Ecosystem-based River Basin Management (EcoBasin) and

Data Need

Takehiro NAKAMURA

Programme Officer (Water)

Division of Environmental Policy Implementation

United Nations Environment Programme (UNEP)

An “INTEGRATED” approach

Integrated River Basin Management ------ to manage relevant factors in the basins in order to achieve multiple objectives for resource use and protection of the aquatic environment. It is also

an approach, which essentially takes a cross-sectoral and interdisciplinary approach to achieve institutional co-ordination and co-

operation.

UNEP’s approach

Approaches to monitoring, assessment and management

Integrated Coastal Area and River Basin Management (ICARM)(www1.unep.org/icarm)

Ecosystem-based approach (follow-up to Wetlands and Integrated River Basin Management)

Ecosystem-based approach = Ecosystem function-based approach

Ecosystem functions = functions for human benefits (flood control,water quality control, etc.), ability to produce products that are ofeconomic value (agriculture, fishery, etc.), and ecosystem attributes(cultural heritage and biodiversity value, etc.).

Ecosystem functions and their values depend on interacting elementswithin the ecosystem, such as water, soil, atmosphere and vegetation,through hydrological, geochemical and biophysical processes.

Consider various functions together within one system (River basin),so that its integrity can be maintained.

Ecosystems in a river basin ---- functions, uses and attributes that canprovide valuable contribution to quality and availability of waterresources for human life and socio-economic development.

Different types of Ecosystems involved in River Basins

Forest ecosystemAgricultural ecosystemAquatic/Wetland ecosystem

----> examples of ecosystem functions

(WRI classification)

Table 1 Ecosystem Functions in Wetlands: Examples from Asia and the Pacific (modified from UNEP/Wetlands International,1997)

Wetland Ecosystem Function Examples from Asia and the PacificFlood Control (floodwater storage, flood peak reduction, flooddesynchronisation)

Agusan Marsh, Philippines

Water Supply Direct abstraction Maintenance of river flow Ground recharge Prevention of saline water intrusion

Tamiraparani River Floodplain, Tamil Nadu,IndiaGanges floodplain, India and BangladeshMarshes of Khao Sam Roi National Park,Thailand

Water Quality Maintenance and Purification Removal of agricultural pollutants Treatment of mine drainage Domestic and industrial waste water treatment

Chaohu Lake, Anhui Province, ChinaArtificial wetlands, Baiyan coal mine, Sichuan,ChinaEast Calcutta Wetlands, India

Coastal Storm Protection and Erosion Prevention Mangroves adjacent to Brisbane, Australia

Reduction of net Green House Gas emission -

Transport Ogan-Komering lebaks, South Sumatra

Recreation and Eco-tourism Olango Island, Philippines

Forest resources (timber, fuelwood, tannin etc.) Sundarbans, India and Bangladesh

Wildlife resources (meat, furs, skins, etc.) Mangroves of Malaysia, India and Bangladesh

Fisheries Danau Sentarum complex, Kapuas River,Kalimantan, Indonesia

Plant Resources (food, medicine, fodder, etc.) Mangroves of Southeast Asia

Agricultural Resources Freshwater beels and hoars of Bangladesh

Maintenance of Biodiversity Sundarbans, India and Bangladesh

Cultural and Heritage Significance Lake Lanao, Philippines

Ecosystem-based River Basin Management

Reduce ecosystem vulnerability and maximise ecosystem

resilience based on the identified ecosystem functions to address

environmental and resource issues

Deforestation Siltation changes in damages toSoil erosion water storage loss frequency bank destruction habitats Land reclamation magnitude changed riverSlope farming hydrology damages to housing Climate change and heavy and frequent hydrograph type damages to farmland Variability rain

________ ____________________ __________________________ _________________ _________________ ____________ ___________

Population growth economic loss human death/

injuryEconomic Ecosystem Resiliencedevelopment Response food loss

PreparednessLand use plan

|-----------------------------------------------------------------------------|Narrowly defined vulnerability

Flood ‘Vulnerability’ (Ecosystem function indicators)

