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The SIJ Transactions on Advances in Space Research & Earth Exploration (ASREE), Vol. 1, No. 2, November-December 2013 ISSN: 2347 6087 © 2013 | Published by The Standard International Journals (The SIJ) 43 AbstractOver the past decade in Taiwan, ecological engineering methods acted principally in river remediation and slope protection. In order to examine the effectiveness of stream restoration, the Index of Stream Restoration Guidance (ISRG) and Radar-Graphic Method (RGM) were used to describe the overall stream condition. Six criteria must be considered in the evaluation of a stream’s ecological environment: water quality, habitat quality, eco-hydrology, flood prevention, aesthetic and recreational demand, and bank stability. Using the assessment results in the Jilong River overall improvement project, a river located in northern Taiwan, five conclusions were drawn: (1) ISRG scores on stream’s ecological environment and biological performance are higher at the upstream than at the middle and downstream; (2) good ecological performances were observed under the condition of a gentle revetment and wider green belt; (3) type of revetment which are porous and permeable will create better biodiversity; (4) the ecological performance at the middle and downstream depends on the human disturbance; (5) the proposed methodology establishes a quantitative assessment tool and provides a guide to planning and implementing stream restoration projects. KeywordsBiodiversity; Index of Stream Condition; Jilong River; Radar-Graphic Method; Stream Ecological Engineering; Stream Restoration. AbbreviationsEphemeroptera, Plecoptera, Trichopetera (EPT); Indexes of Biological Integrity (IBI); Index of Stream Condition (ISC); Index of Stream Restoration Guidance (ISRG); Family-level Biotic Index (FBI); Radar-Graphic Method (RGM); Rapid Bioassessment Protocol III (RBP III). I. INTRODUCTION UE to the increase of ecological awareness, Taiwan started to seek advanced technology from other countries in order to modify traditional civil engineering practices which prioritized development and human demands. In the late 1990s, a field research associated with environment beautification was launched. The new philosophy of ecological engineering began to attract academic institutes’ attention gradually. Government also initiated all sorts of funding for the purposes of a) the possible limitation of applying it in Taiwan, and b) establishing localized applicable methods in river reconstruction. Slightly after the water resources related agencies’ action, this new trend started to affect soil conservation practices by introducing river bank stabilization methods. Followed by valuing the advantage over water quality control, ecological engineering also contributes to Taiwan’s environmental engineering since 2003. This abstract is a brief introduction to the subject of ecological engineering method, which is a whole new concept in the field of civil engineering. The advantages of using the ecological engineering method are not only to satisfy the demand of safety (i.e. natural hazards control) but also that of protecting ecosystem and landscape aesthetic. In Taiwan, typhoons are very common during the summer and bring huge amount of precipitation with them. The development and management works of the rivers in Taiwan were, in the early days, primarily focused on water control for hydraulic facilities, but also considered overall eco-environment. The requirement of landscape creation and eco-environment protection from people are on the rise with the recent ecological protection concepts. For this reason, Taiwan Water Resource Agency executed the “Jilong River Overall Master Plan (Earlier Plan)” from 2002 to 2005 [National Taipei University of Technology, 2012] to reduce D *Assistant Professor, Department of Civil Engineering, National Taipei University of Technology, Taipei, TAIWAN, ROC. E-Mail: [email protected] **Professor, Department of Civil Engineering, National Taipei University of Technology, Taipei, TAIWAN, ROC. E-Mail: [email protected] ***Chief Secretary, Water Resources Department, New Taipei City Government, New Taipei City, TAIWAN, ROC. E-Mail: [email protected] ****Master, Department of Civil Engineering, National Taipei University of Technology, Taipei, TAIWAN, ROC. E-Mail: [email protected] Chia-Chun HO*, Jen-Yang LIN**, Tsung-Ming YANG*** & Kuan-Han CHOU**** The Radar-Graphic Method for Evaluation of the Effectiveness of Stream Ecological Engineering

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  • The SIJ Transactions on Advances in Space Research & Earth Exploration (ASREE), Vol. 1, No. 2, November-December 2013

    ISSN: 2347 – 6087 © 2013 | Published by The Standard International Journals (The SIJ) 43

    Abstract—Over the past decade in Taiwan, ecological engineering methods acted principally in river

    remediation and slope protection. In order to examine the effectiveness of stream restoration, the Index of

    Stream Restoration Guidance (ISRG) and Radar-Graphic Method (RGM) were used to describe the overall

    stream condition. Six criteria must be considered in the evaluation of a stream’s ecological environment: water

    quality, habitat quality, eco-hydrology, flood prevention, aesthetic and recreational demand, and bank stability.

    Using the assessment results in the Jilong River overall improvement project, a river located in northern

    Taiwan, five conclusions were drawn: (1) ISRG scores on stream’s ecological environment and biological

    performance are higher at the upstream than at the middle and downstream; (2) good ecological performances

    were observed under the condition of a gentle revetment and wider green belt; (3) type of revetment which are

    porous and permeable will create better biodiversity; (4) the ecological performance at the middle and

    downstream depends on the human disturbance; (5) the proposed methodology establishes a quantitative

    assessment tool and provides a guide to planning and implementing stream restoration projects.

