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REStRuctuRing the resettled landscape GUIdInG InFOrMal actIVItIes and settleMent In the rIparIan landscape OF the VOlta laKe, Ghana. MIranda schUt & Ilse Verwer waGenInGen Ur / KU leUVen. nOV.‘09
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Cote d’Ivoire
Burkina Faso
Togo
Benin
Mali Niger
ghana
20 KM
50 KM
30 KM
50 KM
traditional village
lake shore
VRA resettlement
city
initial, controlled
river Niger
lagoon, Ghana
sea shore, Ghana
secondary, spontaneous migration
100 KM
500 KM
100 KM
migration
prObleM stateMent
Volta BaSin dam in thE Volta RiVER Volta lakE, RESEttlEmEntS
mixed activities
reality
Schematic illustration: the riparian landscape around the Volta Lake, a conflict of interest
The REliEf of the Ghanaian landscape forces the water flow of the Volta RiVER SyStEm through the natural gorge near Akosombo, creating an opportunity to gEnERatE hydRo-ElEctRicity. Combined with natural resources & transport, the creation of the akoSomBo dam in the 1960’s formed the cornerstone of Nkrumah’s develop-ment plan for independent Ghana.
The formation of the Volta lakE resulted into the RESEttlEmEnt of +700 villages into 52 resettlements around the newly created Lake.
The Volta lakE covers a surface of 8500 km2, but its influEncE extends far beyond the inundated area. The adaption of the environment to the new circumstances led to a nEw landScapE around the Lake.
The riparian landscape around the Ghanaian Volta Lake offers the potential to support livelihood, without jeopardizing Ako-sombo dam’s efficiency and durability. A sensible integral landscape design can re-structure the riparian landscape and guide informal activities & settlement.
migration resulting from the creation of the volta lake
hypOthesIs
restricted area 280 ftcontourline
50mbufferzone
activities limited
? invisible ?vra policy
The creation of the Volta Lake resulted in migRation to the Lakeside. People areattRactEd by the potEntialS that the Lake offers.This generates infoRmal actiVitiES and SpontanEouSly SEttlEd at thE lakE-SidE.
However, the lifESpan of the Akosombo dam is threatened by SEdimEntation. This jeopardizes ElEctRicity gEnERation in the future.The main cause is ERoSion, created by the increase of human activities in the RipaRian zonE.
To Stop ERoSion and protect the Dam, the Volta RiVER authoRity prohibited activities and settlement below the 280ft con-touR linE. On top of that a 50 m buffer zone was added. However, within the landscape the restricted area is not ViSiBlE. So, dESpitE the policy of the VRA the Lakeside continues to attRact SEttlERS.
There is a conflict of intERESt in the riparian zone, caused by contRadictoRy nEEdS of parties on national, regional and local scale. The approach the VRA uses to stop sedimentation is incompatible with the needs and lifestyle of the inhabitants around the Volta Lake.
1960’s
20081m
REStRuctuRing the resettled landscape
85. - .3 -
84.o -
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77.o -
76.o -
75.o -
74.o -
73.o -
72.o -
71.o -
70.o - July
Aug
ust
Sep
tem
ber
Oct
ober
Nov
embe
r
Dec
embe
r
Janu
ary
Febr
uary
Mar
ch
Apr
il
May
June
[VRA, 2006Volta Lake Trajectory1980-2005]
o MAX
o MIN
Averagedrawdownmagnitude
increasing high flow slowing slow flow from the Volta basin
precipitation atthe Volta lakerainy dry rainy
flooded phase
floodingincreasing area
drying dry condition of the drawdownzone
dry
VRA Propertie280
230
240
250
260
270
mft
01
25
10 K
M
Perennial stream 280 feet contour line
fiShERyThe growth of the fiSh population in the Volta Lake attRactEd pEoplE to the Lakeside. The fish stock is however dEclining.
dRawdown agRicultuRE [Tonu nyigba]Land immediately around the Lake, used for settle-ments and dRawdown agRicultuRE. [Tsikata, 2006, p.308-309]High nutRiEnt availability, proximity to thewatER. Even though the VRA BannEd drawdown agri-culture, it is still practised on a subsistence level.
liVEStockliVEStock takes advantages of the vegetation in the dRawdown zonE. conflictS could rise with the drawdown farmers.
