La contabilidad ambiental como instrumento para el desarrollo sostenible

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(1)% ( ,36'/'/. LA CONTABILIDAD ANBIÉNTAL COMO INSTRUMENTO PARA EL DESARROLLO SOSTENIBLE Por: Camilo Montoya. 7. En este documento se presenta una síntesis de algunos aspectos centrales sobre contabilidad ambiental. Entre ellos, una breve • reseña histórica de la gestación de la idea, las diferentes aproximaciones que existen sobre el tema, la explicación del programa de Contabilidad Ambiental aplicado al caso colombiano y, los objetivos finales que se obtendrían de su implementación. 1. PRESENTACION. El surgimiento del Comité Interinstitucional de Cuentas Ambientales para Colombia -CICA-, hace ya dos años, debe explicarse a la luz de algunos hechos que son presentados a continuación: - La formulación, por primera vez, de una política ambiental para Colombia, parte integral del Plan de Desarrollo "La Revolución Pacífica", la cual consignó explícitamente la necesidad de cuantificar el Patrimonio Natural del país. - El contenido de la nueva constitución política colombiana, que asigna al Estado la obligación de preservar las riquezas naturales de la nación, y específicamente ordena a la Contraloría General de la República, ejercer el control fiscal, que entre otros criterios debe considerar la valoración de los costos ambientales.. •. - El reconocimiento internacional a la problemática ambiental, especialmente motivada por la cumbre de Brasil 92, y el papel que la Agenda 21 le dá a la Contabilidad Ambiental como importante instrumento para la construcción del desarrollo sostenible. La Universidad Nacional de Colombia a través del Centro de Investigaciones para el Desarrollo -CID- tiene a su cargo la secretaría técnica del Comité Interinstitucional para las Cuentas Ambientales en Colombia. El ponente fue miembro fundador del CICA y en la actualidad coordina los estudios sobre Patrimonio Natural Regional. 171.

(2) - El dinámico proceso, que recientemente terminó con la of icialización por parte de Naciones Unidas de una propuesta para elaborar las Cuentas Económicas-Ambientales, como parte de la revisión 4 propuesta para modificar la estructura vigente del sistema de cuentas nacionales. En el contexto anterior, son convocadas varias entidades del estado, para adelantar un proceso interinstitucional cuyos principáles objetivos son los siguientes: - Desarrollar una propuesta metodológica para la elaboración de las cuentas ambientales y la valoración de los más importantes recursos naturales, considerando sus principales funciones ecos istéinicas. -. Definir las alternativas para articular las cuentas ambientales al actual sistema de cuentas nacionales. Contribuir a la obtención de los recursos técnicos y financieros necesarios para realizar los diferentes proyectos o estudios básicos que a juicio del CICA se consideren pertinentes. Promover un amplio consenso interinstitucional en torno al diséfio e implementación de las cuentas ambientales.. 2. LAS DIFERENTES APROXIMACIONES A LA CONTABILIDAD AMBIENTAL Los enfoques existentes sobre Contabilidad Ambiental plantean algunos problemas comunes, los cuales son tratados de distinta manera, o bien, se presentan con diferentes énfasis en el conjunto del sistema que se proponga. Algunos de ellos son: - La importancia que se otorgue a la estructuración de las cuentas físicas como expresión del balance de los recursos naturales y de los ecosistemas. - La priorización que se dé a la valoración económica de las existencias (stocks) y/o de los usos (flujos) de los recursos naturales, como producto de la transformación económica del patrimonio natural. La forma específica como se entiendan los llamados costos ambientales, asociados en algunos casos a los costos de depreciación y degradación del capital natural y en otros, a los gastos defensivos privados y públicos para el medio ambiente.. 172. e.

