Document Type
Presentation
Publication Date
8-1-2014
Abstract
The reclaimed water produced in an urban wastewater treatment plants (WWTP ) seems to be suitable for agricultural irrigation. The selection of agricultural parcels for its application requires the collection and analysis of complex information (e.g. characteristics of the reclaimed water, soils characteristics, type of crop production and maximum needs of water and nutrients, land use, environmental and legal restrictions) and GIS tools for georeferentiation complex information and multi-criteria analysis. The main objective of the study was to identify the suitable agricultural parcels for irrigation with reclaimed water, taking into account its characteristics, the type and needs of the dominant crop production, and environmental and technical criteria, using a GIS multi-criteria analysis. Reclaimed water data from 2009 to 2011 was analysed, namely flow rate, pH, temperature, EC, BOD5, COD, TSS, TN, NH4-N, NO3-N, TP, B, Ca, Cl, Mg, Mn, K, Na, Cd, Pb, Cu, Cr, Ni, Zn, total coliforms, faecal coliforms, E. Coli. The average monthly volume of reclaimed water produced at the WWTP was 272,581 m3. The quality data suggests that there is no risk for groundwater contamination by nitrate. The average EC (0.4 dS m-1) is not a risk for soil salinity, and the concentration of heavy metals and phytotoxic compounds are below the recommend values for crop irrigation. However, the pathogenic content is not suitable for irrigation and disinfection is needed before the application of the reclaimed water. By overlapping 5 thematic maps (water sources, land uses, slopes, urban areas and crops), and environmental and technical criteria to the parcels with dominant crops (fruit trees, corn, olive trees and vine) it was obtained a Suitable Map for reclaimed water application. A total of 47.5 ha of crops can be irrigated with the annual volume of reclaimed water produced at the WWTP.
Comments
Session R33, Hydrologic Modeling: Use and Integration of GIS