introduction study area...dypsis lutescens butea monosperma mussaenda erythrophylla casuarina...

1
Table 3. Basic Details of surveyed parks in Panaji including the current daily water supply and demand The urban greenery fulfils both regulatory and cultural services through a variety of species of plants and trees, well-kept groundcover, hedge rows. It cany hold enormous quantities of carbon in their biomass and sequester carbon. Their service of land surface temperature reduction and regulating many parameters of microclimate (urban climate regulation) are among the widely regarded regulatory ecosystem services (Chichilnisky and Heal, 1998; Ramaiah and Avtar, 2019). In addition, their services in bioremediation through assimilation of excess nutrients, detoxification processes, purification of water and oxygenating the air are vital. As far cultural services, the urban green spaces serve inspirational, therapeutic, recreational and tourism, biodiversity conservation motifs as well as science and educational interests. Environmental benefits of UGS have been well documented, but they are often unclear, unquantified, and/or outweighed by potential costs. In view of this, a case study from Panaji India was undertaken for showcasing the importance of treated water in sustainable management of UGS in Indian cities. It is a widely acknowledged fact that management of wastewater and pollution prevention in urban settings require a cost-effective approach. In view of this, a study was undertaken by the GSES. Spectral indices and LULC changes were deduced and published earlier (Ramaiah et al 2020). This presentation focusses on the results of the daily water requirement, carbon stocks and sequestration potential of different plant types (trees, hedge-plants and lawn/groundcover grass) in Mahavir Park, one of the largest parks in Panaji city. These results are a part of many other analyses carried out. is to estimate water requirement in UGS (and carbon sequestration potential in this of the entire UGS) as per the main objective (below). Using this information possible reduction in LST and ecological and societal benefits are highlighted . To evaluate whether treated water from Panaji sewage treatment facility could adequately meet the water requirements of Panaji city’s 1.86 sq km UGS area and the possible ecological regulatory services/benefits met, in relation to some UN SDGs Acknowledgements Methodology Framework Introduction Objective Study Area Details of Sewage Treatment Facility and Treated Water Quality Salient Observations Concluding Remarks Significance of Treated Water in RES Manish Ramaiah is grateful to JASSO for Fellowship, Hokkaido University for facilities, and Prof. Ram Avtar for valuable guidance and constant support. An Ecological Assessment on Sustainable Enhancement of Regulatory Ecosystem Services from Urban Green Spaces Using Recycled Water Manish Ramaiah 1 , Ram Avtar 1,2 1 Graduate School of Environmental Science, Hokkaido University, Sapporo 060-0810, Japan; 2 Faculty of Environmental Earth Science, Hokkaido University, Sapporo 060-0810, Japan. Panaji City, Goa, India Derivation of Daily Requirements of Water Primary data: Mahavir Park 1529’47.31” N; 73 49’07.91” E Total area: 37199 m 2 Trees: 3130 in 22101 m 2 [27 spp] Hedge-plants: >15 sp in 2700 m 2 Groundcover: Paspalum 6400 m 2 Derivation of ET OP DRW of trees, hedge plants, groundcover DRW Estimation All of Panaji UGS Day time Night time 0 = 0.408∆ −+ 37 + 273 2 − ÷ ∆ + 1 + 0.24 2 0 = 0.408∆ −+ 37 + 273 2 − ÷ ∆ + 1 + 0.96 2 WRtr X No of trees in all of 1.86 Sq Km UGS WRhp m -2 X Total area of hedge rows in UGS WRgc m -2 X Total area of lawns in UGS WR Tr (Ld - 1 ) = ET oP × # PF × ( * R × R × 3.14) WR hp (L m - 2 d - 1 ) = D X PF X ET oP X K d WR gc = 4.57 Lpdm - 2 (as per CIMIS) Formulae net radiation (Rn, MJ m −2 h −1 ), ground heat flux density (G, MJ m −2 h −1 ), psychrometric constant (, kPa K −1 ), mean air temperature (T,C), wind speed (u2, m s −1 ), saturation vapor pressure (es, kPa), vapor pressure (e, kPa), slope of SVP at temp T (, kPa K −1 ) WR=Water Requirement, ET oP = ETo Panaji, Evapotranspiration (cm d -1 ); PF=Plant Factor Kd= Canopy density (=1.02) 21.60 sq km City area 1.860 sq km UGS area 0.784 sq km Lawn area 0.236 sq km Hedges area 0.538 sq km Trees area Trees 67275 in UGS Panaji City UGS details # Two plant factors (0.6 for somewhat cooler Oct-Jan and 0.7 for warmer Feb-Jun periods) were used for calculating tree DWR; * Canopy/crown radius of different tree species calculated on-site based estimations from Mahavir Park; Coupling of carbon, water, and energy cycles is integral to impacts of urban vegetation on climate (Pataki et al., 2011). This nexus will have much advantages when recycled water is reused. This is one of the important Sustainable Development Goals of the UN. The two climate-regulating services of carbon sequestration involve direct removal of carbon dioxide from the atmosphere and indirect effects of vegetation on local cooling through shading and transpiration in warm climates (Livesley et al 2016) The UGS are “purported to offset greenhouse-gas (GHG) emissions, remove air and water pollutants, cool local climate, and improve public health.(Pataki et al 2011). To make use of these services, the municipalities in the cities aspiring to be “smart” especially in developing countries such as India have to focus efforts on designing and implementing ecosystem-services-based “green infrastructure” in urban environments. Even prior to Plato (c. 400 BC), there already was an awareness of ecosystems services supporting the humankind. The earlier civilization was in the knowing that deforestation -in complex ways- could lead to soil erosion and drying of springs. During the last 200 years, many modern ideas of ecosystem services have emerged. These developments have continued to expand our knowledge of the intricate functional mechanisms that are at play. These developments must inspire urban population to benefit through ecologically sustainable resource reuses. Park Area (m 2 ) Trees (n) Hedge Area (m 2 ) Lawn (m 2 ) Current Supply (LPD) Daily Water Requirement (Litres per Day. LPD) Trees # Hedges Lawn Demand Kala Academy 10630 250 360 2675 10000 5991.25 2437.20 12224.75 20653.20 NGRF Office Park 5000 290 160 2250 4800 6949.85 1083.20 10282.50 18315.55 SGRF office Park 6500 180 800* 1625 6000 4313.70 5416.00 7426.25 17155.95 Mahavir Park+Art Park 37211 3130 2700 6410 8400 75010.45 18279.00 29293.70 122583.20 Garcia da Orta Garden 4000 150 405 1500 15000 3594.75 2741.85 6855.00 13191.60 Ambedkar Park 10000 480 1620 6500 16000 11503.20 10967.40 29705.00 52175.60 Joggers Park 11500 400 2340 6900 16000 9586.00 15841.80 31533.00 56960.80 Total 84841 4880 8385 27860 76200 116949.20 56766.45 127320.20 301035.90 # currently no direct watering of trees except for a small number nearer the hedge lanes or groundcover. Daily demand of water estimated at an average of 24 litres per tree, *nursery plot including narrow access lanes for watering, nursing/caring A key informant-based survey questionnaire was prepared and required details were sought from the offices of the sewage treatment plant located at Tonca in Panaji City. The STP handles 15 MLD raw sewage daily and produces ca. 14 MLD treated water. Data on the quality of raw sewage received and water quality achieved post-treatment were also obtained (Table 1) and the treated water outflow point shown below (Fig 1) Parameters Tolerance limit Raw sewage Outlet values Colour/odour - -- Clear, odorless Suspended solids (mg.l -1 ) 100 400 10 Particle size suspended solids units <850 u. 140 5 Dissolved inorganic solids max. (mg.l -1 ) 2100 480 246 pH 5.5 9.0 6.88 7.56 Oil and grease. Max. (mg.l -1 ) 10 86 NA Ammoniacal nitrogen as N. Max. (mg.l -1 ) 50 74 NA Total Kjeldahi nitrogen as N. Max. (mg.l -1 ) 100 28 NA BOD 5 at 20 Max. (mg.l -1 ) 30 540 33 COD. Max. (mg.l -1 ) 250 960 64 Mercury as Hg. Max. (mg/l) 0.01 0.097 BDL Lead as Pb. Max. (mg.l -1 ) 0.1 0.035 0.002 Hexavalent chromium as Cr 0+ Max. (mg.l -1 ) 0.1 0.147 NA Zinc as Z. Max. (mg.l -1 ) 5 0.369 0.008 Nickel as Ni Max. (mg.l -1 ) 3 0.214 0.08 Chloride as Cl. Max. (mg.l -1 ) 1000 2400 20 Dissolved phosphate as P. Max. (mg.l -1 ) 5 14 0.01 Sulphate as SO 4 Max. (mg.l -1 ) 1000 550 11 Sulphide as S. Max. (mg.l -1 ) 2 5 0.8 Coliform count number/100ml 25 to <60/100ml 240x10 6 Nil to 40 Fig 1. Recycled water outflow point. The safety limits achieved are listed in Table 1. A few WQ Indicator ones depicted in Fig 3 later Water Requirements of Trees in Mahavir Park: It is evidenced that daily water requirement (DWR) is different for different species solely based on the canopy area/diameter of a given species of tree. The DWR of 3130 trees in Mahavir Park (Fig 2 a-c) during Oct-Jan period is 79346 litres (on an average of 25.35 litres/tree). During Feb-June, the total volume of water required is 92570 litres (average 30 litres/tree). Larger the canopy area, higher was the volume of water required. For hedge plants in an area of 2700 m 2 , @6.77 litres (calculated per the formula given above) the DWR is 18280 litres and for groundcover in an area of 6400 m 2 @ 4.57 Litres 29248 litres. But the water applied in the park is only 8400 litres. It is to be noted that trees are not watered at all. Thus there is very high water-stress for both hedge rows and groundcover. 0 200 400 600 Samanea saman Delonix regia Tamarindus indica Inga dulcis Terminalia catappa Lagerstroemia speciosa (a) DWR of Larger Trees (>125 m 2 CA) Mahavir Park, Panaji Canopy area (m2) DWR Oct-Jan (Ld-1) DWR Feb-Jun (Ld-1) 0 20 40 60 80 100 Syzygium cumini Peltaphorum pterocarpum Spatodea companulata Alstonia scholaris Mimusops elengi Sapindus mukorossi Mammea suriga Acacia auriculiformis C. pulcherima Bauhinia purpurea Tecoma capensis Cassia javanica (b) DWR of Medium Sized Trees in Mahavir Park, Panaji Canopy area (m2) DWR Oct-Jan (Ld-1) DWR Feb-Jun (Ld-1) 0 10 20 30 40 50 Millettia pinnata Dypsis lutescens Butea monosperma Mussaenda erythrophylla Casuarina equisetifolia Cassia fistula Phyllantus emblica Hyophorba lagenicaulis Polyalthia longifolia Canopy area M 2 or DWR (L) Tree species (c) DWR of Small Sized Trees in Mahavir Park, Panaji Canopy area (m2) DWR Oct-Jan (Ld-1) DWR Feb-Jun (Ld-1) Litres or m 2 Fig 2. Canopy areas of larger (a), medium (b), and smaller (c) sized trees in Mahavir Park in Panaji, Goa, and their daily requirement of water (L d -1 ) 10 25 33 64 1 11 4 SS TDS BOD COD Nitrate Sulphate Coliforms Concentration(mg^-1) Parameters Treated water characteristics Fig 3 Post-treatment characteristics of some important water quality indicator parameters of out-falling treated water. (Coliform counts are numbers, other parameters in mg l -1 concentrations). In all routinely parameters, monitored by the facility, the safe dischargeable limits are achieved routinely Following Results Used for Estimating the DWR of all Parks in Panaji DWR (Litres) for trees @ 27.18 L d -1 tree -1 = 3130*27.18 = 85074 DWR (litres) for hedge plants (HP) in 2700 m 2 @6.77 L m 2 = 18279 DWR (L)m