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8/11/2019 Evaluation of Urban Forestry and Housing Patterns in Awka Metropolis of Anambra State, Nigeria
1/17
Journal of Environment and Earth Science www.iiste.org
ISSN 2224-3216 !a"er# ISSN 222$-%&4' (nline#
)ol.4* No.14* 2%14
32
Evaluation of Urban Forestry and Housing Patterns in Awka
Metropolis of Anambra State, Nigeria
+,++* . /.* (0IENSI* E. +. EEN+JI* E. E.
e"artment of ,eogra"h5 and eteorolog5* 7acult5 of Environmental Sciences* Nnamdi +8i9iwe niversit5
+w9a* Nigeria.!. . 0. $%2$* +w9a* Nigeria.
Abstrat
:his stud5 evaluated ur;an forestr5 and housing "atterns in +w9a metro"olis of +nam;ra State in Nigeria* with
the aim of esta;lishing the trend of housing and ur;an forestr5 < ur;an greening in the stud5 area over a "eriod of
ten 5ears 2%%1-2%1%# and to suggest wa5s of im"roving ur;an agriculture for a ;etter environmental =ualit5 in
+w9a and other cities with high rate of develo"mental "ro>ects < ur;ani8ation. In other to esta;lish this trend* the
linear regression and correlation coefficient of the land use data over the time "eriod was calculated using the
conce"t of housing and ur;an forestr5 as a ;enchmar9. :he data anal5ses confirmed that there is a significant
correlation ;etween housing "attern ur;ani8ation# and the vegetal distri;ution of trees forestr5# in +w9a. +lso*
housing and ur;an forestr5 in +w9a metro"olis is s"atiall5 distri;uted in s"ace? as shown in the results from the
satellite imageries. :he result of the least s=uare regression showed that the rate of forest dis"lacement is as a
result of the increasing structural develo"ment in the stud5 area. :he wor9 thus concluded ;5 recommending the
ado"tion of some tree "lanting techni=ues among ur;an structures and the re"lacement of failed trees ;5 new one
to ;e underta9en ;5 the government* ur;an "lanners* land develo"ers* the communit5 and ever5 individual.
!"# $ntrodution
!"! %akground to Study
r;an forestr5 or ur;an greening is an integrated a""roach to the "lanting* care and management of all
vegetation in cities* towns* townshi"s and informal settlements in ur;an and "eri-ur;an areas. r;an greeningincludes the com"onents of ur;an forestr5* ur;an agriculture or "ermaculture and agroforstr5* shown in the
figure ;elow.
Fig. 1: Urban Agroforest
r;an forestr5 can ;e defined as an integrated a""roach to the "lanting* care and management of trees in ur;an
and "eri-ur;an areas of secure economic* environmental and social ;enefits for ur;an dwellers.r;an agriculture "roduces and mar9ets foods and fuel largel5 in res"onse to the dail5 demand of consumers
within a town* cit5 or metro"olis* on land and water dis"ensed throughout the ur;an and "eri-ur;an area.
!ermaculture is a sustaina;le form of agriculture highl5 a""ro"riate to ur;an areas* and com"rises a s5stem of
farming and gardening that com;ines "lants* animals* ;uildings* water* the landsca"e and "eo"le in a wa5 that
"roduces more energ5 than it uses.r;an agroforestr5 is the com;ination of agriculture and forestr5 on the same land with livestoc9 or cro""ing
enter"rises running underneath a regime of widel5 s"aced trees either simultaneousl5 or in se=uence.
