PERPUSTAKAAj UMP

1 1111 III Ill III Ill II 1111 HI 111111111 STUDY or 0000092685 SELECT THE

IDEAL HYDROLOGY STATION

SIT! MARINI BINTI SAAT

A thesis submitted in partial fulfilment of the

requirements for the award of the degree of

Bachelor of Civil Engineering

Faculty of Civil Engineering and Earth Resources

Universiti Malaysia Pahang

JUNE 2013

ABSTRACT

Hydrology is often defined as a science dealing with the properties, distribution, and circulation of water. The purpose of hydrologic study is to determine the type and amount of hydrologic data needed. To collect the data, the hydrology stations need to be select before doing the fieldwork. The physical criteria of the hydrology station will affect the result of the research. The objective of this study is to identify the factor and criteria to select the ideal hydrology station for water discharge station and water quality station. The impact of the unfulfilled criteria of the hydrology station to the water flow and selected water quality's parameters will be det$mined. The parameter that will be test on this study is water flow rate, Q (m3 /s), total suspended solid, TSS (mgIL), chemical oxygen demand, COD (mgIL), and biochemical oxygen demand, BOD (mg/L). Three factors involve in this study are; i) river features, ii) existing of obstruction on the water flow and iii) the distance between two hydrology station. Velocity area method is used to determine the total flow rate. For this study, Sungai Galing Besar has been chosen as a study area. This study shows that unfulfilled criteria of the hydrology station give effect to the selected parameter's reading. The result at the station of curved stream shows the velocity become lower and the TSS, COD and BOD reading will increase. At the station that having the obstruction on water flow, the velocity are increase because of the cross section area are decrease. The longest distance between two hydrology stations give the readings of the parameter are more different. For the medium distance, the difference reading is about average. While for the short distance, the difference reading is too small. From the result, the medium distance is acceptable as the distance between two hydrology stations. So that, the criteria of hydrology station need to be consider before conduct the hydrology study to obtain the accurate result.

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ABSTRAK

Hidrologi sering ditakrifkan sebagai sains yang berkaitan dengan sifat-sifat, pengedaran, dan peredaran air. Tujuan kajian hidrologi adalah untuk menentukan jenis dan jumlah data hidrologi yang diperlukan. Untuk mengumpul data, stesen-stesen hidrologi perlu pilih sebelum melakukan kerja lapangan mi. Kriteria fizikal stesen hidrologi akan memberi kesan kepada hasil kajian. Objektif kajian mi adalah untuk mengenalpasti faktor dan kriteria untuk memilih stesen hidrologi sesuai üntuk stesen mengukur kadar, aliran air dan stesen kualiti air. Kesan akibat tidak mengikut kriteria stesen hidrologi kepada aliran air dan parameter kualiti air yang dipilihdapat ditentukan. Parameter yang akan di uji didalam kajian mi adalah kadar aliran 1r, Q (m3/s), kadar pepejal terampai, TSS (mgfL), kadar oksigen kimia, COD (mg/L), dan kadar oksigen biokimia, BOD (mg/L). Tiga faktor yang terlibat dalam kajian mi adalah; i) ciri-ciri sungai, ii) terdapat halangan pada aliran air dan iii) jaràk di AAtara dua stesen hidrologi. Kaedah 'Velocity Area Method' digunakan untuk menentukan kadar aliran keseluruhan sungai. Untuk kajian mi, Sungai Galing Besar telah dipilih sebagai kawasan kajian. Kajian mi menunjukkan bahawa stesen hidrologi yangttidak memenuhi criteria memberi kesan kepada bacaan parameter yang dipilih. Keputusan di stesen aliran melengkung menunjukkan halaju menjadi lebih rendah dan kadar TSS, COD dan BOD akan meningkat. Di stesen yang mempunyai halangan pada aliran air, halaju meningkat kerana luas keratan sungai mengecil. Jarak yang jauh di antara dua stesen hidrologi menyebabkan perbezaan bacaan parameter lebih berbeza. Bagi jarak sederhana, perbezaan bacaan adalah purata. Manakala bagi jarak dekat, perbezaan bacaan adalah terlalu kecil. Dari hasil kajian, jarak sederhana adalah sesuai diguna sebagai jarak antara dua stesen hidrologi. Oleh itu, kriteria stesen hidrologi perlu dipertimbangkan sebelum menjalankan kajian hidrologi untuk mendapatkan hasil yang tepat.