(3) a El grado de articulación propuesta entre la Contabilidad Ambiental y el Sistema de Cuentas Nacionales, a través de diferentes modalidades que van desde la aceptación total del "marco central" del sitema propuesto por Naciones Unidas, hasta postular la necesidad de un nuevo "marco central". - Evidentemente, la discusión sobre los métodos de valoración y los procesos a utilizar para valorar stocks, flujos y costos ambientales complementan el conjunto de propuestas que diferencian las propuestas. No obstante lo anterior, no existen límites muy marcados entre las • diferentes propuestas, por el contrario predominan los matices en la estructuración de los sistemas de contabilidad ambiental y la más frecuente; es la combinación de las líneas temáticas descritas anteriormente. 3. LOS PROPOSITOS CENTRALES DE UN SISTEMA DE CONTABILIDAD AMBIENTAL 3.1. Conocer los costos ambientales resultantes de las diferentes modalidades de manejo que se implementen para aprovechar los recursos naturales y la oferta ecosistémica. 3.2. Generar nuevos indicadores del desarrollo, que tengan en cuenta la depreciación y degradación del patrimonio natural. Este propósito se logrará mediante la incorporación de la contabilidad ambiental al sistema de Cuentas Nacionales (SCN). 3.3. Servir de instrumento al Ordenamiento Territorial y posibilitar, mediante ejercicios de simulación, conocer los costos y beneficios económicos, ecológicos y sociales de la política de gestión ambiental. 3.4. Fortalecer el Sistema de Información Ambiental que sirva a los planificadores y abs diseñadores de política para tomar decisiones y orientar el aprovechamiento de los recursos naturales hacia el desarrollo sostenible. 3.5. Orientar la investigación sobre la oferta natural, privilegiando el manejo integral de los recursos para el mejoramiento de la calidad de vida de los pobladores.. e. 173.

(4) 4.. EL PROGRAMA DE CONTABILIDAD AMBIENTAL PARA COLOMBIACon el nombre de "Plan Básico", se ha presentado un documento elaborado por el CICA (Comité Interinstitucional de Cuentas Ambientales) como primera aproximación a lo que constituirá, en un futuro, un Programa de Contabilidad Ambiental para Colombia. Este documento esta -concebido fundamentalmente como un instrumento de negociación para la Cooperación Técnica Internacional y ha tenido en cuenta para su estructuración, las diferentes experiencias internacionales en Contabilidad Ambiental y las particulares condiciones técnicas, financieras e institucionales de nuestro país para el montaje de un Sistema de Contabilidad Ambiental. El Plan está integrado por cuatro líneas principales: 4.1- Bases Conceptuales y Metodológicas dé las Cuentas del Medio Ambiente. Mediante un marco general, se busca integrar en forma consistente las diferentes líneas o componentes del sistema. Es conocido ampliamente, que no existe aún, un sistema universalmente aceptado para la estructuración y elaboración de las Cuentas Ambientales, por ello, es preciso unificar criterios que permitan mediante un- marco metodológico común, hacer converger los diferentes esfuerzos teóricos y prácticos. Cobra mayor importancia esta actividad, si se tiene. en cuenta que el sistema que se piensa implementar, ha sido pensado comosistema descentralizado- que contará con sus desarrollos regionales. En principio, dos de los resultados esperados en el corto plazo son: un sistema clasificatorio del patriomonio natural o del medio ambiente y una opción metodológica para incorporar las Cuentas Ambientales al Sistema de Contabilidad Nacional (SCN). 4.2. Identificación y seguimiento de los Recursos Naturales y los Ecosistemas Mediante Imágenes de Satélite.. e. Dentro de sus actividades más importantes se encuentran: - Reconocimiento e inventario de la información cartográfica y de satélite disponible en las diferentes instituciones nacionales y regionales. - Diagnóstico de la capacidad técnica y humana para la estructuración y coordinación de un- sistema a nivel regional y nacional. e 174.

(5) -. Elaboración de un proyecto con factibilidad económica y técnica, para ser presentado al Fondo Nacional del Ambiente.. 4.3. Análisis y Reclasificación del Gasto Ambiental En este proyecto confluyen los interéses de dos instituciones participantes en el CICA. El DANE que busca, con una orientación funcional del gasto, hacer un análisis sectorial del mismo, iniciando por la reclasificación y análisis del gasto de las empresas industriales, en lo concerniente a las actividades de protección del medio ambiente y la CONTRALORIA GENERAL, cuya función de Control Fiscal Ex-Post, las obliga a diseñar una metodología para la recolección, agregación y presentación de datos consolidados sobre gastos de inversión en programas y proyectos ambientales de entidades del sector público y en algunos casos, del sector privado. 4.4. Las Cuentas de Patrimonio Natural Regional y Nacional.. En principio, las cuentas de Patrimonio Natural Regional buscan desarrollar metodologías para la valoración de los recursos y los ecosistémas y buscar la manera de articular dichas cuentas con los sistemas de Información Territorial y las Cuentas Económicas Regionales. Es la forma específica de descentralizar el desarrollo del Plan Básico dotando a los técnicos regionales, especialmente a los pertenecientes a las Corporaciones Regionales, de nuevos instrumentos para orientar los procesos de ordenamiento territorial y el desarrollo sostenible. Las Cuentas de Patrimonio Regional son instrumentos concretos que permiten en el corto plazo evitar un mayor deterioro de la base natural y ofrecer a múltiples entidades un mayor conocimiento del patrimonio con que cuenta cada región. Este proceso se ha iniciado con los estudios de la Cuenca Alta del Río Negro en CORNARE, el antiguo DELTA del Sinú con C.V.S,. y la Cuenca del Río Guamués con CORPONARIÑO.. 175.

