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Biophysical Conditions and Land Use Methods Contributing to Watershed Degradation in Makueni County, Kenya

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Land use changes, rapid population growth, poverty, climate change variability and lack of livelihoods diversification aggravate watershed degradation through inappropriate land use methods resulting to water scarcity, land and water pollution, and governance issues. Soil erosion and siltation has led to land denudation, habitat loss and farm lands losing their soil fertility and compromising food security. The purpose of this study was to find out how land use methods influenced the biophysical and socioeconomic conditions to accelerate watershed degradation and their effects on livelihoods in Makueni County, Kenya. The study investigated the land use methods practiced and how they affect the biophysical conditions influencing watershed degradation in Makueni County. The study used a descriptive survey research approach to obtain data on socioeconomic characteristics of the study sites as well as historical trends of land use. Remote sensing and GIS was used to determine land use categories in the study area. Structured and semi-structured questionnaires were used to collect data from the community and key informants. The data collected was analysed using Statistical Package for Social Sciences (SPSS) and Microsoft Excel 2010. The study established that decline of ground water 90% (S.E=0.602 z=-0.725 sig.=0.468), increase in surface runoff 55% (S.E=0.314 z=0.394 sig.=0.693), increase in soil erosion 86% (S.E=0.660 z=-1.875 sig.=0.061), changes in rainfall and temperatures 75% (S.E=0.374 z=-0.547 sig.=0.585), decline in soil fertility 70% (S.E=0.362 z=-1.370 sig.=0.171) and drying of rivers 37% (S.E=0.398 z=1.739 sig.=0.082), contributed to watershed degradation. This predisposed farmers to adopt inappropriate farming methods and unsustainable livelihood strategies which compromised the watershed's environmental integrity. The study made recommendations for efficient watershed management.
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Biophysical Conditions and Land Use Methods Contributing to Watershed
Degradation in Makueni County, Kenya
Kieti RN1*, Kauti MK1 and Kisangau DP2
1School of Environment and Natural Resources Management, South Eastern Kenya University (SEKU), Kitui, Kenya
2School of Pure and Applied Sciences, South Eastern Kenya University (SEKU), Kitui, Kenya
*Corresponding author: Kieti RN, School of Environment and Natural Resources Management, South Eastern Kenya University (SEKU), Kitui, Kenya, Tel: +254 736
116989; E-mail: Kietiraphael66@gmail.com
Received Date: September 28, 2016; Accepted Date: November 04, 2016; Published Date: November 07, 2016
Copyright: © 2016 Kieti RN, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted
use, distribution, and reproduction in any medium, provided the original author and source are credited.
Abstract
Land use changes, rapid population growth, poverty, climate change variability and lack of livelihoods
diversification aggravate watershed degradation through inappropriate land use methods resulting to water scarcity,
land and water pollution, and governance issues. Soil erosion and siltation has led to land denudation, habitat loss
and farm lands losing their soil fertility and compromising food security. The purpose of this study was to find out
how land use methods influenced the biophysical and socio-economic conditions to accelerate watershed
degradation and their effects on livelihoods in Makueni County, Kenya. The study investigated the land use methods
practiced and how they affect the biophysical conditions influencing watershed degradation in Makueni County. The
study used a descriptive survey research approach to obtain data on socio-economic characteristics of the study
sites as well as historical trends of land use. Remote sensing and GIS was used to determine land use categories in
the study area. Structured and semi- structured questionnaires were used to collect data from the community and
key informants. The data collected was analysed using Statistical Package for Social Sciences (SPSS) and
Microsoft Excel 2010. The study established that decline of ground water 90% (S.E=0.602 z=-0.725 sig.=0.468),
increase in surface run-off 55% (S.E=0.314 z=0.394 sig.=0.693), increase in soil erosion 86% (S.E=0.660 z=-1.875
sig.=0.061), changes in rainfall and temperatures 75% (S.E=0.374 z=-0.547 sig.=0.585), decline in soil fertility 70%
(S.E=0.362 z=-1.370 sig.=0.171) and drying of rivers 37% (S.E=0.398 z=1.739 sig.=0.082), contributed to watershed
degradation. This predisposed farmers to adopt inappropriate farming methods and unsustainable livelihood
strategies which compromised the watershed’s environmental integrity. The study made recommendations for
efficient watershed management.