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TABLE OF CONTENTS

DESCRIPTION PAGE

SUPERVISOR'S DECLARATION i

STUDENT'S DECLARATION

DEDICATION iii

ACKNOWLEDGEENT iv

ABSTRACT v

ABSTRAK vi

TABLE OF CONTENTS vii

LIST OF TABLES xi

LIST OF FIGURES xii

LIST OF ABBREVIATIONS xiii

CHAPTER 1 INTRODUCTION

1.1 Introduction 1

1.2 Problem Statement 2

1.3 Objectives 3

1.4 Scope of Study 3

1.5 Expected Outcome 4

1.6 Significant of Study 5

CHAPTER 2 LITERATURE REVIEW

2.1 Introduction 6

2.2 Classification of Hydrology Station 7

2.2.1 Primary Station 7 2.2.2 Secondary Station 8

VII

VII!

2.2.3 Special Purpose Station 8

2.3 Type of Hydrology Station 8

2.3.1 Water Discharge Station 9 2.3.2 Sediment Station 9 2.3.3 Water Quality Station 9 2.3.4 Weather Station 10 2.3.5 Water Level Station 10

2.4 Criteria of Hydrology StationSite 11

2.5 Impact of Unfulfilled Hydrology Station's Criteria 12

2.6 Velocity Area Method 14

2.7 Type of Current Meter 19

2.7.1 Pygmy AA meter 20 2.7.2 AquaCalc Pro Open Channel Flow Computer 21 2.7.3 Proieller Water Current Meter 22 2.7.4 Global FP1 11 Flow Probe 23

2.8 Water Quality's Parameters - 24

2.8.1 Total Suspended Solid (TSS) 24 2.8.2 Chemical Oxygen Demand (COD) 25 2.8.3 Biochemical Oxygen Demand (BOD) 25

CHAPTER 3 STUDY AREA

3.1 Introduction 26

3.2 Pahang 27

3.3 Pahang River 28

3.4 Kuantan 28

3.5 Kuantan River 29

3.6 Sungai Galing 29

3.7 Station Description 31

CHAPTER 4 METHODOLOGY

4.1 Introduction 36

4.2 Selection of Study Area 38

4.3 Site Observation 38

4.4 Marking The Station 39

4.4.1 Station 1 40

4.4.2 Station 2 41 4.4.3 Station 3 41 4.4.4 Station 4 41

4.5 Data Collection 42

4.5.1 Measuring the Cross Section 42 4.5.2 Measuring the Velocity 44 4.5.3 Computing the Flow Rate 45 4.5.4 Obtaining the data for Water Quality's Parameters 47

CHAPTER 5 DATA ANALYSIS AND DISCUSSION

5.1 Introduction 48

5.2 Data Analysi,on Flow Rate 49

5.2.1 Flow Rate for Day 1 49 5.2.2 Flow Rate for Day 55 5.2.3 Flow Rate for Day 3 61

5.3 Total Flow Rate for 3 Different Days 67

5.4 Flow Rate, Rainfall Relationship 68

5.5 Data Analysis on Factor 1: River Features 69

5.5.1 Analysis for Day 1 70 5.5.2 Analysis for Day 2 71 5.5.3 Analysis for Day 72 5.5.4 Discussion 73

5.6 Data Analysis on Factor 2: Existence of the Obstruction on Flow 74

5.6.1 Analysis for Day 1 75 5.6.2 Analysis for Day 76 5.6.3 Analysis for Day 3 77 5.6.4 Discussion 78

5.7 Data Analysis on Factor 3: Distance between Two 79

Hydrology Stations

5.7.1 Analysis for Day 1 80 5.7.2 Analysis for Day 81 5.7.3 Analysis for Day 3 82 5.7.4 Discussion 83

CHAPTER 6 CONCLUSION AND RECOMMENDATION

6.1 Conclusion 84

6.2 Recommendation 85

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REFERENCES

87

APPENDICES

A Cross Section of Each Station for Day 1 89

B Cross Section of Each Station for Day 2 91

C Cross Section of Each Station for Day 3 93

D Example of Total Flow Rate Calculation 95

E Calculation for Difference Reading Value 96

F Data for Total Suspended Load (TSS), Chemical Oxygen Demand 97

(COD), Biochemical Oxygen Demand (BOD)

