KEITA, NIGER
THE IMPACT ON ENVIRONMENT AND LIVELIHOOD OF 20 YEARS FIGHT AGAINST DESERTIFICATION
Andrea DI VECCHIA∗, Giancarlo PINI†, Federica SORANI‡, Vieri TARCHIANI*
Working Paper n. 26 - 2007
ISSN 1774-4943 ISBN 978-88-96128-26-0
Summary. The Keita Department, in the Republic of Niger, is composed by a complex system of watersheds subject to strong wind and water erosion. The Keita Project (PDR-ADM) launched in 1984 in a region close to the environmental collapse. The main objective was to increase food security while combating desertification through the reduction of soil erosion and reforestation. More than 20 years of soil conservation and
land reclamation interventions make Keita an open air laboratory where is possible to carry out studies on the impacts of fight against desertification actions from the environmental and socio-economic points of view. Between 1984 and 2002 woodlands increased more than 300%, wood production by 49% while leaf biomass by 57% and cereal production by 41%. Keita has proven that desertification control and recovery is
demanding projects lasting decades because reclamation needs twice the time necessary for degradation and prevention is extremely less costly than reclamation.
Acronyms
CER Certified Sequestration Units
CeSIA Study Center for Informatics Applications in Agriculture
CIRPS Interuniversity Research Center for Sustainable Development
FAO Food and Agriculture Organization of the United Nations
F CFA African Financial Community Franc
FLD ADM Ader Doutchi Maggia Local Development Fund
Ha Hectares
GDP Gross Domestic Product
IBIMET CNR National Research Council Bio Meteo Institute
LCCS Land Cover Classification System
MAE DGCS Directorate General for Development Cooperation Min. For. Aff.
PAFAGE Environment Management Assistance & Training Support Project
PDR ADM Ader Doutchi Maggia Rural Development Project
PEICRE Environment Recover & Conservation Realizations Assessment Project
ROSELT Long Term Watch Observatories Network
UBT Tropical Livestock Unit
UNCBD United Nations Convention on Biological Diversity
UNCCD United Nations Convention to Combact Desertification
UNFCCC United Nations Framework Convention on Climate Change
UTL Local Technical Unit
WDI World Development Indicators
Andrea Di Vecchia, Giancarlo Pini, Francesca Soriani, Vieri Tarchiani
KEITA, NIGER: THE IMPACT ON ENVIRONMENT AND LIVELIHOOD OF 20 YEARS FIGHT AGAINST DESERTIFICATION
1. The Keita ecosystem
The Keita Department is located in the centre of the Republic of Niger and
covers, an area of more than 4,860 sq km composed of a plateau with rocky slopes
and valleys, forming a complex system of watersheds subject to strong winds and
water erosion. The Soudano Sahelian climate with a short rainy season (June -
September) and a yearly average between 400 and 500 mm, represents one of the
main limiting factors due to the intra-annual and inter-annual variable rains.
Between 1960 and 1990 a decrease of yearly average rainfall was observed,
particularly during the month of August, with a latitude shift of 30 km from
Northeast to Southwest. In 1962 plateaus and slopes were entirely covered by
forest. Starting in 1972 evident signs of forest degradation appeared and in 1984
this forest had completely disappeared.
The decade ranging between the two last great dryness of 1973 and 1984
represents a kind of line of demarcation between two environmental and socio-
economic systems with very different characteristics. A negative synergistic
process, which seemed irrepressible, struck the ecosystem bringing it close to the
break point. Crop productions dropped down and herds were decimated. In 1984
the area seemed directed to become again a zone with a reduced population as it
was at the beginning of the century and without future.
The Keita valley has always represented a border for the Sahara desert,
allowing the development of a multiethnic community composed by peasants
coming from Southern regions and nomads from the North. The total population
increased from 65,000 inhabitants in 1962 to 230,000 in 2003.
2. The Keita Project
The Ader Doutchi Maggia Rural Development Project (PDR-ADM), known as
Keita Project, launched in 1982 in the framework of the Italian Initiative for the
Sahel to reduce food insecurity. It become operational in 1984 and since then it
has been active through three phases ended in 2003. The main objective was to
increase food security over a very large area, while combating desertification
through the reduction of soil erosion and reforestation. A new initiative (Fond
Local de Developpement dans l’Ader Doutchi Maggia, FLD-ADM) is starting
with the objective to complete existing interventions, fund local investments and
transfer the management and property to local institutions and organizations.
