Characterization of Irrigated Holdings in the Terra Ch«A Region of Spain: a First Step Towards a Water Management Model

Water Resources Management (2005) 19: 23Ð36 C Springer 2005

Characterization of Irrigated Holdings in the Terra Ch«a Region of Spain: A First Step Towards a Water Management Model

C. J. ALVAREZ« ∗,J.J.CANCELA and M. FANDINO˜ Department of Agroforestry Engineering, University of Santiago de Compostela. Lugo, Spain (∗author for correspondence, e-mail: [email protected])

(Received: 15 October 2003; in final form: 3 May 2004) Abstract. The European Union’s Water Framework Directive, and in Spain the National Irrigation Plan, call for the sustainable and integrated use of water resources. Here we report the results of a questionnaire administered to irrigation users in the Terra Ch«aregion of northwest Spain, as the basis for a water management model, and to allow identification of a representative subsample of respondents for ongoing monitoring of irrigation use in this region. The proposed management model should fulfill the dual aims of sustainable water management, namely to promote long-term social and economic development and at the same time ensure long-term environmental protection.

Keywords: integrated water management, irrigation communities, questionnaire, sustainability

1. Introduction Integrated water management, as currently understood, aims (a) to guarantee sustainable use of water resources, (b) to protect and if necessary restore water quality, and (c) to remove water-availability constraints on social development. In areas with significant irrigation, sustainable water management needs to achieve two goals simultaneously: maintenance of irrigated agriculture, and conservation of the associated natural environment (Cai et al., 2003). Water management should promote efficient water use with the key aims of achieving sustainable social and economic development, and of ensuring sustainable environmental protection (Bouwer, 2000; Shangguan et al., 2000). Throughout much of Europe, the demand for water resources is steadily increasing, so that it becomes essential to develop legislation to respond to this challenge and to conserve water resources for present and future generations. The EU Water Framework Directive (WFD) extends protection to all water resources, with the aim of achieving good ecological status by the year 2015. The WFD establishes a water pricing policy in which the price charged to consumers (including agricultural consumers) reflects the true cost. In many regions, this would clearly imply reduced profits in irrigated agriculture (Berbel and G«omez- Lim«on, 2000; G«omez-Lim«on and Berbel, 2000). 24 C. J. ALVAREZ« ET AL.