G Daily total rain for February and March year 2013 98

x

LIST OF TABLES

Table No. Title Page

2.1 Table for computing the flow rate 19 4.1 Table for computing the flow rate 46 4.2 National Water Quality Standard for Malaysia 47 5.1 Flow Rate at Station 1 50 5.2 Flow Rate at Station 2 51 5.3 Flow Rate at Station 3 52 5.4 Flow/Rate at Station 4 53 5.5 Flow Rate at Station 1 56 5.6 Flow Rate at Station 2 57 5.7 Flow Rate at Station 3 58 5.8 Flow Rate at Station 4 59 5.9 Flow Rate at Station 1 62 5.10 Flow Rate at Station 2 63 5.11 Flow Rate at Station 3 74 5.12 Flow Rate at Station 4 65 5.13 Distance between two stations 79

A

LIST OF FIGURES

Figure No. Title Page

2.1 Cross-sectional area of a stream 16 2.2 Measure the width of the stream 16 2.3 Measure the depth of the stream 17 2.4 Measure the velocity using current meter 18 2.5 Pygmy Meter 20 2.6 AquaCaic Pro 21 2.7 Propeller Water Current Meter 22 2.8 Global Water Flow Probe 23 3.1 Location of Pahang state 27 3.2 Location of the Sungai Galing 30 3.3 Location of the Study Area 31 3.4 Location of Station 1 32 3.5 Location of Station 2 33 3.6 Location of Station 3 34 3.7 Location of Station 4 35 4.1 Flow chart methodologies 37 4.2 Picket 39 4.3 Hammer 40 4.4 Measuring Tape 43 4.5 Arrow 43 4.6 Current Meter 45 5.1 Graph Flow Rate for day 1 54 5.2 Graph Flow Rate for day 1 for each sub station 554 5.3 Graph Flow Rate for day 2 60 5.4 Graph Flow Rate for day 2 for each sub station 60 5.5 Graph Flow Rate for day 3 66 5.6 Graph Flow Rate for day 3 for each sub station 66 5.7 Total Flow Rate for 3 Different Days 67 5.8 Graph Flow Rate versus Rainfall 68 5.9 Graph data combination for day 1 70 5.10 Graph data combination for day 2 71 5.11 Graph data combination for day 3 71 5.12 Graph data combination for day 1 75 5.13 Graph data combination for day 2 76 5.14 Graph data combination for day 3 77 5.15 Difference Reading versus Distance for day 1 80 5.16 Difference Reading versus Distance for day 2 81 5.17 Difference Reading versus Distance for day 3 82

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LIST OF ABBREVIATIONS

DID Department of Irrigation and Drainage Q Flow Rate of water (m3/s) A Cross Sectional Area (m2) V Actual Velocity (m2/s) s Time in Second m Meter mg Milligram L Litre/ d Depth (m) b Strip Width (m) 51 Station 1 S2 Station 2 S3 Station 3 S4 Station 4 TSS Total Suspended Solid COD Chemical Oxygen Demand BOD Biochemical Oxygen Demand Day 1 First day of collecting data Day 2 Second day of collecting data Day 3 Third day of collecting data

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CHAPTER 1

INTRODUCTION

2.1 Introduction

Hydrology is often defined as a science dealing with the properties,

distribution, and circulation of water on the surface of the land, in the soil and

underlying rocks, and in the atmosphere. There are no exact methods for hydrologic

analysis. Different methods that are commonly used may produce significantly

different results for a specific site and particular situation. Although hydrology is not

an exact science, it is possible to obtain solutions which are functionally acceptable.

The purpose of hydrologic study is to determine the type and amount of

hydrologic data needed. Hydrologic studies involve learning about the properties of

water and its maintenance. Those are vital to the health and sustainability of water

resources, providing maintenance and management skills necessary for

environmental protection. The hydrology work are such as managing lakes, rivers

and oceans, monitoring the quality and quantity of surface and ground water, taking

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samples and flow measurements, installing gauges and surveying cross-sections of

water ways.

Knowledge and understanding of hydrology is important in many

applications. For examples, flood mitigation engineer has to estimate the flood

discharge and volume to size a flood storage pond and to determine channel capacity.

