تلفیق شاخص اقتصادی و زیست محیطی در ارزیابی خطر بیابان زایی:مطالعه موردی INTEGRATING ECONOMIC AND ENVIRONMENTAL INDICATORS IN THE ASSESSMENT OF DESERTIFICATION RISK: A CASE STUDY

Desertification  involves  many  countries  featuringdifferent  ecological,  economic,  and  socialconditions. In Mediterranean Europe, high human pressure, economic development, and climatic changescombine  to  produce  land  consumption,  soil  erosion,salinization,  and  fire  risk,  all  considered  as  keyfactors  to  start  desertification  processes.  For  many  years  the  term  desertification  has  been  strictlyassociated  to  geo-physical  conditions,  but  in  verycomplex  ecosystems  the  study  of  the  interaction  ofphysical  patterns  with  population  and  social  characteristics  is  necessary  to  better  delineate  areas  atrisk.The aims of this paper are therefore (i) to reviewrecent findings in term of desertification processes andrisk  assessment  in  the  Mediterranean  basin,  (ii)  toillustrate  a  simplified  model  in  which  social  andeconomic  variables  may  significantly  accelerate  land  degradation  leading  to  desertification,  (iii)  tosuggest  a  set  of  demographic,  economic,  and  institutional  indicators  suitable  to  contribute  to  theassessment  of  desertification  risk  in  the  Mediterranean  basin,  (iv)  to  built  a  synthetic  index  based  on  amultivariate approach and, finally, (v) to comparesuch index with a standard index of desertificationriskonly referring to geo-physical conditions. As a conclusion, new findings to be achieved in the contextofhuman impact on environment as an original contribution to the study of desertification were delineated.Keywords:desertification risk, indicators, demography, economy, ItalyIntroductionDesertification  is  a  complex  phenomenon  which  reduces  the  soil  fertility  involvingecological  and  economic  processes  that  characterise  the  environment  at  differentgeographic  scale  [۱].  The  most  widely  accepted  definition  of  desertification  is  the  onegiven by the United Nation  Convention:. It defines desertification as ‘land degradationin  arid,  semi-arid  and  dry  sub-humid  areas  resulting  from  various  factors,  includingclimatic  variations  and  human  activities’  [۲].  The  term  desertification  was  generallyassociated  to  geo-physical  conditions  (e.g.  soil,  slope,  vegetation  cover)  coupled  withdrought  features  [۳]  and  water  availability  [۴],  but  in  Mediterranean  land  the  study  ofthe  interaction  of  physical  patterns  with  population  dynamics  is  necessary  to  betterdelineate  areas at  risk  [۵].  In  fact,  desertification  impacts  on  the  social,  economic,  andagricultural activities, and it is perceived as an ensemble of disasters affecting drylands,without  a  clear  understanding  of  the  involved  processes  [۶].  The  complexity  of  thisphenomenon represents a limitation for the scientific approach andfor the developmentof  efficient  action  plans  [۷].  However,  the  interest  for  these  problems  was  renewed  inthe last years, also considering the role of man in the way which external forces such asmarket,  demography,  tourism,  and  agricultural  policies,  influence  the  society-resourcesystem [8].The  heterogeneity  of  cause-effects  relationships  and   the   interlinkages  betweendesertification factors and human activities  prevent to find an efficient methodology  toevaluate  the  desertification  process  state  [۹].  Consideringthe  multiplicity  of  statistical sources  used  in  geographical  studies  it  is  hard  to  provide  sound  information  ondesertification  trends also  in  more  developed  countries.  In  fact,  desertification  risk  hasbeen  rapidly  increased  in  Mediterranean  Europe  where  human  pressure,  climaticchanges and intensive economic development combine to produce soil degradation anderosion,  as  well  as  salinization  and  fire  risk,  all  considered  as  key  factors  to  startdesertification  processes  [۱۰].  Moreover,  technological  advancement,  industrialisationof agriculture, and subsidy policies have accelerated the rate ofland degradation duringthe last 50 years in environmental sensitive areas [11].In  this  paper,  indicators  suitable  to  assess  desertification  risk  in  the  Mediterraneanbasin  were  discussed  with  a  special  emphasis  on  demographic  andeconomic  aspects,providing  key  examples  from  Italy  at  both  national  and  regional  scales[12].  Newfindings  to  be  achieved  in  the  context  of  human  impact  on  environmentwere  alsodelineated as an original contribution to the study of desertification.