In addition, the WFD aims to prevent water pollution at the source, establishing control mechanisms to ensure that all pollution sources are sustainably managed. In this regard previous studies have pointed out the utility of environmental indices in decision-making of this type (Manoliadis, 2001). At the same time, the need to reconcile environmental protection with the socioeconomic goals of farmers implies a need for coordination of policy instruments, particularly the WFD and the Common Agricultural Policy (G«omez-Lim«on et al., 2002). This reconciliation of the socioeconomic goals of individuals with the environmental goals of the community requires the cooperation of all parties involved in water management (Loucks, 2000). Indeed, participatory local analysis, taking into account the opinions of stakeholders including farmers and irrigation communities, is the basis for sustainable agricultural development (Stevenson and Lee, 2001), and requires the development of appropriate methodologies for analysis of the environmental, social and economic advantages of irrigation management (Pereira et al., 2002). The current Spanish legal framework pursues a series of global aims that coincide with the integrated water management aims of the WFD, notably the rationalization of agricultural water uses (Embid, 2003). The legislation has advanced markedly between the passing of the 1985 Water Law and of the recent National Irrigation Plan. Ley 29/1985 de Aguas [1985 Water Law] and Ley 46/1999 de modificaciones de la Ley de Aguas [1999 modifications of Water Law] : These laws establish that all waters are of the public domain, and considers hydrological planning as a funda- mental goal in the planning and management of water resources and hydrographic basins. Planes Hidrologicos« de Cuenca [River-Basin Hydrological Plans] Real De- creto 1664/1998 (24 July 1998): These plans aim to guarantee the supply of water to irrigable areas, to regulate use during periods of water shortage, and to increase the efficiency of water use through modernization and rehabilitation of irrigable areas. Plan Hidrologico« Nacional [National Hydrological Plan], Ley 1/2001 (5 July 2001): The aims of this plan are similar to those of the 1985 Water Law and the European WFD. Note that though the application of this plan has met with significant ecological and political problems (Arrojo, 2003; Ib«añez and Prat, 2003), notably continuing conflicts among the different regions of the Spanish state (Beceiro, 2003; Sauri and Del Moral, 2001). Plan Nacional de Regad«õos [National Irrigation Plan], Real Decreto 329/2002 (5 April 2002): This plan aims to harmonize water policy objectives with improvements in the standard of living of farmers, and with rural development and increased competitiveness in agricultural markets. The National Irrigation Plan (MAPA, 2001) aims to contribute to the consolidation of a diversified and competitive national agricultural system, within the context of the Common Agricultural Policy, achieving an improvement in CHARACTERIZATION OF IRRIGATED HOLDINGS IN SPAIN 25 farmers’ living standards and an increase in the productivity and profitability of agricultural holdings, and thus helping stem population loss from rural areas. In addition, this plan will contribute to the modernization of infrastructures for the distribution of irrigation water, the rationalization of resource use, and the reduction of agriculture-related contamination of surface and subsurface waters. The National Irrigation Plan also incorporates environmental criteria for water management in irrigated areas, with the aim of avoiding land degradation, and favouring the conservation and recovery of groundwater resources, and of areas of ecological interest. As a starting point for this plan, it is essential to evaluate the current situation in Spain, through characterization and monitoring of each major irrigated area. There have been previous studies aimed at characterizing irrigation systems, irrigation use and application problems in various regions of Spain (Solbes, 2003; Del Moral et al., 2003). The present article reports a pilot study of an area in northwest Spain, proposing a methodological approach that may be useful in other areas. Specifi- cally, this article reports a study of the Terra Ch«a area of the region of Galicia, in the North I Hydrographic Basin. The aim of the study was to assess the current situation of irrigated holdings, and to explore users attitudes to potential improvements in irrigation infrastructure, thus facilitating irrigation system planning in line with current national and European legislation. It is worth noting at the outset that in our view it would be beneficial to improve the existing Spanish legislative and institutional framework in regards to irrigation, with the aim of facilitating the par- ticipation of irrigation users and other stakeholders in water management planning (Barreira, 2003).

2. Study Area Galicia is a region of 29 434 km2 area in northwest Spain, occupying an evidently peripheral position within Europe. Population is about 2.7 million inhabitants, about 75% of whom live in rural areas (Crecente et al., 2002). Galicia currently has over37000 dairy holdings, although in recent years the number of holdings has declined and mean holding size has increased (Pereira et al., 2003). The present study was performed in the Terra Ch«a (Flat Country) region of Galicia, an area that was developed agriculturally by the Spanish government (In- stituto Nacional de Colonizacion« , National Colonization Institute; Instituto de Re- forma y Desarrollo Agrario, National Institute for Reform and Development) in the 1950s and 1960s. This colonization programme involved land drainage, irrigation system development, and construction of roads and housing. The colonies were located in the municipalities of Castro de Rei and Cospeito (Villanueva and Leal, 1990) (Figure 1). A total of four colonies were set up, in three major sectors. The basic characteristics of each colony are as follows (Cancela et al., 2002) (Figure 2). 26 C. J. ALVAREZ« ET AL.

Figure 1. Map showing the location of the study area.