The irrigation engineer needs to understand the rainfall pattern and its temporal

variation, the evaporation and infiltration losses peculiar to his project area to

estimate irrigation requirements. The water resources engineer needs to estimate the

amount of flow available from the catchment of his proposed dam site, losses due to

evaporation and seepage so that he can work out the dam storage capacity required to

support a given flow abstraction rate.

2.2 Problem Statement

There are many type of hydrology station involve in hydrology field. The

hydrology station is such as, water discharge station, water quality station, sediment

station, weather station and water level station. The stations are classification

according to the purpose of the station and the type of data needed.

Before getting a data, the ideal hydrology stations need to be selected for

doing the fieldwork and taking the sample. The criteria of the hydrology station need

to be considered while choosing the location of the hydrology station. The criteria

are such as, the river stream should be straight, there are no obstruction on the water

flow and must be using the appropriate distance between two hydrology stations.

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Nowadays, there are lack of information and knowledge about the

consideration of factor and criteria of the hydrology station among the researcher.

The unfulfilled criteria of the hydrology station will affect the result of the research.

To get the precise result from the research, the information about the factor and

criteria of the hydrology station need to be consider.

2.3 Objectives

The objectives of this study are as follows;

1. To identify the criteria needed in selecting the best location for hydrology

station.

2. To study the impact of unfulfilled criteria in selecting the hydrology

station to the water flow and water quality data.

2.4 Scope of Study

The scopes of this study are as follows;

1. Sungai Galing will be the study area for this study.

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2. This study is conducted to identify the criteria needed in selecting location

for water discharge stations and water quality stations only.

3. Four parameters was selected which is water flow rate (Q) for analysis

water discharge, total suspended solid (TSS), chemical oxygen demand

(COD), and biochemical oxygen demand (BOD) for analysis water

quality at Sungai Galing.

4. Three factors involve in this study are; i) river features, ii) existing of

obstruction on the water flow and iii) the distance between two hydrology

station.

5. Velocity Area Method will be use as the method to obtain the data for

water flow rate,

2.5 Expected Outcomes

By doing the fieldwork at the river, site observation and literature study, the

criteria for selecting the location of the hydrology station was identified. From the

fieldwork, the impact of unfulfilled criteria in selecting the hydrology station to the

flow rate and water quality result can be determined. It is expected for this study that

will come out with the thesis that contains of criteria of the hydrology station and the

factors to select the ideal hydrology station before start the hydrological studies. The

results of this study will give guide to other researcher in selecting the ideal

hydrology stations before start their research.

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2.6 Significance of Study

Selection of ideal hydrology station is needed before starts a data collection

for flood mitigation studies, river flow or rainfall. It is important to the researcher to

choose the ideal area to do the fieldwork for taking a sample. The suitable location is

one of the criteria that should be considered while choosing the hydrology station. It

is because the unfulfilled criteria of the hydrology station will give effect to the

parameters results. A researcher should have knowledge about the factor and criteria

in selecting the hydrology station. This study will helps researcher to have a guided

in selecting the ideal hydrology station.

CHAPTER 2

LITERATURE REVIEW

2.1 Introduction

The term hydrology can be divided into two terms. Hydro relating to water,

and loge, a Greek word meaning knowledge, thus hydrology is the study, or

knowledge of water. Hydrology is a multidisciplinary subject that deals with the

occurrences, circulation, storage, distribution and properties of surface and ground

water on the earth. The domain of hydrology includes the physical, chemical and

biological reaction of water in natural-and man-made environment (Vidya, 2008).

Hydrological observations could be broadly defined as the scientific way for

collection of flow data at a specific location along the river. The reliability of the

data is an important attribute for assessing the water resources in terms of quantity,

quality, distribution in time and space and its potential for planning and development

of projects to meet different water demands. The observations at various

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hydrological stations mainly include the gauge, discharge, suspended sediment, bed

material and water quality (Sharma, n.d., p. 7).

Stream flow or discharge is the volume of water that moves through a specific

point in a stream during a given period of time. Discharge is usually measured in

units of cubic feet per second (cfs). To determine discharge, a cross-sectional area of

the stream or river is measured. Then, the velocity of the stream is measured using a

Flow Rate Sensor. The discharge can then be calculated by multiplying the cross-

sectional area by the flow velocity.

