WATER POVERTY INDEX IN SUBTROPICAL ZONES: THE CASE OF HUASTECA POTOSINA, MEXICO Briseida LÓPEZ ÁLVAREZ 1 *, Germán SANTACRUZ DE LEÓN 1 , José Alfredo RAMOS LEAL 2 and Janete MORÁN RAMÍREZ 2 1 El Colegio de San Luis, A. C. (COLSAN). Parque de Macul 155, Frac. Colinas del Parque, San Luis Potosí, S.L.P., C.P. 78299 2 Instituto Potosino de Investigación Científico y Tecnológico (IPICYT). Camino a La Presa de San José 2005, Col. Lomas 4ta Sección, San Luis Potosí, S.L.P., C. P. 78216 *Autor para correspondencia: [email protected](Recibido mayo 2014; aceptado febrero 2015) Key words: water access, water quality, water availability, human development, hydric resources, Valles River ABSTRACT Tools are needed in order to evaluate an integrated water resource management, and to encourage the management and coordinated usage of water resources along with the environmental and socioeconomic factors. One of those tools is the Water Poverty Index (WPI), which enables the evaluation of water poverty in terms of the physical and socioeconomic factors related to water availability. The WPI, as calculated in this study, is derived from the weighted sum of six key components –resources, access, usage, capacity, quality and environment– on a scale of 0 to 100. The objective of this work was to calculate the Río Valles Basin WPI for 2010. This region is a semi-tropical area with abundant water resources, such as large springs. Its annual mean precipita- tion is 1100 mm. In the Río Valles Basin, the volume of surface water used per year is 81.33 Mm 3 , which represents 91 % of the total resource. The volume of groundwater used per year is 8.17 Mm 3 , representing the remaining 9 %. Usually 45 Mm 3 /year is stored in La Lajilla dam. These data indicate that surface water is the main source of supply for uses such as agriculture, which is the activity with the largest water demand. A WPI score of 59 was obtained for the Río Valles Basin. Palabras clave: acceso al agua, calidad de agua, disponibilidad de agua, desarrollo humano, recursos hídricos, Río Valles RESUMEN Para evaluar la gestión integrada de los recursos hídricos se necesitan herramientas para fo- mentar su administración y uso coordinado con el ambiente y los factores socioeconómicos. Una de estas herramientas es el Índice de Pobreza del Agua (IPA), que permite evaluar la pobreza del agua en términos de los factores físicos y socioeconómicos relacionados con su disponibilidad. El IPA, como se calculó en este estudio, se deriva de la suma ponderada de seis componentes clave: el acceso, el uso, la capacidad, la calidad y el ambiente, en una escala de 0 a 100. El objetivo de este trabajo fue calcular el IPA de la cuenca del Río Valles para el año 2010. Esta región es semitropical, con abundantes recursos hídricos, Rev. Int. Contam. Ambie. 31 (2) 173-184, 2015
12
Embed
WATER POVERTY INDEX IN SUBTROPICAL ZONES: THE CASE OF ...scielo.unam.mx/pdf/rica/v31n2/v31n2a7.pdf · HUASTECA POTOSINA, MEXICO Briseida LÓPEZ ÁLVAREZ1*, Germán SANTACRUZ DE LEÓN1,
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
WATER POVERTY INDEX IN SUBTROPICAL ZONES: THE CASE OF HUASTECA POTOSINA, MEXICO
Briseida LÓPEZ ÁLVAREZ1*, Germán SANTACRUZ DE LEÓN1, José Alfredo RAMOS LEAL2 and Janete MORÁN RAMÍREZ2
1 El Colegio de San Luis, A. C. (COLSAN). Parque de Macul 155, Frac. Colinas del Parque, San Luis Potosí, S.L.P., C.P. 78299
2InstitutoPotosinodeInvestigaciónCientíficoyTecnológico(IPICYT).CaminoaLaPresadeSanJosé2005,Col. Lomas 4ta Sección, San Luis Potosí, S.L.P., C. P. 78216