    Keywords—Biodiversity; Index of Stream Condition; Jilong River; Radar-Graphic Method; Stream Ecological

    Engineering; Stream Restoration.

    Abbreviations—Ephemeroptera, Plecoptera, Trichopetera (EPT); Indexes of Biological Integrity (IBI); Index

    of Stream Condition (ISC); Index of Stream Restoration Guidance (ISRG); Family-level Biotic Index (FBI);

    Radar-Graphic Method (RGM); Rapid Bioassessment Protocol III (RBP III).

    I. INTRODUCTION

    UE to the increase of ecological awareness, Taiwan

    started to seek advanced technology from other

    countries in order to modify traditional civil

    engineering practices which prioritized development and

    human demands. In the late 1990s, a field research associated

    with environment beautification was launched. The new

    philosophy of ecological engineering began to attract

    academic institutes’ attention gradually. Government also

    initiated all sorts of funding for the purposes of a) the

    possible limitation of applying it in Taiwan, and b)

    establishing localized applicable methods in river

    reconstruction. Slightly after the water resources related

    agencies’ action, this new trend started to affect soil

    conservation practices by introducing river bank stabilization

    methods. Followed by valuing the advantage over water

    quality control, ecological engineering also contributes to

    Taiwan’s environmental engineering since 2003. This

    abstract is a brief introduction to the subject of ecological

    engineering method, which is a whole new concept in the

    field of civil engineering. The advantages of using the

    ecological engineering method are not only to satisfy the

    demand of safety (i.e. natural hazards control) but also that of

    protecting ecosystem and landscape aesthetic.

    In Taiwan, typhoons are very common during the

    summer and bring huge amount of precipitation with them.

    The development and management works of the rivers in

    Taiwan were, in the early days, primarily focused on water

    control for hydraulic facilities, but also considered overall

    eco-environment. The requirement of landscape creation and

    eco-environment protection from people are on the rise with

    the recent ecological protection concepts. For this reason,

    Taiwan Water Resource Agency executed the “Jilong River

    Overall Master Plan (Earlier Plan)” from 2002 to 2005

    [National Taipei University of Technology, 2012] to reduce

    D

    *Assistant Professor, Department of Civil Engineering, National Taipei University of Technology, Taipei, TAIWAN, ROC.

    E-Mail: [email protected]

    **Professor, Department of Civil Engineering, National Taipei University of Technology, Taipei, TAIWAN, ROC. E-Mail: [email protected]

    ***Chief Secretary, Water Resources Department, New Taipei City Government, New Taipei City, TAIWAN, ROC.

    E-Mail: [email protected]

    ****Master, Department of Civil Engineering, National Taipei University of Technology, Taipei, TAIWAN, ROC.

    E-Mail: [email protected]

    Chia-Chun HO*, Jen-Yang LIN**, Tsung-Ming YANG*** & Kuan-Han CHOU****

    The Radar-Graphic Method for

    Evaluation of the Effectiveness of

    Stream Ecological Engineering

  • The SIJ Transactions on Advances in Space Research & Earth Exploration (ASREE), Vol. 1, No. 2, November-December 2013

    ISSN: 2347 – 6087 © 2013 | Published by The Standard International Journals (The SIJ) 44

    the risk of flooding and improve the environment. Figure 1

    below shows the failure of the Jilong River revetment which

    suffered a serious flooding in 2001. Because of this,

    ecological engineering methods were adopted to rebuild the

    revetment. Figure 2 shows the current status of this revetment

    using gabion method and vegetation blanket. In order to

    understand the effectiveness of revetment while using

    ecological engineering method, the ecological investigation

    and basis of construction work of the Jilong River was

    divided between the upstream, midstream and downstream.

    The project was completed over several years, mainly due to

    the fact that the river ecological data had to satisfy the design

    and guidelines of an eco-environment adapted for the river.

    Thus, the investigation of the before and after conditions

    were necessary. After reviewing the effect of the environment

    due to the changes brought by the master plan, reinforcement

    strategies and suggestions should be proposed as to reach

    higher ecological environment influence.

    (a) Upstream (b) Midstream

    Figure 1: A Failure Cases of Revetment

    (a) Upstream (b) Midstream

    Figure 2: The Current Status after Construction

    II. THE ASSESSMENT OF THE STREAM

    CONDITION

    The effectiveness of the stream remediation mostly focused

    on the hydraulic structure safety. It is rarely from an

    ecological point of view that we examine the effectiveness.

    However, the performance of the biological environment

    should be included in the assessment of stream remediation

    projects. Researchers have published several studies on the

    biotic index.

    2.1. Biological Index

    Previous studies proposed a different index for bio-

    environment. Karr (1991) adopted fish to be a bio-indicator

    and proposed the Indexes of Biological Integrity (IBI).