+ll these com"onents can ;e a""lied to im"rove the =ualit5 of environments in the ur;an areas* generall5 in o"en
s"aces. r;an o"en s"ace management is not onl5 confined to "ar9s and roadsides ;ut includes household
gardens* factories* ;usiness areas* mine dum"s* transmission lines* flood "lains* ta@i ran9s* roofto"s* schools*
clinics and churches.r;an forest and trees contri;ute to a ;etter =ualit5 of living environment in cities* for e@am"le ;5 im"roving air
=ualit5 and conse=uentl5 the health of ur;an residents. :he leaves of trees can ta9e u" man5 "ollutants e.g.o8one* nitric acid va"our* nitrogen dio@ide* ammonia* sul"hurdio@ide and "articles aerosols and dust#. Some of
these "ollutants can cause serious health "ro;lems. :rees also "rovide valua;le shading from the sun. +n
Urban Agroforestry
UrbanForestry
UrbanAgriculture
8/11/2019 Evaluation of Urban Forestry and Housing Patterns in Awka Metropolis of Anambra State, Nigeria
2/17
Journal of Environment and Earth Science www.iiste.org
ISSN 2224-3216 !a"er# ISSN 222$-%&4' (nline#
)ol.4* No.14* 2%14
33
individual tree can "rovide a sun "rotection S!E# of 6 to 1%* which means a level of e@"osure to ultraviolet
radiation of one si@th to one-tenth of full sun N7 1&&.
05 offering an attractive environment for recreational activities* ur;an forest* ma5 seduce "eo"le with a
sedentar5 lifest5le to ;ecome more active during their leisure time. +ctivities such as recreational wal9ing and
c5cling alread5 have a "ositive effect on oneAs health. +shcroft 2%%2* ,rahn and Stigsdotter 2%%3#.
Just visuall5 e@"eriencing a natural sitting reduces stress* this stress relief is as measured through muscle tension;lood "ressure in green and non-forested environment lrich et al 1&&1#. oreover* viewing or visiting natural
environments com"ared to ;uilt ur;an environments without natural elements after stressful or mentall5 fatigued
situations* "roduces greater "h5siological changes toward rela@ation and faster recover5 of attention-demanding
cognitive "erformances !arsons et al 1&&'#. Besearch has shown that even =uite ordinar5 ur;an green areas
have a stress-reducing influence in ever5da5 life. In Sweden* ,rahn and Stigsdotter 2%%3# demonstrated that the
more often one visit to green areas the less often one re"orts sic9ness from stress.
+ utch research confirmed that the relationshi" ;etween the amount of green s"ace in the living environment
and self-re"orted health is "ositive* even after controlling for relevant socio-demogra"hic and socio-economiccharacteristics e )ries et al 2%%%#.
In "articular* forest edges* which are man5 in ur;an settings* are essential for human aesthetic e@"erience and
visual "erce"tion. + well-designed edge consists of mi@ture of ;ush and tree s"ecies* which have not onl5
aesthetic ;ut also ecological im"ortance Cucas 1&&1#.
r;an greening has /limatic Engineering effects* Ecological 0enefits and enhances +ir Dualit5. If green s"acesand trees are wides"read in ur;an areas* it will "rovide an effective means to im"rove air conditions locall5 and
"rovide shelter from ultraviolet radiation. Nowa9 et al 2%%2#. + recent large-scale stud5 in the est idland
region of England estimated the overall removal rates of air "ollutants ;5 the ur;an forest to ;e nota;le. Stewart
et al 2%%1#. :he availa;le data suggests that "lanting additional trees on land theoreticall5 availa;le for this
"ur"ose could lead to a significant reduction in concentrations of air;orne "articles in the est idlands once
these trees have matured. !lanting of all availa;le land could achieve a reduction of u" to 2% of small air;orne
"articles.
r;an forestr5 moderates and modifies the climatic characteristics of the ur;an areasF one of the "rimar5 causes
of this modification is that in the "rocess of ur;ani8ation* vegetated land surfaces are converted into concrete and
as"halt surfaces Both* 2%%2#. :he tem"erature difference ;etween air a;ove concrete runwa5s and ad>acent
grass can ;e as much as 4%/. :his is due to the reflectivit5 al;edo# differences ;etween the surfaces !omerant8
et al 2%%%#. ar9 "avement materials can store more heat than natural surfaces and lighter-coloured materials
oulas et al* 2%%4? S5nnefa et al* 2%%6#. :rees have considera;le a""lications in the develo"ment of ;etter
ur;an livelihoods and environments. :hese comfort and other ;enefits can ;e affected negativel5 ;5
unfavoura;le human activities e.g. ;ush ;urning* deforestation* use of to@ic chemicals or fertili8ers for various
agricultural "ur"oses and the "aving of the natural environment etc.