2.2 Classification of Hydrology Station

The main criteria for classification of a site for hydrological observation will

be the purpose for which it is established. Depending on the purpose, the

hydrological observation station could be classified into three types (Sharma, n.d., p.

10).

2.2.1 Primary Station

These are also termed as key gauging stations, principal stations or bench

mark stations and are maintained on long term basis to generate representative flow

series of the river system.

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2.2.2 Secondary Station

These are essentially short duration stations intended to be operated only for

such a length of period as is enough to establish the flow characteristics of the river

or stream.

2.2.3 Special Purpose Station

These are also termed as specific purpose stations or project stations or

temporary stations meant for projects and are discontinued when the purpose is

served. The purpose could vary from design, management and operation of the

project to monitoring and fulfilment of legal agreement between co-basin states. The

primary as well as secondary stations also many a times serve as special purpose

stations.

2.3 Type of Hydrology Station

There are many type of hydrology station involve in hydrology field. The

stations are divided according to the purpose of the station and the type of data

needed.

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2.3.1 Water Discharge Station

Water discharge stations or gauge station consist of records of stage and

measurements of discharge of streams or canals, and stage, surface area, and volume

of lakes or reservoirs. A stream gauge, stream gage or gauging station is a location

used by hydrologists or environmental scientists to monitor and test terrestrial bodies

of water. Hydrometric measurements of water surface elevation or

volumetric discharge (flow) are generally taken and observations of biota may also

be made.

2.3.2 Sediment Station

Sediment station is a area that vertical cross-sectional plane of a stream,

usually normal to the mean direction of flow, where samples of suspended load are

collected on a systematic basis for determining concentration, particle-size

distribution, and other characteristics (McGraw, 2003).

2.3.3 Water Quality Station

Water quality station is the place that the equipment will be install to get the

water quality data, the data were used to determine the water quality status weather

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in clean, slightly polluted or polluted category and to classify the rivers in Class I, II,

III, IV or V based on Water Quality Index (WQI) and Interim National Water

Quality Standards for Malaysia (INWQS) (N.R.E, 2010).

2.3.4 Weather Station

Weather station is one of a network of observation posts where

meteorological data is recorded. This station are used a device that contains many

sensors (thermometer, rain gauge, barometer, etc.) to measure atmospheric data such

as temperature, air pressure or humidity (Intergiot, 2006).

2.3.5 Water Level Station

Water level station is a facility for the systematic measurement of the water

levels of rivers, seas, lakes, and canals. It consists of a device for reading the water

level and of bench marks, which are geodetic structures that fix the position of a

point whose height has been determined. Staff gauges are equipped with a calibrated

wooden or metal staff, which is vertically attached to a structure and pile gauges are

equipped with piles that have been driven perpendicularly into the shore or bank

("Encyclopaedia," 2010).

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2.4 Criteria of Hydrology Station Site

The purpose in establishing a river stage station is to obtain a truly

representative record of river levels whether for the direct use of this information or

as a step towards the measurements of the river discharge. Therefore the selection

criteria must generally conform to certain ideals as advocated by the World

Meteorological Organization (WMO) for the degree of reliability of observations

will depend in part on these conditions being met.

One of the main criteria when selecting a suitable site for establishing a river

stage station is would be to choose a stretch that has both firm and stable banks and

bed, resistant to any scouring or erosion. Ideally there should be a straight section

upstream at least five times the width of the channel and for downstream twice the

width (DID Manual, 2009). Other researcher said factors in selecting a location for

gaging station sites is the course of the stream is straight for about 300 ft upstream

and downstream from the site (Robert, n.d.). According to the article from Kuusisto

(1996) the cross-section should be located at a point where the stream is nominally

straight for at least 50 m above and below the measuring station. Other than that, the

reaches for upstream and downstream of the proposed station gauge are straight and

uniform (Sharma, n.d., p. 11).

Next criterion for hydrology station site is the bed should also be free of any

obstructions including vegetation and there should not be any structures e.g. bridges

in proximity to the gauging station, both upstream and downstream (DID Manual,

2009). Other researcher said the streambed is not subject to scour and fill and is free

of aquatic growth (Robert, n.d.; Kuusisto, 1996). According to article from Sharma

(n.d., p. 11), the reach is free from rock outcrops, weed growth and pools.

