Water Balance Study: Manoa Valley Sept 2 to Nov 4, 2016 Tineill Dudoit - Shellie Habel - Madi Miyamura Shintaro Russell - Kenui Topp
Mānoa Valley Site Area: Mānoa Valley, (11,187,443 m^2 ) faces along the South-eastern steep slopes of The Koʻolau mountain range Experiences almost daily rainfall Differing gradients of elevation, climate, land uses, crops and soil types, including native forests, thick vegetation and dense shrub/tree areas
Purpose - Estimate Water availability for Mānoa Valley case study area - Gather other groups inputs and outputs from Mānoa valley case study - Compute and complete water balance using ArcGis, totaling various meteorological processes, parameters and estimated rates of water inputs and outputs that affected Mānoa Valley and Mānoas water budget in total From Sept 2 - Nov 4, 2016
Estimate Total Outputs -Change in soil moisture - Distributed groundwater recharge - Distributed evapotranspiration (Canopy and surface/soil Evaporation) Source:http://climate.socialsciences.hawaii.edu/Courses/GEOG405/GEOG%20405%20Water%20Bala nce.pptx.pdf source:https://laulima.hawaii.edu/access/content/group/2c084cc1-8f08-442b-80e8-ed89faa22c33/book/chap ter_7/balance.htm
AW = Available Water AWC = Available Water Content*Root Depth GWR = Groundwater
INPUT DATA REQUIREMENTS (DAILY, WEEKLY, OR MONTHLY INTERVAL) P RAINFALL RO RUNOFF IRR IRRIGATION PE POTENTIAL EVAPOTRANSPIRATION INPUT PARAMETERS AMC AVAILABLE SOIL MOISTURE CAPACITY (EQUIVALENT WATER DEPTH PER SOIL DEPTH) AWC = AMC * ROOT ROOT ROOT DEPTH SINIT INITIAL SOIL MOISTURE CONTENT CF CROP FACTOR (COEFFICIENT TO ADJUST PE) OUTPUT SEND SOIL MOISTURE CONTENT SOIL.OUT RCHG RECHARGE RCHG.OUT E EVAPOTRANSPIRATION EVAP.OUT
Available Water Capacity Available Water Capacity is the difference between field capacity which is the maximum amount of water the soil can hold and the wilting point where the plant can no longer extract water from the soil Source:http://soilquality.org.au/
Available Water Capacity Is the water held between field capacity and the wilting point Is the maximum amount of soil moisture available for the ET process. Can be expressed either as a ratio or in water depth units
Available Water Capacity Changes in Soil Water. Field capacity minus wilting point is the amount of water available to plants Source:http://www.extension.umn.edu
Soil Types 1. rrt = Rough Mountainous Land 2. rcl = Cinderland 3. rrk = Rock Land 4. LoC = Lolekaa Silty Clay, 8 to 15 percent slope 5. LoD = Lolekaa Silty Clay, 15 to 25 percent slope 6. LoE = Lolekaa Extremely Stony Clay, 3 to 35 percent slope
Soil Types 7. LoF = Lolekaa Silty Clay, 40 to 70 percent slope 8. TAE = Tantalus Silt Loam, 15 to 40 percent slope 9. TAF = Tantalus Silt Loam, 40 to 70 percent slope 10. TCC = Tantalus Silty Clay Loam, 15 to 40 percent slope 11. HnA = Hanalei Silty Clay, 0 to 2 percent slope 12. HnB = Hanalei Silty Clay, 2 to 6 percent slope
Soil Types 13. HoB = Hanalei Stony Clay, 2 to 6 percent slope 14. MIA = Makiki Stony clay Loam, 0 to 3 percent slope 15. LoB = Lolekaa Silty Clay, 3 to 8 percent slope
AWC Values for each Soil Type 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. rrt = Rough Mountainous Land LoF = Lolekaa Silty Clay, 40 to 70 percent slope TAE = Tantalus Silt Loam, 15 to 40 percent slope LoD = Lolekaa Silty Clay, 15 to 25 percent slope TAF = Tantalus Silt Loam, 40 to 70 percent slope HoB = Hanalei Stony Clay, 2 to 6 percent slope LoC = Lolekaa Silty Clay, 8 to 15 percent slope LoE = Lolekaa Silty Clay, 25 to 40 percent slope rrk = Rock Land HnA = Hanalei Silty Clay, 0 to 2 percent slope rcl = Cinderland TCC = Tantalus Silty Clay Loam, 15 to 40 percent slope MIA=Makiki Stony Clay Loam, 0 to 3 percent slope LoB=Lolekaa Silty Clay, 3 to 8 percent slope HnB=Hanalei Silty Clay, 2 to 6 percent slope AWC = 0.135 AWC = 0.110 AWC = 0.120 AWC = 0.110 AWC = 0.120 AWC = 0.170 AWC = 0.110 AWC = 0.110 AWC = 0.140 AWC = 0.170 AWC = 0.030 AWC = 0.110 AWC = 0.140 AWC = 0.110 AWC = 0.170
Putting Together the Parameters Imported a shapefile from nrcs.usda.gov into ArcGIS This geospatial file contains the different types within our watershed ArcGIS takes these soil types and splits them into polygons and separates them into each grid cell
Putting Together the Parameters Divide the soil type area by the total area within each cell to get the % soil type in each gridcell AWC for each soil type can be found in the Soil Survey of the State of Hawaii Multiply the AWC to the % soil type(s) in each grid cell
Putting Together the Parameters The AWC for each soil type in each grid cell is then added together for a weighted average of AWC in each grid cell The values for weighted average of AWC in each grid cell is used as a parameter in the Water Balance Model
Putting Together the Parameters: geospatial files AMC Root Depth Crop Factor
Root Depth Per Square: Root depth x % paved + Root depth x % forest = Weighted Average Root Depth % AWC x weighted root depth = Depth of water
Crop factor A correction factor for ET land covers/crop that is not under standard conditions excellent soil moisture, conditions etc. (Crop factor x % paved) + (crop factor x %heavily forested) + (crop factor x % forested) = Weighted
Irrigation Used an Irrigation water balance file off of USGS Blue = 0 ( NO irrigation) Colored= 1 (Irrigation)
Modeled Soil Moisture vs Observed Soil Moisture
Total Precip (mm)
Total Potential Evap (mm)
Total Actual Evap (mm)
Total Runoff (mm)
Total Recharge (mm)
Precipitation-Recharge Threshold
Precipitation-Recharge Threshold
Manoa Watershed Totals Average Total Depth Per Cell (mm) Volume (m^3) Volume (gallons) Precipitation 916 1087532 290 million Evaporation 163 192967 51 million Runoff 437 518564 137 million Recharge 325 385639 102 million
Giambelluca, T.W., X. Shuai, M.L. Barnes, R.J. Alliss, R.J. Longman, T. Miura, Q. Chen, A.G. Frazier, R.G. Mudd, L. Cuo, and A.D. Businger. 2014. Evapotranspiration of Hawai i. Final report submitted to the U.S. Army Corps of Engineers Honolulu District, and the Commission on Water Resource Management, State of Hawai i.