Paraevaluarlagestiónintegradadelosrecursoshídricossenecesitanherramientasparafo-mentarsuadministraciónyusocoordinadoconelambienteylosfactoressocioeconómicos.UnadeestasherramientaseselÍndicedePobrezadelAgua(IPA),quepermiteevaluarlapobrezadelaguaentérminosdelosfactoresfísicosysocioeconómicosrelacionadosconsu disponibilidad. El IPA, como se calculó en este estudio, se deriva de la suma ponderada deseiscomponentesclave:elacceso,eluso,lacapacidad,lacalidadyelambiente,enunaescalade0a100.ElobjetivodeestetrabajofuecalcularelIPAdelacuencadelRíoVallesparaelaño2010.Estaregiónessemitropical,conabundantesrecursoshídricos,
Rev.Int.Contam.Ambie.31(2)173-184,2015
B. López Álvarez et al.174
comograndesmanantialesyunaprecipitaciónmediaanualde1100mm.EnlacuencadelRíoValleselvolumendeaguasuperficialutilizadaesde81.33Mm3/año, lo que representa el91%deltotaldelrecursoutilizado.Elvolumendeaguasubterráneautilizadaesde 8.17 Mm3/año,loquerepresentael9%restante,normalmentesealmacenan45Mm3/año enlapresadeLaLajilla.Estosdatosindicanqueelaguasuperficialeslaprincipalfuentedeabastoparadiversosusoscomolaagriculturaqueeslaactividadconlamayordemandade agua. El IPA que se obtuvo para la cuenca del Río Valles fue de 59 puntos.
INTRODUCTION
IntegratedWaterResourcesManagement(IWRM)isaprocesstofosterthemanagementandcoordinatedusageofwaterresources,aswellastheenvironmen-tal and socioeconomic factors in order to maximize socialandeconomicbenefitsinanequitablemannerwithout compromising the sustainability of vitalecosystems (IWRM-UNESCO2009).To evaluateIWRM,toolsareneededandthoseshouldtakeintoaccount these elements.Oneof those tools is theWaterPovertyIndex(WPI),whichmakesitpossibletoevaluatewaterpoverty indifferentstudyscales–countries, regions or communities– taking intoaccountphysicalandsocioeconomicfactorsrelatedtotheavailabilityofwater(Lawrenceet al.2002).
TheRVB comprises the following cities andmunicipalities:municipalityofAquismón,CitiesofMaíz,CiudadValles,ElNaranjoandTamasopoinSanLuisPotosíand themunicipalitiesofAntiguoMorelos, Nuevo Morelos, Ocampo and Tula in Ta-maulipas (Fig. 1).
Development of the WPI for Huasteca PotosinaTheWPI is based on the structure andmeth-
odologies proposed byUNESCO in theHumanDevelopment Index as part of theUnitedNationsDevelopmentProgramme(2002).
ThemethodologyproposedbyLawrenceet al. (2002)includesfivekeycomponents.Nevertheless,theapplicationoftheWPItotheRVBincludedwaterquality as anadditional component (Table I) since Mexico’ssurfaceandgroundwaterhaveseriouslevelsofnaturaland/oranthropicpollution,therebylimitingitsuse(Santacruz2007,Carranco-Lozada2013).
Although thismethodology includes six basiccomponents, depending on different scenarios, subcomponents could be also considered. For in-stance,intheResourcecomponentwhereground-waterisincluded,theaquifersinthesystemcouldbethesubcomponents(López-Álvarezet al.2013).In terms of the subcomponents of surfacewaterthesecouldberepresentedbydifferentwaterbodies(reservoirsandrivers)inthestudyarea.Inaddition,fortheQualityoftheresourceboth,groundwaterorsurfacewatersubcomponenthasitsownqual-ityvalue (López-Álvarezet al.2013).RegardingtheUsage component this could be subdividedinto urban, agricultural and industrial usage as subcomponents. Socioeconomic data related to a population can be used as subcomponent of Access andCapacity.ForthecomponentofEnvironment,data such as land use, erosion rate, flood zones,naturalprotectedareas,vegetation types,anden-dangered and protected animal spatial distribution could be used as subcomponents. In general theevaluationofeachcomponentcanbeascomplexastheamountandqualityofinformationavailable.