for groundcover (GC) in 6410 m 2 @4.57 Lm 2 = 29294 The water currently supplied only to HP and GC is only 8400 litres Parameters Primary data from 7 Surveyed Parks # Estimates for the whole Panaji UGS City area Km 2 21.60 UGS area; Km 2 (% of city area) 1.858 (8.60%) Hedge plants area (@12.72% of UGS, m 2 8385 236000 Groundcover area (@ 42.23% of UGS; m 2 25860 784000 Water used in UGS (MLD) 0.0762 2.66* Hedge-plant DWR @ 6.77L m -2 (MLD) 0.057 1.599 Groundcover DWR @ 4.57Lm -2 (MLD) 0.012 3.585 Total DWR (MLD) 0.11 5.184 % DRW shortage hedge + groundcover 49.60 51.30 DRW @ for hedge + ground cover (MLD) 0.184 5.185 Trees area in ha 3.25 53.82 No of trees [@ 1 tree in 8 (±13) m -2 ] 4880 67275 Average DWR/tree @ 23.87L (MLD) 0.117 1.606 Trees’ DWR % of available treated water 15.25 (of 14 MLD available) In all seven parks, the daily of water requirement of hedge plants and groundcover is not fully met. But, the volume of treated water of 14 MLD drained out from the STP exceeds the daily water demand by over 50%. Therefore, this water can be diverted for use in the UGS. By doing so, the following are the major ecological benefits are possible. By making use of the regional evapotranspiration rates of 8.89 mm -1 d -1 for Panaji can help to recognise the importance of UGS for example in achieving urban heat balance and other advantages. Quantitative data (unpublished results) is worked for points 3-5 in Fig 4. Urban Green Space ecosystem service and function (Figure from Livesley et al 2016) Picture from Dr Ambedkar Park, Panaji, Goa. A good proportion of regular staff is women. Many Known Regulatory Ecosystem Services of UGS can be ENHANCED by Using Treated Water Available in All Good Cities References: Chichilnisky, G., & Heal, G. (1998). Economic returns from the biosphere. Nature, 391(6668), 629630. https://doi.org/10.1038/35481 Livesley, S. J., McPherson, E. G., & Calfapietra, C. (2016). The Urban Forest and Ecosystem Services: Impacts on Urban Water, Heat, and Pollution Cycles at the Tree, Street,and City Scale. Journal of Environmental Quality, 45(1), 119124. https://doi.org/10.2134/jeq2015.11.0567 Norton, B. A., Coutts, A. M., Livesley, S. J., Harris, R. J., Hunter, A. M., & Williams, N. S. (2015). Planning for cooler cities: A framework to prioritise green infrastructure to mitigate high temperatures in urban landscapes. Landscape and Urban Planning, 134, 127138. Pataki, D. E., Carreiro, M. M., Cherrier, J., Grulke, N. E., Jennings, V., Pincetl, S., Pouyat, R. V., Whitlow, T. H., & Zipperer, W. C. (2011). Coupling biogeochemical cycles in urban environments: Ecosystem services, green solutions, and misconceptions. Frontiers in Ecology and the Environment, 9(1), 2736. https://doi.org/10.1890/090220 Ramaiah, M., & Avtar, R. (2019). Urban Green Spaces and Their Need in Cities of Rapidly Urbanizing India: A Review. Urban Science, 3(3). https://doi.org/10.3390/urbansci3030094 Ramaiah, M., Avtar, R., & Rahman, Md. M. (2020). Land Cover Influences on LST in Two Proposed Smart Cities of India: ComparativeAnalysis Using Spectral Indices. Land, 9(9). https://doi.org/10.3390/land9090292 Regulatory ecosystem services achievable using treated water for UGS Sustenance Treated Water-Use Aided Regulatory Ecosystem Services 1 Recycled water for trees Balances urban heat (LST) 5 Improves employment opportunities Including women and frail persons 3 compensates partially the evapotranspiration losses 2 Reduces/eliminates groundwater extraction: 6 Enhanced thermal comfort, shading; added tourist attraction 4 Aids stress-free plant growth Enhances carbon storage. Fig 4. Qualitative assessment on the advantages offered by the treated water use in UGS which helps RES