    Depending on the IBI score, the biological condition can be

    classified within four categories, as shown in Table 1.

    Table 1: The Biological Condition Category and Score Range of IBI

    Biological Condition Category Score Range

    Non-impaired 30-39

    Slightly impaired 21-29

    Moderately impaired 11-20

    Severely impaired 0-10

    Base on the water quality and water pollution resistance

    of fish, a Family-level Biotic Index (FBI) was proposed by

    Hilsenhoff (1998). Table 2 shows the FBI score range.

    Table 2: Water Quality and Score Range of FBI

    Water Quality Score Range Water Quality Score Range

    Excellent 0.00-3.75 Fairly Poor 5.76-6.50

    Very Good 3.76-4.25 Poor 6.51-7.25

    Good 4.26-5.00 Very Poor 7.26-10.00

    Fair 5.01-5.75

    Plafkin et al., (1989) adopted seven bio-indexes to

    evaluate water quality and stream environment, and therefore

    the Rapid Bio-assessment Protocol III (RBP III) was advised.

    The indexes include taxa richness, Hilsenhoff biotic index,

    ratio of scrapers/fil. collectors, ratio of EPT (Ephemeroptera,

    Plecoptera, Trichopetera) and chironomid abundances,

    contribution of dominant taxon (%), EPT index, and

    community loss index. Table 3 shows the biological

    condition scoring criteria.

  • The SIJ Transactions on Advances in Space Research & Earth Exploration (ASREE), Vol. 1, No. 2, November-December 2013

    ISSN: 2347 – 6087 © 2013 | Published by The Standard International Journals (The SIJ) 45

    Table 3: Biological Condition Scoring Criteria of RBP III

    Water Quality Biological Condition Scoring Criteria

    6 4 2 0

    Taxa richness >80% 60%-80% 40%-60% 85% 70%-85% 50%-70% 50% 35%-50% 20%-35% 75% 50%-75% 25%-50% 90% 80%-90% 70%-80%

  • The SIJ Transactions on Advances in Space Research & Earth Exploration (ASREE), Vol. 1, No. 2, November-December 2013

    ISSN: 2347 – 6087 © 2013 | Published by The Standard International Journals (The SIJ) 46

    Figure 3: Assessment of Stream Condition using the ISC [Ladson et

    al., 1999]

    2.3. Index of Stream Restoration Guidance (ISRG)

    Base on the Index of Stream Condition (ISC) and

    incorporation factors unique to Taiwan, Lin et al., (2005)

    proposed the Index of Stream Restoration Guidance (ISRG)

    and developed six indices for evaluating stream restoration

    projects using the ecological engineering methods. These

    indices include considerations for stream ecological

    environment, water quality and habitat, eco-hydrology, flood

    prevention, aesthetics and recreation demands, and bank

    stability requirements. The indicators and score within those

    six indices are shown in Table 5. According to the score of

    those six indices, the Radar-Graphic Method (RGM) was

    used to evaluate the effectiveness of stream ecological

    engineering. Figure 4 shows the best performance of RGM on

    stream restoration. Three of the indices scores (flood

    prevention, aesthetics and recreation demands, and bank

    stability requirements) are very low. It indicates not only that

    the hydraulic design for this stream is satisfactory but also

    that the effectiveness of ecological environment is superior.

    Table 5: Indicators used in the Index of Stream Restoration Guidance [Lin et al., 2005]

    Sub-Index Indicators within Sub-Index Score

    (X) Conversion Coeff. Sub-Index Score

    A. Stream ecological environment

    Width of streamside zone 0-4

    (X)(10/10) 0-10 Longitudinal continuity 0-4

    Cover of vegetation 0-2

    B. Bank stability requirements

    Geology of river bank

    0-4 (X)(10/4) 0-10 Erosion of river bank

    Erosion of bank toe

    C. Water quality and habitat River pollution index 0-16

    (X)(10/20) 0-10 Fish species and populations 0-4

    D. Flood prevention

    Protected targets

    Flood history

    Flood damages

    Investment cost

    0-10 (X)(10/10) 0-10

    E. Eco-hydrology

    Ecological instream flows 0-10

    (X)(10/18) 0-10 Aquatic habitat environment 0-4

    Bed stability 0-4

    F. Aesthetics and recreation demands

    Landscape aesthetics

    Promenade recreation

    Environmental education

    Irrigation

    0-10 (X)(10/10) 0-10

    Figure 4: Illustration of the Best Performance of RGM on Stream

    Restoration

    This paper is a case study using ISRG and furthermore

    the ecological environment investigation was carried out in

    great detail to confirm the feasibility of RGM.