ThemathematicalstructureonwhichtheWPIisbased is expressed as:
Formost components aweight analysis is ap-pliedtodefinetheimportanceofeachsubcomponent(Ramos2002).Theweightanalysisisexpressedas(equation 3):
∑ =
= N
i i
iii
WXwXrWx1
* (3)
whereXri and Xwi arethescoresforeachXi compo-nentandtheirtheoreticalweightsandWiisthesumofthetheoreticalweights.
Sinceeachcomponentcanbeformedbymorethanone subcomponent, theweightw applied to eachsubcomponent(Xai)intheWPIstructurecanbe obtained from the values associatedwith thesubcomponents. For example, in the case of theResource component percentages related to themanagementofthedifferentsupplysourcescanbeusedasweights.FortheAccesscomponent,percent-agesofthepopulationwithaccesstodrinkingwaterorwithwatertreatmentsystemsandpercentagesofagriculturallandswithaccesstoirrigationcanbeconsideredasweightsforthesesubcomponents.FortheCapacitycomponentsocioeconomicconditions,populationincomedata,mortalityratesofchildrenunder5yearsofage,theeducationindexandtheGini coefficient can be used asweight elements.Percentageofwaterusedfordomestic,agricultural
Foreachcomponent,thesumofthesubcompo-nentsmultipliedbyaweightfactormustequal1.Toobtainthefinalvalue,theWPIneedstobenormal-izedbyweightingoncemorethesubcomponentsandthesumshouldequal1.Theassignedweightsdependon thedegreeof importanceor influenceofeachcomponentineachregion.Theweightwi is assigned to each component (Xi) in theWPIstructure for that region. It isworthmentioningthattheresultscanbeexpressedasascorerangingfrom0to100.
approximateareaof3216km2 and is divided into four subbasins: “Río Los Gatos”, “Río El Salto”, “Río Mesillas”and“RíoValles”.Itislocatedinthedrain-ageareaoftheEasternSierraMadreasevidencedbythelargespringsfoundintheHuastecaPotosinaregion (Fig. 1).
The climates are sub-humid with medium andhighhumidityandsummerrains,andsemi-hotand sub-humidwith summer rains.The annualmeanprecipitationis1100mm–higherthanthenationalmean of 772mm (Santacruz 2008).The volumeofwaterused in theRVB is81.33Mm3/year forsurfacewater,whichrepresents91%ofthetotalresource used and 8.17 Mm3/yearforgroundwater,representingtheremaining9%.Usually45Mm3/yeararestoredinLaLajilladam.Thesedataindi-cate thatsurfacewater is theprimaryresource inthestudiedbasin.
TheweightsassignedtotheResourcesubcompo-nentswerederivedfromthepercentagesofsurfaceandgroundwatersourcesusedasseeninequation4in the followingmathematical expression (López-Álvarez et al.2013):
Access (A)Seventy-five percent of the population in the
RVBlivesinCiudadValles,ElNaranjoandNuevoMorelos.Thesethreepopulationcenterscontainmostof the drinkingwater (90%coverage) andwatertreatment (30% coverage) services (Fig. 2).Therestofthepopulation(38694inhabitants)livesinsmallanddispersedlocalitieslackingpublicservices(INEGI2010a).
A total of 81.2%of theEconomicallyActivePopulation (EAP)works in the three populationcentersmentioned,performingsecondaryandtertiaryactivities.The remainingpercentageworks in theprimarysector(agricultureandlivestock).Forthissector thereare84405haofagricultural land,12399ofwhichhavesomekindof irrigationsystem(INEGI2007).