Sector I, A Espi˜neira is located in the municipality of Cospeito, and contains only one colony, comparising 12 landowners who were installed in 1966 on an area of 351 ha (17 ha per landowner, 10 irrigated, 7 dry); the remaining area was divided into 14 lots assigned to existing landowners and to landowners in Sector III. Sector II, ArneiroÐVega de Pumar is located in the municipalities of Castro de Rei and Cospeito, and contains two colonies, comprising 44 and 22 landowners respectively, installed in 1967/68 on a total area of 1, 502 ha. Sector III, Matodoso is located like Sector II in the municipalities of Castro de Rei and Cospeito, and contains one colony, created between 1958 and 1962. The colony covered an original area of 1, 039 ha, distributed among 114 landowners with housing within the colony, and 10 landowners with housing outside. The Terra Ch«aistraditionally a dairy production area, so that the main crop is pasture, and secondarily forage maize; though in recent years the area under maize has increased, and this crop currently occupies about 20% of the cropped area (G«omez et al., 2003). Increases in dairy smallholding productivity in this region require an increase in either cropped area or in cropping productivity. Since an increase in cropped area has not been possible because of difﬁculties in land leasing and high land prices, improved forage varieties have been introduced (L«opez et al., 1999). Pasture and CHARACTERIZATION OF IRRIGATED HOLDINGS IN SPAIN 27

Figure 2. Map showing the location of irrigation sectors. maize may be planted continuously or in rotation; other alternatives have been tested in experimental trials, but have proved less effective (Lloveras, 1996; L«opez et al., 2000). Climate is cool (mean temperature 11 ◦C), with continental characteristics since the area is surrounded by low mountain chains isolating it from the sea. Mean annual precipitation is 1, 018 mm, and mean daily evaporation during the dry months 3.41 mm (as determined by the Penman-Monteith method; G«omez et al., 2003). The dry months are JuneÐSeptember, with July being the driest; indeed, July rainfall is often less than half of June or August rainfall (Castelao and D«õaz-Fierros, 1992). Soils in the Terra Ch«aregion are cambisols (68% of total area), gleisols (22%), and fluvisols (10%) (Castelao and D«õaz-Fierros, 1992). The summer drought and soil properties mean that irrigation is essential for summer forage production. The Terra Ch«aregion contains a number of wetland sites which maintain high biodiversity and in some cases have traditionally had economically important uses. These sites did not receive specific protection until the late 1970s, and indeed prior to the 1970s these sites were subject to progressive drainage and destruction. Close 28 C. J. ALVAREZ« ET AL. to the irrigated areas considered in the present study are lagoons and associated wetland habitats at Cospeito (in Feira do Monte, Municipality of Cospeito), Caque (in Castro Ribeiras de Lea, Municipality of Castro de Rei), and Veiga de Pumar (in the Municipality of Castro de Rei), in addition to numerous smaller lagoons, all falling with the Parga-Ladra-T«amoga Site of Community Interest. Together, these sites constitute one of the few ecologically significant inland wetland areas in Galicia. The Cospeito Lagoon was in fact partially drained (70 ha) by the National Colonization Institute in the 1960s. However, this site was recently recovered, and currently has protected status (Espacio Natural en Regimen« de Proteccion« General, Xunta de Galicia), as well as falling within the Parga-Ladra-T«amoga SCI.

3. Materials and Methods To characterize irrigated smallholdings in this area we developed a questionnaire for landowners, with the aim of obtaining accurate information on the current situation. Accurate information of this type is necessary for the development of awater management model in line with current legislative requirements (Schultz, 2000). We consider that an understanding of the attitudes and concerns of the landowners is just as important as technical data. The basis for the design of this questionnaire was the census of irrigated holdings published by the National Colonization Institute in 1956. This census, covering a total of 193 holdings, indicated the sector in which each holding was located, and the area of dry and irrigated land in that holding; it also specified the location of each plot. However, this information dates from almost 50 years ago (Cardes«in, 1987; INC, 1956). A provisional questionnaire was first designed and administered to 10 landowners (see Rodr«õguez et al., 1996; Borges, 1998; USDA, 1998; Cuesta, 2001). The results obtained allowed estimation of the cost and time requirement of the final version; we also modified confusing questions, and included new questions. We administered the questionnaire to all 193 landowners in the study area, in view of the heterogeneous results obtained with the provisional questionnaire. In the future, however, it will be possible to apply the questionnaire annually to a representative subsample of the total population, to obtain ongoing updates. The final questionnaire was divided into four main blocks: (1) landowner profile (age, educational level, income, means of acquisition of the holding); (2) holding profile (notably area and principal products); (3) water management aspects (waste water treatment, irrigation systems and use, irrigation communities); and (4) attitudes (towards technological improvements, irrigation water pricing, expectations, etc.). The questionnaire was administered by eight agricultural technicians, each of whom covered a specific part of the study area. Quality control was achieved by ran- domly telephoning 10% of the respondents, and checking about 10% of questions. CHARACTERIZATION OF IRRIGATED HOLDINGS IN SPAIN 29