(6) THE ROLE ODECISiON SUPPOflT SYSTS IN RAI1ONAL WATER REGOURCES PLANNING AND MANAGEMENT: A CASE STUDY IN SPAIN JOAQUÍN ANDREU and JOSÉ CAPILLA Departamento de ingeniería Hidráulica y Medio Ambiente Universidad Politécnica do Valencia Apartado 22012 D 46 8O-Va$enda D Spain ASTRACT: Rabanal water use Implies efflcient, integral and eustainabis management of the resource. lbs systems and the solutions to alleviate their problema wW be more and mora compiex evevyday. Therefore, technoioglcally advenced tools will haya to be usad In order to anatyzs the systems In an Intagrated fashion and to address clasaical uncertainties relatad elthar lo uses, demands, or resources, as wail as new fssues as for instance climatic chango impacta. The existing gap betwean water rasources systems analysts or modelera end the real world practitioners has to be narrowed dom. The feasibility and reality of this transition PFOCOSS la demonstrated In the paper by descrlbing two decision support systems (05$) af difforent acabe levela that ha yo been Impiementad in thu Segura Basin Water Agency, in Spain, and which are currently beon usad to anawer questiona addressed to make a rational use of the rasource. Flrst, a regional DSS comprlsing the wtoIe basin and inciuding optimization and almulation modules Is presented. Afterwards, a 05$ for single aqullers embeddad into the geographical information system of the agency is described. The su000ssful appllcatlon of thase tools in a rather cornplax water resources system as the Segura Basin, has also an effect of promoting ile use In ather agencies, confirmlng that, undar sorne conditiona, etato of the art tools are weH accepted and usad. INTRODUCflON As in the rest of the world, Ihe comptexity of water relatad problema le increasing evéry day. In Spáin. Aleo, the compbexfty of tha solutlons raquirad lo solva these problema la lncroa8in9.. Moat of the easiest struçjraj s0kltinn5 haya boan already cé,led out. Tha uses of water, as weu as the objectives to fuif fil are multipie. The national renewable resources can be estimatod In the order of 114 km 3 whfte the total use of water amounts to 37 km 3 (M.O.P.T., 1993). Currentty, new structural proects are objected by sorne sectora of the publio, and interbasin transfers are facing social opposftion. Under these circumetances, and before carrying out new structurat dov&opmenis and transfera, it le of cruclaj impoftanoe to be sure that ratlonal use of the existing systemshasla boing performecj. An efficlant, lntegrated and sustainable devebopment of water rasources to prevali ovar the easy way of pouring down more concrete Into Ihe baeins. Thia does not mean that f, after applylng these cnterl*, sorne structurai SOtUtøn huw up as neoessary, thoy shoutd not be implementad. In order to SuccGssfuliy analyze tha planning and manag ement of complex systems it ja esaentiJ that the most advanced as possible tools be used, In Spain, as In any ather country In th world, there ls an unavoldeble gap betwaen the state of the art of water rssouroes 176.