Rain-fEd agRicultuRE [Kpodzi nyingba]Land more or less distant from the Lake, largely acquired as faRmland by migrants. [Tsikata, 2006, p.308-309]dEplEtEd soils, Rain-fEd agriculture. Main type of agriculture, but reliance on rain makes the harvest VulnERaBlE.
IV
III
II
Iproduction zones in the riparian landscape
01
25
10 K
M
accessibility of settlements in the riparian landscape
<800ft<300ft
SEttlEmEnt pattERnThe Lakeside settlements form an ExcEption to the original SEttlEmEnt pattERn.
taRREd RoaddiRt Roadfoot path TOPOGRAPHy
The poSition of the RoadS iS linkEd to thE topogRaphy. The accESS to thE lakESidE SEttlE-mEntS iS limitEd because the connEction iS pERpEndiculaR to the topography and original road network.
official pontoonunofficial pontoonwEEkly fERRypRiVatE canoEThe communities are forced to tRanSpoRt oVER watER.
The good connEctionS to and from kpando toRkoR form an exception.280 feet contour line
SEction with an impression of the landscape. accESS to lakESidE SEttlEmEntS. The relief forms a BaRRiER between the original settlement and the Lakeside. Often, lakESidE VillagES can only be REachEd By foot, crossing large distances or StEEp mountainouS terrain.
View from the mountain over the Lake
01
25
10 K
M
1 Km
100 Ft
0 Ft
300 m
500 Ft
1000 Ft
200 m
100 m
0 m
kpando torkor,explosive growth at the Lakeside 2.702 in 2000
Informal marketat the Lake edgenext to the pontoons
kpando,steady growth connected to the road17.684 in 2000
Church as relict of the German Colonial history
0 Km
The soil is very vulnerable for severe erosion: within 40+ yEaRS, the foundations of the buildings became bare.
erosion
sanitation & Waste
facilitiESBecause of the informal nature of the Lakeside settlements, there is a lack of BaSic facilitiES, for example sanitation.
domEStic waStE watERThe lack of facilitiES forces people to use the Lake water for domEStic puRpoSES.
waStE diSpoSalSolid waste is diSpoSEd in thE dRawdown zonE and washed away into the Lake.
climate change
280
ft
NO
V. 2
010
NO
V. ‘
90
JULY
‘84
NO
V. ‘
84JU
LY ‘9
0
LOW
HIGHaverage
Kpando Tokor
Kete Krachi
280
ft
NO
V. 2
010
NO
V. ‘
90
JULY
‘84
NO
V. ‘
84JU
LY ‘9
0
LOW
HIGHaverage
JULY
201
0JU
LY 2
010 LOW, 256 ft
JULY ‘90: 256 ft
NOV. ‘90: Highest level in 25 years, 275 ft
JULY ‘84: Lowest level in 25 years, 235 ft
NOV. ‘84: 263 ft
280ft VRA security line
JULY 2010 Possible fall of level after climate change, 230 ft
NOV. 2010 Possible rise of level after climate change, 290 ft
average HIGH, 268 ftWATERLEVELS
LOW, 256 ft
JULY ‘90: 256 ft
NOV. ‘90: Highest level in 25 years, 275 ft
JULY ‘84: Lowest level in 25 years, 235 ft
NOV. ‘84: 263 ft
280ft VRA security line
JULY 2010 Possible fall of level after climate change, 230 ft
NOV. 2010 Possible rise of level after climate change, 290 ft
average HIGH, 268 ftWATERLEVELS
0 km 1 km 2 km 3 km
0 km 1 km 2 km 3 km
Drawdownzone
Unsafearea
Permanently Submerged
Drawdown zone Unsafe areaPermanently Submerged
The water level in the Volta Lake is influEncEd by thE pREcipita-tion in the entire Volta BaSin.
Seasons cause a fluctuation in the watER lEVEl throughout the year.