    III. THE EVALUATION RESULTS OF JILONG

    RIVER USING RGM

    “Jilong River Overall Master Plan (Earlier Plan)” was

    proposed after permission of the Taiwan Executive Yuan in

    May, 2002. The 3 year plan was executed between 2002 to

    2005 and received a funding of $12 billion US dollars. The

    plan has now been completed for 7 years and has undergone a

    Indicator

    RatingCorresponding reference category

    Example values:

    pH range

    4 Very close to reference state 6.5-7.5

    3 Minor modification from reference state 6.0-

  • The SIJ Transactions on Advances in Space Research & Earth Exploration (ASREE), Vol. 1, No. 2, November-December 2013

    ISSN: 2347 – 6087 © 2013 | Published by The Standard International Journals (The SIJ) 47

    number of typhoons. In order to know the performance of this

    plan, RGM was used to evaluate of the effectiveness of

    stream ecological engineering in this study. Further analysis

    of significant improvement master methods has been

    performed to provide as criterion for further master plan of

    other reaches. Assessment of non-significant master methods

    has been executed and reinforcement strategies have been

    proposed in this study. In order to understand the

    effectiveness of stream ecological engineering, three survey

    stations were investigated which were located upstream,

    midstream and downstream. According to the six sub-index

    of the ISRG, to calculate their scores and graph the RGMs.

    3.1. Upstream of Jilong River

    The upstream channel of Jilong River, with a length of

    11.7km and a mean height of 12.6m, was improved using

    gabion, stone-paved and geo-grid reinforced revetment. River

    investigation of current status and the change of environment

    before and after master plan have been executed to review the

    influence and improvement of the master plan. The

    assessment results at the upstream are shown on Table 6.

    Table 6: The Assessment Results of ISRG at the Upstream of Jilong River

    Sub-index Indicators within sub-index Point

    (X) Conversion Coeff. Sub-Index Score

    A. Stream ecological environment

    Width of streamside zone 3

    7(10/10) 7.0 Longitudinal continuity 3

    Cover of vegetation 1

    B. Bank stability requirements

    Geology of river bank

    1 1(10/4) 2.5 Erosion of river bank

    Erosion of bank toe

    C. Water quality and habitat River pollution index 12

    16(10/20) 8.0 Fish species and populations 4

    D. Flood prevention

    Protected targets

    Flood history

    Flood damages

    Investment cost

    1.8 1.8(10/10) 1.8

    E. Eco-hydrology

    Ecological instream flows 10

    16(10/18) 8.9 Aquatic habitat environment 3

    Bed stability 3

    F. Aesthetics and recreation demands

    Landscape aesthetics

    Promenade recreation

    Environmental education

    Irrigation

    3 3(10/10) 3.0

    Radar-Graphic Method (RGM)

    A. Stream Ecological Environment

    The sub-index of stream ecological environment includes

    width of streamside zone, longitudinal continuity and cover

    of vegetation. Figure 5 shows the current situation of stream

    ecological environment. The width of the streamside zone is

    127.5 meters and it is 2.56 times the breadth of the river’s

    active channel. This area shows a good performance from the

    vegetation except the zone under the bridge, furthermore the

    vegetation cover rate at the upstream is 78% done by

    shrubbery and grass. The comprehensive improvement

    observed in result to our field investigation ensued in a sub-

    index score of 7.0 on stream ecological environment.

    Figure 5: The Current Situation of Stream Ecological Environment

    at the Upstream of Jilong River [Ho et al., 2013]

    02468

    10A

    B

    C

    D

    E

    F

    A: Stream ecological environment

    B:Bank stability requirements

    C:Water quality and habitat

    D:Flood prevention

    E:Eco-hydrology

    F:Aesthetics and recreation demands

  • The SIJ Transactions on Advances in Space Research & Earth Exploration (ASREE), Vol. 1, No. 2, November-December 2013

    ISSN: 2347 – 6087 © 2013 | Published by The Standard International Journals (The SIJ) 48

    B. Bank Stability Requirements

    In order to know the river bank stability and its erosion

    situation, the bathymetry survey of each cross-section were

    employed in this study. Choosing one of the cross-sections at

    the upstream and comparing its bathymetry results between

    the 2006 and 2011 survey (see Figure 6), we can notice a

    slight difference in the improvement works completed after 1

    year (2006) and 6 years (2011) of Section K-70. We can

    therefore say that the bank stability requirement is very low

    and scored 1.0 point; hence the sub-index score is 2.5.

    Figure 6: The Results of the Bathymetry Survey in 2006 and 2011.

    (Section K-70)

    C. Water Quality and Habitat

    There are 5 water quality monitoring stations at the upstream

    of Jilong River. Their evalutation of the average value for

    total phosphorus in 2011 is 0.005 mg/L, turbidity is 8.97

    NTU, conductivity is 182 mho/ cm-25°C, and pH is 7.8. According to the scoring criteria of ISRG, the score for the

    river pollution index is 12 points.

    Moreover, the aquatic life in Jilong River was

    investigated from 2010 to 2012 and recorded 14 species of

    fish at the upstream. All of the fish are native species

    including the Varicorhinus barbatulus, Acrossocheilus

    paradoxus, Zacco platypus, Formosania lacustre, and so on

    (Figure 7). Hence, in accordance with the scoring criteria of

    ISRG, the score of fish species and populations is 4 points.