The tabulated data were directly introduced into SPSS v.11.5 (Statistical Packages for the Social Sciences), which facilitates coding with value tags. Some of the data obtained were compared statistically with data for Galician agricultural holdings as a whole (data from a survey performed in 2002 by the Department of Agricultural and Forestry Engineering of the University of Santiago de Compostela; signiﬁcance level 97%, margin of error 5%).

4. Results

4.1. SOCIAL CHARACTERISTICS OF THE HOLDINGS A total of 74.7% of the landowners currently work as farmers on their holdings (Table I). On average, these landowners have been farming their holdings for 24 years. Of the landowners, 60.1% are aged less than 55 years, suggesting that the holdings are being handed down to the next generation. Age distribution is compared with that of Galicia as a whole in Figure 3. Sex distribution is compared with that of Galicia as a whole in Figure 4: as can be seen, most landowners in Galicia as a whole are women, whereas most landowners in the study area are men. This suggests that the holdings considered in the present

Table I. Respondents responses to the question Do you farm the holding yourself?

Responses Frequency (%) No 2 1.2 Yes 127 74.7 In the past 41 24.1 Total 170 100.0

Figure 3. Age distribution of the respondents in the present study, and of agricultural landowners in Galicia as a whole. 30 C. J. ALVAREZ« ET AL. study are sufficiently profitable to be the main means of family support. This is in line with the finding that for 55.2% of the landowners considered, all income is derived from the holding. The mean size of family units in the study area was four people, with 43.7% of families comprising three or five people (Figure 5). In 58.0% of cases the landowners spouse also worked on the holding; there are practically no waged labourers. Educational level is in general low: 13.5% of the landowners had no school education, and 79.1% received only basic schooling (Table II). Income is likewise low: 73.6% of the total reported month income is less than 1, 800 euros, versus 83% among Galician agricultural landowners as a whole (Figure 6). This difference is attributable to the predominance of dairy farming—currently an activity with low profitability—in the study area. Responses to the questions relating to attitudes are listed in Table III. As can be seen, 57.1% of the landowners would like to expand the irrigated area of their land; 90.0% consider it necessary to improve existing irrigation infrastructure; 71.2% of landowners would be prepared to contribute financially to the improvement of

Figure 4.Sex ratio of the respondents in the present study, and of agricultural landowners in Galicia as a whole.

Figure 5. Frequency distribution of family unit size for the respondents in the present study, and for agricultural landowners in Galicia as a whole. CHARACTERIZATION OF IRRIGATED HOLDINGS IN SPAIN 31

Table II. Educational level of the 163 respondents, and of Galician agricultural landowners as a whole

Study area Galicia Educational level Frequency (%) Frequency (%) No schooling 22 13.5 717 20.1 Primary 129 79.1 2477 69.5 Secondary 11 6.7 338 9.5 Higher 1 0.6310.9 Total 163 100.0 3563 100.0

Figure 6. Frequency distribution of annual income (euros) for the respondents in the present study, and for agricultural landowners in Galicia as a whole. the infrastructure. By contrast, only 38.8% of landowners are interested in ﬁnancial support for training, and only 20.6% would favour the use of waste waters for irrigation. These ﬁndings are perhaps attributable to the respondents’ lack of awareness about these issues.

