"USE LAST DIGIT = 0" 

Q1. (a) Streamflow varies over a water year, and one of the popular methods of studying this streamflow variability is through flow duration curve. The flow duration curve is usually used for water resources planning. The daily streamflows of a river for three consecutive years are shown in Table Q1-1 (a) to Table Q1-1 (e). For convenience, the daily streamflows are grouped into class intervals and the numbers of day the streamflows belonged to each class, are shown in the table. Instructions: Selection of Table based on the LAST Digit' of your 'Index No.' The 'Streamflows by Classes' and the Number of Days' used for calculations are based on the 'LAST Digit' of your 'Index No.': The LAST Digit' of your 'Index No.' 0 or 1 2 or 3 4 or 5 6 or 7 8 or 9 Table Table Q1-1 (a) Table Q1-1 (b) Table Q1-1 (c) Table Q1-1 (d) Table Q1-1 (e) Table Q1-1 (a): Streamflows for three consecutive years in a river Streamflows by classes No. of Days Streamflows by classes No. of Days (m/s) (m/s) 146-155 5 76-85 109 136-145 9 66-75 110 126-135 35 56-65 144 116-125 42 46-55 135 106-115 54 36-45 122 96-105 66 26-35 96 86-95 16-25 88 80 Table Q1-1 (b): Streamflows for three consecutive years in a river Streamflows by classes (m/s) 146-155 136-145 126-135 116-125 106-115 96-105 86-95 No. of Days Streamflows by classes No. of Days (m/s) 10 76-85 109 11 66-75 122 35 56-65 144 38 46-55 122 54 36-45 111 66 26-35 96 90 16-25 87 Ql(a). (Continued) Table Q1-1 (c): Streamflows for three consecutive years in a river Streamflows by classes No. of Days Streamflows by classes No. of Days (m/s) (m/s) 146-155 7 76-85 110 136-145 9 66-75 115 126-135 35 56-65 150 116-125 42 46-55 135 106-115 46 36-45 106 96-105 66 26-35 100 86-95 16-25 94 80 Table Q1-1 (d): Streamflows for three consecutive years in a river Streamflows by classes No. of Days Streamflows by classes No. of Days (m/s) (m/s) 146-155 8 76-85 109 136-145 9 66-75 112 126-135 36 56-65 130 116-125 55 46-55 128 106-115 58 36-45 121 96-105 70 26-35 96 86-95 75 16-25 88 Table Q1-1 (e): Streamflows for three consecutive years in a river Streamflows by classes No. of Days Streamflows by classes No. of Days (m/s) (m/s) 146-155 4 76-85 99 136-145 11 66-75 110 126-135 40 56-65 130 116-125 47 46-55 135 106-115 60 36-45 122 96-105 66 26-35 101 86-95 80 16-25 90 (1) (ii) Develop the flow duration curve for the river. (10 marks) Identify the significant low flow of the river used for water resources assessment. (2 marks) Q1(a). (Continued) (ii) Estimate the probability of water shortage to occur if the minimum requirement of water extraction from the river for domestic water supply is 60 m/s. (2 marks) (iv) The population of the area has been found to increase due to urbanization. Estimate the possibility of water shortage to occur if the minimum requirement of water extraction from the river for domestic water supply has increased to 80 m/s. (2 marks) (v) Determine the change in frequency to have water shortage between the conditions in Q1(a)(iii) and Q1(a)(iv). (3 marks) (vi) The streamflow in the river was found to have decreased, in general, after the 3 years of record as shown in Table Q1-1 due to climate change. Explain in brief how this change affects the flow duration curve developed in Q1(a)(1). (3 marks) (vii) Identify TWO (2) methods to increase the water supply capacity from the river. (3 marks) (b) A flood is an unusually high stage in a river, normally the level at which the river overflows its banks and inundates the adjoining area. At a given location in a river, flood peaks vary from year to year and their magnitude constitutes a hydrologic series, which enable one to assign a frequency to a given flood peak value. The annual maximum flow series of a river for the period of 20 years are shown in Table Q1-2 (a) to Table Q1-2 (e) to analyse the flood probability of the river. Instructions: Selection of Table based on the 'LAST Digit' of your 'Index No.' The Annual maximum flows (m/s) used for calculations are based on the LAST Digit' of your 'Index No.': The 'LAST Digit' of your 'Index No.' O or 1 2 or 3 4 or 5 6 or 7 8 or 9 Table Table Q1-2 (a) Table Q1-2 (b) Table Q1-2 (C) Table Q1-2 (d) Table Q1-2 (e) Q1b). (Continued) Table Q1-2 (a): Annual maximum flows of a river Year Year Annual maximum flows (m/s) 108 98 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 Annual maximum flows (m/s) 120 135 132 155 133 125 122 151 140 150 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 140 133 110 154 130 133 140 129 Table Q1-2 (b): Annual maximum flows of a river Year Year 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 Annual maximum flows (m/s) 121 142 132 155 132 125 123 151 142 150 