Upload: others

Post on 22-Jan-2021

2 views

Category:

Documents


0 download

TRANSCRIPT

Page 1: Introduction Study Area...Dypsis lutescens Butea monosperma Mussaenda erythrophylla Casuarina equisetifolia Cassia fistula Phyllantus emblica Hyophorba lagenicaulis Polyalthia longifolia

Table 3. Basic Details of surveyed parks in Panaji including the current daily water supply and demand

.

The urban greenery fulfils both regulatory and cultural services through a variety of species of plants and trees, well-kept groundcover, hedge rows. It cany hold enormous quantities of carbon in their biomass and sequester carbon.

Their service of land surface temperature reduction and regulating many parameters of microclimate (urban climate regulation) are among the widely regarded regulatory ecosystem services (Chichilnisky and Heal, 1998; Ramaiah

and Avtar, 2019). In addition, their services in bioremediation through assimilation of excess nutrients, detoxification processes, purification of water and oxygenating the air are vital. As far cultural services, the urban green spaces

serve inspirational, therapeutic, recreational and tourism, biodiversity conservation motifs as well as science and educational interests.

Environmental benefits of UGS have been well documented, but they are often unclear, unquantified, and/or outweighed by potential costs. In view of this, a case study from Panaji India was undertaken for showcasing the

importance of treated water in sustainable management of UGS in Indian cities. It is a widely acknowledged fact that management of wastewater and pollution prevention in urban settings require a cost-effective approach. In view

of this, a study was undertaken by the GSES. Spectral indices and LULC changes were deduced and published earlier (Ramaiah et al 2020).

This presentation focusses on the results of the daily water requirement, carbon stocks and sequestration potential of different plant types (trees, hedge-plants and lawn/groundcover grass) in Mahavir Park, one of the largest parks in

Panaji city. These results are a part of many other analyses carried out. is to estimate water requirement in UGS (and carbon sequestration potential in this of the entire UGS) as per the main objective (below). Using this

information possible reduction in LST and ecological and societal benefits are highlighted .

To evaluate whether treated water from Panaji

sewage treatment facility could adequately meet the

water requirements of Panaji city’s 1.86 sq km UGS

area and the possible ecological regulatory

services/benefits met, in relation to some UN SDGs

Acknowledgements

Methodology Framework

Introduction

Objective

Study Area

Details of Sewage Treatment Facility and Treated Water Quality

Salient Observations

Concluding Remarks

Significance of Treated Water in RES

Manish Ramaiah is grateful to JASSO for Fellowship, Hokkaido University for

facilities, and Prof. Ram Avtar for valuable guidance and constant support.

An Ecological Assessment on Sustainable Enhancement of Regulatory Ecosystem Services from Urban Green Spaces Using Recycled WaterManish Ramaiah1 , Ram Avtar1,2

1Graduate School of Environmental Science, Hokkaido University, Sapporo 060-0810, Japan;2Faculty of Environmental Earth Science, Hokkaido University, Sapporo 060-0810, Japan.

Panaji City, Goa, India

Derivation of Daily Requirements of Water

Primary data: Mahavir Park 15◦29’47.31” N; 73 ◦49’07.91” E

Total area: 37199 m2

Trees: 3130 in 22101 m2 [27 spp]

Hedge-plants: >15 sp in 2700 m2

Groundcover: Paspalum 6400 m2

Derivation of ETOP

DRW of trees,

hedge plants,

groundcover

DRW Estimation

All of Panaji UGS

Day time

Night time

𝐸𝑇0 = 0.408∆ 𝑅𝑛 − 𝐺 + 𝛾 37

𝑇 + 273 𝑢2 𝑒𝑠 − 𝑒 ÷ ∆ + 𝛾 1 + 0.24𝑢2

𝐸𝑇0 = 0.408∆ 𝑅𝑛 − 𝐺 + 𝛾 37

𝑇 + 273 𝑢2 𝑒𝑠 − 𝑒 ÷ ∆ + 𝛾 1 + 0.96𝑢2

WRtr X No of trees in all of 1.86 Sq Km UGS

WRhp m-2 X Total area of hedge rows in UGS

WRgc m-2 X Total area of lawns in UGS

WRTr (Ld-1) = EToP×#PF× (*R × R × 3.14)

WRhp (L m-2d-1) = D X PF X EToP X Kd

WRgc= 4.57 Lpdm-2 (as per CIMIS)

Formulae

net radiation (Rn, MJ m−2h−1),

ground heat flux density (G, MJ m−2h−1),

psychrometric constant (, kPa K−1),

mean air temperature (T,◦C),

wind speed (u2, m s−1),

saturation vapor pressure (es, kPa),

vapor pressure (e, kPa),

slope of SVP at temp T (, kPa K−1)