A strip of land along the shore is pE-Riodically SuBmERgEd and ExpoSEd when the water recedes: the dRawdown zonE._1 Condition of the drawdown zone._2 Flow from the Volta basin_3 Precipitation at the Volta Lake
Communities SEttlE within close proximity of the Lakeside, BElow thE 280 ft contouR linE set as BoundaRy by the VRA, to max-imize the accESS to the drawdown zone and Volta Lake.
As a result of climatE changE, the rainfall pattern could become moRE ExtREmE, shifting towards a higher peak within a short period.
The consequence could be a laRgER dRawdown zonE, putting the dwellers near the Lake-shore at RiSk of flooding.
analysIs, case OF KpandO tOrKOr
The watER lEVEl in the Volta Lake.
120 M
MA
XM
INA
VE
RA
GE
_ 1
_ 2
_ 3
This creates a draWdoWn zone
WaterlevelsAverage. HIGH, 268 ft. LOW, 256 ft.JULy ‘84 lowest level in 25 years, 235 ftNOV. ‘90 highest level in 25 years, 275 ft280 ft VRA security line2010 Effect of climate change
cOnclUsIOn
productivity- The first settlers were attRactEd to the Lakeside, because of the potEntial the Lake offered for fiShing. - The agricultural practices increased when the potEntial of the nutrient rich soil in the dRawdown zonE was recognised.- But the REStRictionS of the VRa forced the practices into [small scale] infoRmality.- The majority of farmers depend on Rain-fEd agRicultuRE, threatening food SEcuRity.- iRRigatEd farming could introduce yEaR-Round farming, improving food security
connectivity- Position of settlements at the lakESidE and topogRaphy negatively influence the accessibility.- infoRmal nature of the settlements = lack of facilitiES.
sanitation & Waste- the lack of facilities poses a hEalth thREat
climate change- Lakeside dwellers are in danger of flooding.- Rain-fEd agriculture will be lESS REliaBlE.
locally presured landscape Vulnerable environment
Dense cluster of informal activities
& settlement
280 Ft contourlineVRA
Little say over land
District Assembly
Little means
Erosion
Sedimentation
Health
Water Supply
Climate Change
Food Insecurity
Flood Risk
Lakeside settlers
Pollution
Lack of Facilities
Drawdown Agriculture
Problematic Access
strateGy
[ land-structure / infra-scape ]
Vulnerable environment
Informal activities& settlement
280 Ft contourlineVRA
Little say over land
District Assembly
Little means
Health
Water Supply
Climate ChangeFood Security
Flood Risk
Lakeside settlers
Facilities
Drawdown Agriculture
ROAD
TOPOGRAPHy
Infrastructure
Incentive Planning
Irrigated Agriculture
Anti-ErosionMeasures
WaterHarvesting
restructured landscapeinfrastructureWhen landscape and infrastructure merge, they can REinfoRcE each other [Shannon, K. 2007].
incentive planningAfrican governments often have difficulties controlling development, leading to SpRawl. To regain control over development, incEntiVE planning can be used; A planning approach based on incentives stimulates private initiatives, instead of focusing on con-trol. This creates a bundle of initiatives & finances concentrated along roads and water connections [Duchhart, I. 2007].
interventions:- Road- potaBlE watER & Sanitation facilitiES- lighting & ElEctRicity- Social facilitiES
Drawdown Agriculture
RiverainWoodland
DrawdownZone
WaterCatchment
ExistingPontoon
WaterPurification
NewDwellers
Afforestation
Incentives
Afforestation
IrrigatedAgriculture
Agroforestry
ExistingMarket
Existing Settlement
Exisitingsprinklerirrigation
New road & pontoon
design lEgEnd
KM
010
2040
The uniform VRa policy is aBandonEd, and replaced by a landScapE BaSEd appRoach. - local diVERSity & potEntial - EnViRonmEntal SEnSitiVity - the actual level of dEgRadation of the riparian landscape around the Volta Lake.
