Watershed Planning Notes

Hydro-meteorological data includes precipitation, abstractions, and other meteorological parameters.
Data requirements vary based on watershed planning objectives, such as:
- Hydrological characterization.
- Flood management and control.
- Irrigation and drainage.
- Groundwater planning.
- Water quality management.
- Fisheries and eco-conservation.

Focuses on rainfall, river flow, and groundwater measurement and analysis.
Rainfall data is essential for assessing the interaction between rainfall, river, and groundwater.
Climate data includes precipitation, temperature, and evaporation.
Evaporation data is measured using evaporation pans or estimated via evapo-transpiration, often using the Penman-Monteith Equation (requires air temperature, humidity, solar radiation, wind speed, and day length).

Basic level: catalogue approach presenting statistics related to locations and areas.
Requires a lead agency for website maintenance, updates, content, access control, and query management.
Operational role: data feeds necessary at short intervals for tactical applications.
Evapo-transpiration (ET) estimation requires air temperature, atmospheric humidity, radiation balance, and wind speed integration over a daily period.

Planning and design fall under planning and infrastructure agencies.
Operations (flood forecasting and warning) are managed by water management or meteorological agencies.
Data needed: daily and sub-daily rainfall, wind velocity, and direction.
Flood plain zoning identifies risk categories for planning and development.
Coastal flooding factors: tide, wind speed/direction, atmospheric pressure; storm surges in specific physical structures.

Strategic level involves national planning with meteorological and water management agencies as key data providers.
Daily data tables include variables for potential evapo-transpiration calculation.
Supply sources: surface water and groundwater.
Requires meteorological forecasts (medium and long term) for managing supply.
Automatic Weather Stations (AWS) can provide enhanced information for demand scheduling and ET estimation.

Important in arid and semi-arid climates.
Groundwater characterized by annual drawdown and recharge cycle.
Confined aquifers show delayed response to rainfall.
Groundwater recharge occurs during rainy seasons after soil moisture deficit (SMD) is replenished.
Groundwater flooding occurs when water levels rise above ground level due to extended high rainfall.

Catchment management is the responsibility of water management agencies.
Addresses chemical, biological, and physical characteristics.
Water pollution incidents depend on meteorological conditions.
Combined sewer overflows (CSOs) during heavy rainfall can cause untreated sewage spillage.
Dilution manages waste discharge with residual impurities; rainfall frequency and dry weather duration are vital.
Salinity and sedimentation are exacerbated during droughts.

Fisheries depend on water quality maintenance.
Requirements include temperature monitoring and drought forecasting.
High temperatures combined with low flow can stress or kill fish stocks.
Conservation involves physical and biological relationships in water-bodies and wetlands.

Involves data on physical/ natural features of the watershed, watershed boundaries, floodplains, wetlands and water bodies.
For hydrological characterization, the data on slope, permeability of the ground surface, roughness of the ground surface, obstructions is required.
For flood management and control, the data on wetlands and water bodies, channel cross sections, other natural and artificial flood mitigation structures is required.
For irrigation and drainage, data on optimum water table depth, canal linings, canal flow capacity, crop type, crop area are necessary.
For groundwater management, the data on annual changes in water table depth, crop root zone depths, wetlands and water bodies is needed.
For water quality management, the locations of point and non-point pollution sources, total maximum daily loads (TMDLs), spatio-temporal variations in pH, turbidity, total suspended solids, total dissolved solids, biochemical oxygen demand (BOD) etc. May be needed.
For fisheries and eco-conservation, the data on dissolved oxygen, spatio-temporal variations in aquatic plants and animals having eco-conservation capabilities is required.

Data consists of data on forests, grass/ range lands, cultivated lands, orchards, wildlife reservations, recreation areas, urban/ rural areas, water bodies, eroded areas etc.
LULC influences interception, infiltration, surface runoff, surface storage, groundwater runoff, groundwater storage, evapo-transpiration (ET).
LULC influences meteorological parameters such as temperature, humidity and wind velocity, which in turn impact the estimation of ET.

Soil data can be an important factor in determining the amount of erosion and storm water runoff that occurs in the watershed of interest.
It can enable the estimation of water retained within the soil, analyze the slope stability or the flow of groundwater through the soil pores.