WR=Water Requirement,

EToP = ETo Panaji,

Evapotranspiration (cm d-1);

PF=Plant Factor

Kd= Canopy density (=1.02)

21.60 sq km City area

1.860 sq km UGS area

0.784 sq km Lawn area

0.236 sq km Hedges area

0.538 sq km Trees area

Trees

67275

in UGS

Panaji City UGS details

#Two plant factors (0.6 for somewhat cooler Oct-Jan and 0.7 for warmer Feb-Jun periods) were used for calculating

tree DWR; *Canopy/crown radius of different tree species calculated on-site based estimations from Mahavir Park;

Coupling of carbon, water, and energy cycles is integral to impacts of urban vegetation on climate (Pataki et al., 2011).

This nexus will have much advantages when recycled water is reused. This is one of the important Sustainable

Development Goals of the UN. The two climate-regulating services of carbon sequestration involve direct removal of

carbon dioxide from the atmosphere and indirect effects of vegetation on local cooling through shading and transpiration

in warm climates (Livesley et al 2016)

The UGS are “purported to offset greenhouse-gas (GHG) emissions, remove air and water pollutants, cool local climate,

and improve public health.” (Pataki et al 2011). To make use of these services, the municipalities in the cities aspiring to

be “smart” especially in developing countries such as India have to focus efforts on designing and implementing

ecosystem-services-based “green infrastructure” in urban environments.

Even prior to Plato (c. 400 BC), there already was an awareness of ecosystems services supporting the humankind. The

earlier civilization was in the knowing that deforestation -in complex ways- could lead to soil erosion and drying of

springs. During the last 200 years, many modern ideas of ecosystem services have emerged. These developments have

continued to expand our knowledge of the intricate functional mechanisms that are at play. These developments must

inspire urban population to benefit through ecologically sustainable resource reuses.

Park Area(m2)

Trees(n)

HedgeArea (m2)

Lawn(m2)

CurrentSupply

(LPD)

Daily Water Requirement (Litres per Day. LPD)

Trees# Hedges Lawn Demand

Kala Academy 10630 250 360 2675 10000 5991.25 2437.20 12224.75 20653.20

NGRF Office Park 5000 290 160 2250 4800 6949.85 1083.20 10282.50 18315.55

SGRF office Park 6500 180 800* 1625 6000 4313.70 5416.00 7426.25 17155.95

Mahavir Park+Art Park 37211 3130 2700 6410 8400 75010.45 18279.00 29293.70 122583.20

Garcia da Orta Garden 4000 150 405 1500 15000 3594.75 2741.85 6855.00 13191.60

Ambedkar Park 10000 480 1620 6500 16000 11503.20 10967.40 29705.00 52175.60

Joggers Park 11500 400 2340 6900 16000 9586.00 15841.80 31533.00 56960.80

Total 84841 4880 8385 27860 76200 116949.20 56766.45 127320.20 301035.90#currently no direct watering of trees except for a small number nearer the hedge lanes or groundcover. Daily demand of water estimated at an

average of 24 litres per tree, *nursery plot including narrow access lanes for watering, nursing/caring

A key informant-based survey questionnaire was prepared and required details were sought from the offices of the sewage treatment plant located at

Tonca in Panaji City. The STP handles 15 MLD raw sewage daily and produces ca. 14 MLD treated water. Data on the quality of raw sewage received

and water quality achieved post-treatment were also obtained (Table 1) and the treated water outflow point shown below (Fig 1)