TheAccess(A)componentincludesthepercent-age of the populationwith access to pipedwater(Aap)fortheirbasicneeds,thepercentageofwater
Thesubcomponentswereweightedusingaweightanalysis(Ramos2002,López-Álvarezet al.2013)whichshowssubcomponentAapasthemostsignifi-cant and Aiastheleastsignificant.
Capacity (C)InMexico, the HumanDevelopment Index
(HDI)isevaluatedatmunicipallevel.AlthoughtheRVBcoversseveralmunicipalities,onlythreehavenotablesocialandeconomicinfluence(Santacruz2007):NuevoMorelos, ElNaranjo andCiudadValles.ThemunicipalityofNuevoMorelos,Tam-aulipas,hadaHDIof0.753 (placing itat35outof 43) in 2005,whichwasbelow the statemean(0.85)forthatyear.ElNaranjoandCiudadValles,inSanLuisPotosí,hadanHDIof0.810(9outof58)and0.838(4outof58),respectively.Ofthesemunicipalities onlyCiudadValleswas above thestatemeanof0.816.
waterusagehasreflectedtheadvancesintechnologyoftheperiod.Thevolumeofwaterusedandextractedfromdifferentwater bodies, primarily theVallesRiver is 89.85 Mm3/year,accordingtotheComisiónNacional delAgua (NationalWaterCommission,CONAGUA,Spanish acronym) and theRegistroPúblicodeDerechosdelAgua(PublicWaterRightsRecord, REPDA, Spanish acronym). From this 89.85 Mm3/year,89.2%isused inagricultureforirrigatingcrops,suchassugarcane(Saccharum of-ficinarum).Atotalof81.06%ofthevolumeofwaterused in agriculture comes from surface sources and therestfromgroundwater(Fig. 3).
IntheRVB7.53%ofthewatervolumeextractedis for agro-industrial uses and2.43% for public-urban uses.
Thiscomponentincludesthreesubcomponents:waterfordomesticuse(Ud),waterforagro-industrialuse (Ui)andwaterforagriculturaluse(Ua). It is deter-minedfromequation7(López-Álvarezet al.2013):
aid UUUU 9.008.002.0 ++= (7)
Theweight assigned to the subcomponents isbasedonthepercentageofwaterusedintheRVB.
thisactivityandtheamountofwaterused.Thisre-lationshipwasappliedtowaterforagriculturaluseandprovides an approximatemeasurement of theefficiencyofwater usage (Lawrenceet al. 2002).Agro-industryandagricultureintheRVBrepresents 4 and1%of the stateGDP, respectively (INEGI2010b).
qualityandquantityareimportantanditsdegradationimpactstheenvironmentand,inparticular,humanhealth(Azqueta2002,Soares2003).Waterpollutioncanoccurfromnaturaloranthropogeniccauses.Theimpropermanagementofwaterresourcesisoneofthemain reasons for its deterioration.UNESCO(1998)indicatesthatanevaluationofthequalityandquantityofavailablewaterisaprerequisiteforthe
developmentandmanagementofwaterresources.In theRVB,CONAGUA has differentwater
qualitymonitoringstations,primarilyinthe“RíoElSalto”and“RíoValles”subbasins.Intermsofthephysical,chemicalandbacteriologicalinformationregardingwaterqualityatthesemonitoringstations,the temporal behavior of quality parametersweredetermined and comparedwith themaximum al-lowablelimitsaccordingtotheMexicanregulationNOM-127-SSA1-1994. It is important tomentionthat onlyCiudadValles haswastewater treatmentplants(whoseoperationsandefficiencyisquestion-able).Domesticwastewater is discharged directlyintoreceptorwaterbodies,increasingthepresenceofpollutants,especiallythosethatarebacteriological.
