INTRODUCTION HYDROLOGY AND WATER RESOURCES HYDROLOGY AND WATER RESOURCES RG744 INSTITUTE OF SPACE TECHNOLOGY SEPTEMBER 09, 2015

HYDROLOGY: DEFINITION NATURAL SCIENCE THAT DEALS WITH THE TRANSPORT AND DISTRIBUTION OF WATER (LIQUID, GAS, SOLID) IN THE ATMOSPHERE, ON AND BENEATH THE EARTH'S SURFACE

HYDROLOGY STUDY OF: Occurrence Circulation Storage Quality Distribution of surface and ground water on the earth

HYDROLOGY INCLUDES? DOMAIN OF HYDROLOGY INCLUDES: Physical, Chemical and Biological processes/reactions of water in natural and man made environment STUDY OF HYDROLOGY MAY INCLUDE TOPICS FROM TRADITIONAL Fluid mechanics, Hydrodynamics, Water resources engineering Water quality and contaminant transport

SCOPE OF HYDROLOGY Maximum probable flood Water yield Groundwater development Maximum intensity and frequency of storms

HYDROLOGIC DATA REQUIRED? 1.CLIMATOLOGICAL DATA 2.HYDRO-METEOROLOGICAL DATA 3.PRECIPITATION RECORDS 4.STREAM-FLOW RECORDS 5.SEASONAL FLUCTUATION OF GW TABLE 6.EVAPORATION DATA 7.CROPPING PATTERN, CROPS AND THEIR CONSUMPTION 8.WATER QUALITY DATA (BOTH SURFACE AND GW) 9.ETC.

WHY WE NEED TO MANAGE WORLD’S WATER RESOURCES?

1.4 billion Km 3 of water on Earth Distribution of Earth Water Resources

Reservoir Volume (cubic km x 1,000,000) Percent of Total Oceans Ice Caps/Glaciers Deep Groundwater Shallow Groundwater Lakes Soil Moisture Atmosphere Rivers Biosphere Water Inventory at Earth's Surface

DISTRIBUTION OF FRESH WATER ON EARTH

GLOBAL WATER USAGE TREND ACCELERATING 1975: 700 km 3 /y 2002: 6,000 km 3 /y CAUSES Population Increase Better Living Standards Others

HYDROLOGIC CYCLE Continuous process Water evaporates from water surfaces Moves inland as moist air masses Precipitation falls from clouds

HYDROLOGIC CYCLE Water is conserved: Neither created nor destroyed

COMPONENTS OF HYDROLOGIC CYCLE Quantity of each component depends on?

COMPONENTS OF HYDROLOGIC CYCLE PRECIPITATION Major element that drives Hydrologic Cycle depending on various weather parameters and systems INFILTRATION Function of soil moisture conditions and soil type RUNOFF Overland flow in a down gradient direction STORAGE Surface and groundwater EVAPOTRANSPIRATION Evaporation: the conversion of water to water vapor from a water surface Transpiration: loss of water vapor through plant tissues and leaves

HYDROLOGIC ANALYSIS Hydrologic analysis is done to determine rainfall-runoff response from a watershed area Hydrologic Cycle is a complex series of processes but under well defined conditions with simple assumptions the response of a watershed can be made

PRECIPITATION When atmospheric moisture becomes so heavy to remain suspended in clouds All form of water that comes to earth from atmosphere (rainfall, snowfall, hail, frost and dew) Rainfall is the predominant form Ocean evaporation is the greatest source (90%)

PRECIPITATION IS VARIABLE !!! EXAMPLE: YEAR TO YEAR VARIATION

SOURCE: GLOBAL PRECIPITATION CLIMATOLOGY PROJECT (GPCP) BY GEWEX RADIATION PANEL (GRP)

PRECIPITATION SIMILAR MAP FOR THE REGION OF PAKISTAN (PAKISTAN METEOROLOGICAL DEPARTMENT) SOME FIGURES (AVERAGE ANNUAL RAINFALL) WEATHER AND CLIMATE OF PAKISTAN

SURFACE RUNOFF WATER THAT FLOWS OVER LAND AFTER STORM EVENTS QUANTITY DEPENDS ON: Climatic Factors: Rainfall frequency and intensity Geological Factors: surface permeability Geometrical Factors: shape of watershed, slope Biological Factors: Vegetation cover ZERO RUNOFF? RUNOFF = RAINFALL?