    Consequently, the sub-index score of water quality and

    habitat is 8.0.

    (a) Varicorhinus barbatulus (b) Acrossocheilus paradoxus

    (c) Zacco platypus (d) Formosania lacustr

    Figure 7: The Native Fishes at the Upstream of Jilong River

    D. Flood Prevention

    The land purpose surrounding the Jilong River’s upstream is

    predominantly based on agriculture and forestry. The

    protected targets in potential flooding regions consist of only

    some of the constructions such as roads, bridges, and

    buildings. The heavy rainfalls brought by typhoon NARI in

    September 2001 had not caused significant damages to roads

    and properties at this area. In view of the above, the sub-

    index score of flood prevention is 1.8.

    E. Eco-Hydrology

    The score for the ecological instream flows is 10 because the

    flow rate throughout the year has been consistently greater

    than 0.5 cms, even without lateral construction in the river

    channel at the upstream. It is a near ideal aquatic habitat with

    numerous pieces of coarse wood debris from indigenous

    species and so scored 3 points. Furthermore, it has good

    vegetative cover, some minor isolated erosion, and no

    continuous damage to the bank structure or vegetation itself,

    bringing the indicator for the bed stability to 3 points. Finally,

    when calculating the sub-index for the eco-hydrology, we get

    a score of 8.9.

  • The SIJ Transactions on Advances in Space Research & Earth Exploration (ASREE), Vol. 1, No. 2, November-December 2013

    ISSN: 2347 – 6087 © 2013 | Published by The Standard International Journals (The SIJ) 49

    F. Aesthetics and Recreation Demands

    The upstream of Jilong River has some small-scale farms by

    the streamside which makes use of stream water for

    irrigation. Therefore, the sub-index score of aesthetics and

    recreation demands is 3.0.

    The chart of Radar-Graphic Method is also show in

    Table 6. It indicates the steep riverbank caused by the poor

    performance of vegetation at the upstream; hence the score of

    sub-index A is not high. The good water quality and flow rate

    provide an excellent biological environment and

    consequently got the high score on sub-index C and E.

    Moreover, the riverbank is located on the bedrock, and

    therefore does not produce the erosion of bank toe. For this

    reason, the score on bank stability requirement is low.

    Briefly, the ecological engineering method achieved

    remarkable improvement in the upstream and the shape of the

    RGM presents a triangle arrow.

    3.2. Midstream of Jilong River

    The midstream channel of Jilong River has a length of

    19.9km and a mean height of 10.2m. Besides gabion, stone-

    paved and geo-grid reinforced revetment, the revetment

    improvement works used a number of concrete banks to

    protect the residents living by the river side as well as spread

    vegetation blanket on the surface of concrete banks.

    Investigation of the river’s current status and the before and

    after environment change of the master plan have been

    executed to review the influence and improvement of the

    master plan. The assessment results at the midstream are

    shown on Table 7.

    Table 7: The Assessment Results of ISRG at the Midstream of Jilong River

    Sub-index Indicators within sub-index Point

    (X)

    Conversion

    Coeff.

    Sub-Index

    Score

    A. Stream ecological environment

    Width of streamside zone 4

    9(10/10) 9.0 Longitudinal continuity 4

    Cover of vegetation 1

    B. Bank stability requirements

    Geology of river bank

    1 1(10/4) 2.5 Erosion of river bank

    Erosion of bank toe

    C. Water quality and habitat

    River pollution index 11

    14(10/20) 7.0 Fish species and populations

    3

    D. Flood prevention

    Protected targets

    Flood history

    Flood damages

    Investment cost

    4.0 4(10/10) 4.0

    E. Eco-hydrology

    Ecological instream flows 8

    12(10/18) 6.7 Aquatic habitat

    environment 2

    Bed stability 2

    F. Aesthetics and recreation demands

    Landscape aesthetics

    Promenade recreation

    Environmental education

    Irrigation

    7.5 7.5(10/10) 7.5

    Radar-Graphic Method (RGM)

    A. Stream Ecological Environment

    Figure 8 shows the current situation of stream ecological

    environment. The width of the streamside zone is 136.7m and

    it is 3.12 times the breadth of the river’s active channel.

    Because of the wide and gentle beach, the vegetation shows a

    nice performance in this area. Furthermore, the vegetation

    cover rate at the midstream is 89% done by shrubbery and

    grass. The comprehensive improvement observed in result to

    our field investigation ensued in a sub-index score of 9.0 on

    stream ecological environment.

