22. A Dissipative, Self-organizing and Open Water System: The Case of Tlaxcala

This chapter is a synthesis of parts of the book by Úrsula Oswald Spring (2005), El Valor del Agua: Una Visión Socioeconómica de un Conflicto Ambiental, Mexico, D.F., Coltlax, Gobierno de Tlaxcala, Conacyt: 11-228.

The methodology of open dissipative and self-regulating systems with interrelations among the natural and socio-economic system was progressively developed in the research programme “Food System and Society”, sponsored by United Nations Research Institute for Social Development. See also Chaps. 15, 17, 21.

This aquifer consists of permeable water-bearing rocks from alluvial and lacustrine origin, whose southern portion is mainly composed of alluvial material with good permeability and transmissibility.

The most popular method to establish the vulnerability index of an aquifer is an Aquifer Vulnerability Index (AVI; Stempvoort et al. 1992), which analyses the hydraulic conductivity of each layer constituting the vadose zone and its thickness. DRASTIC measures depth, net recharge, medium aquifer, soils, topography, impact on the vadose zone and hydraulic conductivity (Rodríguez et al. 2001). SINTACS (Civita/De Maio 1997) takes into account seven parameters, allowing georeferenced overlaying maps to understand additional risk factors, such as expanding urban sprawl and sources of pollutants (from landfills, pantheons, industries, toxic waste disposal, etc.). These three methods are useful and depend on the accuracy of the required data and the availability of finances for the study. In any case, according to the “First Law of Vulnerability” all groundwater resources are vulnerable (Rodríguez et al. 2001) and, despite risk and vulnerability studies, there is an uncertainty in spatial data, which justifies the “Second Law of Groundwater Vulnerability”, which implies that uncertainty is inherent in all vulnerability assessments (Rodríguez et al. 2001).

The volcanic formation is reflected in its geology with extrusive igneous rocks from the Quaternary and Tertiary periods of earth history. Mesozoic contributed only 0.07 per cent of deposits, while 22.23 per cent of soils were formed during the Quaternary.

Liquid fertilisation of the crops during the irrigation, which reduces chemicals and water.

The talavera or majolica pottery industry developed after the Spanish conquest in Puebla and Tlaxcala because of the natural clay found there. The tradition goes back to the 16th century and the tales or plates are covered with a white glaze. The design of the pieces is highly regulated by tradition. However, recently new designs and colours were introduced, which has stimulated demand in the international market.