Keywords: Land use changes; Watershed degradation; Watershed
management
Introduction
Land/watershed degradation is a global problem, with adverse
eects on the functionality of watersheds which provide essential
goods and services to local communities and national economies
which rely on them for their livelihood outcomes [1]. Human activities
and particularly accelerated soil erosion rates are the main cause of
land degradation. It contributes to alteration of watersheds, leading to
decrease in agricultural productivity as well as all the other natural
ecosystems, loss of soil fertility compromising farmer’s income and
watershed’s environmental integrity [2-4]. e African continent is
faced with the unparalleled environmental degradation with about
70% of its population being rural, directly depending on land and
natural environment for its livelihoods and wellbeing [5]. Rapid
population growth, poverty and social inequities contribute to
watershed degradation [6,7]. e African savanna landscapes provide
economic and ecological services sustaining livelihoods, now
threatened by the twin problems of soil erosion and decrease of
vegetation cover and depletion of wood land cover [8]. In Kenya and
Makueni County, the situation is exacerbated by rapid population
growth, high poverty levels, land use changes/ poor land use systems
and deforestation (increase of farm lands and exploitation of existing
forests for charcoal burning, fuel wood, medicinal herbs construction
materials and fodder), leading to food crises and land/watershed
degradation [9-11].
Soil erosion and siltation has led to land denudation, habitat loss
and farm lands losing their soil fertility and compromising food
security. Farmers tend to intensify agricultural activities in perceived
fertile areas, oen in fragile ecosystems. In the absence of robust soil
and water conservation, the challenges of soil erosion increase, leading
to soil detachment and increased run-o on soil surface [4,8,12]. Land
form changes owing to infrastructure development in form of roads,
oen create new landscape factors which change soil properties from
the additional drainage culverts in road and other infrastructural
projects [13]. is new development increases both on-site and o-site
disturbances of the ecosystems. ese changes impact negatively on
the biophysical and socio-economic arrangements of the environment
in the County [14-16]. e declining soil fertility, poverty,
deforestation, diminishing land holdings and erratic rainfall patterns
contribute to watersheds degradation [17]. e study’s main objective
was to investigate the land use methods practiced and how they aect
the biophysical conditions inuencing watershed degradation.
Land/watershed degradation is more than soil erosion [18]; it makes
consideration to all interactions on land with users leading to any kind
of degradation. e natural processes (biophysical), human activities
(socio-economic systems) and the poverty nexus exacerbate watershed
degradation in Makueni County. It is caused by both human and
natural processes. It is important to make distinction between human
Journal of Ecosystem & Ecography Kieti et al., J Ecosys Ecograph 2016, 6:4
DOI: 10.4172/2157-7625.1000216
Research Article OMICS International
J Ecosys Ecograph, an open access journal
ISSN: 2157-7625
Volume 6 • Issue 4 • 1000216
induced degradation and that is caused by climate change which land
users have no control over. According to Barbier et al. [7] land
degradation is linked to food insecurity and vulnerability to climate
change as well as poverty, which impacts negatively on farmers
livelihoods and land management practices. It is also important to note
that land/watershed degradation is a social problem aecting all the
people at all stages of development not only as a causative factor but
also as victims of these actions [18]. As poverty increases, people tend
to overexploit land resources further increasing degradation [12,19].
Land use ultimately varies on the type of crops planted, size of plot per
land use type, land management and cropping systems. Land quality in
man modied ecosystems degrades over time, aecting the ability of
the same ecosystem to deliver the goods and services intended. It also
leads to loss of biodiversity and decline in crop productivity [19].
Farmers’ awareness on the importance of proper land management
and SWC practices as well as recognition that human activities and soil
erosion are drivers to the current degradation is an important step
towards sustainable exploitation and utilisation of land resources [12].
Support of diversication of rural livelihoods and entrenchment of
local ecological knowledge and social values [20] in holistic approach
to land management oers the best solution to solve these problems.
e increase of vegetation covers in farmlands and grazing lands
[12,18,21], for both indigenous and exotic trees, will eventually
increase livelihoods resilience for farmers and environmental integrity.
e intensication of agricultural extension services to farmers ensures
that there is sustainable development and regeneration of crop and
grazing lands for the benet of the current and future generations of
farmers in the fast changing dynamics owing to climate change and
reducing farmlands. e aim of the study was therefore to understand
the bio-physical conditions and land use methods contributing to
watershed degradation in Makueni county.