Parameters Tolerance limit Raw sewage Outlet values

Colour/odour - -- Clear, odorless

Suspended solids (mg.l-1) 100 400 10

Particle size suspended solids units <850 u. 140 5

Dissolved inorganic solids max. (mg.l-1) 2100 480 246

pH 5.5 – 9.0 6.88 7.56

Oil and grease. Max. (mg.l-1) 10 86 NA

Ammoniacal nitrogen as N. Max. (mg.l-1) 50 74 NA

Total Kjeldahi nitrogen as N. Max. (mg.l-1) 100 28 NA

BOD5 at 20 Max. (mg.l-1) 30 540 33

COD. Max. (mg.l-1) 250 960 64

Mercury as Hg. Max. (mg/l) 0.01 0.097 BDL

Lead as Pb. Max. (mg.l-1) 0.1 0.035 0.002

Hexavalent chromium as Cr0+ Max. (mg.l-1) 0.1 0.147 NA

Zinc as Z. Max. (mg.l-1) 5 0.369 0.008

Nickel as Ni Max. (mg.l-1) 3 0.214 0.08

Chloride as Cl. Max. (mg.l-1) 1000 2400 20

Dissolved phosphate as P. Max. (mg.l-1) 5 14 0.01

Sulphate as SO4 Max. (mg.l-1) 1000 550 11

Sulphide as S. Max. (mg.l-1) 2 5 0.8

Coliform count number/100ml 25 to <60/100ml 240x106 Nil to 40

Fig 1. Recycled water outflow point. The safety

limits achieved are listed in Table 1. A few WQ

Indicator ones depicted in Fig 3 later

Water Requirements of Trees in Mahavir Park: It is evidenced that daily water requirement (DWR) is different for different

species solely based on the canopy area/diameter of a given species of tree. The DWR of 3130 trees in Mahavir Park (Fig 2 a-c)

during Oct-Jan period is 79346 litres (on an average of 25.35 litres/tree). During Feb-June, the total volume of water required is

92570 litres (average 30 litres/tree). Larger the canopy area, higher was the volume of water required. For hedge plants in an area of

2700 m2, @6.77 litres (calculated per the formula given above) the DWR is 18280 litres and for groundcover in an area of 6400 m2

@ 4.57 Litres 29248 litres. But the water applied in the park is only 8400 litres. It is to be noted that trees are not watered at all. Thus

there is very high water-stress for both hedge rows and groundcover.

0

200

400

600

Samanea

saman

Delonix regia Tamarindus

indica

Inga dulcis Terminalia

catappa

Lagerstroemia

speciosa

(a) DWR of Larger Trees (>125 m2 CA) Mahavir Park, Panaji

Canopy area (m2)

DWR Oct-Jan (Ld-1)

DWR Feb-Jun (Ld-1)

0

20

40

60

80

100

Syzygium

cumini

Peltaphorum

pterocarpum

Spatodea

companulata

Alstonia

scholaris

Mimusops

elengi

Sapindus

mukorossi

Mammea

suriga

Acacia

auriculiformis

C. pulcherima Bauhinia

purpurea

Tecoma

capensis

Cassia

javanica

(b) DWR of Medium Sized Trees in Mahavir Park, Panaji

Canopy area (m2)

DWR Oct-Jan (Ld-1)

DWR Feb-Jun (Ld-1)

0

10

20

30

40

50

Millettia

pinnata

Dypsis

lutescens

Butea

monosperma

Mussaenda

erythrophylla

Casuarina

equisetifolia

Cassia fistula Phyllantus

emblica

Hyophorba

lagenicaulis

Polyalthia

longifolia

Ca

no

py

are

a M

2o

r D

WR

(L

)

Tree species

(c) DWR of Small Sized Trees in Mahavir Park, Panaji

Canopy area (m2)

DWR Oct-Jan (Ld-1)

DWR Feb-Jun (Ld-1)

Lit

res

or

m2

Fig 2. Canopy areas of larger (a), medium (b), and smaller (c) sized trees in Mahavir Park in Panaji, Goa, and their daily requirement of water (L d-1)

10

25

33

64

1 11 4

SS TDS BOD COD Nitrate Sulphate Coliforms

Conce

ntr

atio

n(m

g^-1

)

Parameters

Treated water characteristics

Fig 3 Post-treatment characteristics of some important water

quality indicator parameters of out-falling treated water.

(Coliform counts are numbers, other parameters in mg l-1

concentrations).

