Efficiency Analysis of Policies Against Desertification by Applying Dea: a Case Study in the River Guadalentin Catchment (Almeria, Spain)
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EFFICIENCY ANALYSIS OF POLICIES AGAINST DESERTIFICATION BY APPLYING DEA: A CASE STUDY IN THE RIVER GUADALENTIN CATCHMENT (ALMERIA, SPAIN) Joaquin Solana-Gutierrez Leopoldo Rojo-Serrano Sara Ramos-Algama Universidad Politecnica de DG Medio Natural y Politica TRAGSATEC Madrid Forestal C/Principe de Vergara 208 ETSI Montes C/Abascal 12 28040 Madrid-Spain (Ciudad Universitaria) 28040 Madrid-Spain [email protected] 28040 Madrid-Spain [email protected] [email protected] ABSTRACT This paper deals about an attempt to evaluate the different policies against desertification carried out during a twenty five year period (1978-2003) in the eight municipalities which compound the river Guadalentín catchment (Murcia, Spain). The approach is based on DEA and the European Environmental Agency indicator studies, the former to measure the efficiency and the second to select the best environmental indicators. The analysis has been reiterated with three different sets of outputs related to the different levels and aspects of the desertification process- from the merely soil losses to the overall desertification process in which population losses are considered. As a result a set of efficiency indexes has been obtained for each municipality, which show clearly the contribution of each action against desertification. These results are very valuable to establish future long term desertification policies in similar territories. THE APPROACH TO ANALYSING THE have a substantial influence on the degree of POLICIES desertification. However, it is internationally accepted [7,8] that the factors contributing to Numerous environmental measures have been desertification include erosion, deforestation, taken by the different authorities to alleviate loss of landscape diversity and human the problem of desertification in south-eastern depopulation. Monitoring the system and the Spain [1,2]. In the past national strategy was factors involved requires a system of indicators aimed at repopulating large areas, but in recent which reflect its development [9,10]. years policies have shifted towards changing crop types, generally financed by European This study takes policy against desertification Union schemes [3,4]. Doubts arise when the to mean the management and implementation question is raised of whether this is the best of plans and projects in a region with the aim policies and which activity is the most efficient of mitigating desertification. Such way of achieving the objectives [5]. management would include economic and Desertification is a slow and complex process; fiscal tools such as subsidies for giving up a variety of actions have been taken and their farming activities, subsidies for improving effects have been diluted over time. It must agro-forestry infrastructure, soil conservation also be admitted that this is a multidimensional practices, environmental assistance, training or multi-attribute process: there is a physical aid and so on [11]. component, a biological component and a social component, and therefore studying it With regard to the information used, it was involves seeking indicators to reflect the impossible to gain access to some data due to process as a whole [6]. statistical confidentiality clause protecting the It must be remembered that the slowness of the personal details of each landowner. Moreover, process means that the results can only be it is hard to date the information which exists assessed after decades. Moreover, the concerning the reforestation measures carried complexity of the process means that measures out, because several years can pass between an which are theoretically unconnected with it application for a subsidy and the actual Guadalentín valley or Águilas- measure, which makes estimates of running- Mazarrón.[12,13] down and capitalization rather imprecise. The soils are little evolved, with few horizons, For the above reasons, it was decided that the and are difficult to differentiate. Their depth policies would be analyzed in terms of and physical and chemical features are physical variables such as the area reforested, determined by the type of geological strata; the area subject to water planning and soil deeper soils lie over soft substrates and in flat conservation practices, the reduction in the areas, while shallower ones lie over hard, dryland farming area, the increase in irrigated rocky substrates and on slopes. farmland or the land declared a protected The vegetation in the region consists of non- natural area. Thus, “policies” are characterised deteriorated scrub, retreating scrub, pinewoods here through a set of indicators associated with with juniper. In highland and foothill areas the