Materials and Methods
e study area
e general study area lies within Makueni watershed (Figure 1) of
the larger Athi water basin. e semi-arid areas of Makueni County
found in the Chyulu-Athi River catchment areas within Athi
catchment area in Kenya’s water sub-catchment of 3F or drainage area
3 in the Lower Midland (LM) zones extending over elevation of
800-1300 m, with annual average rainfall of 400-1000 mm [16,22]. LM
4 is a marginal cotton zone with fair to poor conditions for cotton and
maize, fair for pigeon peas and good for sisal. LM 5 is lower midland
livestock and millet zone with natural pastures able to support low
density grazing [23]. e main rivers that drain the catchment include
Athi, Kiboko, Kibwezi and Masongaleni which are perennial
tributaries. e ephemeral tributaries include wake, Kaiti, Muooni,
Kikuu, avu, Kambu and Mtito-Andei rivers. All these rivers traverse
the county from West to East and drain into the Athi River which
forms the Makueni-Kitui counties boundary in the East [16,22].
e county’s rainfall distribution is bimodal received in two rain
seasons. e short rain season is between November and December
and the long rain season between March and April. e upper hilly
parts of Mbooni and Kilungu hills receive an average of 800-1200 mm
of rainfall per annum; while the drier southern low lying areas receive
an average of 300-400 mm per annum. e mean rainfall in the two
seasons range between 200-350 mm (half of the annual precipitation)
largely inuenced by the altitude among other factors, which is mostly
depressed, barely enough to sustain the major staple food crops of
maize and beans grown in the county [10]. e agro-ecological
conditions in the area support agricultural activities predominantly
comprised of rain fed agriculture, crop and livestock production which
dominates land use and household livelihoods in small-scale
subsistence farming [10,23]. Rapid population growth, deforestation,
diminishing land holdings, erratic rainfall patterns and conict in
water use are among the factors considered to inuence watershed
degradation in the study area [10,17,22].
Figure 1: Makueni County’s sub-watersheds: Source, PAFRI [24].
e study was done in Kaiti sub-watershed, which lies in the upper
area of the county, characterized by high population and density of
120,116 and 248 persons per square kilometer respectively as
compared to the average of 110 persons per square kilometer for the
county [10]. According to Muriuki [17], high population has a bearing
on the state of the watershed due to the increasing human activities
and their eects on the wellbeing of the downstream communities in
the county. Soil erosion in the sub-watershed is a major problem due to
farming on steep slopes with siltation of manmade reservoirs
experienced in the downstream of Kaiti River. Data was collected
between the months of June-August, 2015 using household survey,
Focus group Discussion and key informant questionnaires.
Kaiti sub-watershed, covers an area of 660 km2 and is located
between 10º 38 South and 10º 51´ South and 37°14´ East and 37°41´
East. Kaiti sub-watershed (Figure 2) shows the specic study site in
Makueni County. It lies in the fertile upper parts of the county which
experience average rainfall of 800 mm-1200 mm. It comprises of
Kilungu, Kee, Kalama, Kaiti and Wote divisions. e sub-watershed
topography is characterized by mountainous terrain including Kilungu
and Mbooni hills. Kaiti River and its numerous tributaries originating
from the hills serve the watershed which inuence surface water
sources and ground water recharge capacity [17].
Citation: Kieti RN, Kauti MK, Kisangau DP (2016) Biophysical Conditions and Land Use Methods Contributing to Watershed Degradation in
Makueni County, Kenya. J Ecosys Ecograph 6: 216. doi:10.4172/2157-7625.1000216
Page 2 of 8
J Ecosys Ecograph, an open access journal
ISSN: 2157-7625
Volume 6 • Issue 4 • 1000216
Figure 2: Map of Kaiti sub-watershed: Source: PAFRI [24].