(7) systems analysie and modelhng and the uses of practltloners at tha real world laval. Nevartheiess, aven thought It 19 Imposslble to closa complotaty thls gap it scientific arid technological development does not stop, It is our bailaf that In our country and many Other places (Loucks, 1992) it can be narrowed down very much In the near futura. Thia beef la basad on oria sida on (he fact that thare are many Improvements In (he world of cornputers that make It posaible to develop decielon support systems (DSS) that are very much usar frlendly ¡han eva, before. This Includg s among othere: -Graphical capabilities ard srnproved computational apeed. central memory capacities, as well as data storage devices at ralatively 10w costs. -Better aM more powarrul basic commerclsl software, as br lnstance, compllers, geograffilcal informatlon systems (GIS), expert systems shaile, etc. On the other side, the new generatons of technlclans and deciston makers worklrtg in (he institutions relatad to water problema ha yo had sorne degree of computar sclance ¡ri thelr education. So, thay aro not roluctant to accept the help that can be providad by a computar basad decision support ay stem, and (hay alzo know the Ilmitatioris of computers. In order to demonstrate that (he shortenlng of (he gap can be achievad, two applfcations In (he Segura Alvar Basin are presentad next, in which state & (he art tools are u$ad arid Implemented br a more rational use of water resources. THE SEGURA BASIN WATER RESOURCES SYSTEM The Segura Alvar basln la located In South seat Spain and la approxlmately 18,630 km 2 j ares, The climate la semiarid. Water 1-9 usad mainly for supply to irrigatad lande (currently about 260, 000 ha demandlng 1,850 hm/year) aM to niuniipalitIes and lnd hm3/yaar). Besldes, hy uatrlø (about 211 droelactrc power la produced aM llood control Isa conce m basin. 'Fha system compijssa In thekwer a surfac subsyatom, a subsurface subaystem and three maln cOnVay ance and distribution Subsytøni. Also a water transfer from (he Tagus Alvar about 250 hin away) exista. ibera are In (ha systeñi 14 si.srfaoe reservojrs: 11 In (he Segura Rivor and tributarias, 2 in a water d1strIbuon subsystem, and 1 In (he Tagus River st tha haads of the interbasin transfer. Also, 19 aqulfer unita exlst, 10 of thom hydrauticaliy connected (o (he surface s~. iba vary irregular renewabga resourc from (he basln grour water) plus Importad res (~ 1,000 hm3fyear, Inoluding g ura (about 200 hmn/year) hay curren water d a been far exceeded by emands. Therefore, (he thaoretjcaf deficjt (bout 5 30hm3/year), which la fuDy allocated (o irr1gaton, transiates hito un and aquifar overexpojtafj derirrigation high degree of water reuse, Iow re Fi abilIty, Four aqulfor unuts ha y been officlaIly d eclarad as arid emergency plana are undergoing. Ononal top usara of this, (hero is a compiax water rights Systeni in fha basiri in which prioritje of tradftj prevaJ ovar (he more recent deveIopme, In a water resourcas environment like thls one, characterizad by (he complexlty of b physi by acarclty of resuurcas aM ca SM social aspects, i ncludlng a strong relationshjp ground and surface waters, between (ha onty way to evaluate. SM devIse pIsáis and managen strategies (o soive (he exletlr,g problema le by mesáis of (he use of mathematjj modeHing, (nciuding op tIm j tjon and simutafion modele. In Vio remainlng of (he paper, two DSS Currenfly worklng in fha Basin Agency are presentad, Firat, a DSS model animujatian d a s Segura InCludIrig en optimlzaflon fha managament of (he whole basín inckpig (he mnocJals fo, of wo o v la dascribad. Next, a DSS erexpialtad aqwf Iinkad to (he generalGIS of tho agancy la commnanted. 177.

(8) e. AQUATOOL: A GNEAUZD DECISION SUPPORT SYSTEM FOR WATER. RESOURCE. AQUATOOL is a 05$ wtich Includes baslc&ly a basin optimization module, a basín simulation module arid an aquifer modelling module. The system le not $peclflc for a given basln, It le rather Intended for generaflzg d usa as it aflows by means of graphic deslgn and Input data the representatlon of different water rasources systam configurationa. The appucation to the Segura rhmr basin demonstrates the capabuftles of tha package. AQUATOOL le currentty implemented en computers of Ihe type IBM. PC compatible. The control unft le the Microsoft Windows Environment, with a first leve¡ ¡cona menu lncludlng three optiona: - OPTiGEs Thle geta fha usar into the optsmizaUn module. SIMGES. This geta fha usar Into fha eimulaton módulo. AQUIVAL.- ibis geta he user into fha aquifor p reprocessfng and simulation. module.. Thls 055 le .used in the Segura Basln Water Agancy to do, among other thlngs, fha foUowing: (1) Input and modify if necessasy 1 In a graphical way, fha conflgurafton of a water rescurces systam echeme either for optlmization purposes (OPTIGES module) or for sirnulation p urposes (SIMGES module). Thia includes fha PoaSibiIfty of gettlng a hard copy of the deslgn. (II) Input and manage date bases containing fha physicaj charactarisjç 5 of the componente of the schemes as w&I as (he management charact g rjstjos (iii) Input asid manago, fha spatlaj deflnftjon of en aquifar and date base contalnlng its hydrodynan,i parainef as walt as the daflnftlen of sireases (e.g. pumping, non point recharge, etc...) end control variables (a,g. In given volumes undar gtven zona., etc..,),heads poInts (lv) Perform an optimlzat g on of (he management for a given alter time hor1z,, using different hydrologicaj data. nativo and a gíven (y) Perform a simulation of the managem horizon using 1fa'ent a given alternativa and a given time hydrological date asidbraleo different operafing poflcles, (vi) Pern rror aof PreProcessg ir of a dlstibu r a component the aboy aquifer mod& in order to be Included as e simulation module. ft also aliows a separata slmuietion of (he aquifar, as MY grounaf modal. (vil) Obtajn fha wrftten report 1 resulte of fha optimizatjon and simutaflon modules fu fha form of a values and raliebility eliher indicato,s. detailJ br tha whole time horjzo os' summerjzed as mean Vi (. ¡¡) Obtajn (ha reeults of (he opt imizat,on and sImuIato In (he graphJ and mean values graphj . forrn of time serles (b) Obtain fha resulte of fha op timizaflon asid simulation etored in filas usad as input data that can be br any kind of 8peciflc Po AOUATOOL roceaslng not lflclue in Thes e capablitjes have ShO,i lo be useful In order fo: a) $oreefl design aftemafjves by meaj of fha optimj tjon module. altarnaj by meana of fha opti uja froi (he analy of (he mlzatlen module obtalnlng. b) Screon manag oPerating crftg. apVmal e) Check and refine *m 8creer aftarnat8 by resulta. d) Perfor, ee moar q of fha sl rssltJ y analys by co mulaflan moduj0. or fu (he oParatfng ruie, mpeing (he resu afta, changea in fha design e) hydrPerfomi riak anafysf5 by s1mufatj and/or optimlzlng uslng clifferant yntheflc oiogicai time serles. (Le. Monta...rio anaJysis). 178.

