Forecasting Water Intake from Lake Michigan for Lake County Indiana - Nonlinear Regression Analysis and Artificial Neural Network Models Approach: 1990 – 2008

摘要

This study provides an analysis of water withdrawal from 1990 to 2008 in Lake County ofrnNorthwest Indiana. Utilizing the Winter Base-Rate Method, this report assesses and predictsrnconsumptive water-use via historical data; and it projected water withdrawal data through 2013rnusing nonlinear regression analysis and artificial neural network models. The withdrawal datarnused in this study is provided by the Indiana Department of Natural Resource and IndianarnDepartment of Environmental Management. Using a statistical tool, data was systematized in arndatabase by sectors: energy production, industry, irrigation and agriculture, miscellaneous, andrnpublic supply.rnResults indicate that total water withdrawal has declined from 838 billion gallons in 1990 to 603rnbillion gallons in 2008-an approximate 28 percent decrease. During the same period,rnwithdrawal in the following has been documented:rna.) energy production, from 338 billion to 182 billion (-46%);rnb.) industry, from 469 billion to 386 billion (-18%);rnc.) irrigation and agriculture, from 1.2 billion to 3.33 billion (+168%); andrnd.) miscellaneous, from 1.3 billion to 1.5 billion (+15%); andrne.) public supply, from 28.68 billion to 30.1 billion (+5%).rnThe energy production and industry sectors account for 97 percent of total water withdrawal.rnApproximately 99.96 percent of total water withdrawal is from surface water, while only 0.04rnpercent is from ground water (well).rnFurthermore, analysis shows that the average summer withdrawal is 375 billion gallons andrnaverage winter withdrawal is 328 billion gallons-a difference of some 13 percent. Therndifference may reflect such factors as evaporation, outdoor use, consumptive-use, and waterrndemand. During summer months, the influent water temperature increases; therefore, additionalrnwater is needed to produce the same amount of energy, while cooling the reactors andrncondensers in the energy production sector. Based on Winter Base-Rate equations the annualrnconsumptive-use coefficient (%) is 7.9; summer consumptive-use coefficient (%) is 17.3; andrnmonthly consumptive-use coefficient (%) are 6.3, 13.16, 19.06, 19.29, 11.55, and 11.09 for thernrespective months of May, June, July, August, September, and October.rnThe Logarithmic Regression model indicates a downward water withdrawal trend and an averagernvalue of 553 billion gallons per year from 2009 to 2013. The ANN model shows that waterrnwithdrawal will vary from 552 to 451 billion gallons per year.