CSRE, IIT BOMBAY
Project Title: Assessment
of Drought and Its Management Scenarios over Beko Watershed –
A Decision Support System
Thematic Area: Drought Prone
It covers Chhatna and Kashipur blocks and
a part of Bankura-I, Bankura-II, Ganagajalhati, Saltora, Indpur,Onda,
Hura, Para, Santuri, Raghunathpur and Puncha blocks (Fig.1).
23034’ N and 23011’ N latitudes
86031’ E and 87009’E longitudes
It covers 182300 Hec. Area approximately.
It covers Beko-Dhalkisor-Gangheswari watershed
zone, known as Beko/Bako watershed, and 2A2C8 (source: AIS&LUS).
Assessment of information and technology
required related to drought mitigation for users and identification
of data availability and data gap in phase-I
Assessment of drought integrating meteorological,
hydrological, Socio-economic data
Integrated drought impact assessment based
on available soil and satellite and other land based data and
Modeling of seasonal drought forecasting
Perspectives on other drought management
Apprise the availability and gap of data
for phase-II & III
Abstract: The main theme
of the project is towards development of few components of decision
supporting system (DSS) for drought management in a watershed.
The required information and technology for local administration
and end-users are to be assessed first through field survey and
discussion. Both causes and effects of drought will be assessed
individually and integrated using meteorological, hydrological,
geo-hydrological, Socio-economic and remote sensing data. The
degree of assessed drought hazard will be mapped using the techniques
of Geographic Information System (GIS). Using existing database
the seasonal/annual drought forecasting/early warning system model
will be developed. The type of forecasting model will be arrived
at depending on the requirement of end-users after the statistical
survey. Other land based management scenarios, viz., ground water
potential zone; rainwater harvesting potential zone and cultural
practices will also be reviewed. The available data network and
required data network will be figured out at the end of the study.
The current research project has been considered as phase-I against
a three-phased integrated drought management system over DPAP
Highlights/Findings: It is
a sub humid zone. Summer season (March – May) is too hot. The
weekly averaged ambient temperature and humidity ranges are 12-43oC
and 15-100% respectively. The normal annual rainfall over the
area is good but the normalized deviation of monthly rainfall
extends frequently from –1(no rainfall conditions where normal
rainfall exists) to +2(double of the normal rainfall) and above.
End users experience the late onset as well as early withdrawal
of monsoon, a major reason for crop failure. They frequently face
the drought conditions even for their livelihood.
The area corresponds to eastern fringe of Chhotanagpur plateau
and gradually merges with depositional fluvial terraces of Damodar-Dwarkeswar-Kangsaboti
River. The terrain is mainly granite and gneiss with enclaves
of metasedimentaries and metabasics.
The river system, Dwarkeswar as Beko Nala originated from upland
of Purulia. Gandheswari is the principal tributary of Dwarkeswar
and originated from northwestern upland of Bankura. The drainage
of Dwarkeswar is mainly dendritic, parallel to sub-parallel in
pattern (Figure1). There are few reservoirs for minor irrigation,
viz., Majra, Indrabill and Jharsia. A large number of ponds, those
are mainly under the owner of the land, were found over the area.
The historical study says the geological parameters have significant
control on ground water occurrence over the study area. The aquifer
systems are three types: weather mantle, saprolitic zones and
fractured zones of the country rocks. Draft demand is much higher
than present recharge rate. The irrigation is required even in
kharif season as the crop yield is sensitive to water scarcity.
Agricultural drought is predominated due to soil hazards. The
cultivable land is mainly mono-cropped due to water scarcity during
Rabi and summer season. No certain plan is yet declared to develop
spatially distributed irrigation covering DPAP area. The land
use/land cover is classified into five major categories: forestland,
agricultural land, wasteland, water bodies and settlement. The
forestland further can be classified into scrubland, land without
scrub, natural forestland and planted forest land. Principal crop
is rice. Wheat and maize are also under principal crops. Land
capability is moderately good. The problem of soil and ground
water storage is added complexity to fight against drought. Population
density is not significantly high other than the township area.
Daily/monthly Rainfall and weather related
parameters over DPAP area
Well-distributed seasonal ground water table
data, thrice in a year
Daily River discharge data
Satellite remote sensing data in a time
Topographic sheet and geographic information
Soil related data for the study of land
Output: The major reasons
for adverse situation over this watershed under Chhotonagpur plateau
was observed due to Aberrant rainfall, high heat effect, geomorphic
stress & soil stress. The predictability of favourable weather
is dominated by uncertainty factors. The end-users frequently
face the drought conditions even for their livelihood. The irrigation
is required even in kharif season as the crop yield is sensitive
to water scarcity. Preliminary assessment on available information
found the relationship between rain and crop. There is a good
correlation between cultivated land and annual rainfall. More
detail data analysis is in progress to establish the relationship.
The correlation is most significant with the rainfall in July
month and cultivated land (Figure2). In general 15% of total cultivable
land of DPAP blocks is under irrigation in DPAP area of Bankura
district (Table1). The scenario of irrigation is monitored through
field survey, which is relatively better in Purulia where rate
of water draining is more. People prefer jore-bundh, a minor irrigation
system (Figure3, Figure4). Ground water storage in general is
insufficient, as most of the dugwells and wells are dry in summer
even in winter season. Draft demand is much higher than present
recharge rate. A land use study and field survey noticed that
a significant part of wasteland may be cultivable waste land.
Other part of wasteland consists Rocky/stony waste and land without
scrub. Soil depth is mostly moderate (22.5cm - 45cm) in the study
area. Severely eroded steep upland with exposed rocks is having
shallow soil depth (<7.5cm). Soil depth is deep (45cm-90cm)
in light textured soil. In valley bottom soil depth is very deep
(90cm-150cm). Land slope is mostly southeasterly.
A significant gap in ground level documentation is found to implement
DSS especially for drought hazard.
(Note: The study is in progress)
Date of project completion:
Total Cost of Project: Rs.15,
Dr. RINA JANA,
C.S.R.E., I.I.T. BOMBAY,
POWAI, MUMBAI 400 076.
TEL: (022) 2576 7679,
FAX: (022) 2572 3190