(9) f) Use the mad, once an atematIve la Implornented, as an ad In ihe operWJori cf he water resources system (off-in), mainly br water aliocatlon among conilleting demand& and to study Impacta of changas In the sytem. AIac, tha use of the DSS has contributed to gahi undarstanding about the system tssf he physical, and management aspect. In wht toliows, OPT1GES (optimization), ani. SMGES (smulation) modules aro presentad. AQUI VAL, Ihe module br acuer preprocesslng kflC simuletion has boen croatod in order to Include a dietributed model of en aqulfer In MGES module uslng the elgenvalues approach. Iba efticlsncy of the approach does not rndor cumbersome the simutation of the aqulfar In fha basin mod&, whlle ft malnteins fhe. dsrae of eccuracy given by finte dfferancos of flnfte elemento modele. Tbe efficfency le due 1,9 the possbiftty of preprocesslng performed byQUlVAL.1..e appro&ii le 'wem (Andreu atdShuquIfto, 1987), and the module wffl not be dasc1bed hero fo ot clerty of the papar. ©PTC: THE MODULE FOP WATER JESOURCES SYSTEMS OPTM2ATIO1. Iba Interface ailows br fha graphlc definition and/or edftlng of tha echeme of a water resourcas system, as well as br the managament of fha data basao relatad to each type of elemant avallable. Schemes can be dafined by meana of five typos of olement: - Piados wfthout *tarugo capaclty.- ThIs aHows fha usar lo include. rlver juncfon,. points where a hydrologlcaf inflow occure, diversion pointe, end tntaka pointa. - Plodee wlth storaga capacfty.- These are br reaervolrs. The usar must give fha. useful reselvoir capacky for different manths= wfthin the year. Also a prlority fr storage can be defined, Charino.... This allows fha usar lo include natural channela (le. river reaches),. as well a$ canals and ditohes end interbasin transfars. Maximum monthty fiows can b definad as well as a minimum monthly fiow Algo--&- prioriy can be defined for. minimum flows. Domanda..- The user must define the monthiy darnand and a prkrtty for aech damand. Hydrofc Inflows, They reflect inflow frito fha system corresponding te a aUbbasin batweon fha nodo wfisre applied and fha nodo corrospondlng. Lo fha next upstream hydr ologlc iriflow. Ibe usar must give a name of a file containlng fha hydrolog lcal data bar each hydrologlc lnflow. The usar has availabla a larga alza 'work papera of whlch shefto gete awl reen, ndofl w' on t o 'Iba window can moya over the papar. y salecting en element arnong the aboye nOntíoned five types from fha rnanu, fha usar can stamp' Itany wheroln fha papar, Once fhe alement la 8tamped fha usar procoeda to input fhe Whn thls la dono It switches again to fha data of fha alemant Int a date bese.. g raphjc detlnttlon of fha achema. Ibo usar can aleo yo or delate an already aLampad element as weø asfoedft 09data. lbs sehama can be saved and late, retrieved. It si so can be printed or pIottd fitting V510 PiCture Into either an A4 or A3 alza papar, coiec frorn fha rnonu option to mo. Once fha sicheme la dafined, togethar with fha Iength of time. fo be Optim izad, fha usar has #10 000n fo p rocead to fha optjrnjzlon proceas Iba Gt a weighte sum of óbjéctjve fucfln la the nimization fha doiicfts of demande and prlorftjas doclarod by fha minimum flow. Ib. w&ghts reffect ,j,6 use,. OPTIGES Produces written reporte about input date, detaifa of Ñ optimai values of and a aummary of (ha optlmjzato, lflcludlng mean values and performcnce critarfa, Otonaiy aH or come of thoe 'aporta can be obtained. Aleo, fijos are produ, which 179. 9.