Thepresenceofbacteriologicalpollution in themainwater supplysource reducesconsiderably theavailabilityofwaterforhumanusepurposesinthebasin.At themonitoring stationsnamedAADAPAand Birmania by CONAGUA –the latter beingdownstream from the former– themost probablenumber (MPN) in the samples taken in the year2005variedfrom47000to700000MPN/100mL. SánchezandHernández(1996)foundtotalcoliform
1
Sampling date
Total coliformsFecal coliformsNOM-127 (Zero CFU/100 mL)
valuesof2500MPN/100mLatdifferentpointslocatedthroughoutthemainchannelinthissubbasin.TheyalsodetectedthepresenceofenterobacteriasuchasEscherichia coli, Proteus, Klebsiella pneumoniae, Shigella dysenteriae and Serratia marcescens.
ThiscomponentwasevaluatedusingtheWaterQuality Index (WQI) developed byMcclelland(1974).Thisindexisanumericalrepresentationofthechemicalparameteranalyzed.Theindexisobtainedfromaddingandponderingthespecificweightsob-tained from a geometric mean (equation 8):
=i
ii
PPC
kWQA∑∑
(8)
whereCiisthepercentagevalueassignedtotheparam-eters, Piistheweightassignedtoeachparameter,k is theconstantwhichtakesthevalueof1forclearwaterwithnoapparentpollution,0.75forclearwaterwithaslightcolor,foam,andslightunnaturalapparentturbid-ity,0.50forwaterwithacontaminatedappearanceand0.25forsewagewithfermentationsandodors.
Toobtain thewater quality component for thesurfaceandgroundwateravailableinthestudyarea,thefollowingexpressionisused(López-Álvarezet al.2013,equation9):
AgrnAsur QQQ 09.091.0 += (9)
whereQAsur and QAgrnaretheWQIforsurfaceandgroundwater from the aquifer, respectively.Theweightfactors(0.91and0.09)usedinthiscomponentwereassignedaccordingtothepercentageofusagefromthesesourcesintheregion.
themainsourceforavarietyofeconomicactivities,itsdomesticuseislimitedbecauseitsqualityisverypoor forhumanconsumption.For example,waterfromtheRíoVallescontainstotalcoliformvaluesofasmuchas273000CFUandfecalcoliformvaluesof170000CFU,causinggastrointestinalandder-matologicalillnessesamongthehumanpopulation(Gómez and Velarde 1996).
TheWQIscorewas51forsurfacewaterand66.7fortheaquifer(SantacruzandRamos2010).Thesevalueswereused inequation (9),basedonwhichthe score of 0.52 for componentQwas obtained.Whilethislimitsitsuseforhumanconsumption,itis acceptable for agricultural irrigation (Santacruz andRamos2010).
UsageRegarding thiscomponent,agriculturalactivity
playsanimportantroleanddemandsahighvolumeoftheresourceforgravityirrigationsystems,whosemaximumefficiencyisestimatedat50%.Thevalueof itsproductionhas little influenceon the state’sGDPandtheregionaleconomy.
Domestic use is deficient becausemost of thedrinkingwaterservicesarelocatedinthemunicipalcapitalofCiudadValleswhiletherestofthelocalitieslacktheseservices.
Anormalizedvalueof0.31wasobtainedduetothe centralizationof drinkingwater and treatmentservicesinthemainpopulationcentersandthelackofthoseservicesinrurallocalities.
CapacityInthecityofSanLuisPotosí,anotableconcen-
trationofservicesandeconomicactivityexists.Thissituationpolarizesthesocioeconomicconditionsinthe rest of the state, and therefore theHDI in thestudyzoneislow.
Themortalityrate,incomeandGinicoefficientusedtoevaluatetheCapacitycomponentgavesimilarvaluestothoseobtainedintheSLPValley(López-Álvarez et al. 2013),while the education indiceswerelowerthanthoseobtainedintheSLPV,whichisreflectedinthenormalizedscoreof0.35forthiscomponent.