StRatEgic locatEd SEttlEmEntS at the Lakeside are developed into cEntRalitiES.From here development can open up the hinterland. A nEtwoRk and fRamE-woRk is created within the riparian landscape of the Volta Lake, improving agriculture, access and trade.
desIGnregional strategy restructured landscape
280
ft
NO
V. 2
010
LOW
HIGHaverage
LOW
HIGHaverage
JULY
201
0
280
ft
NO
V. 2
010
JULY
201
0
300
ft
Kpando TokorVolta Lake
Kete Krachi
300
ft
0 km 1 km 2 km 3 km
0 km 1 km 2 km 3 km
Productive zone
ROADStructuring element in the riparian landscape
Fishing Spontaneous settlement triggered by Incentives
Productive zone
ROADstructuring element in the riparian landscape
Fishing Spontaneous settlement triggered by Incentives
01
25
10 K
M
Instead of attempting to stop devel-opment, the strategy tRiggERS dEVElopmEnt Via incEntiVE planning in other areas of the riparian landscape.
A [new] Road is used as a phySical StRuctuRing ElEmEnt in the riparian landscape, creating ViSual claRity in the spatial organization
All the other dESign pRin-ciplES and intERVEntionS are linkEd to thE main Road, striving to tRiggER SElfStEERing dEVElopmEnt.
The nEw Road positioned in the riparian landscape. pRoductiVE zoning and iRRigation poSSiBilitiES in the riparian landscape.
To adapt to the growing population, the level of agRicultuRal pRoduction should be raised. This is possible if the potEntial in the riparian landscape is used.
zonES are distinguished with differ-ent productive potentials, based on - Topography - Vulnerability for erosion- Water & nutrients availability
This results in three categories; Drawdown agriculture, Agro-forestry Afforestation
Respons to climatE changE, iRRigatEd faRming is introduced to ensure year-round farming. The water retention capacity of the landscape is increased by creating catchmEntS for the water from the perennial streams.
01
25
10 K
M
The Road is linked to the 300 ft contour line to StimulatE SEttlEmEntS to dEVElop higher up the slope, away fRom thE lakE. This will create a SafER Situation in times of extreme water level heights.
nEw Road Borehole improving environmental hygiene
Semi-paved road Mobola Plum Parinari Curatellifolia- Orientation & recognition- Micro climate: Shade
Start of sewage system
NOW
PHASE
desIGn INCENTIVE PLANNING
REStRuctuRing the resettled landscape
Fence to protect crops from cattle
Water from the Lake is used for irrigation
Vetiver Grass Anti-erosion
Impression of dRawdown agRicultuRE, with tREadlE pump.
Crops
Impression of agRo-foREStRy and intERcRopping.
Trees- Soil conservation Nitrogen fixiation Windbreak- Animal fodder Fire wood
CropsIntercropping mixMaize / Sorghum
5m1m
mens
0 m10
10
Dense linear hedges ofVetiveria Nigritana, Black vetivergrass
Rows of Acacia albida, Ana treeBorassus aethiopium, African fan palm
dRawdown agRicultuRE path agRofoREStRy
SEction of the transition, with anti-ERoSion mEaSuRES.
dEtail agRicultuRal plotS in dRawdown zonE and agRo-foREStRy.
1:1000Impression of crops planted on tERRacES.
CropsIrrigation channel Retaining wallAnti-erosion
0m10
10
RiVER iRRigatEd pRoduction fiEldS
SEction of the iRRigation SyStEm with tERRacES, created by REtaining wallS.
Riverain woodland along the channel protects the shores from erosion
Irrigation channels Terraces
dEtail tERRacEd iRRigation SyStEm connected to a watER catchmEnt.
The new road lays on a dike body, which functions as a barrier to contRol Runoff from perennial streams during the rainy season. The water is collected into a small RESERVoiR, making efficient use for irrigation possible, instead of flowing directly into the Lake. A SluicE SyStEm is used to control the water. When opened, the water runs through a pipeline underneath the road. It enters a sluice head diverting the water in either the direction of the Lake or towards the pRoductiVE fiEldS, using gravity.
A Road comBinEd with incEntiVES functions as a magnEt.
.1 The optimal location to attract people and tRiggER Small ScalE uRBan dEVElopmEnt is at an intERSEction with an existing road.2 On site, infRaStRuctuRE and BaSic facilitiES guide and support the development of a settlement. Roads, a sewage system and other utility lines are allocated in a lay-out that functions as a BaSE for the development. By providing this Spatial fRamEwoRk as a guide, the informal organization of the settlement is limited. This ensures that access roads are wide enough to accommodate walkways, lay-byes, drains and utility lines.