Data collection
e study used a descriptive survey research design [25]. Both
qualitative and quantitative methods were used to gather and evaluate
primary and secondary data from the eld and past studies/reports
respectively. e study used multiple methods such as eld/household
surveys, community maps, observations, Focus Group Discussant
interviews (FGDs), and key informant/experts interviews) to gather
information and sampling of households along the vertical and
horizontal transect lines. It also used triangulation which is a form of
cross-checking and the use of multiple methods both qualitative
(inquiry) and quantitative (validation) methods in studying the same
phenomenon for the purpose of increasing study credibility [26]. e
study used multistage probability sampling methods [27] to sample
locations and community respondents. Kaiti sub-watershed was
purposively selected for investigation based on its population
distribution, density and varied physical characteristics [10,17]. Line
transect approach [19] was used as part of the sampling framework
traversing much of the ecological, socio-economic/land uses and
environmental variability in the study site. Random point samples
along the transect line were used to sample respondents to obtain
information. e sampling was based on spatial organization of
interests of the community respondents [28]. In this case agro-
pastoralism, as a major economic activity among the community
respondents was considered in the sampling of households and focus
discussion groups. e study survey targeted 101 respondents, drawn
from farmers, community groups’ respondents and key informant
categories.
e questionnaires were administered to respondents sampled
systematically along a vertical transect line running from East to West
direction, traversing the watershed along the general ow of river Kaiti.
e study used a variety of methods to gather information.
Quantitative methods using a standardized open and closed
questionnaire was administered to farmers to obtain information at
household level on land uses and farmers perception on land use
changes. e Qualitative methods involved Focus groups (Focus
Group Discussions), involving both men and women because they
have dierent perceptions on environmental changes, land/watershed
degradation and livelihoods strategies and dynamics [29,30]. Key
informants were also used in the study because of their expert opinion
and experience on the ground, to give information on their perception
of the watershed degradation in the study area. Geographic
Information System (GIS) and Remote Sensing were used to determine
major land use categories in the study area [19,31]. Fieen farmers
aged above 60 years were purposively sampled to obtain information
about their perception on environmental changes and how the changes
aect their livelihoods and the general trends on watershed
degradation. ese farmers were sampled on top of the 36 households
interviewed because the scope of the study was intended to capture
changes over a period of 40 years, hence the need to have a sample of
elderly respondents.
ree divisions Kilungu, Kaiti and Wote, which fall within the
general delineated boundaries of Kaiti sub-watershed, were selected for
sampling of the respondents. Kilungu division represented the
upstream communities, Kaiti division the midstream and Wote the
downstream communities of the sub-watershed. Fiy one respondents
were interviewed in each of the 3 divisions. irty respondents for
focus discussion groups were interviewed in Kaiti division where GPS
spatial maps were generated for in-depth study of the sub watershed.
e 20 key informant respondents were drawn from among people
with technical expertise in the divisions and from the county
headquarters.
Data analysis
Data collected was managed and analysed using Statistical Package
for Social Sciences (SPSS), version 19 and Microso excel 2010.
Descriptive tools like percentages and frequencies were presented in
bar graphs and pie charts.
Results and Discussions
Bio-physical conditions and watershed degradation
Biophysical conditions and land use methods inuence watershed
degradation owing to both natural and anthropogenic factors [19], as
people continue to interact with the environment for their livelihood
strategies. e study established that bio-physical changes have
occurred in Kaiti sub-watershed (Table 1).
Bio-physical changes Ecological zone No. and %
Wote Kaiti Kilungu Kaiti sub watershed
No. % No. % No. % No. %
Decline of ground water 13 76 16 95 17 100 46 90
Increase in surface run off 17 100 3 18 8 47 28 55
Citation: Kieti RN, Kauti MK, Kisangau DP (2016) Biophysical Conditions and Land Use Methods Contributing to Watershed Degradation in
Makueni County, Kenya. J Ecosys Ecograph 6: 216. doi:10.4172/2157-7625.1000216
Page 3 of 8
J Ecosys Ecograph, an open access journal
ISSN: 2157-7625
Volume 6 • Issue 4 • 1000216
Sedimentation of rivers and water pans 5 29 2 12 - - 7 14
Increase in soil erosion 15 88 14 82 15 88 44 86
Pollution of rivers 5 29 2 12 - - 7 14
Drying of rivers 9 53 4 24 6 35 19 37
Changes in rainfall/temperatures 10 59 12 71 16 94 38 75
Decline in soil fertility 14 82 7 41 15 88 36 70
Reduction of forest /vegetation cover 15 88 14 82 13 76 42 82
Table 1: Bio-physical changes in Makueni watershed (N=51).
e study’ established that the age, gender and education levels of
the household heads were critical in understanding and explaining the
biophysical conditions in Kaiti sub-watershed and their inuence on
watershed degradation (Table 2). Increase in men as household heads
(S.E=0.076 z=-1.013 sig.=0.737) indicated, that they had better
knowledge and awareness on the biophysical conditions than women
(S.E=0.104 z=0.169 sig.=0.866). e more years the household head
had in education (S.E=0.174 z=0.347 sig.=0.183), the more they
understood the biophysical changes happening in Kaiti sub-watershed.