STORAGE: SURFACE WATER SURFACE WATER Reservoir: Artificial or naturally inland body of water used to store water to meet various demands Lake: Large naturally occurring inland body of water Wetlands: Natural or artificial areas of shallow water or saturated soils that support certain water plants

STORAGE: GROUNDWATER GROUNDWATER Water infiltrating through soil cover of a land surface to a huge waterbody underground In a state of continuous movement Difficult to extract all by practicable means Groundwater recharge: dynamic resource that is replenished by precipitation, seepage from surface waterbodies, conveyance system return flow from irrigation water. Governed by rainfall intensity and soil and aquifer conditions

EVAPOTRANSPIRATION COMBINATION OF EVAPORATION AND TRANSPIRATION

WATERSHED THE GEOGRAPHICAL AREA THAT CONTRIBUTES TO THE FLOW OF A RIVER Basic hydrologic unit within which all measurements, calculations, and predictions are made in hydrology To calculate runoff (volume) expected from a given rainfall event that falls over an area Varies in size from few acres to thousands of square miles

WATERSHED Watershed delineation based on topographic or elevation data Watershed divide (ridge line) separates two watersheds that drain into different outlets Area encompassed by divide is the watershed area Runoff originating at higher elevations moves towards lower elevation in a direction perpendicular to the contour lines to the nearest stream Larger the watershed area greater the surface runoff rate and stream flow rate

HYETOGRAPH? DISTRIBUTION OF RAINFALL OVER TIME

ISOHYETAL MAPS

HYDROGRAPH Hydrologic response of rainfall at the outlet of an area A plot of discharge in the channel vs. time (cubic feet per second)

HYDROGRAPH RESPONSE SHAPE DEPENDS ON?

EFFECT OF BASIN CHARACTERISTICS ON THE FLOOD HYDROGRAPH

IMPACT OF URBANIZATION

WATER RESOURCES POTENTIAL (WRP) UTILIZABLE SURFACE WATER POTENTIAL: AMOUNT OF WATER THAT CAN BE FULLY USED WITHOUT WASTAGE TO SEA

INTERNATIONAL INDICATORS TO MEASURE WRP HOME ASSIGNMENT: SEARCH THIS TOPIC ON INTERNET TO DISCUSS IN THE NEXT CLASS

FUTURE DEVELOPMENT OF WATER RESOURCES Sustainable water utilization Conservation of water (cleaner practices) Non-consumptive use

INDUS RIVER BASIN STATISTICAL FACTS AND FIGURES Drainage/catchment area in Territory of Pakistan = 692,700 Km 2 Draining into the Arabian Sea Mean annual flow of Indus basin rivers=187km 3. Mean average rainfall (Pak) = 205 mm Evapotranspiration = mm Major Irrigation Projects: IBIS

WATER TREATY 1960 BETWEEN INDIA AND PAKISTAN WATER RIGHTS OF INDIA AND PAKISTAN WESTERN RIVERS (INDUS, JHELUM AND CHENAB): PAKISTAN EASTERN RIVERS (RAVI, SUTLEJ AND BEAS): INDIA

HYDROLOGY VS. HYDRAULICS MODELS? HYDROLOGY (SURFACE) how water moves into the drainage system HYDRAULICS water going through the drainage

UNITS cfs or cusec ac-ft ( 1 ac = ft2) MGD (1 MGD = 1.55 cfs) 1 m 3 /s or cumec (1 m 3 /s = 22.8 MGD) 1 gal (1 ft 3 = 7.48 gal) 1 mile 2 (1 mile 2 = 640 acres) 1 mile = 5280 ft