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Another criteria is the flow should not under any circumstances by pass the

station e.g. via outflow stream(s) upstream. The water surface in this reach should be

steeper than the gradient, downstream of this reach (DID Manual, 2009). Banks are

permanent, high enough to contain floods, and free of brush, permanent, stable

control that is effective at all stages, and gage site is far enough upstream (Robert,

n.d.) the velocities at all points are parallel to one another and at right angles to the

cross section of the stream, the depth of flow is greater than 30 cm, the stream does

not overflow its banks (Kuusisto, 1996).

Besides the criteria already mentioned for selecting suitable locations for

stage monitor and cbleway systems, the following items should be also be

considered during this process which is the vehicle and personnel access to the site

during inclement weather, personnel access to equipment for operation and

maintenance, power supply to the site, protection of the equipment and

instrumentation from weather, wildlife and vandalism (DID Manual, 2009).

2.5 Impact of Unfulfilled Hydrology Station's Criteria

Stream flow has two components. The first is flow velocity, and the second is

the volume of water in the stream. Flow velocity is influenced by the slope of the

surrounding terrain, the depth of the stream, the width of the stream, and the

roughness of the substrate or stream bottom. The substrate of the stream bottom also

affects the flow velocity since water moves faster over a smooth surface than a rough

surface. Flow velocity is greater when the stream bottom is comprised of sand and

clay and lower when it is cobble, rock, and boulders (Millikan, n.d., p. 16).

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The volume of water in the stream is affected by the climate of the region.

Areas with more rain and snow will have more water draining into surrounding

streams and rivers. Seasonal changes affect stream volume as well. In the summer

there will be less water in the stream compared to the winter. The number of

tributaries that merge with a stream or river contribute more water to the system,

increasing the stream volume. Humans are also responsible for altering the volume of

water in streams (Millikan, n.d., p. 16).

The stage-discharge relation at some stream-gaging stations is affected by

backwater from reservoirs, tributary streams, or other sources. Such an occurrence

necessitates the use of the slope method in which the slope or fall in a reach of the

stream is a factor in computing discharge (Washington, 2003).

At some stations, stage-discharge relation is affected by changing stage. At

these stations, the rate of change in stage is used as a factor in computing discharge.

At some stream-gaging stations in the northern United States, the stage-discharge

relation is affected by ice in the winter; therefore, computation of the discharge in the

usual manner is impossible (Washington, 2003).

Next is the stream bottom factor account for the friction of the water flowing

past the stream substrate, with the assumption that average stream velocity is only

80% to 90% of the surface velocity. Rough bottom streams interspersed with

submerged plants or rocks have slower water velocities as compared to smooth mud

or bedrock. Thus, streams with cobble or gravel substrates or many aquatic plants

have a bottom factor of 0.8, whereas streams with a smooth mud, silt, or bedrock

substrate have a factor of 0.9 (Wisconsin, 2003).

Sediment is transported downstream either suspended in the water column

(suspended-sediment transport) or moving along bottom of the channel in contact

with the bed (bedload transport). Suspended-sediment transport is determined by

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collecting representative samples to determine the average concentration of the

sediment in suspension. Suspended sediment moves with the flow. Suspended

sediment moves faster in areas of the stream having higher velocities than in areas of

the stream having lower velocities (Robert, n.d.; Holmes, n.d., p. 50).

Sedimentation of streams can have a pronounced effect on water quality and

stream life. Sediment can clog and abrade fish gills, suffocate fish eggs and aquatic

insect larvae, and cause fish to modify their feeding and reproductive behaviours.

Sediment also interferes with recreational activities as it reduces water clarity and

fills in water bodies. In addition to mineral soil particles, eroding sediments may

transport other substances such as -plant and animal wastes, nutrients, pesticides,

petroleum products, metals, and other compounds that can cause water quality

problems (Clark, 1985; Neary et al., 1988).

In addition, stream flow has significant impacts on other water quality

parameters. Fast-flowing, turbulent water at riffles increases dissolved oxygen levels

through aeration. In contrast, low flow conditions typically result in higher

water temperature and decreased oxygen levels. Periods of increased now may result

in greater turbidity, because the fast moving stream has enough energy to displace

larger quantities and sizes of sediment particles (Wisconsin, 2003).

2.6 Velocity Area Method

A variety of methods are used to measure flow rate in open channels. Many

different factors help determine which method is best for given application. These