation of an industrial equilibrium 258 W.}{. Haemcrs, A.E. Brouwer
Association schemes 259 G.J.M. van den Boom
Some modifications and applications of Rubinstein's perfect equili-brium model of bargaining
2G0 A.W.A. Boot, A.V. Thakor, G.F. Udell
Competition, Risk Neutrality and Loan Commitments 261 A.W.A. Boot, A.V. Thakor, G.F. Udell
Collateral and Borrower Risk 262 A. Kapteyn, I. Woittiez
Preference Interdependence and Habit Formation in Family Labor Supply 263 B. Bettonvil
A formal description of discrete event dynamic systems including perturbation analysis
264 Sylvester C.W. Eijffinger
A monthly model for the monetary policy in the Netherlands 265 F. van der Ploeg, A.J. de Zeeuw
Conflict over arms accumulation in market and command economies 266 F. van der Ploeg, A.J. de Zeeuw
Perfect equilibrium in a model of competitive arms accumulation 267 Aart de Zeeuw
Inflation and reputation: comment 268 A.J. de Zeeuw, F. van der Ploeg
Difference games and policy evaluation: a conceptual framework 269 Frederick van der Ploeg
Rationing in open economy and dynamic macroeconomics: a survey
270 G. van der Laan and A.J.J. Talman
Computing economic equilibria by variable dimension algorithms: state of the art
271 C.A.J.M. Dirven and A.J.J. Talman
A simplicial algorithm for finding equilibria i n economies with
linear production technologies
272 Th.E. Nijman and F.C. Palm
Consistent estimation of regression models with incompletely observed
exogenous variables
273 Th.E. Nijman and F.C. Palm
111
2~4 Raymond H.J.M. Gradus
The net present value of governmental policy: a possible way to find the Stackelberg solutions
2~5 Jack P.C. Kleijnen
A DSS for production planning: a case study including simulation and optimization
276 A.M.1~. Gerards
A short proof of Tutte's characterization of totally unimodular matrices
2~7 Th. van de Klundert and F. van der Ploeg
Wage rigidity and capital mobility in an optimizing model of a small open economy
278 Peter M. Kort
The net present value in dynamic models of the firm 2~9 Th. van de Klundert
A Macroeconomic Two-Country Model with Price-Discriminating
Monopo-lists
280 Arnoud Boot and Anjan V. Thakor
Dynamic equilibrium in a competitive credit market: intertemporal contracting as insurance against rationing
281 Arnoud Boot and Anjan V. Thakor
Appendix: "Dynamic equilibrium in a competitive credit market:
intertemporal contracting as insurance against rationing 282 Arnoud Boot, Anjan V. Thakor and Gregory F. Udell
Credible commitments, contract enforcement problems and banks:
intermediation as credibility assurance 283 Eduard Ponds
Wage barga~-ning and business cycles a Goodwin-Nash model 284 Prof.Dr. hab. Stefan Mynarski
The mechanism of restoring equilibrium and stability in polish market
285 P. Meulendijks
An exercise in welfare economics (II)
286 S. Jalrgensen, P.M. Kort, G.J.C.Th. van Schijndel
Optímal investment, financing and dividends: a Stackelberg differen-tial game
287 E. Nijssen, W. Reijnders
Privatisering en commercialisering; een oriëntatie ten aanzien van verzelfstandiging
288 C.B. Mulder
iV 289 M.H.C. Paardekooper
A Quadratically convergent parallel Jacobi process for almost diago-nal matrices with distinct eigenvalues
290 Pieter H.M. Ruys
Industries with private and public enterprises
291 J.J.A. Moors ~ J.C. van Houwelingen
Estimation of linear models with inequality restrictions 292 Arthur van Soest, Peter Kooreman
Vakantiebestemming en -bestedingen
293 Rob Alessie, Raymond Gradus, Bertrand Melenberg
The problem of not observing small expenditures in a consumer expenditure survey
294 F. Boekema, L. Oerlemans, A.J. Hendriks
Kansrijkheid en economische potentie: Top-down en bottom-up analyses
295 Rob Alessie, Bertrand Melenberg, Guglielmo Weber
Consumption, Leisure and Earnings-Related Liquidity Constraints: A Note
296 Arthur van Soest, Peter Kooreman
V IN 1988 REEDS VERSCHENEN
297 Bert Bettonvil
Factor screening by sequential bifurcation 298 Robert P. Gilles
On perfect competition in an economy with a coalitional structure 299 Willem Selen, Ruud M. Heuts
Capacitated Lot-Size Production Planning in Process Industry 300 J. Kriens, J.Th. van Lieshout
Notes on the Markowitz portfolio selection method 301 Bert Bettonvil, Jack P.C. Kleijnen
Measurement scales and resolution IV designs: a note
302 Theo Nijman, Marno Verbeek