    02468

    10A

    B

    C

    D

    E

    F

    A: Stream ecological environment

    B:Bank stability requirements

    C:Water quality and habitat

    D:Flood prevention

    E:Eco-hydrology

    F:Aesthetics and recreation demands

    A: Stream ecological environment

    B:Bank stability requirements

    C:Water quality and habitat

    D:Flood prevention

    E:Eco-hydrology

    F:Aesthetics and recreation demands

  • The SIJ Transactions on Advances in Space Research & Earth Exploration (ASREE), Vol. 1, No. 2, November-December 2013

    ISSN: 2347 – 6087 © 2013 | Published by The Standard International Journals (The SIJ) 50

    Figure 8: The Current Situation of Stream Ecological Environment

    at the Midstream of Jilong River [Ho et al., 2013]

    B. Bank Stability Requirements

    Figure 9 shows a comparison of the results of the bathymetry

    survey performed in 2006 and 2011. Some minor isolated

    erosion cases could be noticed on the river bed from the

    improvement works completed after 1 year (2006) and 6

    years (2011) of the Section K-88. However, the surface of the

    river bank and its toe are still stable as well as no

    displacement happened from 2006 to 2011. So the sub-index

    of bank stability requirement score is 2.5.

    Figure 9: The Results of the Bathymetry Survey in 2006 and 2011.

    (Section K-88)

    C. Water Quality and Habitat

    A total of 4 water quality monitoring stations were

    established at the midstream of Jilong River. Their evaluation

    of the average value for total phosphorus in 2011 is 0.0143

    mg/L, turbidity is 18.54 NTU, conductivity is 325 mho/cm-

    25°C, and pH is 7.5. According to the scoring criteria of

    ISRG, the score of river pollution index is 11 points.

    Moreover, the aquatic life in Jilong River was

    investigated from 2010 to 2012 and recorded 19 species of

    fish at the midstream. At this particular segment of the river,

    not only native fishes were found but also exotic ones such as

    Cyprinus carpip, Oreochromis sp., Channa striata,

    Hypostomus placostomus, and so on (Figure 10). Hence, in

    accordance with the scoring criteria of ISRG, the score of fish

    species and populations is 3 points. Consequently, the sub-

    index score of water quality and habitat is 7.0.

    (a) Cyprinus carpip (b) Oreochromis sp

    (c) Channa striata (d) Hypostomus placostomus

    Figure 10: The Exotic Fishes at the Midstream of Jilong River

    D. Flood Prevention

    The land purpose of Jilong River’s midstream is

    predominantly based on agriculture and small town. The

    protected targets in potential flooding regions include roads,

    bridges, and buildings. Hence, the sub-index score of flood

    prevention is 4.0.

  • The SIJ Transactions on Advances in Space Research & Earth Exploration (ASREE), Vol. 1, No. 2, November-December 2013

    ISSN: 2347 – 6087 © 2013 | Published by The Standard International Journals (The SIJ) 51

    E. Eco-hydrology

    The score of ecological instream flows is 8 due to the flow

    rate throughout the year being greater than 0.5 cms, achieved

    with some lateral construction in the river channel. It is a

    moderate variation from an ideal aquatic habitat with

    moderate visible pieces of coarse wood debris from

    indigenous species, therefore the scored attributed if of 2

    points. Furthermore, as the banks were held by discontinuous

    vegetation and showed a generally stable toe, the indicator of

    bed stability received 2 points. Finally, the calculated sub-

    index score of eco-hydrology is 6.7.

    F. Aesthetics and Recreation Demands

    The riverside of the midstream has a number of bicycle paths,

    parks, and river-accessible spaces. Therefore, the sub-index

    score of aesthetics and recreation demands is 7.5.

    The chart of Radar-Graphic Method is also show in

    Table 7. The current situation displays a nice result on

    vegetation of gabion revetment wall and provides a good

    biological habitat environment. Thus the score of sub-index

    A, C and F are high; nevertheless, they are lower than the

    score observed at the upstream. That can be explained by the

    bad results in water quality and a higher human disturbance

    than at the upstream. In addition, the aesthetics and recreation

    demands are higher than at the upstream.

    3.3. Downstream of Jilong River

    The downstream channel of Jilong River has a length of

    15.2km and a mean height of 8.7m. Because it is adjacent to a

    dense residential area, a large number of concrete banks were

    adopted in its improvement project. In order to build a good

    ecological environment, vegetation blankets were spread on

    the surface of some concrete banks. . Investigation of the

    river’s current status and the before and after environment

    change of the master plan have been executed to review the

    influence and improvement of the master plan. The

    assessment results at the downstream are shown on Table 8.

