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Environmental Engineering I−61350

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  1. An-Najah National University College of Engineering Environmental Engineering I−61350 Chapter 4 Dr. Sameer Shadeed Introduction to Water Resources Dr. Sameer Shadeed

  2. General Introduction • Water means life and it is a basic source in all human activities • Water is a finite resource, essential for agriculture, industry and human existence • Without water of adequate quantity and quality, sustainable development is impossible • Water is becoming scarce in quantity and inadequate in quality in many areas around the world • There is a worldwide consensus that the need for water and water supply systems are increasing rapidly as a direct result of human population growth, improved standards of living and industrial expansion • These facts should be reflected in the way that we utilize the water resources Dr. Sameer Shadeed

  3. The Hydrologic Cycle • The endless movement of water between the Earth’s biosphere, atmosphere, lithosphere, and hydrosphere is called the hydrologic cycle • Water on the Earth may be temporarily stored in various reservoirs including atmosphere, oceans, lakes, rivers, soils, glaciers, snowfields, and groundwater • Water continuously moves from one reservoir to another by way of evaporation, transpiration, condensation, precipitation, runoff, infiltration, groundwater flow, sublimation, and melting Dr. Sameer Shadeed

  4. Importance of The Hydrologic Cycle • The hydrologic cycle is a very important scientific process • Without it, there would not be precipitation (rain, snow, sleet, etc.) • Without precipitation, plant life would not grow and produce oxygen • And without oxygen, humans could not live Dr. Sameer Shadeed

  5. Representation of the Hydrologic Cycle Dr. Sameer Shadeed

  6. How The Hydrologic Process Works • Water vapor enters the atmosphere by evaporation and transpiration. Evaporation is the process of water (oceans, lakes, rivers, etc.) changing into water vapor, while transpiration is the discharging of water vapor into the atmosphere from living vegetation such as leaves, grass, etc • Once water vapor enters the atmosphere, it rises and cools. As the water vapor cools, condensation (change from water vapor into liquid water) begins to form small drops of water. These small droplets of water are what you look at when you see a cloud. As these droplets bounce around and hit one another, they stick together and make larger drops Dr. Sameer Shadeed

  7. How The Hydrologic Process Works • When the drops of water become too heavy to be held up, they fall back to the earth. Depending on the temperature, it can fall as rain, snow, sleet, and many other forms of precipitation • Once the precipitation hits the ground, it begins to seep into the ground. This process is called infiltration. But the soil can hold only so much water. And when the ground becomes saturated, the excess water drains into lakes, rivers, oceans, etc. This excess water is called runoff • Then the hydrologic cycle starts all over again. Dr. Sameer Shadeed

  8. The Hydrologic Cycle In Quran • Rainfall وَالَّذِي نَزَّلَ مِنَ السَّمَاء مَاء بِقَدَرٍ وَهُو الذِي أَرْسَلَ الرِّيَاحَ بُشْرًا َبْين يدَيْ رَحْمَتهِ وَأَنزَلَْنا مِنَ السَّمَاء مَاء طهُوًرا • Runoff أَنزَلَ مِنَ السَّمَاءِ مَاءً فَسَالَتْ أَوْدِيَةٌ بِقَدَرِهَا فَاحْتَمَلَ السَّيْلُ زَبَداً رَّابِياً • Infiltration وَأَنزَلْنَا مِنَ السَّمَاء مَاء بِقَدَرٍ فَأَسْكَنَّاهُ فِي الْأَرْضِ وَإِنَّا عَلَى ذَهَابٍ بِهِ لَقَادِرُونَ • Emergence of springs أَلَمْ تَرَ أَنَّ اللَّهَ أَنزَلَ مِنَ السَّمَاء مَاء فَسَلَكَهُ يَنَابِيعَ فِي الْأَرْضِ • Transpiration أَلَمْ تَرَ أَنَّ اللَّهَ أَنزَلَ مِنَ السَّمَاء مَاء فَأَخْرَجْنَا بِهِ ثَمَرَاتٍ مُّخْتَلِفًا أَلْوَانُهَا • Deep recharge and groundwater movement أَوْ يُصْبِحَ مَاؤُهَا غَوْرًا فَلَن تَسْتَطِيعَ لَهُ طَلَبًا Dr. Sameer Shadeed

  9. Distribution of Water on the Earth • The total amount of water on the Earth is about 1.4 billion km3 Dr. Sameer Shadeed

  10. Inventory of Water At the Earth's Surface Dr. Sameer Shadeed

  11. Elements of the Hydrologic Cycle • Evaporation • Condensation • Precipitation • Overland Flow • Infiltration • Interflow • Groundwater flow • Runoff Dr. Sameer Shadeed

  12. Evaporation • Evaporation: loss of liquid water from land and water surfaces as it is converted to a gas (water vapor) • Transpiration: liquid water moving from soil through a plant and evaporating from the leaves • Evapotranspiration (ET): combination of evaporation and transpiration Dr. Sameer Shadeed

