INTEGRATED URBAN FLOOD MANAGEMENT IN INDIA
Study Area: Hyderabad
Hyderabad is a metropolitan city of India located at 17.3700° N, 78.4800°E. Hyderabad is divided into 16 storm water zones by Greater Hyderabad Municipal Corporation (GHMC). Among the storm water zones, zone 12-Kukatpally and Zone 13-Alwal and Begum pet area being Major flood prone areas. There are several ponds and lakes in the city. Among which Husain Sagar is the largest lake, covering an area 4.4 km2, with a maximum depth of 9.8m. Musi is the only river passing through the centre of the city. Musi is a tributary of Krishna River. It divides the city into old city and new city.
Figure1: Study Area (source: GHMC)
Figure2: Storm network map with zone wise classification of Hyderabad (Source: GHMC)
Table 1 :Length of major drains of various zones of Hyderabad (source: GHMC)
History of flooding:
Hyderabad had major development from last decade due to establishment of Information Technology Parks, with increase in impervious areas. Hyderabad has witnessed major urban flood events in the year 2000 and 2008, with annual rainfall of Hyderabad being 800 mm / year.
Table 2.Floods in Hyderabad during 2000 and 2008 and suggested measures (GHMC)
Data Collected From Various Sources
DATA FOR ZONE FROM GHMC
- Existing storm water drain details
- Rainfall data
- Survey details of drain
- Details of lakes, water bodies etc.
- GHMC Storm master plan
- Details of culverts in various zones
Existing storm water drain details
- Length of drains
- Width of drains
- Depth of drains
- Survey details of drain
- Details of node/junctions
- Sub Hourly rainfall data, 15 minute rainfall data from 1978-2007
- Intensity duration frequency curves
- Details of lakes, water bodies
- The details of water bodies, storm water drains and complete AutoCAD drawing.
- Slope details for catchment ,Contour drawing
- Land use details
DATA FROM IMD
- Hyderabad hourly rainfall data (1971-2014)
- Hyderabad hourly temperature data (1971-2000)
DATA FROM HMWSSB
- Sewerage Master Plan
- Sewerage master model showing dimensions and details of system
- Ground water prospects map
- Peak reservoir levels of Osman Sagar and Hussain Sagar(1981-2014)
- Schematic diagram of existing mains and STPs along river Musi
- Schematic diagram of Proposed mains and STPs along river Musi
- Master plan for Hyderabad Development area( Revised)
- Water bodies details given in GIS
- Kukatpally (Begumpet) nalla details
- Design report for remodelling of the existing drain
- Kukatpally nala full details: various Cross section details
- Details of Catchment areas & Flood Calculations for Kukatpally
DATA FROM SURVEY OF INDIA
- 56K series Toposheets of 1:50,000 and 1:25,000 for GHMC area.
- Urban flood modelling of the study catchment for capacity analysis of storm system
- Identifying the critical locations of overflow and the number of sensors required in the storm network
- Developing a tailor made hydrological model to best suit Indian catchment conditions
- Finding out the best probability distribution function for IDF curves
- Developing low cost water level sensors and communication systems
- Coming up with a real time flood forecasting, monitoring using sensor network, which will be deployed at various critical locations
- Identifying the flood prone area by terrain map using ArcGIS
- Generating flood inundation maps
- Developing a comprehensive decision support system for flood mitigation
- Modelling for urban floods in climate change scenario’s
Modeling is completed for zone 13 of Hyderabad.
- The data given has been processed pertaining to storm network details, line diagram has been drawn in SWMM. Catchment details have been given. Time series data has been input for 15 min 2007 rainfall, being highest rainfall event. All the required modelling parameters are input and Modelling is completed for zone 13 of Hyderabad. The critical locations of overflow are identified
Flood inundation mapping for Hyderabad is done
- Inundation mapping is done by connecting major ponds of the city and Musi river.
Decision support system for IDF
- Probability distribution functions: Gumbel's extreme value, Log Pearson type, Normal, Log normal, Weibull are coded in MATLAB and Chi-square test is used as fit test.
- Developing IDF curves to come up with best probability distribution function.
Tailor Made Hydrologic Model
- An indigenous model is under development in the similar lines of SWMM in MATLAB/ Simulink to suit Indian catchment
- Runoff, Routing and Water quality blocks are completed. Other routing and simulation methods to be included
Currently working on:
- Modeling zone 12 of Hyderabad
- Zone 12 of Hyderabad is one of the major storm water zones of Hyderabad covering Kukatpally area
- All the required data has been procured from various agencies
- Modeling is under progress in SWMM.
Rainfall Data Analysis
- Sub hourly rainfall data for years 1978-2007 has been procured from GHMC
- Hourly data from 2007-2014 has been procured from IMD
- The hourly rainfall data has to be converted into sub hourly rainfall data by looking at the trend of historical data using stastical techniques , which is under progress.
Developing 1m contour from Toposheets
- The toposheets are being Clipped and mosaiced for the area of GHMC.
- Contours for 1m meter interval is in progress.
- Land use/Land cover Map is under progress for the GHMC area clipped.
- Zone Map is being generated.
- Using Arc Scene the low-lying areas will be identified.
Field survey of the study area has been conducted on 19 May 2015
Photos of field survey at study area
Interaction with Government Officials
- MOU signed with GHMC
- Regular meetings with GHMC officials
- GHMC officials are active members in project discussion