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SUPPLEMENT TO THE ANNUAL REPORT OF THE

FIRST REPORT ON MALARIA IN MOPAD (MARCH 1926)

BY LIEUT.-COL. H. H. KING, I.M.S.

AND

CIVIL ASSISTANT SURGEON K. V. KRISHNAN.

      Institution of survey.—In 1923 an epidemic of malaria was reported in Mopad
area in the north-west of Nellore District, in which an irrigation work had been
completed in 1921. Recent reports showed that malaria was steadily getting
/worse. Accordingly at the request of the Director of Public Health the present
survey was carried out in March 1926 by the King Institute. Dr. Krishnan did
all the field work and has collaborated in the writing of this report. One of the
objects of the survey was to ascertain how far irrigation was responsible for the
increase of malaria in the locality.

      Description of area.—The Mopad area is situated in the north-west portion of
the Nellore District (in Kanigiri Taluk) near the foot-hills of the Eastern Ghats
and about 50 miles from the east coast of the Madras Presidency. It will be
apparent from a look at the attached map (see map of second report) that the
Mopad area is bounded on the north by the Maneru river (or rather river bed),
on the south by the main Mopad canal, on the east by the junction of the Maneru
and Pilaperu rivers and on the west by the Mopad Reservoir and the table-land
adjoining it. The whole area is almost level and is about 7 miles long and 3
miles broad. It contains three main villages and four subsidiary hamlets.
Although intersected by the two streams, Maneru and Pilaperu, and by numerous
irrigation canals, there is very little cultivated land except in the immediate
neighbourhood of each village. This is partly because in many places the soil is
rocky, and partly because of the lack of labour which the people attribute to
malaria. The country around the Mopad area is covered for miles with thin scrub
jungle intersected by low rocky hills mostly destitute of verdure, thus giving it a
dry and barren appearance. Topes and trees are practically absent,

      Irrigation works.—The Mopad area was in an unproductive zone where the
occurrence of famine was common. So as a protective measure, a reservoir was
built to irrigate it and adjacent areas. The reservoir has been formed by the
construction of an earthen dam across the river Maneru where it flowed out
between two hills west of Mopad. It has a capacity of 2,000 millions cubic feet.
The main canal flows in a south-westerly direction through the Mopad area
towards Nekunampet in the Kävali Taluk, where it ends. The area that can be
irrigated is 12,500 acres; but the area actually now under irrigation is only 4,000
acres. Of these the area now under irrigation in the Mopad is only 1,600 acres
which is a tenth of the Mopad area. The water is used mainly for wet cultiva-
tion. Irrigation goes on throughout the year except in June and July when the
main channel is closed for annual repairs.

      The soil.—The soil consists mostly of porous red sand and red loam, but in
some parts is black loam and black clay. In places there is an apparent absence
of soil and preponderance of rock and stone. The soil along the banks of the
Maneru and in the immediate vicinity of the villages is the most suitable for
cultivation. The sub-soil water in most places was found to be high, being not
more than 6 to 8 feet from the surface and this despite it being the dry season. In
some villages (Kattakindapalli) the sub-soil water was almost on a level with the
ground. The people say that before the irrigation project, the level of the water
in wells was far deeper, being about 25 feet (this is given as the previous average
level in reports of the Irrigation Department) and also that the quality of well
water was better and more drinkable. But, now, the water level in the wells has
risen considerably and the water has become brackish and undrinkable. Hence
wells have fallen into disease and there are only a few left. Drinking water is
now obtained from the canals and rivers.

      The climate.—The climate is hot and dry throughout the greater part of the
year, it is cooler and less dry from October to January. There are no sudden