  13. Evapotranspiration Simulation Faria Catchment • For the rainy day 9 of February 2006, actual evapotranspiration is considerable whereas for the dry day 5 of February 2007, actual evapotranspiration is small Dr. Sameer Shadeed

  14. Condensation • Condensation: cooling of water vapor (gas) until it becomes a liquid (opposite of evaporation) • As air rises it cools and water condenses forming clouds and eventually rain • As air falls it warms and condensation does not occur • Fog and dew are examples of condensation due to cooling Dr. Sameer Shadeed

  15. Precipitation • Precipitation occurs when 100% relative humidity is exceeded, which occurs usually due to cooling of the air mass • Cooling of the air mass occurs due to increase in altitude • Increased air mass altitude (rise) can be attributed to three processes: weather fronts, convective processes, and orographic effects Dr. Sameer Shadeed

  16. Areal Rainfall • In estimating water budgets, one needs to determine an effective uniform depth (EUD) of rainfall over the drainage basin • If the rain-gauge network is of uniform density, then a simple arithmetic average of the rainfall data is sufficient to determine the EUD Dr. Sameer Shadeed

  17. Areal Rainfall • If the network is not uniform, adjustments will be necessary to calculate the spatially distributed rainfall for an area, the point rainfall needs to be converted to areal rainfall • The most accurate method is to draw a precipitation contour map with lines of equal rainfall (isohyets) • A simpler method is the Theissen method, which uses a weighting factor for each rain gauge Dr. Sameer Shadeed

  18. Areal Rainfall An example of isohyetal lines and Theissen polygons of a rain gauge network in the West Bank Dr. Sameer Shadeed

  19. Faria catchment (Rainfall) • The winter rainy season is from October to April • The rainfall in the catchment varies with space and time • The rainfall distribution within the catchment ranges from 640 mm at the headwater to 150 mm at the outlet to the Jordan River Dr. Sameer Shadeed

  20. Overland Flow • Some rain or snow melting will drain across the land to a stream channel, and such topographic movement of a thin film of water on land surface is called overland flow Dr. Sameer Shadeed

  21. Infiltration • For porous surface soil, some rain or snow melting will seep into the ground • The downward movement of water into the soil layer is termed infiltration • Infiltration into soil varies with soil type and depends on rate of precipitation and on ambient soil moisture Dr. Sameer Shadeed

  22. Surface Factors Controlling Infiltration • Degree of Surface Crusting • Clay content of the surface • Effect of drop impact • Degree of Surface Porosity • Soil texture • Soil structure • Vegetation cover • Cracks and other macropores Dr. Sameer Shadeed

  23. Measuring Infiltration • Double rings infiltrometer is used to determine the infiltration rate Dr. Sameer Shadeed

  24. Interflow • Most of the infiltrated water will percolate more or less vertically through the unsaturated zone • The infiltrated water may move horizontally in the unsaturated zone where layers of soil with a low permeability exist beneath the surface • The horizontal movement of water in the unsaturated zone is referred to as interflow Dr. Sameer Shadeed

  25. Groundwater Flow • The underground topographic flow of groundwater because of gravity is called groundwater flow • The amount of groundwater discharge to a stream is directly proportional to the hydraulic gradient toward the stream Dr. Sameer Shadeed

  26. Groundwater Storage • Groundwater Recharge • Water added to groundwater usually through percolation down through the soil to the water table • Groundwater Discharge • Water lost from groundwater usually through springs, wells, streams, and rivers Dr. Sameer Shadeed

  27. Recharge Discharge Recharge Discharge Recharge and Discharge Dr. Sameer Shadeed

  28. Groundwater Aquifers • Confined • Unconfined Dr. Sameer Shadeed

  29. Groundwater Flow Model MODFLOWModel contour map Dr. Sameer Shadeed

  30. Runoff • When Precipitation reaches the surface of the earth it will either infiltrate into the soil or runoff over the surface • Runoff is the total flow (overland flow, interflow, and groundwater flow to a stream) Dr. Sameer Shadeed

  31. Some Main Factors Affecting Runoff • Rainfall amount: High rainfall amounts produce more runoff than low rainfall amounts • Rainfall intensity: For the same total amounts of rain, more runoff will occur with rain falling in short periods of time as opposed to rain falling in a longer period of time • Soil type: More runoff will occur with clay soils while sandy soils are able to absorb more rainfall • Soil moisture: When the top layer of soil is moist, there will be more runoff than if the soil moisture content is low • Vegetation: Vegetative cover may slow the runoff from rainfall. As vegetation takes-in water, the runoff is retarded • Topography: Runoff varies as the terrain varies. A mountainous terrain will have a faster runoff rate than one of a flat terrain • State of ground: Rainfall over frozen ground produces more runoff than rainfall over non-frozen ground Dr. Sameer Shadeed

  32. Rainfall Factors Affecting Infiltration and Runoff • Storm intensity • Storm duration • Distribution in time • Distribution over the catchment Dr. Sameer Shadeed

  33. Runoff (Faria catchment) • 2 Parshall flumes were constructed at the upper part of the catchment • One at Al-Badan sub-catchment (83 km2) outlet • and the other at Al-Faria sub-catchment (56 km2) outlet • Runoff data (10-min time step) were collected for the three rainy seasons 2004-2007 Dr. Sameer Shadeed