    Table 8: The Assessment Results of ISRG at the Downstream of Jilong River

    Sub-index Indicators within sub-index Point

    (X) Conversion Coeff. Sub-Index Score

    A. Stream ecological environment

    Width of streamside zone 2

    5(10/10) 5.0 Longitudinal continuity 2

    Cover of vegetation 1

    B. Bank stability requirements

    Geology of river bank

    1.8 1.8(10/4) 4.5 Erosion of river bank

    Erosion of bank toe

    C. Water quality and habitat River pollution index 10

    12(10/20) 6.0 Fish species and populations 2

    D. Flood prevention

    Protected targets

    Flood history

    Flood damages

    Investment cost

    8.0 8(10/10) 8.0

    E. Eco-hydrology

    Ecological instream flows 7

    10(10/18) 5.6 Aquatic habitat environment 2

    Bed stability 1

    F. Aesthetics and recreation

    demands

    Landscape aesthetics

    Promenade recreation

    Environmental education

    Irrigation

    8.5 8.5(10/10) 8.5

    Radar-Graphic Method (RGM)

    A. Stream Ecological Environment

    Figure 11 shows the current situation of the downstream

    ecological environment. The downstream width of the

    streamside zone is 102.3m and it is 0.67 times the breadth of

    the river’s active channel. In this region, the concrete banks

    hold a discontinuous vegetation and has a cover rate of 63%

    achieved by shrubbery and grass. The comprehensive

    02468

    10A

    B

    C

    D

    E

    F

    A: Stream ecological environment

    B:Bank stability requirements

    C:Water quality and habitat

    D:Flood prevention

    E:Eco-hydrology

    F:Aesthetics and recreation demands

    A: Stream ecological environment

    B:Bank stability requirements

    C:Water quality and habitat

    D:Flood prevention

    E:Eco-hydrology

    F:Aesthetics and recreation demands

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    ISSN: 2347 – 6087 © 2013 | Published by The Standard International Journals (The SIJ) 52

    improvement observed in result to our field investigation

    ensued in a sub-index score of 5.0 on stream ecological

    environment.

    Figure 11: The Current Situation of Stream Ecological Environment

    at the Downstream of Jilong River [Ho et al., 2013]

    B. Bank Stability Requirements

    Figure 12 shows a comparison of the results of the

    bathymetry survey performed in 2006 and 2011. An obvious

    erosion of the river bed of Section K-101 can be noticed from

    the improvement works completed after 1 year (2006) and 6

    years (2011); moreover, some damage to the bank structure

    and vegetation can be clearly noticed. The situation of this

    region is moderate bed degradation and therefore the sub-

    index of bank stability requirement score is 4.5.

    Figure 12: The Results of the Bathymetry Survey in 2006 and 2011.

    (Section K-101)

    C. Water Quality and Habitat

    A total of 4 water quality monitoring stations were placed in

    the downstream of Jilong River and their monitored average

    value for total phosphorus in 2011 is 0.0265 mg/L, turbidity

    is 27.9 NTU, conductivity is 383 mho/cm-25°C, and pH is

    7.6. According to the scoring criteria of ISRG, the score of

    river pollution index is 10 points.

    Moreover, the aquatic life in Jilong River was

    investigated between 2010 and 2012 and recorded 22 species

    of fish at the downstream. Most of the exotic fishes and the

    peripheral division freshwater fishes in midstream were also

    reported to be living in the downstream, such as Mugil

    cephalus, Nematalosa nasus, Awaous melanocephalus,

    Acanthopagrus schlegeli, and so on (Figure 13). Hence, in

    accordance with the scoring criteria of ISRG, the score of fish

    species and populations is 2 points. Consequently, the sub-

    index score of water quality and habitat is 6.0.

    (a) Mugil cephalus (b) Nematalosa nasus

    (c) Awaous melanocephalus (d) Acanthopagrus schlegeli

    Figure 13: The Peripheral Division Freshwater Fishes at the Downstream of Jilong River

    D. Flood Prevention

    The land surrounding the Jilong River’s downstream is

    predominantly urban. It is a densely inhabited district and the

    protected targets in potential flooding regions include roads,

    bridges, and buildings. This region also is an important

    business area. Heavy rainfalls brought by typhoon NARI in

    September 2001 caused serious damages to the roads and

    properties at this area. Hence, the sub-index score of flood

    prevention is 8.0.

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    E. Eco-hydrology

    The score of ecological instream flows is 8 due to the flow

    rate throughout the year being greater than 0.5 cms, achieved

    with some lateral construction in the river channel. It is a

    moderate variation from an ideal aquatic habitat with

    moderate visible pieces of coarse wood debris from

    indigenous species, therefore the scored attributed if of 2

    points. Furthermore, as the banks were held by discontinuous

    vegetation and showed a generally stable toe, the indicator of

    bed stability received 1 point. Finally, the calculated sub-

    index score of eco-hydrology is 5.6.

    F. Aesthetics and Recreation Demands

    The downstream riverside has a number of bicycle paths,

    parks, playground, tennis court, and river-accessible spaces.

    Therefore, the sub-index score of aesthetics and recreation

    demands is 8.5.

    The shape of RGM for the downstream section (Table 8)

    is different to the results shown at the upstream and

    midstream sections. Because of the dense human habitation

    surrounding the downstream, the flood prevention, aesthetics

    and recreation demands are more important than for the

    upstream and midstream. This results in a higher score on

    sub-index D and sub-index F. A concrete revetment was used

    to protect the inhabitants living adjacently to the river. Due to

    the steep and smooth surface of the concrete revetment, a

    poor plant growth was observed. These conditions paired

    with some serious human disturbance results in a poor

    biological performance in the downstream and consequently

    the score of sub-index A, C and E was lower than for the

    upstream and midstream.