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 Annual maximum flows (m/s) 109 98 140 132 110 153 129 142 144 130 Table Q1-2 C): Annual maximum flows of a river Year Year 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 Annual maximum flows (m/s) 118 135 140 155 133 125 122 151 140 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 Annual maximum flows (m/s) 108 98 140 121 110 154 130 125 141 125 150 Q1(b). (Continued) Table Q1-2 (d): Annual maximum flows of a river Year Year 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 Annual maximum flows (m/s) 110 150 132 155 131 125 110 151 145 150 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 Annual maximum flows (m/s) 108 98 139 138 110 150 130 133 140 129 Table Q1-2(e): Annual maximum flows of a river Year Year 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 Annual maximum flows (m/s) 117 135 132 155 133 125 117 151 140 150 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 Annual maximum flows (m/s) 108 98 139 117 110 154 133 133 145 129 (i) Analyse the flood probability of the river using plotting position method. (11 marks) (ii) Various frequency distribution functions can be used for the predications of extreme flood values. Confirm the Gumbel's extreme value distribution can be applied to predict the extreme flood values for this annual maximum flow series by using the average recurrence intervals of 50-year and 100-year. (6 marks) Qi(b). (Continued) (iii) A flood mitigation project is proposed based on the annual maximum flow that occurs once in 100 years in the river. Determine the safety margin for flood board design if a safety factor of 1.3 is desired in the design. (3 marks) (iv) Estimate the change in project risk if the project life is changed from 50 years to 75 years. (3 marks) (v) Explain in brief the advantages and disadvantages of flood frequency analysis method in flood estimation as compared to the other methods. (4 marks) (c) The term flood control is commonly used to denote all the measures adopted to reduce damages to life and property by floods, and it can be classified into two methods namely structural method and non-structural method. Explain in detail the difference between structural method and non-structural method in terms of reliability, possibility of implementation, sustainability, and cost effectiveness. (8 marks) Q1. (a) Streamflow varies over a water year, and one of the popular methods of studying this streamflow variability is through flow duration curve. The flow duration curve is usually used for water resources planning. The daily streamflows of a river for three consecutive years are shown in Table Q1-1 (a) to Table Q1-1 (e). For convenience, the daily streamflows are grouped into class intervals and the numbers of day the streamflows belonged to each class, are shown in the table. Instructions: Selection of Table based on the LAST Digit' of your 'Index No.' The 'Streamflows by Classes' and the Number of Days' used for calculations are based on the 'LAST Digit' of your 'Index No.': The LAST Digit' of your 'Index No.' 0 or 1 2 or 3 4 or 5 6 or 7 8 or 9 Table Table Q1-1 (a) Table Q1-1 (b) Table Q1-1 (c) Table Q1-1 (d) Table Q1-1 (e) Table Q1-1 (a): Streamflows for three consecutive years in a river Streamflows by classes No. of Days Streamflows by classes No. of Days (m/s) (m/s) 146-155 5 76-85 109 136-145 9 66-75 110 126-135 35 56-65 144 116-125 42 46-55 135 106-115 54 36-45 122 96-105 66 26-35 96 86-95 16-25 88 80 Table Q1-1 (b): Streamflows for three consecutive years in a river Streamflows by classes (m/s) 146-155 136-145 126-135 116-125 106-115 96-105 86-95 No. of Days Streamflows by classes No. of Days (m/s) 10 76-85 109 11 66-75 122 35 56-65 144 38 46-55 122 54 36-45 111 66 26-35 96 90 16-25 87 Ql(a). (Continued) Table Q1-1 (c): Streamflows for three consecutive years in a river Streamflows by classes No. of Days Streamflows by classes No. of Days (m/s) (m/s) 146-155 7 76-85 110 136-145 9 66-75 115 126-135 35 56-65 150 116-125 42 46-55 135 106-115 46 36-45 106 96-105 66 26-35 100 86-95 16-25 94 80 Table Q1-1 (d): Streamflows for three consecutive years in a river Streamflows by classes No. of Days Streamflows by classes No. of Days (m/s) (m/s) 146-155 8 76-85 109 136-145 9 66-75 112 126-135 36 56-65 130 116-125 55 46-55 128 106-115 58 36-45 121 96-105 70 26-35 96 86-95 75 16-25 88 Table Q1-1 (e): Streamflows for three consecutive years in a river Streamflows by classes No. of Days Streamflows by classes No. of Days (m/s) (m/s) 146-155 4 76-85 99 136-145 11 66-75 110 126-135 40 56-65 130 116-125 47 46-55 135 106-115 60 36-45 122 96-105 66 26-35 101 86-95 80 16-25 90 (1) (ii) Develop the flow duration curve