Estimation of time dependent parameters in lineair models using cross sections, panels or both
303 Raymond H.J.M. Gradus
A differential game between government and firms: a non-cooperative
approach
304 Leo W.G. Strijbosch, Ronald J.M.M. Does
Comparison of bias-reducing methods for estimating the parameter in dilution series
305 Drs. W.J. Reijnders, Drs. W.F. Verstappen
Strategische bespiegelingen betreffende het Nederlandse kwaliteits-concept
306 J.P.C. Kleijnen, J. Kriens, H. Timmermans and H. Van den Wildenberg Regression sampling in statistical auditing
307 Isolde Woittiez, Arie Kapteyn
A Model of Job Choice, Labour Supply and Wages
308 Jack P.C. Kleijnen
Simulation and optimization in production planning: A case study 309 Robert P. Gilles and Pieter H.M. Ruys
Relational constraints in coalition formation 310 Drs. H. Leo Theuns
Determinanten van de vraag naar vakantiereizen: een verkenning van
materi~le en immateriële factoren 311 Peter M. Kort
Dynamic Firm Behaviour within an Uncertain Environment
312 J.P.C. Blanc
V1
313 Drs. N.J. de Beer, Drs. A.M. van Nunen, Drs. M.O. Nijkamp
Does Morkmon Matter? 314 Th. van de Klundert
Wage differentials and employment in a two-sector model with a dual labour market
315 Aart de Zeeuw, Fons Groot, Cees Withagen On Credible Optimal Tax Rate Policies 316 Christian B. Mulder
Wage moderating effects of corporatism
Decentralized versus centralized wage setting in a union, firm, government context
31~ Jbrg Glombowski, Michael Kruger
A short-period Goodwin growth cycle
318 Theo Nijman, Marno Verbeek, Arthur van Soest
The optimal design of rotating panels in a simple analysis of variance model
319 Drs. S.V. Hannema, Drs. P.A.M. Versteijne
De toepassing en toekomst van public private partnership's bij de grote en middelgrote Nederlandse gemeenten
320 Th. van de Klundert
Wage Rigidity, Capital Accumulation and Unemployment in a Small Open Economy
321 M.H.C. Paardekooper
An upper and a lower bound for the distance of a manifold to a nearby point
322 Th. ten Raa, F. van der Ploeg
A statistical approach to the problem of negatives i n input-output analysis
323 P. Kooreman
Household Labor Force Participation as a Cooperative Game; an Empiri-cal Model
324 A.B.T.M. van Schaik
Persistent Unemployment and Long Run Growth 325 Dr. F.W.M. Boekema, Drs. L.A.G. Oerlemans
De lokale produktiestructuur doorgelicht.
Bedrijfstakverkenningen ten behoeve van regionaal-economisch onder-zoek
326 J.P.C. Kleijnen, J. Kriens, M.C.H.M. Lafleur, J.H.F. Pardoel
Sampling for quality inspection and correction: AOQL performance
Vii 327 Theo E. Nijman, Mark F.J. Steel
Exclusion restrictions in instrumental variables equations
328 B.B. van der Genugten
Estimation in linear regression under the presence of
heteroskedas-ticity of a completely unknown form 329 Raymond H.J.M. Gradus
The employment policy of government: to create jobs or to let them
create?
330 Hsns Kremers, Dolf Talman
Solving the nonlinear complementarity problem with lower and upper bounds
331 Antoon van den Elzen
Interpretation and generalization of the Lemke-Howson algorithm 332 Jack P.C. Kleijnen
Analyzing simulation experiments with common random numbers, part II: Rao's approach
333 Jacek Osiewalski
Posterior and Predictive Densities for Nonlinear Regression. A Partly Linear Model Case
334 A.H. van den Elzen, A.J.J. Talman
A procedure for finding Nash equilibria in bi-matrix games 335 Arthur van Soest
Minimum wage rates and unemployment in The Netherlands
336 Arthur van Soest, Peter Kooreman, Arie Kapteyn
Coherent specification of demand systems with corner solutions and endogenous regimes
337 Dr. F.W.M. Boekema, Drs. L.A.C. Oerlemans
De lokale produktiestruktuur doorgelicht II. Bedrijfstakverkenningen ten behoeve van regionaal-economisch onderzoek. De zeescheepsnieuw-bouwindustrie
338 Gerard J. van den Berg
Search behaviour, transitions to nonparticipation and the duration of unemployment
339 ~~.J.H. Groenendaal and J.W.A. Vingerhoets The new cocoa-agreement analysed
340 Drs. F.G. van den Heuvel, Drs. M.P.H. de Vor
Kwantificering van ombuigen en bezuinigen op collectieve uitgaven 1977-1990
341 Fieter J.F.G. Meulendijks
viii
342 W.J. Selen and R.M. Heuts
A modified priority index for Gunther's lot-sizing heuristic under
capacitated single stage production
343 Linda J. Mittermaier, Willem J. Selen, Jeri B. Waggoner, Wallace R. Wood
