Water resources Pacific school of engineering Department of civil engineering Guide By Group Mimansha Pandya (E)

Prepaid By Roll No.Name 05CHHOTALA HITESH B. 07CHOVATIYA HARSH Y. 17HADIYA SAGAR H. 28MANDANI JIGNESH V. 61VAVALIYA MAULIK A.

Table of Content Global overview Volume of water stored in the water cycle’s reservoirs The water cycle Water uses Threats to fresh water resources Various types of dam

Global Overview While 67% of Earth’s surface is covered by water, only less than 2.7% of global water is freshwater. Most of the freshwater (2.05%) are locked in ice caps and glaciers. Only less than 0.7% is available for human use.

Over two thirds of the earth's surface is covered with water, 97.2% of which is contained in the five oceans. The Antarctic ice sheet, containing 90% of all fresh water on the planet, is visible at the bottom. Atmospheric water vapour can be seen as clouds, contributing to the earth's albedo.

Iceberg and Polar cap store most of the fresh water on Earth

Volume of water stored in the water cycle's reservoirs ReservoirzVolume of water (10 6 km³) Percent of total Ocean Ice caps & glaciers Groundwater Lakes Soil Moisture Atmosphere Streams & rivers Biosphere

Competing water uses (I)

Threats to fresh water resources Climate change causes change in frequencies of droughts and floods. Depletion of aquifers caused by over-consumption as a result of population growth. Pollution and contamination by sewage, agricultural and industrial runoff.

The Indian situation Surface and ground water availability - 1,869 BCM of this, 40 % is not available. Groundwater Consumption: 92% - Agricultural 5% - Industrial 3% - Domestic. Surface water Consumption: 89% - Agricultural 2% - Industrial 9% - Domestic.

The Indian situation  Groundwater is the major source of water in the country with 85% of the population dependent.  Groundwater water table decline - 33 centimeters per year.

What is a dam? A dam is a barrier built across a stream, river or estuary to hold and control the flow of water for such uses as drinking water supplies, irrigation, flood control and hydropower generation etc.

Parts of a dam Dam body: Body forms the main part of a dam as an impervious barrier Reservoir: It is the artificial lake behind a dam body Spillway: is that part of a dam to evacuate the flood water from reservoir. Water intake structures: is a facility to withdraw water from a reservoir. Sluiceway: Gerektiğinde baraj gölünü tamamen boşaltmak, dolusavak kapasitesini azaltmak, akarsu mansabına bırakılacak suyu salmak amacına yönelik tesisler. Diversion facilities: To redirect the streamflow from construction area

Upstream Reservoir Dam body Spillway Downstream

Classification of Dams According to dams height According to dams height If crest elevation and foundation level is greater than 15 m then it can be considered as a Large Dam. If crest elevation and foundation level is greater than 15 m then it can be considered as a Large Dam. If dam height is less than 15 m then Small Dam. If dam height is less than 15 m then Small Dam. If dam height is greater than 50 m then High Dam If dam height is greater than 50 m then High Dam

Classification of dams: Dams are classified on several aspects, some of the important aspects are as follow: 1) Based on Hydraulic Design:  Over flow dams (e.g. concrete dams)  Non over flow dams (e.g. embankment dams) 2) Based on Structural Design:  Gravity dams  Arch dams  Buttress dams 3) Based on Usage of Dam:  Storage dams  Diversion dams  Detention dams Dams are classified on several aspects, some of the important aspects are as follow: 1) Based on Hydraulic Design:  Over flow dams (e.g. concrete dams)  Non over flow dams (e.g. embankment dams) 2) Based on Structural Design:  Gravity dams  Arch dams  Buttress dams 3) Based on Usage of Dam:  Storage dams  Diversion dams  Detention dams

GRAVITY DAMS Gravity Dams use their triangular shape and the sheer weight of their rock and concrete structure to hold back the water in the reservoir. Sarıyar Dam – Sakarya River; Height= 90 m Reservoir Capacity= 1.9 billion m 3

ARCH DAMS Arch Dams utilize the strength of an arch to displace the load of water behind it onto the rock walls that it is built into. Karakaya Dam – Fırat River; Height= 173 m Reservoir Capacity= 9,5 billion m 3

BUTRESS DAMS Buttress Dams use multiple reinforced columns to support a dam that has a relatively thin structure. Because of this, these dams often use half as much concrete as gravity dams Elmalı II – Göksu River; Height= 42.5 m Reservoir Capacity= 10 million m 3

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