Farmers were able to identify decline of ground water 90% (S.E=0.602
z=-0.725 sig.=0.468), increase in surface run-o 55% (S.E=0.314
z=0.394 sig.=0.693), increase in soil erosion 86% (S.E=0.660 z=-1.875
sig.=0.061), changes in rainfall and temperatures 75% (S.E=0.374
z=-0.547 sig.=0.585), decline in soil fertility 70% (S.E=0.362 z=-1.370
sig.=0.171) and drying of rivers 37% (S.E=0.398 z=1.739 sig.=0.082),
which were signicant at 10%. ese factors were deemed to cause
biophysical changes, which contribute to watershed degradation in the
area.
Parameter Estimates Std. Error z-score Significance
Age of household head male -0.025 0.076 -0.336 0.737
Age of household head female 0.018 0.104 0.169 0.866
Education level of household head 0.060 0.174 0.347 0.728
Decline of ground water 0.0-0.437 0.602 -0.725 0.468
Increase in surface run-off 0.124 0.314 0.394 0.693
Sedimentation of rivers 0.006 0.575 -0.010 0.992
Increase in soil erosion -1.238 0.660 -1.875 0.061
Pollution of rivers -0.761 0.491 -1.548 0.122
Drying of rivers 0.693 0.398 1.739 0.082
Changes in rainfall and Temps. -0.204 0.374 -547 0.585
Decline in soil fertility -0.495 0.362 -1.370 0.171
Note: Significance level of 10%
Table 2: Logistic regression results for Land use eects and Biophysical changes (parameter estimates).
It was clear that reduction of forest and vegetation cover due to
farming and grazing activities has led to increase in soil erosion and
reduction of soil fertility [21], which has impacted negatively on crop
and livestock production, and the livelihood strategies [32]. is was
more pronounced in Wote and Kaiti Divisions which have less
aorestation eorts as compared to Kilungu in the upper watershed.
Degradation and depletion of riparian vegetation and ecosystem has
contributed to adverse changes with riverbeds becoming drier leading
to loss of important biodiversity like Phragmites plant species and
animal/bird habitats [11], a trend fairly observed in all the rivers/
streams in the study area.
e decline of ground water 95% and 100% respectively and drying
up of rivers and streams were mentioned in the mid and the upper
watershed area. Water scarcity is more pronounced now in Kilungu
were respondents reported streams and springs to have dried up
forcing them to trek long distances in search of water. is contrasted
with the past where they conrmed water was found to be plenty and
common in the streams and ridges. Everything has changed to the
worse, because, where as they were using the water to plant vegetables
and arrow roots in the past, they have completely abandoned growing
of some of these food crops. is can be attributed to climate change
eects and rainfall variability, noted in the last couple of decades
Citation: Kieti RN, Kauti MK, Kisangau DP (2016) Biophysical Conditions and Land Use Methods Contributing to Watershed Degradation in
Makueni County, Kenya. J Ecosys Ecograph 6: 216. doi:10.4172/2157-7625.1000216
Page 4 of 8
J Ecosys Ecograph, an open access journal
ISSN: 2157-7625
Volume 6 • Issue 4 • 1000216
[30,32]. e entire watershed faced similar problems as most of the
respondents could identify water scarcity as a problem on the increase.
is state of events then explains why despite farmer’s willingness to
use irrigation farming, only 4% of the respondents in the watershed
reported to have been currently involved in micro-irrigation farming.
e decline of ground water and fast drying of riverbeds (37%) were
mentioned as the greatest impediment to sustainable agriculture and
addressing of the perennial food insecurity in the area.
