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IAPRS & SIS, Vol.34, Part 7, “Resource and Environmental Monitoring", Hyderabad, India, 2002
consisting of schist and quartzite. The soil is loamy to sandy
loamy. Hydro-geo-morphologically the study area mainly
consists of alluvial plain, pediment and structural hills. The
study area has sub-tropical continental monsoon climate. The
total average rainfall of 445.9 mm distributed over a period of
23 to 35 Days is erratic. May and June are the hottest months,
while January is the coldest. Temperature variations are high:
4°C to 25°C during winter and 30° to 40°C during summer.
Relative humidity is generally low. The area is also experiences
climate uncertainty and there is sporadic occurrence of drought.
AIM & OBJECTIVES
It is very difficult to develop the large area in one stretch
due to some geo-environmental or economic conditions.
So there is a need to prioritize the area while applying the
development program. The aim of the study is to prioritize
the micro-watersheds based on the morphometric
parameters with the help of GIS technique.
DATA USED
IRS-IC LISS-III, Geo-coded FCC, dated 8" October 1998
and 8 march 1999, updated drainage map, Survey of India
toposheet No. 54A/13, 54A/14, 54E/1 and 54E/2, was used
for the present study.
METHODOLOGY
The updated drainage network map and. micro-watershed
boundary was on screen digitized in MapInfo and exported
to ArcInfo GIS software for data preparation like editing
and converted into real coordinate system. These data was
finally exported to MapInfo Professional GIS software for
morphmetric analysis. The data was calculated in two
aspects linear aspect and areal aspect. Linear aspect
includes stream order, number of streams, length of stream
and bifurcation ratio. Areal aspect includes micro-
watershed perimeter, area, stream frequency, drainage
density, and drainage texture. The stream order was
calculated by Strahler's stream-segment method. Each
finger-tip channel is designated as a segment of the first
order stream. At the junction of any two first order
segments, a channel of the second order is produced and
extends down to the point where it joins another second
order channel produce the third order and so on. There are
fifty-four micro-watershed in the block, out of these five
micro-watershed was not included in the present study
because of no streams in this block. The length of stream,
number of stream, area and perimeter of micro-watershed
was calculated in MapInfo by its command syntax. The
geometry of the micro-watershed was studied by
calculating the form factor, circularity index and
elongation ratio by using the following formulas.
1. Horton’s Form Factor
F = A/L?
Where F is Form factor indicates elongation ratio of the
basin; A is area of the basin; L is Basin length.
2. Miller's Circularity Index
C=4nA/P
Where c is Circularity Index; A is area of the basin; P is
perimeter of the basin.
3. Elongation ratio
R 2 2/L * VA/ n
Where R is Elongation ratio; L is basin length; A is area of
the basin.
The formula of other parameters is following:
Bifurcation ratio 2 Nu/Nu,,
Where Nu is number of stream of particular order,
Nu,, is numbers of stream of next higher order.
Drainage density = Length of the stream/Area of the basin
Stream frequency = Number of stream/ Area of the basin
Texture ratio 2 2/Ly * VA/ x
Where L, is Basin length and A is Area.
After calculation the drainage morphometric parameters,
the thematic map is prepared with three categories i.e.
High, Medium and Low. The value of the morphometric
analysis was shown in Table — 1.The rank of micro-
watershed was also calculated for the prioritization.
The rank was calculated for each watershed. Four
parameters like Bifurcation ratio, drainage density, stream
frequency and texture ratio. The higher value these
parameter was given the first rank, next higher to 2" and
so on. In the next three parameter like form factor,
circulatory ratio and elongation ratio, the lowest value was
the first rank, next higher value has second rank and so on.
The mean rank was calculated for each micro-watershed.
Then the priority was set. The lowest mean value was set
to first priority, next higher mean rank has second priority
and so on. So the highest mean value was low priority &
low mean value has high priority.
There was 49 priority was calculated as shown in Table -
2. These 49 priorities were classified into three categories
like high, medium and low priority. These categories were
mapped in MapInfo software. Maps are also prepared for
the all parameters of morphometry of the micro-watershed
as shown in Map-2.
ANALYSIS AND RESULT
The study of drainage in the Ferozpur Jhirka reveals that
most of the drainage in the Aravalli slopes originate on the
local hills and traverse through the village, which they are
locally called as nala or kholla. The drainage and their
tributaries are ephemeral and carry water only for short
duration during monsoons period, beyond which no
surface flow is observed. Generally these streams do carry
little amount of water, which is not in any significance to
agriculture. The drainage bed is almost flat, showing sand
deposits, with banks rising to a maximum height of seven
to tem meters, showing ravine formations.
525