(10) contain the results of thaoptimization, in order to be avaliable for speclfic applications not provided In AOUATOOL. Finafly, the resulte can be immedlatety di€played on the screen in a graphlcai way. Representatlon of the results for each elemont of the seheme, either in the form of a time series of values, or in the form of mean monthly values, can be obtainod. Theso graphlcs are of much heip whon anayzing the solutions in order te cope with tho enormaus amount of numerical resulte and in order te devtse operatlflg rulos thaI can be axtracted from tha optimal behaviour. Hard copies of thase graphs are aveliable al tho touch of a key.. SlMGES THE MODULE FOR THE SMULAT1ON OF THE MANAGEMENT OF WATER RESOURCES SYSTEMS SIMGES le a generalized module for simulation of the management of a water rosaurqa system, including conjunctiva use of surface and ground waters. This impiles:. - A more detailed representation of the water resaurces system than with the modu'e OPTIGES. Therefdra more types of elernents are provided and the phyalcal charactertstics of the elemente need to be moro extensiv&y descibed. - Ths operating polioles br each elernent and br the system as a whoie ha yo lo be given by the user. Thls makes the process of entering dala much more laborious, 1-lera, the Importance of the graphic Interface to manage Ihe data bases is oven greator in arder to facilitate the work and to avoid errors. As in the provious modulo, the interface aliows br the dofinition of achemes,, thaI can have any of the following components: - *des without etorage capaclty,- Sknllariy lo OPTIRED, ths aliows the usór te. include river junctions as weli as hydrologtcai latlows, divarsion and Intako pointe. - Nodea wlth otorage cepacfty.- These are br surfaoe reservoira. Data must be provided br monthiy maximum and minimum etorage, as well as lar evaporation, filtrations, size of outlets, etc. Chennels.- Maiogous to OPTIRED, but la Ihis case threo types of chenneis aro providod; channela with no loases nor connection to the groundwatar; channois with infiltration losses thaI go lato an aqulfer; and channeis hydrauflcally connactod lo an aquifer. Dapending en the heads the aqulfar can dotract fiows from the river or vio* verse, - Consumpliva demande,- For instance, irrigated zones or municipal and industrial suppiy. Monthly demanda must be input. Tho demanci can be suppfled from up lo threa intakes frorn tha surfaco system, each latako wlth a rnaxlmum month$y and yearty supply, wlth dlfferont Irrigation elficiencies and surfaee Irrigation retume te dfffsrent points of tho systom. Aleo, the zono has the posslbUity of pumping from en aquifer up to a given pumping capaclty. The usar aleo aseigns a prlorfty numbor to. the Zane. - Hydro&octric piante (nonoonsumptiy o domands). They make of the water, but no slgnificant amaunt le usad up. They are defined by thairuse maximum flow capaclty and Ihe pararnetere noeded lo C2441AN the eientrk'111v nrM, 'tinn. nn u*fl L. 1. Uk'. t í i vt j iníy flOWS.. - r1lIlfi1.1 IIIOdQIUF. approaches;. •. f. IñIIIJnci, um. i bu !flQiUO. USIng 111u fuliowing types ci'. - Reservolr type. There le no other discharge from th aquifer Iban the pumped water. - Aquifer with diacherge through a spring. 180.

