Ecorestoration of Banni Grassland - Global Restoration Network

Ecorestoration of
Banni Grassland
2. STUDY AREA
2.1 Location
Banni, the largest single stretch of grassland in
India, is located on the northern border of Bhuj
taluka (23° 19' 23° 52' N latitude and 68° 56' to 70° 32'
E longitude) of Kachchh district in the Gujarat State.
It encompasses an area of 3,847 sq. km and forms a
low alluvial tableland. The entire area is more or
less flat and without any gradient. Banni has 52
villages, which are under 17 panchayats (Census
1991). The plains of Banni geomorphologically
resemble an embayment, which is bounded by the
Kachchh mainland upliftment in the south, the
Pachchham upliftment in the north and the Wagad,
and Bela upliftment in the east. In the southern part
of Banni there is an intervening stretch of salty
waste known as Little Rann of Banni, which
separates the Banni from the mainland of Kachchh
(Figure 1).
The name Banni was derived from a Kachchhi word
‘Banna/’, which means “Banni hui” in Gujarati
(made up); signifying that the land has been formed
by detritus. There are views that Banni was formed
by the sediments brought down by the rivers such
as Indus, Luni, Banas and Saraswati which, in the
recent geological past, flowed through this area
from the north and east (Kadikar, 1994).
2.2 Climate
The climate of Banni is arid. There are three predominant
seasons; monsoon extends between end
of June to September, October and November being
the transition months, winter lasts from December
to March and summer spreads between April
to June. The temperature of Banni is high during
most of the time and it reaches a maximum of 48-
49°C during May-June (the hottest months). The
winter temperature goes down to 10° C with January
and February being the coldest months. The
total annual rainfall, occurring through south-west
monsoon between June and September, is very low
with an average of 317 mm per year with a coefficient
of variation of 65 per cent (GAU, 1989). The
16
rainfall is extremely erratic and variable in distribution,
therefore, droughts are a recurring phenomenon.
2.3 Banni Soil
The soils of Banni are inherently saline and consist
of recent alluvium mixed at places with aeolian
sandy deposit and the entire area has deep to very
deep clayey and coarse textured soils in
discontinuous patches. In Banni, soil material
containing clay loam to silty clay loam is termed as
moderately fine textured soils, which ranks first in
distribution and covers 59 per cent of the total area.
The salinity of the soil is highly variable from 1.0
(very low) to over 15.0 Mmhos/cm (very high).
About 90 per cent of the Banni area falls under
moderate to very high salinity and the pH ranges
between 6.5 and 8.5. The soil salinity also changes
with the depth of the soil horizon. Though, the
subsurface water in Banni exists at shallow depth
of about 3m, it is highly saline, thus not suitable for
drinking or irrigation purposes. Further, the
presence of high silt and clay content lessens the
vertical and lateral movement of surface and
subsurface water. About 70 per cent of the Banni
area fall under very slow to slow permeability range
(0.00 to 0.13 cm/hr) which subsequently leads to
waterlogging in the low-lying areas during good
rainfall years.
2.4 Vegetation
Banni supports the growth of perennial and
palatable grasses of high productivity, which grow
in low to moderate saline areas. They are
Sporobolus pallidus, Sporobolus helvolus,
Dichanthium annulatum, Cenchrus ciliaris,
Cenchrus setigerus, Desmostachya bipinata etc.
High saline areas are colonised by perennial grasses
of low productivity and palatability such as
Aeluropus logopoides, Eurochondra sp. etc.
Among the tree species Acacia nilotica was once
distributed all over Banni. The shrub and tree strata
were mainly composed of Prosopis cineraria.