Figure 3 Schematic illustration of causal chain for floods in the Yangtze River basin (Modified from Nakamura, 2000)

Pressure RootCauses

CausesFloodEvents Primary

ImpactsSecondaryImpacts

MacroImpacts

Classification and inventory of different ecosystems; Identification and assessment of ecosystem functions; Quantification and economic valuation of ecosystem

functions; Official recognition of ecosystem functions; Trade-offs between the ecosystem functions identified

and between the ecosystem functions and the ICARMpriorities;

Increased awareness of the ecosystem functions; and Setting management objectives for wise and maximum

use of ecosystem functions, identified and recognised.

1

Figure 1. Trade-offs between ecosystem functions and between ecosystem functions and management and developmentobjectives of the Integrated Coastal Area and River Basin Management (modified from Ritchie and James, 1997)

Requirements for Integrated Coastal Area andRiver Basin Management (ICARM) and socio-economic development

Ecosystem functions function use, or attribute

Impacts of human development activities onEcosystem functions

positive neutral, or negative

Other ecosystem function values positive neutral, or negative

Other development values positive neutral, or negative

‘Vulnerability’ Index (Indicators)

Indicating ecosystem vulnerability and resilience

Initiated for ‘flood vulnerability’ (China, Vietnam, Bangladesh, Iran(?), Central

Africa(?))

Land ManagementPractices

National Landscapechange

Vulnerability tofloods

Climate ChangeVariability

Change in BasinEcology

Human Populationand Activities

Vulnerability Index

Indicators on land use

Indicators on Agriculture

Indicators on Risk to Life

Indicators on Populations

Indicators on Housing

Indicators on Environment(ecosystem)

Land UseIndicator RationaleLand surface area (km2) The land surface has various functions for controlling water

retention and run-off, and has potential for human productiveactivities.

Population Population is indicative for the size of productive activitiesand life.

AgricultureIndicator RationaleWhen flooding occurs (1=immediately prior or duringharvesting period; 0 otherwise)

Flooding in any fallow periods will have little impact oncrops; flooding extending over the harvest period will destroycrops

Duration (0 = less than 5 days;1 = 15 days; 2 = 6 weeks ormore during growing seasons)

Loss to standing crop is dependent on duration of flood;extended flooding may preventing planting of the next crop.

Crop type (0-2, depending oncrop type significance in thebasin)

Some crops are more important than the others in a specificriver basin.

Arable land area/land surface(%)

The arable land surface is indicative of the size of agriculture.

Depth (< 2 metres = 0; > 2metres = 1) – loss of draftanimals and livestock

Loss of draft animals will impoverish the population and makeagricultural production very difficult

Risk to life

Flashy catchments Behind natural or artificial defencesSteepness of sloop > 0.3 (1)

< 0.3 (0)Behind a natural orartificial defence line(including in naturaldepression)

Yes (1)No (0)

Ratio of discharge of200 year return periodflood to annual averageflood*1

> 20 (1)< 20 (0)

Depth of flooding > 2 metres (1)< 2 metres (0)

Slope stability under200 year return periodrainfall intensity

Low (1)High (0)

Velocity of flood flow > 2 metres/sec (1)< 2 metres/sec (0)

Potential warning leadtime

< 12 hours (1)> 12 hours (0)

* use 200 year 24 hour intensity rainfall for small area in absence1 return period and ratio should be adapted to national or regional conditions

EconomyScore Indicator Rationale

% Economic value of flood losses* asequivalent to a % of the GrossNational Product OR as a % ofGovernment income

Represents the difficulty of fundingreplacements to buildings, servicesand goods lost in the flood

% Percentage of capital value of thebasin’s buildings, infrastructure andplant (if statistics available)

Represents likely impact on long termeconomic growth

% Critical industrial sites at risk (%production in specific categoriese.g. power)

Represents the extent to whichflooding will disrupt productionelsewhere in the basin (use highest %of industrial sectors identified)

% % basin’s stable food productionthat might be lost in a flood(measured as proportion of averagedaily intake)

Represents the difficulty of replacingfood supplies from reserves or imports

% Population at risk as a proportion ofthe basin’s population

Represents the difficulty of shelteringdisplaced population

* exclude reductions in indirect and direct taxes as in economic terms these are transferpayments; economic value of flood losses should be measured using the standardmethods for assessing flood losses.

