I⋅D⋅R INSTITUTO DESARROLLO REGION AL $VF$ $SSOLFDWLRQVGHV6FLHQFHVGHO$FWLRQ3DULV PAPER PRESENTED IN THE PROJECT: “The environmental impact of maize cultivation in the European Union: practical options for the improvement of the environmental impact”. (Contract. nº B4-3040/98/000796/MAR/D1). PART II: WATER QUANTITY AND QUALITY, LIMITING FACTORS AND SURVIVAL ELEMENTS OF THE LAS TABLAS DE DAIMIEL AND GUADIANA RIVER HIGH BASIN. Autores: José Arturo de Juan Valero. Doctor Ingeniero Agrónomo José María Tarjuelo Martín-Benito. Doctor Ingeniero Agrónomo. José Fernando Ortega Álvarez. Ingeniero Agrónomo Mª Isabel Casanova Martínez. Ingeniero Técnico Agrícola Albacete, 12th August 1999 UNIVERSIDAD DE CASTILLA – LA MANCHA Telf. +34 – (9) 67 599200 Fax +34 – (9) – 599233 CAMPUS UNIVERSITARIO DE ALBACETE E02071 – ALBACETE (España) ,1'(; 1.-THE GUADIANA RIVER HIGH BASIN ............................................................................3 2.-THE WEST MANCHA HYDROLOGIC SYSTEM ............................................................ 7 3.-THE WEST MANCHA 23 AQUIFER ............................................................................... 10 4.- CAMPO DE MONTIEL HYDROGEOLOGIC SYSTEM ................................................16 5.-THE CAMPO DE MONTIEL 24 AQUIFER..................................................................... 18 6.-THE “HUMEDALES” IN THE WET MANCHA ..............................................................20 7.- LAS LAGUNAS DE RUIDERA NATURAL PARK........................................................ 22 8.- LAS TABLAS DE DAIMIEL NATIONAL PARK........................................................... 25 9.- THE PRODUCTION SYSTEMS AND THE CROPPING UTILISATION SYSTEM DEVELOPED IN THE WEST LLANURA MANCHEGA. EVOLUTION AND PRESENT PROBLEMS ..........................................................................................................38 10.-IDEAS FOR AN AGRICULTURE OF THE XXI CENTURY IN THE WEST MANCHA AND CAMPO DE MONTIEL AQUIFERS ZONES ...........................................54 2 7+(*8$',$1$5,9(5+,*+%$6,1 Guadiana River and its influents run in Castilla-La Mancha, Extremadura, Andalucía and Portugal. The Spanish area of the Guadiana basin covers 60256 km2, whereas the Portuguese zone occupies about 11600 km2. The Guadiana head, called High Basin, covers 16037 km2 of the South Castellana Plateau. This area extends between Montes de Toledo, Sierra de Altomira to the North; Albacete Llanos and the Sistema Ibérico to the East; and Sierra Morena and Sierra de Alcaráz to the South flowing in an East-to-West direction towards Extremadura. This area is situated in Castilla-La Mancha Community, distributed among Ciudad Real, Toledo, Cuenca and Albacete provinces, taking the water from Guadiana River and its influents from its rise to the El Vicario dam, near Ciudad Real (Figure 1). Since a planning point of view, the Guadiana Hydrographical Confederation (CHG) divides the High Basin into 7 subzones: Subzone 1.1: High Guadiana to Peñarroya dam (1950 km2). It covers the Campo de Montiel sector, which drains toward the Guadiana Alto- Lagunas de Ruidera. Subzone 1.2: Llanura Manchega (10713 km2). It occupies the central part of the High Basin, including Los Ojos del Guadiana and Las Tablas de Daimiel. Subzone 1.3: Azuer to Vallehermosa dam (524 km2). Azuer River rises from a drainage in a South sector of Campo de Montiel, near Villahermosa. It flows into this district to Villahermosa dam, after it introduces itself into the Llanura Manchega. Subzone 1.4: Riansares (1355 km2). Riansares river rises in Sierra de Altomira (Cuenca), meeting the Cigüela near Quero (Toledo). Subzone 1.5: Cigüela (1685 km2). This river emerges in Altos de Cabrejas (Cuenca), linking to the Guadiana in Las Tablas de Daimiel. Subzone 1.6: High Záncara to Torrebuceit dam (144 km2). The Záncara rises very near the Cigüela, meeting the Guadiana in Las Tablas de Daimiel. Subzone 1.7: Bañuelos (687 km2). The Bañuelos River rises from the South offset in Montes de Toledo, emptying into Vicario dam. The average altitude of the Guadiana High Basin is about 800 meters. Geologically, it is formed by permeable materials -chalks over a marl and clay impermeable base. The scare basin relief, the absence of a well defined drainage network and the abundance of aquifer formations cause the existence of several lagoons with different sizes, genesis and hydraulic working forming the “Wet Mancha”. 