5drogra"hs show how ur;ani8ation increases the "ea9 flow intensit5 and =uantit5 during rainfall events. r;an
forests and trees can reduce surface runoff and thus alleviate the strain from the ur;an sewage s5stem and
dam"en "ea9 flows of streams. :he main wa5s that individual trees reduce runoff are ;5F
:he interce"tion of "reci"itation* which is stored and
8/11/2019 Evaluation of Urban Forestry and Housing Patterns in Awka Metropolis of Anambra State, Nigeria
3/17
Journal of Environment and Earth Science www.iiste.org
ISSN 2224-3216 !a"er# ISSN 222$-%&4' (nline#
)ol.4* No.14* 2%14
34
:o ;e "recise* ur;an agriculture is an im"ortant as"ect of the ur;an econom5 and the =ualit5 of life in ur;an
areas. It thus ;ecomes "aramount to evaluate the im"acts of housing develo"ment on ur;an forestr5 in +w9a*
where ur;ani8ation is at its "ea9 now.
!"& Aim and 'b(etives
:he main aim of this stud5 is to esta;lish the trend of housing and ur;an forestr5 < ur;an greening in the stud5
area over a "eriod of ten 5ears 2%%1-2%1%# and to suggest wa5s of im"roving ur;an agriculture for a ;etterenvironmental =ualit5 in +w9a and other cities with high rate of develo"mental "ro>ects < ur;ani8ation. :o
achieve this aim* the following o;>ectives were "ursued?
I. to assess the locational "attern and "ercentage distri;ution of ur;an structures in +w9a*II. to assess the locational "attern and "ercentage distri;ution of ur;an forests and trees in +w9a
metro"olis*
III. to assess the s"atial relationshi" ;etween ur;an structures and ur;an forests and trees in +w9ametro"olis and
I). to assess the changes ;rought a;out ;5 the ra"id ur;ani8ation on ur;an forest and trees in the stud5 area.!") *ESEA*+H HP'-HES$S
oF :here is no significant correlation ;etween housing "attern and the vegetal distri;ution of trees in +w9a.
1? there is a significant correlation ;etween housing "attern and the vegetal distri;ution of trees in +w9a.
!". S+'PE 'F -HE S-U/
:he stud5 was focused on the housing and ur;an forestr5 in +w9a metro"olis* targeting to ma" out theforested
8/11/2019 Evaluation of Urban Forestry and Housing Patterns in Awka Metropolis of Anambra State, Nigeria
4/17
Journal of Environment and Earth Science www.iiste.org
ISSN 2224-3216 !a"er# ISSN 222$-%&4' (nline#
)ol.4* No.14* 2%14
3$
+w9a is "redominantl5 a low l5ing region on the western "lain of the anu Biver with all "arts at 333 meters
a;ove sea level.
+w9a has rainforest vegetation with two seasonal climatic conditions. :he5 are the rain5 season and the dr5
season which is characteri8ed ;5
8/11/2019 Evaluation of Urban Forestry and Housing Patterns in Awka Metropolis of Anambra State, Nigeria
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Journal of Environment and Earth Science www.iiste.org
ISSN 2224-3216 !a"er# ISSN 222$-%&4' (nline#
)ol.4* No.14* 2%14
36
there has ;een even less research that investigates ;e5ond the initial distri;ution of trees to consider issues of
reforestation i""erer et al* 1&&%#.
&"& ME-H'/'1'4
:he following data are considered necessar5 for the e@ecution of the researchF
a. :he locational "attern and "ercentage distri;ution of ur;an structures in the stud5 area.
;. :he locational "attern and "ercentage distri;ution of ur;an vegetation in the stud5 area.c. Cand use dataoving over a long interval of time 2%%1 - 2%1%# trend of the time series which refers to the general dimension
in which the time series i.e. the changes in the =uantitative values of the "henomena through time# was used to
descri;e whether there is a significant decrease in ur;an forestr5 due to ur;ani8ation.