Populations

Score Indicator Rationale

0 – no1 - yes

Newly urbanised areaspopulated by migrantsfrom rural areas

Low in social capital (Krishna andShrader 1999), lacking in family andkinship links

0 – below national average1 – above national average

Landless workers in ruralareas

Loss of income from harvesting, lack ofassets against which to borrow

0 – below national average1 – above national average

Elderly/disabled Physical difficulties in coping with theflood

0 – below national average1 – above national average

Poor Lack of capital and ability to borrow

0 – below national average1 – above national average

Ethnic minorities Whilst these are not invariablydiscriminated against in a country, theyfrequently are in most countries

0 – below national average1 – above national average

Female headedhouseholds (bothpermanent and temporaryi.e. partner is a migrantworker)

Likely already to experiencing over-work; gender biases likely to restrictaccess to resources (e.g. in extreme cases,requiring male relative to accompany herin public)

Housing

The housing in the basin is categorised into the following groups:A1 Mud Walls (all roofs)A2(a) Unburnt brick or adobe wall with sloping roofA2(b) Unburnt brick or adobe wall with flat roofA3(a) Stone wall with pitched/sloping roof

Category A

A3(b) Stone wall with flat roof(a) Burnt brick wall with sloping roofCategory B(b) Burnt brick wall with flat roofC1(a) Concrete wall with sloping roofC1(b) Concrete wall with flat roofC2 Wooden walls (all roofs)

Category C

C3 Ekra walls (all roofs)X1 Corrugated iron, zinc or other metal sheet walling (all roofs)Category XX2 Bamboo, thatch, grass leaves,

(Building Materials and Technology Promotion Council 1997)

Risk level could be broken down into various degrees of damage. Forexample:Rating

Very High Damage Risk Total collapse of buildings

4 High Damage Risk Gaps in walls; parts of buildings may collapse; separate parts ofbuildings lose their cohesion and inner walls collapse

3 Moderate Damage Risk Large and deep cracks in walls, fall of chimneys on roofs2 Low Damage Risk Small cracks in walls; fall of fairly large pieces of plaster, pantiles slip

off; cracks in chimneys, part may fall down1 Very Low Damage Risk Fine cracks in plaster; fall of small pieces of plaster(Building Materials and Technology Promotion Council 1997)

As a result based upon some basic criteria and historical records, forexample, it would be estimated that a rural village made up of burnt brickwalls with sloping roofs faces a high risk of damage from a fifty-yearflood.Category A2(a) / Fifty Year flood = High Damage Risk

Environment (Ecosystem)Indicator Rationale

Rate Ecosystems linked to river (0)Ecosystems dependent upon artificiallycreated water regime (1)

Flooding is only a severe threat toecosystems that have developed because ofan artificial water regime.

Number Number of Internationally importantprotected areas;Nationally important protected areas; andLocally important protected areas.

As determined by the nationalgovernment.

Number Number of endangered/rare/indigenousspecies (according to IUCN and nationalRed Books)

As determined by the national government

% Natural and regrowth vegetation coverage The vegetation cover is relevant to copingcapability of the catchment.

% % of degraded land Flooding might cause soil erosion in thecatchment

Degree Degree of slope (average) The soil erosion is relevant to the slopedegree

Ton/hectre

Use of chemical fertilisers (N,P and K) perunit area

This represents possibility of nutrient run-off, which potentially cause pollution.

Ton/hectre

Soil erosion rate This represents possibility of soil loss byfloods.

Rate Recovery time > 25 years (4)Recovery time < 25 years (1)

Some ecosystems can be re-createdrelatively quickly and with a fair certaintyof success. Others have developed overhundreds of years.