(11) - Aqulter hydraulically connected to a surfaco stream, modelled as a single cefi aqulfer. - Aqulfer hydraulicafiy connacted to a surface stream modefied as a multiple ceU aquifar. Distributed model of an aqulfer uslng the eigenues approach (Andreu and Sahuquifio, 1987). - Other types of elemente includad are retum atcmants artificial recharge faclilties and addltional pumping facilities. Besidas to the physlcal characterlstics of the componente, the user must give tho operathig polkes br individual elemento as wefi as tor the system. ThIs Is done by mans Of the foliowing devices: - Target volumea and zoning br reservoire. Each reservoir wiH have a defined by. the usar rulo curve. Aleo minimum asid meximum monthly volumes must be gWen. The ¡atar are usuafly given br ficod control purposes. Automaticaily, the modal dMdes the reservofr capacfty Into Mur zones. - nter reservoir r&stlonehipv,- Priorities ter ditførent resarvoira are defined. As it le usual In thls kind or operating rulos (Martin, 1982) al¡ rasarvoira are normaily maintained in the same zona whenever posaible, and reservoire wtth lowerpriortties devlate before to a lower zona than resérvoirs wlth higher priorities. - Targat minimum f#ow br channeis, - Taret euppfy br demand zones. - Target flow for hydroelectric plante, - Inter demend relatlonahipe, axplained aboye. - Ints, channel relationehipa, givon aleo by priorities. - Inter element rolationehipa. Aleo relativo priorities between demande, target fiows, asid reservoir storage are defined. Wfth aH theee devices It la pos&ble to represent aimost any cornpiex oparaung pollcy for a system, a$ th0 experience demonetrates. Once al¡ the systom is defined, Vis usar can proceed ta the elmulation for a givan horizon. Thi le performed by a mathematical modal on a monthly baeis. In order fo deal wftfl Me decisione at the various elemento br each individual month, the modal uses en optimization subrnodel. Ustng the data supplled by the usar about the echema of the system asid the aboye oparattrig rules, the model alaborates en lntemal conservativa liow networlç designad in arder te simutate Me physical ctwacteristícs of the alement, as well a$ the management rulos. Thjs Intemal network, which le Iraneparont to the usar, ie optimized asid the result le tha allocatlo of, water among differant p urposes whlch minimizo tha weighted deviatione from tha targete. Ihe weights depanci on the priorities. In the sama teshion a$ dascrlbecl in the OPT1GES módute, SIMGES module produces wrlttan reporte of different kinds, and files whlch contain thc results of the simulatlon fo, epaciflc application not lnctuded Ir, AQUATOOL. Aleo graphical displays on %acreen as walt as their hard copies. A<2-9M: A DSS FOR AQUIFER MANAGEMENT As mentioned abo ye, the Guadalentín and Ascoy.-Sopalmo a quitero In tha Segura Rasln have beer declarad offlcially as overexplØited ". This means Viet en emergency plan has fo be devisad in arder to bring them back to retiene! ¡avale of exploltallon. In arder to Vio aqulters and to asees the irnpact of any plan on Ihe aqulfer, a DSS has been buftt up.Study AQSIM le basad the GIS available in the Segura River Water Agency, whlch le en Intergraph Gis. Using fhaen Mj crostatlon version of ihe GIS as the control environmant, en interface has bean 181. a.

(12) but which allows the user to handia and display grsphical i nformation as weH as Informaton. needed in order to run the MODFLOW groundwater flow smutaton modal (McDonatd and Harbaugh, 1984). ~des to the regular graphtcal Informatlon contatned In the GIS of tha Agency, the addition& tayers of informatíon for our purposes are: -Limits of the aqutfers.. -WelJ (ocations. -Piezometer locationa.. -Irrtgatad zonas. -Aquffer discrotlzation. • Tue interface ateo allows Ihe access te the data bases relatad te: -Wettcharactaristfcs. -Well exploltation, -Pzometg r charactortotios. • -Plezometer observatjons. • -Parametera for each cali of the aqulfer dlscretlzation. The aquifere Mera modettad as muttilayered, so each cefl contains Information about the Umlts of fha layare, as welt about hydraulic parametera. Alt this can be done by simpiy pointing out a graphical element, then its record of the data base la displayad on a second acreen, and can be editad. The user can s&ect among preset alternativos, as walt as te desígn hIe1,er own alternativos. Then, he/he can secase to ths procsss of simulation. The resulta of thi modal can be obtained as wntten reporta, as filas, and ateo as contour Unes for givan times. In ordr to bulid thls 083, dlferent modules hay o boen produced ualng differanf toots, For Instance, tha Interface in fha GIS has bean wrftten uslng the Microstation User Comrnancj tenguaga, fha oontroi lo the acxess to data bases has bien prcgrammecj ustng de 11k programmjng language, and tha visualizatton of conteur Unes was perforrnecj using Surpher. a. commands, But, fha usar. dos not realizo this variety of tools whffe uclng debS,. CONCLUSIOkS In this papar. it has been atated that In Spain, as in other places, a transition Irom an era of development te an era of ratlonat use of water 18 taking place. Thls rationality Imples efflclent, integral and sustainabie rnanagam.nt of water. Water resources systems and fha SOIUtIOrIS. te aliavlate th&r problema will be more and more oomplsx everyday. Therefo,e technologlcaJty advanced tools wI fi haya to be usad In. order to anatyze fha systems in anintegrated fashion and te addrose olasalcaj uncertaintias relatad etther to uses, demands, or rasources, as wel as new lsaues as for instanca cilmatie chango Impacto. For this to become possible, the existing gap between water resourcas systems analysta or modelera and the real world practitionere has to be narrowed down, Fortunately, the baste for thls procesa are atready settled. Spectacuiar improvernants in hardware, software, and educational programa br new tachnicians aflow the creation, easy use ánd acceptanca of computar basad dacislon support systems whlch are tha basf U not the only memo fo SuCCessfufly deal with cornplex water resources systems. iba feasibility and reatity of this transftion procese la demonstrated in fha papar by doacribing two DSS at differant scale levela that ha yo bien impiemantad In the Segura Bastn Water Agency, In Spain, and whlch are currently bien usad fo anewer quesflon addreseod fo make a rational use of the rasource in fha basin. First,a regional DSS oomprisng the whole basin and Including optimization aM elmutation modulas was presentad. Atterwarda, a DSS. 182.

