Options for Improving Climate Modeling to Assist Water Utility ...

More documents

Recommendations

Info

Water Utility Climate Alliance White Paper Options for Improving Climate Modeling to Assist Water Utility Planning for Climate Change and storage goals (water demands both within New York City and in the northern supply area), and operating rules. Output variables: Streamflow. Variable Source Loading Function model: A variant of the GWLF (Generalized Watershed Loading Function) model, VSLF simulates water quality and quantity, including dissolved and particulate nutrient loads at daily timescales. Spatial scale: VSLF models have been developed for major reservoir watersheds. Time scale: Daily. Input variables: VSLF is driven by daily time series of measured precipitation and air temperature, spatially averaged over the watershed; and optionally daily solar radiation and relative humidity when the Priestley-Taylor potential evapotranspiration algorithm is used. Output variables: Streamflow, evapotranspiration, potential evapotranspiration, total dissolved phosphorus, total dissolved nitrogen, particulate phosphorus, and total suspended sediments. Reservoir models: NYCDEP routinely uses two classes of reservoir models. One-dimensional (1-D) models are used to examine issues related to nutrient loading and eutrophication. CE Qual W2, a two-dimensional (2-D) reservoir model, is typically used to simulate the transport of turbidity through Catskill system reservoirs. Spatial scale: Reservoir water quality modeling is conducted on the scale of the component watersheds (hundreds of square miles). For turbidity modeling in particular, 25 km 2 grid cells would be optimal in order to better understand the impacts of intense precipitation events. Time scale: 1–6-month forecasts. Input variables: Reservoir water quality modeling is driven by air temperature, dewpoint, solar radiation, wind speed, and direction. The 1-D models are driven by 35 years of meteorological data, reservoir operations data, and VSLF-derived nutrient loads. The 2-D model is driven by gauged tributary flows, operations data, and stream temperature measured as a function of air temperature. Output variables: Nutrient loading and eutrophication, transport of turbidity. Page A-3
Water Utility Climate Alliance White Paper Options for Improving Climate Modeling to Assist Water Utility Planning for Climate Change A.3 Portland Water Bureau Distributed Hydrology, Soil-Vegetation Model: DHSVM is a subregional hydrology model. Spatial scale: PWB’s watershed is approximately 92,000 acres (370 km 2 ) in size. Time scale: Unclear from the materials we received. Input variables: DHSVM is driven by temperature and precipitation, with information in the small grid sizes about vegetation height, soil depth, elevation, slope, and slope aspect. While PWB could use a large amount of temperature and precipitation information for this model, it has tended to use a single National Weather Service station at the Portland Airport. For the climate study mentioned above, PWB used monthly degree change in temperature and monthly percentage change in precipitation. Output variables: Daily streamflow values. Supply and Transmission Model/Water Evaluation and Planning model: Portland uses two mass balance models, based on the Stella platform (STM) and the WEAP platform. More information was available on STM than on Portland’s use of WEAP. Consequently, the information below refers to STM. The STM and its use with the Bureau are described in Palmer et al. (2000). Spatial scale: Covers PWB’s entire service area, with nodes for all major wholesale customers. Time scale: Daily information or rolling seven-day averages for summer supply planning and PWB’s water demand model. Input variables: Streamflows calculated from DHSVM. Output variables: Annual minimum storage, groundwater pumped, length of drawdown, etc. A.4 San Francisco Public Utilities Commission Hetch Hetchy/Local Simulation Model: This is a water supply planning (mass balance) model that simulates SFPUC’s operation of San Francisco’s Hetch Hetchy facilities, the Don Pedro Project, and the Bay Area reservoir, conveyance, and treatment system. This model includes a watershed runoff forecasting routine for water supply and power generation allocations and operations of other Tuolumne Rive stakeholders. The HH/LSM analyzes system operations based on historic hydrology (19202002), including actual hydrological sequences and events, and the model allows the SFPUC to predict the consequences of hydrologic changes to the Page A-4
Page 2:
Options for Improving Climate Model
Page 5 and 6:
Water Utility Climate Alliance Whit
Page 8:
Page 12 and 13:
Page 14:
Page 17 and 18:
Page 19 and 20:
Page 21 and 22:
Page 23 and 24:
Page 25 and 26:
Page 28 and 29:
Page 30 and 31:
Page 32 and 33:
Page 34 and 35:
Page 36 and 37:
Page 38 and 39:
Page 40:
Page 43 and 44:
Page 45 and 46:
Page 47 and 48:
Page 49 and 50:
Page 51 and 52:
Page 53 and 54:
Page 55 and 56:
Page 57 and 58:
Page 59 and 60:
Page 61 and 62:
Page 63 and 64:
Page 65 and 66:
Page 67 and 68:
Page 69 and 70:
Page 71 and 72:
Page 73 and 74:
Page 75 and 76:
Page 77 and 78:
Page 79 and 80:
Page 81 and 82: Water Utility Climate Alliance Whit
Page 118: Water Utility Climate Alliance Whit
Page 142: Water Utility Climate Alliance Whit
show all

Options for Improving Climate Modeling to Assist Water Utility ...

Create successful ePaper yourself

Delete template?

Save as template?