The PDR-ADM approach subdivided the project area into units, named
Elementary Territorial Units (UTE), where the project intervened by (Figure 1):
- reclamation of the plateau (1) and the abandoned land in the valleys (4, 5) for
agricultural and pastoral purposes,
- reforestation of the slopes (2), of the kori banks and dunes,
- creation of wind breaks and forest areas,
- control of the water flow in the kori by banks consolidation and small dams (3, 7).
Simultaneously the Project has also addressed the social and economic
development by building schools, medical centers, wells and roads, and providing
technical assistance and financial support for the creation of new economic
activities.
The main interventions 1984-2003 of PDR-ADM are showed in the table below
(MAE – DGCS, 2003):
Table 1 - Keita, Niger. PDR-ADM interventions until 2003
Reclamation and improvement of agricultural and pasture lands,
reforestation and dune fixation (ha) 34,483
Trees planted (n.) 18,000,000
Road construction (km) 313
Drilled wells (n.) 5
Excavated wells (n.) 708
Rural buildings (sq m) 28,000
Small dams (n.) 40
Dams (n.) 2
Weirs (n.) 251
More than 20 years of soil conservation and reclamation interventions makes
Keita an open-air laboratory where is possible carry out studies on the
environmental and socio-economic impact of fight against desertification actions.
The availability of long series environmental data and information concerning the
age and typology of intervention allows the development of specific
environmental analysis and indicators based on data rather than models. This
extraordinary situation gives the opportunity not only to evaluate the impacts of
PDR-ADM actions but also to model the behavior of natural vegetation (trees and
herbaceous) during the recolonization of degraded lands and foster future
development and potentialities.
3. Project results
The Keita project has played a major role in blocking the tendencies of
ecosystem degradation mainly due to climate changes and human activities and
improved the biophysical and socio-economic well being of the area. It has been
proved by a scientific evaluation of the Project impact (PEICRE, 1996). It was
funded by Italian Aid with the aim to localize and date the different interventions,
collect data, and review their effectiveness over time.
The project actions increased the availability of croplands, often by
reclamation of unproductive areas, and to increase output and productivity (Figure
2). In the same time land degradation and desertification has been limited and
large surfaces have been recovered. The project strengthened also the productive
structure of breeding sector by introducing forage alternative to grass and
improving the veterinary infrastructures and knowledge.
Moreover the productive structure of the area has been changed by the project
presence, the traditional agro pastoral-system, based on rain fed millet and
nomadic flocks, is getting more complex. Cash crops, as onions and sesame, have
been integrated with cereals, irrigation is becoming more diffuse, fish farming has
been introduced in the reservoirs, the commercialization of non-timber forest
products (Arabic gum, leafs, fruits) given by trees plantations was improved. At
the end of the century Keita reach a new environmental equilibrium, reversing the
degradation and desertification trends. Nowadays, Keita is indicated like an
example in the Sahel region and becomes therefore a point of reference in the
definition of policies and strategies to fight desertification in the Country and the
whole region.
In 2002, a second study (IBIMET-CNR, 2002) assessed the Project
contribution in the framework of the three main international conventions
(UNCCD-UNCBD-UNFCCC). The Keita system appeared an excellent test-site
for carbon sequestration. The study estimated that the Keita valley, thanks to the
project interventions, sequestered approx. 132,000 tons per year of CO2. This
output shows the potential that semi-arid regions have in carbon sequestration
within the Kyoto protocol.
Figure 2 – Keita (Niger), 1985-2003. Agro-pastoral production trends
Banquette Tranchée Glacis
The effectiveness of the Keita Project has been confirmed further by the data collected
on the three main types of intervention focused to soil conservation: banquette de
plateau, tranchée, and banquette de glacis.
The banquette de plateau have transformed the plateau, from a marginal resource for
breeding to a main resource with great potential, as demonstrated by the change in the
existing practices of the local population and the arrival of nomads population. This
resource played an important role in the establishment of a more flexible and less
vulnerable economic system. Data collected in 1996 (PEICRE) and 2003 (PAFAGE)
have shown that forage yields have increased by more than 90%.