In order to find the trend* the linear regression and correlation coefficient of the land use data over the time
"eriod was calculated. :he regression anal5sis "rovides an estimating e=uation which e@"resses the functional
relationshi" ;etween the varia;les housing and ur;an forestr5#. :he visual re"resentation of their relationshi"
was shown in a scatter gram* with forestr5 and housing on the 5-a@is and the 5ear on the @-a@is res"ectivel5. :hee=uation used to e@"ress their linear relationshi" is 9nown as the least s=uare regression thusF
M a ;@
here* a is the interce"t
; is the gradient of the line
OaA and O;A were determined using the following formulas res"ectivel5.
b = xy (x) (y)
n
x2 (x)2
n
a = x - (y) . b
n n
where* @ is the housing and 5 is the rainfall amount and n is the num;er of o;servations.
:he correlation coefficient r# measures the strength magnitude# and directional of the trend. It is e@"ressed as
r = xy (x) (y)
n
x2 (x)2- y2 (y)2
n n
In order to determine whether the correlation coefficient value is statisticall5 significant* the student OtA test was
em"lo5ed using &$ level of confidence thusF
t = r n 2
1 r2
)"! P*ESEN-A-$'N 'F *ESU1-S
)"!"! Assessing t5e loational pattern and perentage distribution of urban strutures in t5e study area
:his was o;tained from two sourcesF the varia;le data from a secondar5 source the National ,eological Surve5#and from the researcherAs fieldwor9. ere* a 1%5ear data on the research varia;les were collected.
8/11/2019 Evaluation of Urban Forestry and Housing Patterns in Awka Metropolis of Anambra State, Nigeria
6/17
Journal of Environment and Earth Science www.iiste.org
ISSN 2224-3216 !a"er# ISSN 222$-%&4' (nline#
)ol.4* No.14* 2%14
3
-able .6 Perentage land use distribution for 5ousing and urban forestry in Awka metropolis
ear *esidential
Administr
ative
$ndustry and
+ommere
Hortiu
lture
Agriu
lture
't5er
7egetation
-otal
89:
#! 2' %.3 6 1$. 43 !##
#& 2' & %.3 $.& 1$.1 41. !##
#) 3% 1% 1 $ 1$ 3& !##
#. 3% 1% %.' $.$ 14.2 3&.$ !##
#0 31 1% 1 6.$ 13.$ 3' !##
#; 31 11 1. $ 14.3 3 !##
#< 31.$ 12.$ 2.$ $.$ 14.$ 33.$ !##
#= 32 13 3 $ 13.$ 33.$ !##
#> 34 14 3 $ 14 3% !##
!# 3$ 1$ 3 6 14 2 !##
-otal )!#"0 !!!"0 !;"; 00". !.)"= );&"& !###
!ource: "ationa #eoogica !ur$ey
7rom which the individual data of each varia;le was e@tracted and then the "ercentage distri;ution of the su;-
varia;les residential* administrative and industr5 and commerce# of each "henomena was gotten ;5 summing
the su;-varia;les under the ur;an concrete structures and finding the "ercentage. :hen a""l5ing the final result
to the satellite imager5 to access the visual dis"la5 of the stud5 area with this* an anal5sis is made to access thelocational "attern which was determined to ;e s"atiall5 distri;uted in s"ace.
-able 06 Perentage distribution of urban 5ousing strutures in Awka
ear *esidential Administrative
$ndustry and
+ommere
-otal
89:
#! 2' %.3 )0")
#& 2' & %.3 ) 34 14 3 0!
!# 3$ 1$ 3 0)
-otal )!#"0 !!!"0 !;"; .)=";
!ource: %esearcher&s work.
)"!"& Assessing t5e loational pattern and perentage distribution of urban forest and trees in t5e studyareas
:his is similar to what was done for the ur;an structures a;ove. It also entails e@tracting the numerical varia;les
for ur;an forest and trees from the 1% 5ear data gotten from the National ,eoha8ards and then calculating the
"ercentage distri;ution of the su;-varia;les of ur;an forestr5 orticulture* agriculture and other vegetation#.
8/11/2019 Evaluation of Urban Forestry and Housing Patterns in Awka Metropolis of Anambra State, Nigeria
7/17
Journal of Environment and Earth Science www.iiste.org
ISSN 2224-3216 !a"er# ISSN 222$-%&4' (nline#
)ol.4* No.14* 2%14
3'
-able ;6 Perentage distribution of urban forestry in Awka
ear Hortiulture Agriulture 't5er 7egetation -otal 89:
#! 6 1$. 43 ;."
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