Lecture Topic - Hydrology Introduction to Hydrology Reservoir Storage CE-321 Introduction to Environmental Engineering

HYDROGRAPH

Reservoir Storage

Water Storage PROBLEMS in Alaska

Reservoir Storage Predicting the capacity of a reservoir –Tabular Method –Graphic Method Two examples: Water Storage - Reservoir

Reservoir Storage Tabular Method Month Inflow (I) (MG/mi^2/mo) OutFlow (O) (MG/mi^2/mo) Cumulative Inflow (Graphical) (MG/mi^2) Deficiency I – O (MG/mi^2) Cumulative Deficiency Feb31.0 Mar54.0 Apr90.0 May10.0 Jun7.0 Jul8.0 Aug2.0 Sep28.0 Oct42.0 Nov108.0 Dec98.0 Jan22.0 Feb50.0

Reservoir Storage Tabular Method Month Inflow (I) (MG/mi^2/mo) OutFlow (O) (MG/mi^2/mo) Cumulative Inflow (Graphical) (MG/mi^2) Deficiency I – O (MG/mi^2) Cumulative Deficiency (MG/mi^2) Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb

Reservoir Storage Tabular Method Month Inflow (I) (MG/mi^2/mo) OutFlow (O) (MG/mi^2/mo) Cumulative Inflow (Graphical) (MG/mi^2) Deficiency I – O (MG/mi^2) Cumulative Deficiency Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb

Reservoir Storage Tabular Method Month Inflow (I) (MG/mi^2/mo) OutFlow (O) (MG/mi^2/mo) Cumulative Inflow (Graphical) (MG/mi^2) Deficiency I – O (MG/mi^2) Cumulative Deficiency Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb

Reservoir Storage Tabular Method

Month Inflow (I) (MG/mi^2/mo) OutFlow (O) (MG/mi^2/mo) Cumulative Inflow (Graphical) (MG/mi^2) Deficiency I – O (MG/mi^2) Cumulative Deficiency Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb

Reservoir Storage To construct 1.Plot Monthly Flow, Cumulative - Line OA 2.Construct a Draft Line, used for comparison - Line OC

Reservoir Storage 3.Tangents are constructed Parallel to OC  When the slope of OA is less than that of the tangents the reservoir volume is decreasing  When the slope is greater the volume is increasing  The distance between adjacent tangents represents the volume added or withdrawn during the intervening period 4.The largest withdrawal would indicate the capacity of the a reservoir needed to serve a community.

Reservoir Storage

In both cases you look for data during a drought period

Class Problem DRAFT = 2.0 m^3/s (flow to meet water demand)28 day month sec/28 day month 230 day month sec/30 day month 31 day month sec/31 day month MonthInflow (I) (m^3/s)Inflow (I) (m^3/month) OutFlow (O) (Draft) (m^3/month) Cumulative Inflow (m^3) (Graphical) Deficiency I - O (m^3) Cumulative Deficiency (m^3) Aug (31)1.70 Sep1.56 Oct (31)1.56 Nov2.04 Dec (31)2.35 Jan (31)2.89 Feb (28)9.57 March (31)17.70 April16.40 May (31)6.83 June3.74 July (31)1.60 Aug (31)1.13 Sept1.13 Oct (31)1.42 Nov1.98 Dec (31)2.12 Jan (31)1.78 Feb (28)1.95 March (31)7.25 April24.70 May (31)6.26 June8.92 July (31)3.57 Aug (31)1.98 Sept1.95 Oct (31)3.09 Nov3.94 Dec (31)12.70

DRAFT = 2.0 m^3/s (flow to meet water demand)28 day month sec/28 day month 230 day month sec/30 day month 31 day month sec/31 day month MonthInflow (I) (m^3/s)Inflow (I) (m^3/month) OutFlow (O) (Draft) (m^3/month) Aug (31) E E+06 Sep1.56 Oct (31)1.56 Nov2.04 Dec (31)2.35 Jan (31)2.89 Feb (28)9.57 March (31)17.70 April16.40 May (31)6.83 June3.74 July (31)1.60 Aug (31)1.13 Sept E E+06 Oct (31) E E+06 Nov E E+06 Dec (31) E E+06 Jan (31) E E+06 Feb (28) E E+06 March (31) E E+06 April E E+06 May (31) E E+06 June E E+06 July (31) E E+06 Aug (31) E E+06 Sept E E+06 Oct (31) E E+06 Nov E E+06 Dec (31) E E+06

MonthInflow (I) (m^3/s)Inflow (I) (m^3/month) OutFlow (O) (Draft) (m^3/month) Cumulative Inflow (m^3) (Graphical) Deficiency I - O (m^3) Cumulative Deficiency (m^3) Aug (31) E E E+06 Sep1.56 Oct (31)1.56 Nov2.04 Dec (31)2.35 Jan (31)2.89 Feb (28)9.57 March (31)17.70 April16.40 May (31)6.83 June3.74 July (31)1.60 Aug (31)1.13 Sept E E E+08 Oct (31) E E E+08 Nov E E E+08 Dec (31) E E E+08 Jan (31) E E E+08 Feb (28) E E E+08 March (31) E E E+08 April E E E+08 May (31) E E E+08 June E E E+08 July (31) E E E+08 Aug (31) E E E+08 Sept E E E+08 Oct (31) E E E+08 Nov E E E+08 Dec (31) E E E+08

MonthInflow (I) (m^3/s)Inflow (I) (m^3/month) OutFlow (O) (Draft) (m^3/month) Cumulative Inflow (m^3) (Graphical) Deficiency I - O (m^3) Cumulative Deficiency (m^3) Aug (31) E E E Sep1.56 Oct (31)1.56 Nov2.04 Dec (31)2.35 Jan (31)2.89 Feb (28)9.57 March (31)17.70 April16.40 May (31)6.83 June3.74 July (31)1.60 Aug (31)1.13 Sept E E E Oct (31) E E E Nov E E E Dec (31) E E E Jan (31) E E E Feb (28) E E E March (31) E E E April E E E May (31) E E E June E E E July (31) E E E Aug (31) E E E Sept E E E Oct (31) E E E Nov E E E Dec (31) E E E

MonthInflow (I) (m^3/s)Inflow (I) (m^3/month) OutFlow (O) (Draft) (m^3/month) Cumulative Inflow (m^3) (Graphical) Deficiency I - O (m^3) Cumulative Deficiency (m^3) Aug (31) E E E Sep1.56 Oct (31)1.56 Nov2.04 Dec (31)2.35 Jan (31)2.89 Feb (28)9.57 March (31)17.70 April16.40 May (31)6.83 June3.74 July (31)1.60 Aug (31)1.13 Sept E E E Oct (31) E E E Nov E E E Dec (31) E E E Jan (31) E E E Feb (28) E E E E+06 March (31) E E E April E E E May (31) E E E June E E E July (31) E E E Aug (31) E E E Sept E E E Oct (31) E E E Nov E E E Dec (31) E E E