ese ndings support previous work done by Muia et al. [21]; land
uses and human (anthropogenic) factors highly inuence watershed
degradation in the study area, because the majority of the people
directly depend on the environment for their livelihood outcomes and
survival [32]. Unsustainable utilisation and extraction of natural
resources were identied in the form of unsuitable livelihood strategies
like charcoal burning, timber harvesting and sand harvesting in the
absence of robust livelihood opportunities and diversication options
for the communities [10,32]. Farmers account and key informants
indicated that the local community contributes to watershed
degradation i.e., (poor quality terraces and non-maintenance), as
attested by the increase in soil erosion 86% mentioned by farmers. e
other factors include non- adherence to land use/management policies
in relation to implementation of various development programmes
was also contributing to the problems of degradation in the watershed.
e widespread watershed degradation owing to biophysical
changes is attested in the rills, gullies, sedimentation in rivers,
particularly in the mid and downstream area. ere are barren/bare
grounds, soil deposits in gentle slopes, vegetation change,
accumulation of soil deposit around vegetation clusters and increased
run-o [14,21]. e scenario signies increased land/watershed
degradation, depletion of soil nutrients [17] whose ramications can
only lead to decline of food production/yields, loss of exibility in land
management as large swathes of land become unproductive and
possible diversion of resources to expensive rehabilitation eorts, in an
already cost laden agricultural sector [10]. Reduction of forest/
vegetation cover exposes the soil to water erosion [21], leading to the
decline of soil fertility and loss of arable land, a trend with connections
of the bio-physical conditions obtaining in the watershed. is can
largely be attributed to both natural causes and human activities.
However anthropogenic factors outweigh the former, due to increased
agricultural activities in the watershed.
Land use and watershed degradation
e study revealed that land use changes have occurred in the study
area, with rapid changes as a result of farming and development
activities [14]. e main land use changes identied (Table 3), included
subsistence crops (croplands and grazing lands), human settlements/
institutions, forest/vegetation cover and infrastructure development
such as roads and water masses (earth dams).
e main land use categories identied were comprised of built up
areas, homesteads, schools, road infrastructure and shopping/market
centres and urban areas. Others included herbaceous crops, tree or
shrub, crops, forests and wetlands (Figure 3). Some physical structures
like homesteads, schools road infrastructure, shopping centres and
other institutions were easily identied from satellite images and were
easy to locate and determine. Changes in land terrain and depletion of
riverine vegetation were observed in the study area. However rills,
erosion trends in the farms as well as dierentiation between
indigenous and exotic forests were dicult to make in the farm lots
along the farm edges and boundaries. is is despite the fact that there
are increased agro- forestry eorts in individual farms, across the
watershed.
Land uses Ecological zone No. and %
Wote Kaiti Kilungu Kaiti sub
watershed
No. % No. % No. % No. %
Farming 17 100 15 88 17 100 49 96
Grazing 15 88 14 82 11 65 40 78
Forest and vegetation
cover
10 41 10 59 13 76 30 59
Human settlement 5 29 3 18 10 59 18 35
Infrastructure
development
6 35 3 18 9 53 18 35
Horticulture 2 12 3 18 2 12 7 14
Table 3: Main land use in Makueni.
Figure 3: Land use categories.
Infrastructure development (i.e., roads, schools and earth dams) has
also contributed to land/water degradation in the watershed.
Infrastructure development has considerably increased in the recent
years in form of roads, schools and earth dams [10,29]. ere is neglect
of maintenance of the rural roads which inuence formation of gullies,
crossing over to grazing land and ridges in the upper hilly areas
causing large tracts of land to be denuded. In some cases soil/water
erosion action happens in far places from the roads infrastructure sites.
is has impacted negatively on farms and grazing lands as well as
increasing sedimentation in rivers downstream. e other major land
use changes noticed to have occurred in the study area were the
expansion of cultivation from the higher elevation to the mid and in
the lower elevation zones. is trend intensied from the opening of
Makueni settlement scheme in 1948 onwards [14,23], which was
basically a low lying and densely vegetated grassland. e newly
introduced farming activities, included crop/livestock production,
where food crops like maize, beans, cow peas, pigeon peas and green
grams occupy the greatest percentage of crop production. ese crops
are grown by nearly all farmers with the intensity of legumes
Citation: Kieti RN, Kauti MK, Kisangau DP (2016) Biophysical Conditions and Land Use Methods Contributing to Watershed Degradation in
Makueni County, Kenya. J Ecosys Ecograph 6: 216. doi:10.4172/2157-7625.1000216
Page 5 of 8
J Ecosys Ecograph, an open access journal
ISSN: 2157-7625
Volume 6 • Issue 4 • 1000216
preference depending on the ecological zone, and mostly concentrated
in the mid and upper watershed areas.