municipality, which is the chosen working hills with holm oaks and Mediterranean scrub unit of territory [12]. may be found. Lorca and Puerto Lumbreras have extensive areas with dryland farming, It seems reasonable to believe that all the scrub and fields of esparto grass, with some measures have a positive effect on pinewoods in the hills. There is irrigated desertification, but it is also reasonable to farmland on the Guadalentín plain. To the east argue that not all of them contribute to the goal (Mazarrón), aquatic ecosystems predominate, in the same way. The question posed here is with wetlands, salt lagoons, salt marshes and which policy implemented in the area has salt flats. In the hills of the Sierra de proved the best way of countering Carrascoy, the wet Mediterranean holm oak desertification. woods of Murcia make their appearance. The approach to the problem is firmly based Around Totana cabbage palm is plentiful. In on a variety of criteria, as both the indicators the Sierra Espuña stands of gall oak, of responses (reforestation, water planning, tetraclinis, maple and strawberry tree can be abandonment of crop growing, construction of seen [12,13,15]. dykes and so on) and the indicators of the situation (soil losses, reduction in cover, SOURCES OF DATA AND INDICATORS deterioration of vegetation) involve multiple components. For this study data were handled using a vector-based geographical information A system of indicators must be based on system (GIS), but many measures could only variables which are easy to measure and be assigned at municipal level. Consequently, interpret. The sources of information used to for each municipality there is a multi-criterion produce the indicators were the following: vector of indicators of the current situation (y) and of indicators of taken actions (x), and there Vegetation: Digitized maps were obtained must be an assessment of which of these from the maps of crops and exploitation of vectors achieves the best combination of 1978 and 2003[14,15]. Vegetation was also an measures to optimise the indicators of the essential component in mapping laminar desertification situation. erosion, salinity and structural diversity. LOCATION AND GEOGRAPHY Erosion: Use was made of the information contained in the map of erosive states and in The study took in the agricultural area around the national soil erosion inventory and the data the river Guadalentín, one of six which make were extrapolated to make up two consistent up the region of Murcia, covering an area of laminar erosion maps consistent with the 3,096.4km2 which is divided into eight MUSLE: one for the year 1978 and the other municipalities: Aguilas, Aledo, Alhama de for 2003 [16,17]. Murcia, Librilla, Lorca, Mazarrón, Puerto Lumbreras and Totana. Except for the Diversity: The Shannon-Wiener index was Guadalentín, there are no permanent taken as an indicator of structural diversity of watercourses, though there are two reservoirs: plant life in the region because it is one of the Valdeinfierno and Puentes. The aquifers in the simplest and most widely-used [18]. Taking region are extensive, holding large reserves. structural diversity as a sustainability indicator However, generalised over-exploitation and was quickly accepted by the scientific and the resulting deterioration, basically in the technical community, and these indices are form of increased salinity, has led to a critical currently being used for the Spanish National situation in many areas such as the Statistics Institute (INE) for each municipality DESCRIPTION OF TAKEN MEASURES in the 3rd national forestry inventory [19]. TO PREVENT DESERTIFICATION: PERIOD 1978-2003 Population: The information collected by the The measures which have been taken in the years 1978 and 2003 was obtained [20]. different municipal areas are described and summarized below: Reforestation: The information about corrective forest and water management Aguilas (DMU-1): Considerable planning but measures was obtained from the staff of the little execution of forestry work and the regional and central governments and the abandonment of farmland has ceased; in documentation concerning their proposals addition irrigated land has been extended. [21]. The reforested areas and those covered Erosion level has slowed down a lot and by corrective forest and water management diversity and population have arisen. projects were inspected, and the number of projects carried out was reviewed. Aledo (DMU-2): Considerable reforesting but When the study was planned it was expected little soil practice conservation and the that access to information about the measures abandonment of farmland has ceased; erosion taken and the economic resources and funds has slowed down, diversity has improved and used (Euros invested in reforestation by the population has increased. hectares, Euros invested