The tranchée have proven extreme efficiency in eliminating, or at least strongly
reducing, the water erosion on arable lands and in allowing agriculture activities on
previously abandoned lands. The trees planted represent a valuable resource of wood for
cooking and goat feed.
The banquette de glacis have been effective in reclaiming arable land previously
subjected to desertification and abandoned. Even though, the poor quality of the soil
would not allow yields comparable to those coming from the best arable land in the
valley. The trees planted in the area produced eight times more wood per plant, than the
trees planted in the tranchée and yielded twice as much goat feed than the banquette de
plateau.
Starting from 2003 Keita becomes a ROSELT1 environmental observatory,
operational by the means of PAFAGE Project (CeSIA IBIMET-CNR), funded also
by Italian Aid. The observatory becomes an opportunity to monitor the environmental
and socio-economic changes in the area, in fact existent databases have been updated
and environmental and socio-economic analyses have been carried out.
4. Environmental impacts
The impact of PDR-ADM interventions on the environment has been
monitored by a multitemporal analysis of land cover2. Changes in land cover are
the result of synergies of different factors (climate changes, interventions of PDR-
ADM and demographic pressure).
The environmental status before the beginning of the project testifies the
negative impact of climate and anthropic pressure on the ecosystems. 1962, the
slopes of the highlands were forested but in 1972 some signs of degradation were
Land cover classification is expressed by the LCCS standards of FAO-Africover.
Keita, Niger: the impact on environment and livelihood of 20 years fight against desertification
already evident and in 1984, the forest completely disappeared. Between 1984 and
2002, we assist to a progressive recovery of the natural vegetation (Figure 3).
Approximately, the diachronic land cover study shows that between 1984 and
2002 woodlands increased more than 300% (10,000 ha in 1984 to 45,000 ha in
2002) against a reduction in the shrubby steppes of the 30%. This tendency is
supported, besides the PDR-ADM intervention, also by the progressive increase
of rainfall, which was recorded as from the 1990s.
Even if the same dynamics is observed in the whole Sahelian part of Niger, this
trend has only reached such results in Keita, because of the intervention of PDR-
ADM and the control of the human pressure on natural resources. In addition of
wooden natural vegetation recovery there is also an evident increase of
agricultural surfaces (about 80%) resulting of the substitution of large grassland
areas (decreased about 70%) and of PDR-ADM land reclamation interventions
(about 20,000 ha). These data confirms that the tendency of natural vegetation
recolonisation is reduced by the increase of the human pressure.
More in depth, valleys and glacis are exposed to higher agriculture pressure
and the trend is to the extension of croplands. This happens in three ways: by
reclamation of degraded lands, by reclamation of grasslands or by clearing of
woody vegetation. The first one, supported by the PDR-ADM, concerns the slopes
of the Keita valley and also the sandy dunes of the eastern plateaus (Figure 4).
Land reclamation of grasslands has been push by demographic pressure especially
in the Keita and Insafari valleys. Woody vegetation clearing happens especially in
the secondary valleys where demographic pressure was low before 1984 and
strongly increased later.
Type of land cover 2002 ha 1984 ha Variation %
Woodlands 45,542 10,876 319
Shrub lands 67,422 95,950 -30
Grasslands 17,417 60,277 -71
Rain fed croplands 150,730 84,102 79
Irrigated croplands 1,006 968 4
Bare 124,196 144,998 -14
Dunes 21,847 32,441 -33
Andrea Di Vecchia, Giancarlo Pini, Francesca Soriani, Vieri Tarchiani
By the other hand woody vegetation restoration interests large areas on the
slopes and also in the valleys as gallery forests. This trend on the slopes is
particularly interesting where it is not directly due to Project interventions
(plantation in trenches), because it shows the effectiveness of the watershed
approach and the water management on plateaus and slopes (Figure 5).
Croplands degradation is also observed, due mostly to wind erosion and sand
accumulation. It gives evidence to the fact that desertification is still active even if
PDR-ADM interventions reduced its effects. In this context, the territory
monitoring in the aspects that could indicate a reactivation of the desertification is
very important especially in this phase in which the environment is slowly
recovering equilibrium.
5. Improvement of land productivity
The pressure derived from the population growth is nowadays one of the main
desertification factors, as consequence the classic environmental approach to fight
desertification is doomed to fail if it is not joined with actions aimed to reduce the
pressure through the creation and diversification of sources of income for the
population.