    IV. CONCLUSIONS

    The shape of RGM is represented in the form of a

    triangle arrow for the upstream. It indicates the

    excellent effectiveness of stream ecological

    engineering. Moreover, the scores of ISRG for the

    stream ecological environment and biological

    performance are higher than for the middle and

    downstream.

    For the downstream, high quality and hard

    protective works had to be used to ensure the safety

    of the dense human habitation and therefore induce a

    poor performance of the ecology environment.

    Good ecological performances were observed under

    the condition of gentle revetment and wider green

    belt at the midstream.

    Revetment including porous and permeable

    functions will create better biodiversity, such as

    gabion, stone-paved and geo-grid reinforced

    revetment.

    The ecological performance at the middle and

    downstream was greatly affected by human

    disturbance.

    ISRG and RGM establish a quantitative assessment

    tool and provide a guide on how to plan and

    implement stream restoration projects.

    REFERENCES

    [1] National Taipei University of Technology (2012), “Closure Report of Investigation and Evaluation after Jilong River

    Overall Master Plan (Earlier Plan)”, Chapter No.5, 10th River

    Management Office, Water Resource Agency, Taiwan, Pp.1–46. (in Chinese).

    [2] J.R. Karr (1991), “Biological Integrity: A Long-Neglected Aspect of Water Resource Management”, Ecological

    Applications, Vol. 1, Pp. 66–84.

    [3] W.L. Hilsenhoff (1998), “A Modification of the Biotic Index of Organic Stream Pollution to Remedy Problems and Permit its

    Use throughout the Year”, Great Lakes Entomologist, Vol. 31,

    Pp. 1–12.

    [4] J.L. Plafkin, M.T. Barbour, K.D. Porter, S.K. Gross & R.M. Hughes (1989), “Rapid Bioassessment Protocols for Use in

    Streams and Rivers: Benthic Macroinvertebrates and Fish”.

    U.S. Environmental Protection Agency, Office of Water

    Regulations and Standards, Washington, D.C. EPA 440–4-89-

    001.

    [5] A.R. Ladson & L.J. White (1999), “An Index of Stream Condition: Reference Manual”, Department of Natural

    Resources and Environment, Melbourne, Australia.

    [6] A.R. Ladson, L.J. White, J.A. Doolan, B.L. Finlayson, B.T. Hart, P.S. Lake & J.W. Tilleard (1999), “Development and

    Testing of an Index of Stream Condition for Waterway

    Management in Australia”, Freshwater Biology, Vol. 41, Pp.

    453–468.

    [7] J.Y. Lin, F.C. Yu & M.S. Wu (2005), “Using the Radar-Graphic Method as a Guide for Stream Ecological Engineering

    Methods”, Journal of Chinese Soil and Water Conservation,

    Vol. 36, No. 1, Pp. 89–99. (in Chinese)

    [8] C.C. Ho, J.Y. Lin & K.H. Chou (2013), “An Evaluation of the Effectiveness of Stream Ecological Engineering using the

    Radar-Graphic Method”, 2013 International Congress on

    Natural Sciences and Engineering, ICNSE-511, Pp. 60–67.

    Chia-Chun HO Education: Ph. D., Hydrology and

    Environment, Joseph Fourier University,

    France

    Position: Assistant Professor, Department of

    Civil Engineering, National Taipei

    University of Technology

    Research interest: Environmental and

    Ecological Engineering, Geotechnical

    Engineering, Geosynthetics Application, Erosion Behaviour of

    Revetments

    Number of papers published: 8

    Number of conferences/seminars attended: 26

    Jen-Yang LIN

    Education: Dr.-Ing., Civil Engineering,

    Kassel University, Germany

    Position: Professor, Department of Civil

    Engineering, National Taipei University of

    Technology

    Research interest: Watershed Modelling and

    Management, Ecological Engineering

    Number of papers published: 19

    Number of conferences/seminars attended: 50

  • The SIJ Transactions on Advances in Space Research & Earth Exploration (ASREE), Vol. 1, No. 2, November-December 2013

    ISSN: 2347 – 6087 © 2013 | Published by The Standard International Journals (The SIJ) 54

    Tsung-Ming YANG

    Education: Master, of Construction

    Engineering, National Taiwan University of

    Science and Technology, Taiwan

    Position: Chief Secretary, Water Resources

    Department, New Taipei City Government,

    New Taipei City, Taiwan

    Research interest: Water resource

    Management、Waste water Treatment、Flow Measure

    Number of papers published: 2

    Number of conferences/seminars attended: 11

    Kuan-Han CHOU Education: Master, Civil Engineering,

    National Taipei University of Technology,

    Taiwan

    Position: Engineer, 5th River Management

    Office, Water Resource Agency, Taiwan

    Research interest: Geosynthetics application,

    Erosion behaviour of revetments

    Number of papers published: 1

    Number of conferences/seminars attended: 2