Water Resources AssessmentMain ResourcesSurface waterGroundwaterUnconventional ToolsFlood routing/delineation modelsRunoff modelsGISFinite element Finite differenceLumped parameters models

Surface WaterGeneral Equation

I(t) O(t) = S/tOin InputsPrecipitationBase flowOin OutputsE/ETInfiltrationIntakes

System BoundariesReservoirBalance S/t=(P*Ares+Qin)-(E*Ares+Qout)Residence Time S/I(t)Watershed S/t=(P*A)-(ET*A+Qout)

GroundwaterDefinitionsSaturated Zone: VWater=VvoidsUnsaturated Zone: VWater < VvoidsMoisture Content: VWater < VtotalVoids/Pores: allow the flow of waterWater Table: surface where the water pressure in the pores equals ZeroPorosity: n = Vvoids / Vtotal (~0 - 0.7)Hydraulic conductivity [L/T]= represents how easily water can flow through formationGravel >50 m/dayCourse Sand: K = 30-50 m/dayFine sand: K = 10-30 m/daySilt: K = 1-10 m/dayClay: K < 1 m/day

GroundwaterDefinitionsFormations types with respect to water bearingAquifer = permeable layer that contains and transmits water in large quantitiesConfinedUnconfined Aquiclude = impermeable layer that may contain water but transmissivity is very lowAquitard = semi permeable layer that transmits water in the vertical direction onlyAquifuge = impermeable layer that neither contains nor transmits water

General Cross Section of Gaza Aquifer

GroundwaterDarcy

GroundwaterAverage pore velocity

Problem: A tracer traveled 3 days and 6 hours between 2 wells that are 20 m apart. Water elevation difference between the wells is 0.5m, porosity n=0.15. Estimate v, q, K

Groundwater BalanceSs [1/L] = Specific Storage = volume of water that a unit volume of aquifer releases under a unit decline in hydraulic headS [dimensionless] = Storativity = volume of water that a unit surface area of aquifer releases under a unit decline in hydraulic head

Groundwater BalancePollutants transport mechanismsAdvectionDiffusionDispersionMechanical dispersion coefficient Diffusion coefficient

Average Nitrates Concentrations (PWA, 2005 Data)

Average Chlorides Concentrations (PWA, 2005 Data)

Average Groundwater Level (PWA, 2005 Data)

Soil Map

Built Up Areas

Agricultural Areas