EnvironmentLandusechangesintheRVBwereconsideredto
evaluatetheenvironmentcomponent.Themodifiednaturalareaisapproximately588km2,whichrep-resents24%ofthetotalareaoftheRVB,avalueof0.9wasassignedtothiscomponent.Thisisconsistentwithlandusechangesintheregion,wheretropicalrainforestshavebeenconvertedintoirrigatedagri-culturalland.ThislandusechangehaslessimpactthaninotherregionsofSLPwherenaturalvegeta-tionhasbeenturnedintourbanuseordeforestationwithout recovery had occurred (López-Álvarezet al.2013).
Water Poverty Index for the RVBTheresultingpolygonfortheRVBreflectsseri-
isfarfromthescoresofdevelopedcountries,suchasFinlandwithaWPIof78.TheWPIintheRVBis higher than those in underdeveloped countrieswithwaterpovertyproblems,suchasHaitiwithaWPIof35.1,andisevenhigherthantheWPIforMexicoandtheSLPV,withvaluesof57.5and46,respectively.
TheWPIvaluefortheRVB(59)isprobablyduetothehighavailabilityofwaterandthelowenviron-mentaleffectsinthisarea.Neverthelessitindicatesthattheruralpopulationdoesnothaveaccesstotheresource, its socioeconomic situation is unequal and theuseofwaterisdeficient(Fig. 6).
Throughout history, the environment in theSLPVhasundergoneirreversiblechanges,suchasdeforestation and depletion and pollution of surface andgroundwaterresources.Nevertheless,theenvi-ronmental changes in theRVBare reversible anddeforestedzonesmayberecoveredinashortperiodof time. In termsof theresource, recharge ishighandflowsareverydynamicbecauseofthekarsticcharacteristicoftherock.
Theaboveanalysisshowsthattheabundanceoftheresourcedoesnotensurebettersocioeconomicdevelopment in a region.
In termsof thequality(Q)ofwaterforhumanconsumption,treatmentisrequired.Nevertheless,itisadequateforagriculturalusesandavalueof0.52wasobtained.
Regarding capacity (C), a value of 0.35wasachieved,which reflects the centralization of theeconomicalactivityinthearea,thatisfocusedmainlyinonemunicipality,whiletherestofthelocalitiesareleftbehind.
SeventyfivepercentofthehumanpopulationlivingintheRVBislocalizedinCiudadValles,ElNaranjoandNuevoMorelos.Thispopulationhasaccesstocleanwater, but there aredeficientwastewater treatmentservicesandadequateaccesstoirrigationwater.Therestofthepopulation(25%)hasdeficientornoaccess(A)totheresource,asreflectedbyascoreof0.31.
Themainuseofwaterisforagriculture,whichisthelargestactivityintheregion.Nonetheless,theusage (U) does not significantly contribute to thestate´sGDP,asreflectedbyavalueof0.05forthiscomponent. In addition, domestic use is centered primarilyinCiudadValles,whereasservicesfortherestofthepopulationintheRVBaredeficient.
GómezN.A. andVelardeN.H. (1996).Deteccióndeenterobacterianas en el Río Valles como una fuente de contaminación. Universidad Autónoma de San Luis Potosí,UnidadZonaHuasteca.Mexico,74pp.
INEGI.(2010b).SistemadecuentasNacionalesdeMé-xico. Producto interno bruto por entidad federativa. InstitutoNacionaldeEstadísticayGeografía.[Online]:http://www.inegi.org.mx/prod_serv/contenidos/espa-nol/bvinegi/productos/derivada/regionales/pib/2007-2011/pibe2011.pdf15/03/2014
IWRM-UNESCO (2009). IntegratedWaterResourcesManagement inAction.WorldWaterAssessmentProgramme, United Nations Educational, Sci-entific and Cultural Organization. Report. Paris, France. 18 pp. [Online]: http://unesdoc.unesco.org/images/0018/001818/181891e.pdf26/02/2014.