3 . )LJXUH. The Guadiana River High Basin 4 Since the hydrogeologic point of view, four aquifers systems can be defined. They form five hydrogeologic units, taking into account the Public Works Geologic Service terminology – Spanish Technologic Geo-mining Institute (Fig.2): Sierra de Altomira Acuifer System (nº 19): 04.01 Hidrogeologic Unit. It has an approximate area of 2600 km2. Lithologically, this Aquifer System is constituted by Jurassic and Cretacic chalks and bitter spars separated by marls and lime marls levels. The wall is represented by the Keuper (Triassic) clay facies. The total power of these carbonated materials can reach 1100 m. On this carbonated serie, continental arborescent-evaporite materials (clays, arenytes, puddingstones and gypsums), which can have a thickness of over 300 m, are deposited. This system works as a free aquifer in the chalk and marl outburst and as a confined or semi-confined aquifer in the rest, when they were covered by the Tertiary existing among the alignings. The Jurassic materials form the main aquifer. Mancha de Toledo Aquifer System (nº 20): 04.02 Hidrogeologic Unit (Lillo- Quintanar) and 04.03 Hidrogeologic Unit (Consuegra-Villacañas). This aquifer covers 3550 km2. It has a difficult lithology due to the fact that it includes small outbursts of Cambrian chalks, arenytes, Triassic puddingstones, chalks and Tertiary arenytes separated by clay, marl and gypsum levels. Depending on the materials geologic characteristics, the main permeable spans are formed by the Cambrian chalks, the arenytes of the Triassic base, the marl-calcareous assemblage rich in Tertiary gypsums and the wilderness chalks. Besides, these Palaeozoic, Triassic and Tertiary formations, which are the most significant aquifers, other Pliocene materials and Quaternary sediments are also considered as permeable spans. But due to their variable and scare thickness, they would not form important aquifers. They would be different aquifer units, connected among them by means of less permeable materials. West Mancha Aquifer System (nº 23): 04.04 Hidrogeologic Unit. This aquifer system covers an area of 5500 km2 and it is an essential part of the Guadiana River Basin. It is a morphoestructural hollow, where over a Palaeozoic baseboard (shales and quartzites) and Mesozoic (detrited and carbonated materials), Tertiary continental and Quaternary materials have been deposited on the baseboard and present a general narrowness to the East. Two aquifers separated by an intermediate detrited level are shown in this Hydrogeologic Unit: • Top Aquifer, 3000 km2, constituted by chalks and marly chalk from the Superior Miocene and from Plioquaternary detrited materials. It has an average thickness of 35 m and maximum powers of 200 m in the centre of the Basin. It is a free aquifer. • Intermediate detrited level. It has two spans with different lithology: 1) the top one clay-sandy with gypsums and 2) the bottom one with puddingstones. As a whole, it is an aquitard, which presents locally detrited levels working as aquifers. These materials belong to the Inferior Miocene. 5 • Bottom Aquifer. It is represented in the East sector of the 04.04 Hidrogeologic Unit. It is formed by the infralaying Mesozoic permeable levels to the Tertiary assemblage. Three levels form it; the top one is form by Cretacic chalks and has a power from 10 to 30 m. The intermediate level is formed by oolite chalks of 50-60 m thickness. The bottom level has Inferior Jurassic dolomite-chalk materials with a thickness of 60-90 m. It is a confined or semi-confined aquifer by the detrited unit of the Inferior Miocene. )LJXUH. General map of the Guadiana High Basin. Hydrogeologic Units. 6 Campo de Montiel Aquifer System (nº 24): 04.06 Hidrogeologic Unit. It has an approximate area of 2600 km2. It shows a basement of Primary materials formed by Ordovician quartzites and Siluric shales on which the Mesozoic assemblage of Campo de Montiel was unconformably deposited. Triassic chops up in great areas in the South and West of the aquifer. It is formed by three formations, presenting usual lateral facies changes and thickness variations, from 150 m to 0 m around the Palaeozoic primaryforms. The bottom span is detrited, the middle one carbonated and the top one is formed by a clay, marl and gypsum assemblage belonging to the Keuper facies, and act as an impermeable base of the aquifer. The mean power of the main aquifer is from 75 to 100 m, although 300 m can be reached. It is a free aquifer. 7+(:(670$1&+$+<'52/2*,&6<67(0 The West Mancha is situated in the Southwest of the natural Mancha region. It extends all over 10000 km2, and over townships of Ciudad Real, Cuenca and Albacete. Its altitude varies between 600 and 700 m, bending smoothly in an East-to-West direction. The climate is Mediterranean-Continental type, characterised by extreme thermic conditions. In winter, there can be temperatures of –12ºC and in summer 43ºC can be reached. The mean temperature of January is 5ºC and the mean temperature of July is 24ºC. It is one of the most extreme zones in Spain. This area has an average