In order to appreciate the project impact, not only the impact on environment
but also the improved productivity of the territory due to the intervention has been
studied. The productivity is assessed considering the main products contributing
to population livelihood: agriculture, forestry, and livestock. In the domain of
agriculture only rainfed cereals have been considered, no data being available
about cash crops productions.
Concerning plantations, this study considers only bloc plantation as tranchée
and banquette but doesn’t consider linear plantations as on the banks of the kori.
This choice is based on the methodological consideration that bloc plantations
will be or could be easily and directly managed at household level3 and their
production can directly enter in the livelihood estimation. On the contrary, linear
plantations are of public utility and cannot be exploited for private purposes.
Moreover, linear plantations are difficult to be inventoried and monitored.
Initially the study considered the whole project area and afterwards the analysis
has been focused on the two more common interventions: banquette de glacis
(bench terraces) and tranchée (trench), expressed per hectare.
5.1 General results
The whole project area produced in 2003 about 25,000 tons of wood, that on the local
market corresponds to about 450 millions of F CFA. In 1984 the value of wood
production is estimated (at the actual price) in 300 millions of F CFA. The variation is
therefore of 49%. The availability of leaf biomass is also increased, about 57%.
3
One of the objectives of the PDR-ADM actual phase is indeed to transfer the management of
interventions to local populations.
Keita, Niger: the impact on environment and livelihood of 20 years fight against desertification
5.2 Specific results
In order to appreciate the improvement on the income generation capacity, the
productivity of 1 hectare of glacis and 1 hectare of slope have been estimates both
before and after the PDR-ADM intervention.
The interventions on the glacis (banquette de glacis) had a yearly growth of
production estimated about 1,400% as consequence that in 1985 glacis were
degraded and uncultivated land. Besides the agriculture, that offers the highest
contribution (about 70%), forage produced by trees (fruits and leafs) and gums
produced by Acacias constitute the second contribution with a net increasing of
1,000% each. On banquette the increase of the yearly productions corresponds to
59,000 Francs CFA. Considering that 2003 GDP per capita in Niger was 232 US$
(WDI - World Bank) as 118,000 F CFA the increase of 50% of the GDP per capita
seems to have a great importance. Another important contribution to the economic
productivity is represented nowadays by the possibility of income offered by the
Carbon market in the framework of Kyoto protocol. In the table the CO2 value is
reported as CERs (Certified Sequestration Units) at the hypothetic European market
value (if forestation CERs could be accepted). In the total value of productivity the
CO2 contribution is not considered because it is in concurrence with wood production
whose value is, for the time being, higher. The CO2 is evaluated on the basis of the
carbon sequestered by woody aerial part and the root part of the tree. Carbon/wood
ratio applied is 0.4974 (experimental value for Acacia seyal).
The intervention on the slopes (plantation en tranchée) gives a net growth of
production value of about 700%. This growth is due mainly to forage and wood
components. The CO2, as for banquettes, is not included in the total value, and it
is given as supplementary information. Anyway, the value of CO2 is still less than
the correspondent value of wood fuel.
In comparison, 1 hectare of banquette de glacis is more profitable than 1
hectare of tranchée due principally to the poor soil fertility and the low soil dept
on tranchée. Of course, banquettes and tranchées have different roles incontrol the
erosion, both necessary for an integrated management of the territory.
Globally 6,471 ha of banquette de glacis and 8,097 ha of tranchées have been
built up to now and assuming the average productivity, when all the interventions
will be at normal running, a total value of about 500 millions of F CFA per year
will be reach. It means, transformed in cereals, the satisfaction of cereal needs for
about 19,000 persons.
The population growth reached the 80,000 units from 1984 to 2003, exceeding
four times the capacity of interventions to assure food security. This shows that the
traditional approach focused on strengthening rain fed cereals productions is not
sustainable on the long run and future intervention strategy should consider the whole
range of agro-sylvo-pastoral productions and also their transformation and
commercialization chains in order to support the development of new sources of
income.
6. Conclusions
20 years of PDR-ADM interventions allowed the natural and production
systems recovery and stabilization. For this reason Keita became an example in
the Sahel, one of more interesting and dynamic economic pole of the country and
an attraction for the neighboring populations.