for the river. (10 marks) Identify the significant low flow of the river used for water resources assessment. (2 marks) Q1(a). (Continued) (ii) Estimate the probability of water shortage to occur if the minimum requirement of water extraction from the river for domestic water supply is 60 m/s. (2 marks) (iv) The population of the area has been found to increase due to urbanization. Estimate the possibility of water shortage to occur if the minimum requirement of water extraction from the river for domestic water supply has increased to 80 m/s. (2 marks) (v) Determine the change in frequency to have water shortage between the conditions in Q1(a)(iii) and Q1(a)(iv). (3 marks) (vi) The streamflow in the river was found to have decreased, in general, after the 3 years of record as shown in Table Q1-1 due to climate change. Explain in brief how this change affects the flow duration curve developed in Q1(a)(1). (3 marks) (vii) Identify TWO (2) methods to increase the water supply capacity from the river. (3 marks) (b) A flood is an unusually high stage in a river, normally the level at which the river overflows its banks and inundates the adjoining area. At a given location in a river, flood peaks vary from year to year and their magnitude constitutes a hydrologic series, which enable one to assign a frequency to a given flood peak value. The annual maximum flow series of a river for the period of 20 years are shown in Table Q1-2 (a) to Table Q1-2 (e) to analyse the flood probability of the river. Instructions: Selection of Table based on the 'LAST Digit' of your 'Index No.' The Annual maximum flows (m/s) used for calculations are based on the LAST Digit' of your 'Index No.': The 'LAST Digit' of your 'Index No.' O or 1 2 or 3 4 or 5 6 or 7 8 or 9 Table Table Q1-2 (a) Table Q1-2 (b) Table Q1-2 (C) Table Q1-2 (d) Table Q1-2 (e) Q1b). (Continued) Table Q1-2 (a): Annual maximum flows of a river Year Year Annual maximum flows (m/s) 108 98 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 Annual maximum flows (m/s) 120 135 132 155 133 125 122 151 140 150 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 140 133 110 154 130 133 140 129 Table Q1-2 (b): Annual maximum flows of a river Year Year 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 Annual maximum flows (m/s) 121 142 132 155 132 125 123 151 142 150 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 Annual maximum flows (m/s) 109 98 140 132 110 153 129 142 144 130 Table Q1-2 C): Annual maximum flows of a river Year Year 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 Annual maximum flows (m/s) 118 135 140 155 133 125 122 151 140 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 Annual maximum flows (m/s) 108 98 140 121 110 154 130 125 141 125 150 Q1(b). (Continued) Table Q1-2 (d): Annual maximum flows of a river Year Year 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 Annual maximum flows (m/s) 110 150 132 155 131 125 110 151 145 150 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 Annual maximum flows (m/s) 108 98 139 138 110 150 130 133 140 129 Table Q1-2(e): Annual maximum flows of a river Year Year 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 Annual maximum flows (m/s) 117 135 132 155 133 125 117 151 140 150 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 Annual maximum flows (m/s) 108 98 139 117 110 154 133 133 145 129 (i) Analyse the flood probability of the river using plotting position method. (11 marks) (ii) Various frequency distribution functions can be used for the predications of extreme flood values. Confirm the Gumbel's extreme value distribution can be applied to predict the extreme flood values for this annual maximum flow series by using the average recurrence intervals of 50-year and 100-year. (6 marks) Qi(b). (Continued) (iii) A flood mitigation project is proposed based on the annual maximum flow that occurs once in 100 years in the river. Determine the safety margin for flood board design if a safety factor of 1.3 is desired in the design. (3 marks) (iv) Estimate the change in project risk if the project life is changed from 50 years to 75 years. (3 marks) (v) Explain in brief the advantages and disadvantages of flood frequency analysis method in flood estimation as compared to the other methods. (4 marks) (c) The term flood control is commonly used to denote all the measures adopted to reduce damages to life and property by floods, and it can be classified into two methods namely structural method and non-structural method. Explain in detail the difference between structural method and non-structural method in terms of reliability, possibility of implementation, sustainability, and cost effectiveness. (8 marks)