Public square
StaRt of incEntiVE planning, with the implementation of BaSic infRaStRuctuRE and facilitiES. Location suitable for incentive planning.
This flExiBlE method of planning allows people to settle SpontanEouSly and develop the settlement in their own way, while at the same time they are pREpaREd for development and a growing population.
1:1000The water catchment is located above the newly planned road, at the intER-SEction with a pEREnnial StREam, in a naturally low lying area.
.1
.2
Impression of SluicE SyStEm.
Manual sluice,guiding water towards the production fields.
Channeltowards the Lake
RiverainWoodland
Road
dRawdown agRicultuREThe potential for agriculture in the drawdown zone is exploited. To check erosion and sedimentation, the suitability of a location is assessed based on: - slope percentage, - flooding period, - presence of vegetation - degree of disturbance.agRo foREStRyOn the slightly higher parts of the slope, under less influence of the Lake water, cropland alternates with rows of differentkinds of irregularly planted trees.
Slope percentageless than 15%
plot SizE: Drawdown Agriculture 0.1 - 0.3 ha, Agro-Forestry 0.5 - 1 ha.Parts not used for production can be used as gRazing StRip foR cattlE.
Next to the new main roadAna tree, Acacia albida- Anti-erosion- Orientation - Shade
Spontaneous settlement
The new road is connected to a nearby village/city
Public facility- Community center - Health clinic etc.
Growing number of inhabitants. Evolution into urban settlement.
Gutter connected to waterpurification system
PHASE PHASE
thE nEw SEttlEmEnt in layERS
Topography
Sewer system
Birdseye view
Houses
Road system
cOnclUsIOn
Vetiver Grass Anti-erosion
EVokEd dEVElopmEnt. People are attracted to the higher location. uRBan dEVElopmEnt along the road, with a commERcial aREa.
Public facilities [orange] and spontaneous settlement [white], based on the spatial farmework.
Sewage water from the settlement is treated before being discharged into the landscape.
Trotro station andCommercial areawith storage facilities
Spontaneous, smallroadside marketwith stalls and shops
1:1000
Roads, a sewage system and other utility lines provide a Spatial fRamEwoRk for development.Sites are appointed to accommodate markets and lorry parks.
dEtail a new SEttlEmEnt resulting from incEntiVE planning. dEtail puRification pondS
Facultativeponds
0 m10
10
matuRation pond
SEction of the puRification pondS, connected to the SEwagE SyStEm.
Road
SanitationpuBlic toilEtSAt the start, toilet facilities are introduced. Commonly used in Ghana, a ‘10-seater’ can facilitate an average of 500 people.SEwagE SyStEmWealthier inhabitants can connect their water closet to the under-ground sewage system, created at the start of the development.watERhaRVEStingRainwater is used to flush the toilets with water. watER puRification SyStEm.The liquid waste can be treated with a purification system.
Fish breeding and small scale irrigation.
Solid waStE diSpoSal SitESolid waste can be collected in containers, placed on fixed locations in the settlement. They should be emptied regularly into a dump, at least 500 meters from the settlements.
facultatiVE pondS
Biochemical removal of faecal bacteria with algae in different steps
Road Connection tothe sewage system
Impression of watERpuRification pondS
Impression of SEttlEmEnt
1:1000
Road withundergroundsewage system Informal
meeting placeUrban agriculture
Electricity
Rainwater harvesting
Livestock
A StRatEgic, landScapE BaSEd StRatEgy is used to REStRuctuRE thE RipaRian landScapE around the Volta Lake.
topogRaphy [landscape] and Road [infrastructure] are mERgEd to create a StRuctuRing ElEmEnt in the land-scape. The development of private initiatives is concentrated along this nEtwoRk, using incEntiVE planning: social infrastructure and facilities. It is adaptive to climatE changE. Changes in the future are anticipated by creating a SafE settlement location.
The design is RESouRcE BaSEd, increasing pRoduction by making optimal use of agricultural potEntialS of the land-scape, while pRotEcting thE RESouRcES.