LawrenceP.,Meigh J. andSullivanC.A. (2002).Thewaterpovertyindex:internationalcomparisons.KeeleEconomicsResearchPapers,KeeleUniversity,Staf-fordshire,UnitedKingdom,19pp. [Online]: http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.13.2349&rep=rep1&type=pdf7/04/2015
López-ÁlvarezB.,Ramos-LealJ.A.,Santacruz-DeLeónG.,Moran-RamírezJ.,Moran-Ramírez,J.,Carranco-LozadaS.E.,Noyola-MedranoC.andPinedaMartínezL.F.(2013).CálculodelÍndicedePobrezadelAguaen zonas semi áridas: caso Valle de San Luis Potosí. Rev.Int.Contam.Ambie.29,249-260.
McclellandN.(1974).EPA-907/9-74-001.WaterQualityIndex.Application in theKansasRiverBasin.U.S.EnvironmentalProtectionAgency-RegionVII.,KansasCity,Missouri,USA,226pp.
Morán-RamírezJ.,Ramos-LealJ.A.,López-ÁlvarezB.,CarrancoLozadaS.andSantacruz-DeLeónG.(2013).Comportamiento hidrogeoquímico de flujos subte-rráneos en acuíferos cársticos fracturados, aplicando modelacióninversa:CasoHuastecaPotosina.Bol.Soc.Geol.Mex.1,71-82.
NOM-127-SSA1-1994(1994).NormaOficialMexicana.Modificacion a laNormaOficialMexicanaNOM-127-SSA1-1994,SaludAmbiental.Aguaparausoy
consumohumano.Limitespermisiblesdecalidadytratamientos a que debe someterse el agua para su potabilizacion.SecretaríadeSalud.DiarioOficialdelaFederación.20dejuniode2000.Mexico.
ReyesH.,AguilarM.,Aguirre J. andTrejo I. (2006).CambiosenlacubiertavegetalyusodelsueloeneláreadelproyectoPujal-Coy,SanLuisPotosí,México,1973-2000. InvestigacionesGeográficas.Bol. Soc.Geol.Mex.59,26-42.
SantacruzG. (2007).Hacia unagestión integral de losrecursoshídricosenlacuencadelRíoValles,Huasteca,México.TesisdeDoctorado,FacultaddeCienciasQuí-micas,IngenieríayMedicina,UniversidadAutónomadeSanLuisPotosí,Mexico,308pp.
SantacruzG.(2008).Generaciónytratamientodeaguaresidual en la Zona Metropolitana de la ciudad de San LuisPotosí.BoletíndelArchivoHistóricodelAgua.Comisión Nacional del Agua. Secretaria de Medio AmbienteyRecursosNaturales.Mexico,89pp.
SantacruzG.andRamos-LealJ.A.(2010).EstudiodelcomportamientohidrogeológicodelaReservaSierraAbraTanchipaysuzonadeInfluencia.ReporteTéc-nicoGTZ-CONANP-COLSAN-IPICYT. SanLuisPotosí, Mexico, 71 pp.
SantacruzG. (2012).ElEspejismode lacuencahidro-gráficacomoespacioparalagestióndelosrecursoshídricossuperficiales,elcasodelríoValles,Huasteca.Colección Investigaciones, El Colegio de San Luis, A.C., Mexico, 171 pp.
Siles J., SoaresD. andAlemánE. (2003). La fuerzade la corriente: gestión de cuencas hidrográficasconequidaddegénero.IUCN,RegionalOfficeforMeso-America.EditorialAbsoluto.SanJosé,CostaRica, 266 pp.
UNESCO (1998).Evaluaciónde los recursos hídricos:Manual para la estimación de las capacidades nacio-nales.Biblioteca virtual del Programa hidrológicointernacionalparaAméricaLatinayelCaribede laUNESCO,142pp.[Online]:http://www.unesco.org.uy/phi/biblioteca/archive/files/8402cc013900e2e09e3a026b75b704a8.pdf25/03/201.