3 RESULTS
From 2007 to 2018, 14,076 ha were diagnosed in Vera Cruz, 9,027 ha in
Ocauçu and 27,775 ha in Marília, out of a total of 53 thousand hectares,
corresponding to the Rio do Peixe watershed stretch. In Vera Cruz, 94
agricultural properties were notified, out of a total of 176 properties.
In Ocauçu, 82 agricultural properties were notified and in Marília,
using the Innovative CDA Methodology (Vischi Filho et al. 2017 and
2018), in just nine months, 20 large agricultural properties and 32
small properties were inspected, with a total area approximately 27.7
thousand hectares. It was diagnosed and evaluated from January to
November 2017, in just 9 months of work, 27,775 ha or 3086 ha per month.
This methodology allows the strategy of evaluating, in detail, an area,
which, according to the old methodology, would take 103 months to be
carried out (8 years and 7 months) and in just nine months the work was
accomplished generating time and cost savings, with income of 1377%
favorable to the Innovated CDA Methodology. Erosions and other soil
degradation processes are reported in Table 1. These inspections already
carried out received the conservation technical projects for the areas
and were implemented.
The results obtained with the changes in soil and water conservation
management practices regarding the improvement of vegetation cover were
confirmed by the evaluation of aerial images before the study was
carried out - 2002 - and after the study was carried out - 2013 -
(Figure 2). The results of the ”in loco” survey for land use and
occupation (Table 2) show that the following crops predominate at the
Watershed: pastures with 30,472 ha, coffee with an area of 2,798 ha,
fruit (mango, coconut, and citrus) with 136 ha, eucalyptus with 95 ha,
vegetables with 60 ha, passion fruit with 15 ha, crops of annual cycle
(corn and beans) with 181 ha, sugar cane with 37 ha and in the
environmental condition, natural forest, with 10,606 ha that cover the
slopes of the formation known as ”Itambé”.
The improvement in water quality caused by the control/minimization of
erosive processes and sediments carried to the watercourse were
confirmed by the water quality indicators: Turbidity, Suspended Solids,
Phosphorus and Organic Carbon, analysing the representative graphics the
results of these analyses (Figure 3). The Turbidity of the water
evaluated from 2000 to 2007, considered as before the work was carried
out (BEFORE - T1), presented average values of 192 NUT (Nephelometric
Units of Turbidity), against the average values of 102 NUT, evaluated
from 2008 to 2018, considered as after the completion of the study
(AFTER - T2), a decrease of 53% in the average values. The suspended
solids evaluated from 2000 to 2007 (T1), presented average values of
297 mg l-1 (milligrams per litre), against the average values of 132
mg l-1, evaluated from 2008 to 2018 (T2), a 44% drop in average values.
The phosphorus evaluated from 2000 to 2007 (T1), presented average
values of 0.18 mg l-1 (milligrams per litre), against the average
values of 0.14 mg l-1, evaluated from 2008 to 2018 (T2), a 78% drop
in average values. The Organic Carbon evaluated from 2000 to 2007 (T1),
presented average values of 9.60 mg l-1 (milligrams per litre),
against the average values of 5.19 mg l-1, evaluated from 2008 to 2018
(T2), with a 59% drop in average values. (Vischi Filho et al., 2019).