(13) br single aquifers embeddeci Into the geographlcal Information system of the agency was described. Of oourse, sorne additlonal condltlons to the abo ye mentioned basis have to be fulfdted In. order to auccossfuily narrow down the gap and to not dlsappolnt the expectatlons. In the works presented sorne of thls conditione ha ya been: -A close oommunication batwaen ttie DSS developere and øe technk1ans that wlH use them in the Agency. 1h18 guaranties that tiie final product will be anewering the real questiona that people in the agency are addresslng. -An approach of not tr1,1ng lo solve ah problems at once, but progreesfvehy, golng fram simple questlons to moro complex ones. In this way, the devehopm.nt of toole in the DSS reaponds to real necesaities of the final usare, rather than to academic exercises. -A complete documentation about the toola developed le avahlable. Thls documentation Inchjdee user's manusis for each mathematic& modal, as well as br tha DSS: technhcal manuahs, and appøcatlon exemples. We aleo muatsay that the euccessfuf appl3catkn of theee toole In a rather comp)ex water. resources system a$ the Segura Sasln, has an effect of promoting Its uso In other agencies. In our case, the POIftOChniCSI Univorafty of Valencia 18 worklng al the Ebro Batín Agency, and ttie Tagus 8asln Agency, In order to metal! the AQUATOOL DSS in these agencies. This confirme that, Ib tha precedlng conditlons are given, atate of u»art toole are wall accepted and usad.. EFERENCES. Andreu, J. (1992). Modelo OPTIGES de Optimización de la Gestión de Esquemas de Recursos Hídricos. Manual del Usuario. Ser,. Publ. Un iv, Polftécnca. Valencia. Andreu, J. y A.Sahuquulo. (1987). "Efficlet Aquifer Slmulatjon in. <'f Water Res. Planning and Manag., Vol, 113, Andreu, J.; J.CapIlfa y J.Ferrer (1992).. Complex Systems", jo m.. No. 1, 110-129.. Modelo SIMGES de Simulación de la Recursos Hídricos, Incluyendo Util/zacó,, Conjunta. Manual de! Usuario. Se Gestión de. Politécnica. Valencia,. Andreu '.1.: J.Capilla; E,Sanchis y P.Tor,no (1993),. rv. PubI. Untv.. paraécn Planh'lcacjd,, de Recursos Hídricos,AQUATOQL: Sistema Soporte de Decisión Manual del Usuario. Sen,. Pub¡. Un he. Polit la ica , Valencia. C.H.S. (Confederación Hidrográfica del Segura) (1992). PIan Hidrológico. Proyecte, de Directrices. Junio. C.H.S. (Confederación Hldrogrflca del Segura) (1993). Estudio. ordenación del acuífero de Ascoy-Sopalmo. Loukg. para la redacción del plan de. Completion report. Enero. , D.P. (1992). "Water Resource Systems Modele: Thai, Role in Planning".. Water Res. Planning ar?d Manag., Vol. Journ, of 118, No. 3, 214-223. Martin, Q.W. (1982). Muitjresn,oj, sknuIa g je,, and optimization modal S!M-V Prograin. documion and usera manual,. Texas, USA.. Rep. UM-38, Texas Depan. of Wate, Resources, Austin,. McDØnakI, M. G. and HarbaugP3, A.W. (1984).. Ground-water Flow Model,. A Modular flPrae-DJmens!o,,j F7nIte.'.Djfference. Anteproyecto de Ley. Abril,. Plan Hídrølógico Nacional,. U.S. Geological Suiy, Opon-Filo Report 83-875. M.O.P,T. (Ministerio de Obre Públicas y Transportes) (1993).. 183.

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