Cartas de controle estatístico de Shewhart na avaliação de parâmetros hidráulicos de unidades gotejadoras.

Abstract

In semi-arid region, rational water management is essential for the development of irrigated agriculture. Thus, the present research aims to analyze hydraulic performance parameters of drip units irrigated with urban water supply and partially treated domestic sewage wastewater, from Shewhart statistical control charts. For this purpose, the research was developed at the Federal University of Campina Grande (UFCG), in an experimental area belonging to the Laboratory of Irrigation and Drainage Engineering (LEID), of the Academic Unit of Agricultural Engineering (UAEA). To carry out the research, drip units were evaluated every 24 hours, over 576 hours of operation, totaling 25 tests, with a service pressure of 100 kPa. At each test, the hydraulic parameters were determined: Average Flow - Qm, Distribution Uniformity Coefficient - CUD and Degree of Clogging - GE, for two drip tape models irrigated with urban water supply and wastewater from partially treated domestic sewage. Thus, it was verified that the hydraulic performance parameters (Qm, CUD and GE) of the drip units after 576h of irrigation only with water from the urban supply maintained their values between unacceptable and good for CUD and low medium GE. On the other hand, with partially treated domestic sewage wastewater, the parameters ranged from unacceptable to poor for CUD and medium high GE. Regarding the Shewhart statistical quality control charts, there were variations in the irrigation processes from the detection of changes and indications of lack of process control. As for the drip tape models analyzed, the FS presented better hydraulic performance and the FT more susceptible to clogging, with treated domestic sewage wastewater. For the physicochemical and microbiological characteristics of the partially treated domestic sewage wastewater, regarding the risk of emitter clogging, the values were classified from "Moderate" to "Severe".