Notwithstanding the efforts and the indubitable results of PDR-ADM, the
traditional rain fed production systems are still reaching the saturation and the
ecosystem is suffering the human pressure. PDR-ADM approach was designed to
concentrate on the rapid recover from a decaying environment close to a physical
collapse. Now even the ecological equilibrium is demanding a reviewed strategy,
giving priority to the socio-economic dimension, based on developing alternative
sources of income.Important lessons have be learned from the Keita experience.
Land reclamation and conservation practices for agriculture activities are very
important but not sufficient to assure a perspective of development and the
balance between population needs and productions.
Furthermore recovery for degraded territory, such was the case for Keita, is
demanding projects lasting decade and not only years. Keita proved that the
recovering phase to regain the previous environmental balance is demanding
twice the time necessary for the degradation phase. It also provide basis to
recognize that prevention is extremely less costly than the reclamation.
To assure food security in Sahelian areas only by agriculture activities, with the
present population growth, will be not probably possible and sustainable in the
future. Considering that income produced by rain fed agriculture is not sufficient,
the promotion of initiatives aimed to strength the local economic systems by the
diversification of the production is necessary.
Future interventions to fight desertification need to join land conservation and
rehabilitation practices with specific actions aimed to develop new income
generation scenario in order to assure the sustainability and the success of the
interventions in a long-term view.
Andrea Di Vecchia, Giancarlo Pini, Francesca Soriani, Vieri Tarchiani
Finally deeper knowledge of the non-conventional productions should be a
starting point for the identification of a new and suitable approach aiming to
valorize any possible ‘means’ able at generating new sources of income with low
environmental impacts. Trees are a good example; they are an important source of
income for local population because traditionally they have multiple uses. Besides
the underestimated contribution of secondary products (leaves, fruits, etc) to the
domestic budget, trees are used for wood, other commercial products (gums, etc)
and in the future years, the possibilities given by the Kyoto Protocol in terms of
forestation and trade of the Carbon credits could be considerable.
7. Bibliography
Breman H. and Kessler J.J. (1995), Woody Plants in Agro-Ecosystems of Semi-
Arid Regions with an Emphasis on the Sahelian Countries, Berlin, Springer-
Verlag
Di Vecchia A., Genesio L., Mazzoni S., Miglietta F., Vaccari F.P., and Maracchi
G., (2002), Keita integrated project: an appropriate model for sustainable
development, Florence, IBIMET-CNR
FAO (1995a), Role of forestry in combating desertification, FAO Conservation
Guides, 21, Rome, FAO
FAO (1995b), The Keita Integrated Rural Development Project, Rome, FAO
Gourlay, I.D. (1995), “The definition of seasonal growth zones in some African
Acacia species - A review”, IAWA Journal, 16, pp. 353-359
KeitaLAB (2006), http://www.case.ibimet.cnr.it/keita/, IBIMET-CNR, FCS
Le Houérou, H.N. (1996), “Climate change, drought and desertification”, Journal
of Arid Environments, 34, pp. 133–185
PEICRE (1996), Note de synthèse du Projet PEICRE, Florence, CeSIA -
Accademia dei Georgofili
Pini G., Tarchiani V. (2005), Suivi de la désertification, Observatoire ROSELT de
Keita, Projet PAFAGE, Coopération Italienne, Ministère de l’Hydraulique, de
l’Environnement et de la Lutte contre la Désertification, République du Niger
Reij C. and Steeds D. (2003), Success stories in Africa’s dry lands: supporting
advocates and answering skeptics, Amsterdam, CIS / Vrije Universiteit
Wezel A. and Rath T. (2002), “Resource conservation strategies in agro-
ecosystems of semi-arid West Africa”, Journal of Arid Environments, 51, pp.