4.2. TECHNICAL CHARACTERISTICS OF THE HOLDINGS Most holdings (81.5%) are mainly dedicated to dairy production. Milk production is inﬂuenced by the irrigation system used (Table IV); productivity is higher on holdings with sprinkler irrigation than on holdings with gravity irrigation. Thus holdings with larger herds typically use sprinkler irrigation. Forage production in excess of requirements may be sold; most such excess is fresh or silaged hay, though some forage maize is also sold. In this area 87.1% of holdings have their own wells, mostly artesian. In 65.5% of cases the water from these walls is used as drinking water, though 40.5% of respondents have never had the quality of their water tested, and only 6.5% apply chlorination. There is no centralized sewage treatment in this area: household sewage is in most cases (63.9%) stored in on-site septic tanks (pozos negros) which 32 C. J. ALVAREZ« ET AL.

Table III. Respondents responses to questions regarding attitudes to irrigation

Dont know or Question Yes (%) No (%) no reply (%)

Do you want to continue farming? 60.616.522.8 Would you interested in farming rented land? 70.915.713.4 Would you be interested in increasing the 57.140.62.4 irrigated area of your land? Would you like the distribution system to be 89.45.35.3 improved? Would you be prepared to contribute 71.217.611.2 ﬁnancially to such improvements? Do you think that water should be metered 57.625.317.1 and charged to the user? Would you be interested in training courses? 64.130.65.3 Would you be prepared to contribute 38.853.57.6 ﬁnancially to your own training? Should wastewaters be used for irrigation? 20.670.68.8 have little or no treatment function. Farm sewage is typically stored in open slurry ditches (fosas de pur«õn). In 10.9% of holdings household sewage and farm sewage are sent to the same structure, generally the slurry ditch. Slurry from the slurry ditch is generally used as fertilizer. The mean area of the holdings, according to information provided by the landowners themselves, is 15.22 ha, of which on average 10.12 ha are irrigated, i.e. 67% of the total. The original data from the National Colonization Institute (1956) indicated a mean area of 10.70 ha, with on average 76% irrigated. If we additionally take into account that 82.9% of respondents irrigate or have irrigated sometime in the last 5 years, it is clear that irrigation is centrally important in these holdings. Irrigation is either by gravity or sprinkler systems; the former is more widely used (63.3% of holdings). Farmers apply irrigation alternately, but there is no formal rotation system.

Table IV. Mean milk production quota per holding over the period 1998Ð2003

Sprinkler Gravity 2000/01 2001/02 2002/03 2000/01 2001/02 2002/03 28 28 28 Valid 46 46 46 214 402 220 143 226 163 Mean 133 391 134 372 145 442 100 444 104 331 96 155 SD 66 993 66 989 75 845 52 477 52 477 68 692 Min 23 513 23 513 23 153 400 000 400 000 400 000 Max 351 043 351 043 362 910 CHARACTERIZATION OF IRRIGATED HOLDINGS IN SPAIN 33