  34. Measuring Runoff Al-Badan Flood - 08.02.06 Dr. Sameer Shadeed

  35. Runoff Simulation Dr. Sameer Shadeed

  36. Runoff Simulation Al-Badan and Al-Faria Flood – (4-6.02.05) Al-Badan and Al-Faria Flood – (8-9.02.06) Dr. Sameer Shadeed

  37. Elements of Water Resources • Water Sources • Surface Water (e.g. oceans, lakes, rivers,…) • Underground Water (e.g. springs, groundwater wells) • Imported Water • Treated Water (Reuse) (e.g. desalinated water, treated wastewater from treatment plants) Dr. Sameer Shadeed

  38. Water Resources Management • Measures and activities concerning the supply of water, the improvement of efficiency in its use, the reduction of losses and waste, water-saving practices to reduce costs and to slow the depletion of the water supply to ensure future water availability, and protection of the quality of water resources Dr. Sameer Shadeed

  39. Management Questions • For instance, how can the renewable, yet finite water resources best be used and/or protected? • What would be the maximum total pumping volumes that can be pumped out from an aquifer without exceeding a certain drawdown? • How to maximize pumping rate for a coastal aquifer without causing the occurrence of salt-water intrusion? • Where to construct a dumpsite such that the risk of contaminating a near-by pumping well is minimized? • What is the maximum fertilizer application rate such that nitrate concentration in groundwater does not exceed the maximum contaminant level? • How can we provide a good-quality water for irrigation in a specific area? • How can we use the water resources when the supplies and demands are uncertain? • How can we use the water resources under the predicted climate changes? Dr. Sameer Shadeed

  40. Water Resources Management Purpose • The central purpose of water resources planning and management is to address, and if possible to answer, the previous questions Dr. Sameer Shadeed

  41. International Conflicts about Water Resources • Israel-Palestine-Syria-Jordan: During 50 years 37 armed conflicts about water resources • Turkey-Syria-Iraq: Large dam project in south east Anatolia endangers water supply in Syria and Iraq • Egypt-Ethiopia-Sudan: Conflict about the use of the Nile water Dr. Sameer Shadeed

  42. Water as a Global Resource • Water is a natural resource. It can not be replaced and there is only a limited amount available • It is used as drinking water and is the basis of agricultural production • Quantity and quality are in close connection to human activities Dr. Sameer Shadeed

  43. Drinking Water Today • Supplying drinking water is still an important function today • Many problems • Water quality (bacteria, carcinogens, heavy metals, etc.) • Water quantity (competition with agricultural for water) • Wastewater treatment Dr. Sameer Shadeed

  44. Water Resources in The West Bank • Water resources in the West Bank, Palestine are scarce • This is due to the fact that, geographically, the West Bank is located in arid to semi-arid region • Therefore, societies in the West Bank are very vulnerable to variability of water resources availability • This vulnerability is caused by the strong constraints on the use of natural resources due to limited and low reliable water resources availability in addition to an often high population density and growth rate • The population is strongly dependent on these resources with few short-term options to reduce such dependency Dr. Sameer Shadeed

  45. Water Resources in The West Bank • The existing political situation adds another constraint to the availability of water resources in the West Bank • Contrary to its excellent groundwater potential, the West Bank is void of surface water • Surface runoff is relatively low and there are no permanent lakes • Unless Palestinians gain access to their only river, the Jordan River which is used by Jordanians and Israelis, they exclusively depend on groundwater wells • Springs and harvested rainwater are another two complementary water resources for Palestinians Dr. Sameer Shadeed

  46. Water Resources in The West Bank • The West Bank and Gaza Strip lie over two main aquifers, the Mountain aquifer and the Coastal aquifer, which are shared with Israel • The Mountain aquifer system is divided into the Western aquifer basin (WAB), the Northeastern aquifer basin (NEAB), and the Eastern aquifer basin (EAB) • The EAB and part of the NEAB flow east towards the Jordan River • The WAB, part of the NEAB and the Coastal aquifer all flow westerly towards the Mediterranean Sea Dr. Sameer Shadeed

  47. Water Resources in The West Bank • The groundwater basins are recharged directly from rainfall on the outcropping geologic formations in the West Bank Mountains • Ninety percent of the recharge of the NEAB and the WAB takes place within the West Bank, where rainfall recharges about 145 MCM/year and 366 MCM/year on average for these two basins respectively • The EAB is even an autochthonous (native) Palestinian basin, as it totally lies within the West Bank territory, and this basin receives about 172 MCM/year from rainfall Dr. Sameer Shadeed

  48. The West Bank Groundwater Aquifer Basins Dr. Sameer Shadeed

  49. The principal and conventional water resources available to Palestinians include: Groundwater Surface water Harvested rainwater Non-conventional resources include: Treated wastewater Desalinated water Water Resources in The West Bank Dr. Sameer Shadeed

  50. Rainfall in the West Bank Dr. Sameer Shadeed