In all routinely parameters, monitored by the facility, the

safe dischargeable limits are achieved routinely

Following Results Used for Estimating the DWR of all Parks in Panaji

DWR (Litres) for trees @ 27.18 L d-1 tree-1 = 3130*27.18 = 85074

DWR (litres) for hedge plants (HP) in 2700 m2 @6.77 L m2 = 18279

DWR (L)m for groundcover (GC) in 6410 m2 @4.57 Lm2= 29294

The water currently supplied only to HP and GC is only 8400 litres

ParametersPrimary data from 7

Surveyed Parks#

Estimates for the whole

Panaji UGS

City area Km2 21.60

UGS area; Km2 (% of city area) 1.858 (8.60%)

Hedge plants area (@12.72% of UGS, m2 8385 236000

Groundcover area (@ 42.23% of UGS; m2 25860 784000

Water used in UGS (MLD) 0.0762 2.66*

Hedge-plant DWR @ 6.77L m-2 (MLD) 0.057 1.599

Groundcover DWR @ 4.57Lm-2 (MLD) 0.012 3.585

Total DWR (MLD) 0.11 5.184

% DRW shortage hedge + groundcover 49.60 51.30

DRW @ for hedge + ground cover (MLD) 0.184 5.185

Trees area in ha 3.25 53.82

No of trees [@ 1 tree in 8 (±13) m-2] 4880 67275

Average DWR/tree @ 23.87L (MLD) 0.117 1.606

Trees’DWR % of available treated water 15.25 (of 14 MLD available)

In all seven parks, the daily of water requirement of hedge plants and groundcover is not fully met. But, the volume of treated water

of 14 MLD drained out from the STP exceeds the daily water demand by over 50%. Therefore, this water can be diverted for use in

the UGS. By doing so, the following are the major ecological benefits are possible. By making use of the regional

evapotranspiration rates of 8.89 mm-1 d-1 for Panaji can help to recognise the importance of UGS for example in achieving urban heat

balance and other advantages. Quantitative data (unpublished results) is worked for points 3-5 in Fig 4.

Urban Green Space ecosystem service and

function (Figure from Livesley et al 2016)Picture from Dr Ambedkar Park, Panaji, Goa.

A good proportion of regular staff is women.

Many Known Regulatory

Ecosystem Services of UGS

can be ENHANCED

by Using Treated Water

Available in All Good Cities

References:• Chichilnisky, G., & Heal, G. (1998). Economic returns from the biosphere. Nature, 391(6668), 629–630. https://doi.org/10.1038/35481

• Livesley, S. J., McPherson, E. G., & Calfapietra, C. (2016). The Urban Forest and Ecosystem Services: Impacts on Urban Water, Heat, and Pollution Cycles at the Tree, Street, and City Scale. Journal of Environmental

Quality, 45(1), 119–124. https://doi.org/10.2134/jeq2015.11.0567

• Norton, B. A., Coutts, A. M., Livesley, S. J., Harris, R. J., Hunter, A. M., & Williams, N. S. (2015). Planning for cooler cities: A framework to prioritise green infrastructure to mitigate high temperatures in urban landscapes.

Landscape and Urban Planning, 134, 127–138.

• Pataki, D. E., Carreiro, M. M., Cherrier, J., Grulke, N. E., Jennings, V., Pincetl, S., Pouyat, R. V., Whitlow, T. H., & Zipperer, W. C. (2011). Coupling biogeochemical cycles in urban environments: Ecosystem services, green

solutions, and misconceptions. Frontiers in Ecology and the Environment, 9(1), 27–36. https://doi.org/10.1890/090220

• Ramaiah, M., & Avtar, R. (2019). Urban Green Spaces and Their Need in Cities of Rapidly Urbanizing India: A Review. Urban Science, 3(3). https://doi.org/10.3390/urbansci3030094

• Ramaiah, M., Avtar, R., & Rahman, Md. M. (2020). Land Cover Influences on LST in Two Proposed Smart Cities of India: Comparative Analysis Using Spectral Indices. Land, 9(9). https://doi.org/10.3390/land9090292

Regulatory ecosystem services achievable using treated water for UGS Sustenance

Treated

Water-Use

Aided

Regulatory

Ecosystem

Services

1 Recycled water for trees

Balances urban heat (LST)

5 Improves employment opportunities

Including women and frail persons

3 compensates partially the

evapotranspiration losses

2 Reduces/eliminates

groundwater extraction:

6 Enhanced thermal comfort,

shading; added tourist attraction

4 Aids stress-free plant growth

Enhances carbon storage.

Fig 4. Qualitative assessment on the advantages offered by the treated water use in UGS which helps RES