The water for irrigation is obtained from rivers at a distance of 600 m to 12 km. The water is currently not metered or charged to the farmer, so that the only cost of irrigation to the farmer is the electricity for pumping. In general, the respondents were unable to specify the basic technical parameters of their irrigation systems, even though this is clearly important for efficient and rational water use. This suggests a need for technical support. Within the study area there are seven irrigation communities, and in general the farmers are satisfied with these bodies, though some respondents reported that lack of agreement was a problem. As noted, there is no formal rota system. Most farms use primary tillage only, with secondary tillage uncommon; indeed, some holdings seed directly. Fertilization (mostly cattle slurry and/or 15:15:15 or 8:24:16 NPK chemical fertilizer) is applied by 88.2% of the farmers. It seems likely that in many cases fertilizer application is excessive. In general, slurry is applied after mowing, depending on the weather and tractor access to fields. Most (91.5%) of the respondents claim not to apply slurry close to watercourses, which is of course important for reducing the ecological impact of this activity. Crop pests and diseases do not appear to be an important problem: 42.2% of farmers rated the level of pests and diseases as low, and 40.4% as moderate. 76.0% of respondents claim that they respect the required minimum times between pesticide application and harvesting. About half (48.8%) of farmers reported that they have introduced improvements in their holding, most frequently new stables and milking sheds. Joint ownership of agricultural machinery is not common in this area. Most farmers (74.2%) sell all their milk to the private sector. Only 4.8% of farmers retain a small amount of milk for their own consumption before selling to the private sector. The remaining farmers sell through cooperatives. Less than half of the farmers (45.5%) consider that they have problems with water quality. By contrast, 69.1% consider that they have problems with soil quality. As noted above, one aim of this study was to identify a representative sample of the study population for future studies. The sample was obtained with stratification by holding area, and specification of minimum proportion of variance explained (Robles et al., 2002), resulting in a total of 30 farmers (error 7.9%).

5. Discussion The results of this questionnaire reveal a clear demand among users for improvements in the irrigation infrastructure of this region, in line with the objectives of the National Irrigation Plan. One evident improvement to consider is a switch from gravity irrigation to sprinkler irrigation, which would clearly lead to improvements in a number of respects, including increased efﬁciency of water use, increased irrigated surface area, and system automation. 34 C. J. ALVAREZ« ET AL.

A second measure with evident benefits would be to introduce technical support and advisory services, in view of the observed lack of technical knowledge among the respondents in the present study. Technical support services, provided in col- laboration with irrigation communities, would clearly enable farmers to optimize decision-making regarding the improvement and modernization of their irrigation infrastructure. It would also be of interest for farmers to receive not only short-term technical support, but also longer-term training, enabling farmers to play an autonomous role in the management of the areaís irrigation infrastructures. This aim constitutes one of the basic principles of the 2002 Stockholm Declaration, which also calls for transparent legal mechanisms. The final goal of the Water Framework Directive is to maintain good ecological status of water resources. In the present context, this implies consideration (a) of domestic wastewaters and cattle slurry, which require appropriate treatment before re-use for irrigation, and (b) of the application of chemical products and fertilizers, since incorrect application may give rise to contamination of surface or subsurface waters. The support team should encourage monitoring of well water quality, should introduce a drinking water supply system, and should inform farmers of the most appropriate methods for the storage and treatment of wastewaters on a case-by-case basis, and of appropriate fertilizer doses in regards to the environmental effects. In view of the above, we can conclude that the water management model to be developed should have two central goals: firstly, to develop new irrigation infrastructures that improve the existing system, and secondly, to effectively monitor and manage the new infrastructure in use, with the aim of maximizing sustainability. This management would comprise three components: (a) a technical advisory service for farmers, (b) training for farmers, and (c) water quality monitoring. The present study indicates that effective ongoing monitoring is achievable with a simplified questionnaire applied to a sample of 30 farmers. The first of the above components, the technical advisory service, involves aspects directly related to the questionnaire administered in the present study, though with differences in design and interpretation. The second component, ongoing training, requires quantification of the number of hours of training courses, with monitoring of each participants benefits. Finally, water quality monitoring requires determination of the principal sources of contamination (notably types and quantities of cattle slurry, chemical fertilizers, pesticides, and herbicides), allowing evaluation of the effects per unit area, and thus facilitating environmental management. The work remaining to be done involves the development of a series of indices taking into account the management variables and measuring the sustainability of each holding, allowing effective decision-making in each particular situation. These indices will collate technical, economic, social and environmental data, and will allow monitoring of the development of the management model (i.e. changes in CHARACTERIZATION OF IRRIGATED HOLDINGS IN SPAIN 35 infrastructure, technical advisory support, user training, and water quality monitoring and maintenance). Future efforts should thus be aimed at the analysis of variables that have the greatest effect on farm function. In this way it will be possible to improve the model and adapt its characteristics to the different irrigated areas of this region.