Soil and water conservation in form of terraces were also examined
in the watershed area. By use of satellite imaging, terracing structures
in the area was found to be widespread in the area. Historical
perspectives on soil and water conservation approaches, farmers and
agricultural extension workers account was also used to understand
the extent of adoption of terracing technologies in the study area. In
the 1950s and 1960s decades, farmers testied that land was plenty as
there were still new areas where people could migrate and ease
pressure on land. Shiing cultivation, crop rotation, fallow cropping
and intensive soil and water conservation were commonly practiced
due to availability of land and the farmers’ perceived protability in
crop production and livestock production. Population pressure and
unavailability of more new settlement areas, farm sizes decreased
considerably with fragmentation of the farms increasing at higher rates
to absolve the growing population [32,33].
is led to more land being used for settlement and establishment of
homesteads, agricultural land expansion accelerated, encroaching to
fragile ecosystems, clearing of forests/vegetation cover to increase food
production [17]. e decline of Soil and Water Management
conservation measures led to increased soil erosion and soil fertility
decline. e sustained practices of overgrazing in the low lands over
the decades also increased land/watershed degradation as
demonstrated in the cattle paths along road reserves and farm
demarcation paths. Rills and gullies are commonly evident in many
areas [21]. Farmers have also contributed to this problem by fencing
o and encroaching on road and pathway reserves. In some instances
such roads/pathways have been completely eroded to be unmotorable.
Farmers and key informants indicated that quality terracing has
declined in the recent past with by-laws/agricultural rules on river
bank encroachment not strictly followed and enforced as was the case
in the past [14]. Steep slopes were increasingly being cultivated without
adequate soil conservation measures. Population pressure was fairly
mentioned to have led to clearing of forests, bushes and depletion of
natural vegetation cover to increase crop production for food needs in
the families. Land fragmentation to accommodate young generation
and subdivision of land has contributed to watershed degradation in
the area, with majority of new farms increasingly being used without
proper and adequate conservation measures (terraces) increasingly
encroaching into fragile ecosystems. Generally from eld verication,
observation, satellite images and account of agricultural extension
personnel in the area, terracing structures in the area remain intact as
depicted by this account (Figure 4). However, most of them are in a
state of disrepair, generally neglected and not regularly maintained as
required. In the absence of adequate agricultural extension services in
the last 3 decades, some of the recent constructed terraces are not laid
to contour; aggravating soil and water erosion. Most of the old farmers
interviewed were in agreement, that they beneted immensely from
the conservation technologies when the government was actively
involved in SWC methods in the past.
e ndings of this study are in agreement with previous studies by
14. Tien et al. [14]; Onyango et al. [30]; Ifejika et al. [32] on the
importance of Self Help Groups (SHG) in conservation (terracing)
work in the past. However, currently the ``mwethya’’ group concept
(Figure 5) of SWC has declined in the area with intermittent revival by
NGOs supporting food for work programmes like German Agro-
Action (GAA) and World vision. eir eorts in terracing have
considerably declined because the NGOs operate in limited areas to
have watershed wide impact.
Figure 4: Terracing structures in the study area as depicted by
Google earth satellite image January, 2015.
Figure 5: Activities of ``mwethya’’ groups (self Help Groups) in the
study area.
e respondents indicated that currently welfare and merry go
round activities at 75% were the primary purposes and activities of the
current ``Mwethya’’ groups. Environmental conservation (27%), soil
conservation (22%) and water conservation (14%) were the other
activities of these groups. However they depended much on NGOs
activities and presence, with most of the activities concentrated in
welfare, tree nursery establishment for environmental conservation
[30]. Most of these NGOs implemented short term programmes to
enable sustained action in watershed management, and widespread soil
and water conservation in individual farms.
e absence of proper maintenance of terrace structures, sheet and
rill erosion in terraced farms has developed and was visible in the
farms with neglected conservation structures. Gully formation is
common along the edges of farm boundaries, cattle tracks and
Pathways/roads in the area. is has considerably increased land/water
degradation in the watershed with bare land and gullies seen in open
grazing lands in the lower watershed area and the parched and bare/
scanty vegetated landscapes common in the eastern parts of Kilungu
hills in the upper catchment area. Lack of proper terraces is thus a
further threat to the bio-physical conditions of the watershed as
depicted by the decline of the quality of terraces.