383–4
WORKING PAPERS ON-LINE OF THE CCTM-POLYTECHNIC OF TURIN
Collection directed by Maurizio Tiepolo
1. RODRIGUES SANCHES A.P., CITTADINO A., ARTUSO M. (2003), ‘Conversão
de terras em solos urbanos, Bissau (Guiné-Bissau), 1989-1997. Análise pela
salvaguarda de agricultura urbana e periurbana e pela segurança alimentar’
2. ARTUSO M. (2004), ‘Urbanisation and public health. The case of Commune 3 in
Niamey, Niger’
3. GIGLIO P. (2004), ‘Ce que je pense’
4. ARTUSO M. (2004), ‘Centri europei di ricerca e formazione post laurea in
pianificazione urbana e habitat nei PVS’
5. MOTCHO H. (2004), ‘Urbanisation et rôle de la chefferie traditionnelle dans la
Commune Urbaine de Niamey (Niger)’
6. GIORDANO L., TIEPOLO M. (2004), ‘Agricoltura urbana e periurbana nel Sahel.
Bibliografia annotata 1977-2003’
7. BALLOCCA A., CAROZZI C., TIEPOLO M. (2004), ‘Lutte contre la désertification et
gestion des ressources naturelles dans les régions Tillabéri et Maradi, Niger (1975-2002)’
8. GIORDANO L., LANZA B. (2005), ‘Praia (Capo Verde): la questione fondiaria
all’origine dei quartieri informali’
9. CANONE D., FALCIAI M., FERRARIS S., GIORDANO A. (2005), ‘Valutazione
delle terre e idrologia dei suoli a fini irrigui: Kongou Gorou, Niamey, (Niger)’
10. MATTONE R., PASERO G., RIVOTTI A., DE CAROLIS S. (2005), ‘Raw Earth
Construction in Patagonia’
11. TIEPOLO M. (2005), ‘Processo di decentramento e implicazioni su demanio e
fiscalità immobiliare a Niamey (Niger)’
12. ARTUSO M. (a cura di) (2005), ‘Formazione per il rafforzamento istituzionale dei
Paesi in via di sviluppo. Il ruolo delle Università e delle Amministrazioni locali. Atti
del Convegno tenutosi presso il Politecnico di Torino il 15 novembre 2004’
13. LOVISOLO F., VITALE S. (2006), ‘Povertà, sviluppo e mobilità rurale in Africa
occidentale’
14. ARTUSO M. (2006), ‘L’International Organisation for Standardisation e il piano
d’azione per i Paesi in via di sviluppo’
15. MATTONE R., PASERO G., RIVOTTI A., DE CAROLIS S. (2006), ‘A green roof
to improve comfort in low-cost homes’
16. MOTCHO H. (2006), ‘La réforme de la Communauté Urbaine de Niamey’
17. BATISTELLA SAQUET D., SAQUET M.A. (2006), ‘Indústria, redes e re-
ordenamento da cidade de São Jorge D’Oeste, Sudoeste do Paraná, Brasil’
18. GAGNOR E. (2006), ‘Decentramento e Projet d’appui au développement local.
Conversazioni con il sindaco di Tarka, Niger’
19. ARENA R. (2007), ‘Andhra Pradesh Management Project: An Experience of Land
Drainage, Guntur, India’
20. PINI G., TARCHIANI V. (2007), ‘Les systèmes de production agro-sylvo-pastoraux du
Niger: 1 – Les filières’
21. PINI G., TARCHIANI V. (2007), ‘Les systèmes de production agro-sylvo-pastoraux du
Niger: 2 – La caractérisation agro-écologique’
22. PINI G., TARCHIANI V. (2007), ‘Les systèmes de production agro-sylvo-pastoraux du
Niger: 3 – Description et analyse’
23. CALANDRA (2007), ‘Per un atlante del turismo sostenibile in Africa’
24. BIASION A., BORGOGNO MONDINO E., RINAUDO F., GIULIO TONOLO F.
(2007), ‘High resolution images for map production in Ninigui, Yatenga Region, Burkina
Faso’
25. TIEPOLO M. (2007), ‘Spatial and management plan of Mavrovo National Park,
Macedonia. An Initial assessment’
Questo Working Paper non è stato sottoposto ad un comitato editoriale.
Questo Working Paper è pubblicato per solo scopo di discussione.
Le opinioni espresse in questo Working Paper sono quelle degli Autori e non corrispondono a quelle del loro organismo
di appartenenza né a quelle del CCTM- Centro Città del Terzo Mondo, Politecnico di Torino.
Copyright CCTM-Centro Città del Terzo Mondo, Politecnico di Torino evandro.costa@polito.it dicembre 2007
Esemplare fuori commercio per il deposito legale agli effetti della legge 15 aprile 2004 n. 106.
Biblioteca Nazionale Universitaria di Torino
Biblioteca Nazionale di Firenze
Biblioteca Nazionale Centrale di Roma