References

Arrojo, P., 2003, ‘Spanish National Hydrological Plan: Reasons for its failure and arguments for the future’, Water Int. 28(3), 295Ð302. Barreira, A., 2003, ‘The participatory regime of water gobernance in the Iberian Peninsula’, Water Int. 28(3), 350Ð357. Beceiro, M. S., 2003, ‘Legal considerations of the 2001 National Hydrological Plan’, Water Int. 28(3), 303Ð312. Berbel, J. and G«omez-Lim«on, J. A., 2000, ‘The impact of water-pricing policy in Spain: An analysis of three irrigated areas’, Agric Water Manage. 43(2), 219Ð238. Borges, C., 1998, O Inquerito« a` Exploraçao˜ Agr«õcola como Fonte de Dados, Instituto Nacional de Investiga¸cão Agr«aria, Lisboa. Bouwer, H., 2000, ‘Integrated water management: Emerging issues and challenges’, Agric Water Manage. 45(3), 217Ð228. Cai, X. M., McKinney, D. C. and Rosegrant, M. W., 2003, ‘Sustainability analysis for irrigation water manegement in the Aral Sea region’, Agric Syst. 76(3), 1043Ð1066. Cancela, J. J., Alvarez, C. J., Neira, X. X. and Crecente, R., 2002, ‘Modelo de gesti«on sostenible del agua en Terra Ch«a’, AEIPRO, Actas VI Congreso Internacional de Ingenier«õa de Proyectos, Barcelona. Cardes«õn, J. M., 1987, ‘Pol«õtica agraria y transformaciones en la agricultura gallega: la zona de colonizaci«on de Terra Ch«a (1954–1973)’, Agric Soc. 44, 243Ð279. Castelao, A. M. and D«õaz-Fierros, F., 1992, Os solos da Terra Cha.« Tipos, xenese« e aproveitamento, Servicio de Publicaci«ons da Deputaci«on Provincial de Lugo, Lugo, 9Ð38. Crecente, R., Alvarez, C. and Fra, U., 2002, ‘Economics, social and envirenmental impact of land consolidation in Galicia’, Land Use Policy 19(2), 135Ð147. Cuesta, T. S., 2001, Gestion« y uso del agua en la zona regable del Valle de Lemos, Doctoral Thesis, Universidad de Santiago de Compostela, Escola Polit«ecnica Superior, Lugo. Del Moral, L., van der Werff, P., Bakker, K. and Handmer, J., 2003, ‘Global trends and water policy in Spain’, Water Int. 28(3), 358Ð366. Embid, A., 2003, ‘Water law in Spain after 1985’, Water Int. 28(3), 290Ð294. G«omez, A., Cancela, J. J., Neira, X. X., Cuesta, T. S. and Dafonte, J., 2003, ‘Metodolog«õa para la propuesta de modernizaci«on de la Comunidad de Regantes R«õo Miño-R«õo Pequeño, Lugo’, AERYD, Actas XXI Congreso Nacional de Riegos, M«erida. G«omez-Lim«on, J. A. and Berbel, J., 2000, ‘Multicriteria analysis of derived water demand functions: a Spanish case study’, Agric Syst. 63(1), 49Ð72. G«omez-Lim«on, J. A., Arriaza, M. and Berbel, J., 2002, ‘Conflicting implementation of agricultural and water policies in irrigated areas in the EU’, J. Agric Econ. 53(2), 259Ð281. Ib«añez, C. and Prat, N., 2003, ‘The environmental impact of the Spanish national hydrological plan on the lower Ebro river and delta’, Int. J. Water Resour. Dev. 19(3), 485Ð500. INC: 1956, Plan General de Colonizacion« de la Zona de la Tierra Llana de Lugo, Delegaci«on INC A Coruña, A Coruña. L«opez, F. X., Piñeiro, J., Ru«õz, B., and Sau, F., 1999, ‘Intensificaci«on de la producci«on forrajera en Galicia’, Agricultura Revista Agropecuaria 802, 384Ð386. 36 C. J. ALVAREZ« ET AL.