Example of indicators in the Yangtze River Basin (Ecosystem

functions focussing on flood magnitude and frequency)

Location of Key Rivers and Lakes in the Yangtze River basin

Vulnerability Indicator on topography in the Yangtze River Basin

Rainfall indicator in the Yangtse River Basin

Indicators concerning connectedness to aquatic environment (buffer zones)

Indicators on natural (as opposed to human activities)environment

0 600 1200 Kilometers

N

Nanjing

Hangzhou

Nanchang

Wuhan

Hefei

Changsha

Chengdu

Kunming

Guiyang

Gansu Qinghai

Shanghai

Jiangsu

HubeiZhejiang

Henan

Anhui

Chongqing

Shanxi

Xizang

Guangdong Fujian

Jiangxi

Guangxi

HunanYunnan

Guizhou

Sichuan

IIIIIIIVV

Indicator: Population Density

ÆÕͨ ¹«Â· ¹«Àï ·Ö²¼

0 600 1200 Kilometers

N

Nanjing

Hangzhou

Nanchang

Wuhan

Hefei

Changsha

Chengdu

Kunming

Guiyang

Gansu Qinghai

Shanghai

Jiangsu

HubeiZhejiang

Henan

Anhui

Chongqing

Shanxi

Xizang

Guangdong Fujian

Jiangxi

Guangxi

HunanYunnan

Guizhou

Sichuan

IIIIIIIVV

Indicator: Transportation

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0 600 1200 Kilometers

N

Nanjing

Hangzhou

Nanchang

Wuhan

Hefei

Changsha

Chengdu

Kunming

Guiyang

Gansu Qinghai

Shanghai

Jiangsu

HubeiZhejiang

Henan

Anhui

Chongqing

Shanxi

Xizang

Guangdong Fujian

Jiangxi

Guangxi

HunanYunnan

Guizhou

Sichuan

«ÇêIIIIIIIVV

Indicator: Agriculture cultivated land

Nanjing

Hangzhou

Nanchang

Wuhan

Hefei

Changsha

Chengdu

Kunming

Guiyang

Gansu Qinghai

Shanghai

Jiangsu

HubeiZhejiang

Henan

Anhui

Chongqing

Shanxi

Xizang

Guangdong Fujian

Jiangxi

Guangxi

HunanYunnan

Guizhou

Sichuan

N

0 600 1200 KilometersIIIIIIIVV

Indicator: GDP

0 600 1200 Kilometers

N

Nanjing

Hangzhou

Nanchang

Wuhan

Hefei

Changsha

Chengdu

Kunming

Guiyang

Gansu Qinghai

Shanghai

Jiangsu

HubeiZhejiang

Henan

Anhui

Chongqing

Shanxi

Xizang

Guangdong Fujian

Jiangxi

Guangxi

HunanYunnan

Guizhou

Sichuan

IIIIIIIVV

Indicator: Chemical Fertilizers

0 600 1200 Kilometers

N

Nanjing

Hangzhou

Nanchang

Wuhan

Hefei

Changsha

Chengdu

Kunming

Guiyang

Gansu Qinghai

Shanghai

Jiangsu

HubeiZhejiang

Henan

Anhui

Chongqing

Shanxi

Xizang

Guangdong Fujian

Jiangxi

Guangxi

HunanYunnan

Guizhou

Sichuan

IIIIIIIVV

Indicator: Pesticides

Nanjing

Hangzhou

Nanchang

Wuhan

Hefei

Changsha

Chengdu

Kunming

Guiyang

Gansu Qinghai

Shanghai

Jiangsu

HubeiZhejiang

Henan

Anhui

Chongqing

Shanxi

Xizang

Guangdong Fujian

Jiangxi

Guangxi

HunanYunnan

Guizhou

Sichuan

N

IIIIIIIVV

0 600 1200 Kilometers

Indicator: Nature protected areas

Composite flood vulnerability index in the Yangtze River Basin

Ecosystem-based River Basin Management (EcoBasin)

- Started with flood impact mitigation- Extension to cover other ecosystem functions- Yangtze River case - Detailed assessment for the Lake Dongting basin (county - 10km vs. 10km)- More indicators on Ecosystem Resilience