L«opez, F.X., Piñeiro, J., Ru«õz, B., and Sau, F., 2000, ‘Efecto del sistema de siembra y del riego sobre el ma«õz forrajero en Galicia ’, Agricultura Revista Agropecuaria 815, 364Ð366. Loucks, D. P., 2000, ‘Sustainable water resources management’, Water Int. 25(1), 3Ð10. Lloveras, J., 1996, ‘Alternativas de cultivos y praderas como medio de intensificaci«on forrajera’, III Xornadas Pratensesn ˜ Intensificaci«on da Producci«on Forraxeira, Lugo, 57Ð69. Manoliadis, O. G., 2001, ‘Environmental indices in irrigation management’, Environ. Manage. 28(4), 497Ð504. MAPA, 2001, Plan Nacional de RegadÌos. Horizonte 2008, Direcci«on General de Desarrollo Rural, Subsecretaria, Ministerio de Agricultura, Pesca y Alimentaci«on, Madrid. Pereira, J. M., Alvarez, C. J. and Barrasa, M., 2003, ‘Prediction of dairy housing construction costs’, J. Dairy Sci. 86(11), 3536Ð3541. Pereira, L. S., Oweis, T. and Zairi, A., 2002, ‘Irrigation management under water scarcity’, Agric Water Manage. 57(3), 175Ð206. Robles, R., De la Puente, T. and Alvarez, R., 2002, ‘Determinaci«on del umbral de rentabilidad de las explotaciones de vacuno lechero, en funci«on del tamaño de la explotaci«on’, Seminario de la Asociaci«on Española de Econom«õa Agraria. El sector l«acteo: Transformaciones recientes y retos futuros, Facultad de Veterinaria, Lugo. Rodr«õguez, A., Arriaza, M. and Ruiz, P.,1996, ‘Opini«on de los agricultores frente a posibles mejoras en los regad«õos andaluces’, Actas XIV Congreso Nacional de Riegos, Aguadulce, Almer«õa, 622Ð629. Sauri, D. and Del Moral, L., 2001, ‘Recent developments in Spanish water policy. Alternatives an conflicts at the end of hydraulic age’, Geoforum 32(3), 351Ð362. Schultz, G. A., 2000, ‘Potential of modern data types for future water resources management’, Water Int. 25(1), 96Ð109. Shangguan, Z. P., Shao, M., Horton, R., Lei, T. W., Qin, L. and Ma, J. Q., 2002, ‘A model for regional optimal allocation of irrigation water resources under deficit irrigation and its applications’, Agric Water Manage. 52(2), 139Ð154. Solbes, R. V., 2003, ‘Economic and social profitability of water use for irrigation in Andalucia’, Water Int. 28(3), 326Ð333. Stevenson, M. and Lee, H., 2001, ‘Indicators of sustainability as a tool in agricultural development: Partitioning scientific and participatory proceses’, Int. J. Sust. Dev. World 8(1), 57Ð65. USDA National Agricultural Statistics Service (NASS): 1998, Farm & Ranch Irriga- tion Survey, Census of Agriculture 1997, volume 3, Retrieved March 10, 2003, from http://www.nass.usda.gov/census/census97/fris/fris.htm. Villanueva, A., Leal, J., 1990, La planificacion« del regad«õo y los pueblos de colonizacion« , Historia y Evoluci«on de la Colonizaci«on Agraria en España, vol. III, MAP, MAPA Y MOPT, Madrid.