Citation: Kieti RN, Kauti MK, Kisangau DP (2016) Biophysical Conditions and Land Use Methods Contributing to Watershed Degradation in
Makueni County, Kenya. J Ecosys Ecograph 6: 216. doi:10.4172/2157-7625.1000216
Page 6 of 8
J Ecosys Ecograph, an open access journal
ISSN: 2157-7625
Volume 6 • Issue 4 • 1000216
Farmers’ perceptions on land use and environmental changes
e study attempted to understand farmers’ perception on land use
and environmental changes which have occurred in the watershed as a
result of bio-physical changes and land use methods (Figure 6).
Farmers’ perception in land uses and environmental change
indicated that they considered cultivation in fragile ecosystems (30%),
reduction of forests/vegetation cover (32%), introduction of cash crops
and exotic trees as some of the important land use changes in the
watershed [17]. e other factors mentioned by the farmers were
decline of SWC measures 26%, climate change and rainfall variability
deemed to have contributed to watershed degradation Land use
changes and biophysical changes in the watershed were found to have
occurred with negative impact, variously aecting agricultural
activities. Crop/livestock production was found to be on the decline in
the area. Land sizes have decreased, soil erosion has increased and
natural soil fertility is declining owing to land use and biophysical
changes [14,21]. ese changes have led to the decline of land
productivity, with majority of farmers acknowledging the increasing
food insecurity threats in the watershed.
Figure 6: Land use and biophysical changes contributing to
watershed degradation.
High value fruit crops like mangoes, citrus, avocado and vegetable
growing (14%) are also considered as a major land use change [10,30]
in the area, with many farmers now embracing their growing, with
dierent levels of success. e farmers indicated that fruit tree farming
gives them incentive for soil erosion conservation in form of terracing
to increase water retention for their fruit tree management [14,34].
e introduction of exotic tree species (59%) like
Grevillea robusta
and
Eucalyptus Spp
. were mentioned by farmers as another major land
use change with evidence of these trees grown along farm edges and in
the homesteads and public places like schools and other government/
community institutions [17]. eir preference however has
continuously replaced the natural vegetation and tree species. In some
cases, these trees are planted along riverbanks which may consequently
lead to environmental changes with increased cases of drying up of
rivers in the area. e farmers were aware of the negative eects but
they preferred them due to their fast rate of maturity, timber products
and as a major source of fuel woods in the face of depleted natural
shrubs/vegetation which used to be an important fuel woods energy
sources in the past.
Conclusion
e study revealed that bio-physical changes have occurred in the
watershed, owing to both natural and anthropogenic causes.
Population changes/ growth and increase in poverty inuences land
use and bio-physical changes, which have signicantly contributed to
watershed degradation. Land uses/methods such as subsistence crop
farming, human settlement and infrastructure development (roads,
schools and earth dams); have over the years increased in the area with
varied degree of watershed degradation inuences especially in the
road sub sector in the rural landscape causing serious secondary
erosion in the hilly areas. Forests, bushes, riverine ecosystems and
wetlands were other notable land use categories observed in the
watershed. Cash crop farming and exotic trees planting were a major
land use observed in the area.
e decline of SWC measures and terracing in the face of declining
agricultural extension services and inadequate government support
and funding of SWC programmes has impacted negatively in the
watersheds environmental integrity. Poor land use methods,
inappropriate agricultural technologies and high cost of agricultural
inputs have considerably slowed and compromised terraces
development in the area. e trend threatens the biophysical
conditions in the watershed with further degradation due to poor
quality terracing. To understand the scope of the problem, it is
important to take into account the drivers of these bio-physical
changes and farmersperception on them and their impacts. Farmers
clearly understood the changes occurring in the area over the years like
terracing (its peak and decline), cash crops farming and exotic tree
species introduction which positively impacted on their lives. Fruit tree
farming and agricultural intensication has been on the rise in the
recent past. ese changes continue to inuence land use and
biophysical changes in the watershed. Farmers also acknowledged their
individual actions and land management decisions contributed to
watershed degradation.
is study conrms that population change has a bearing on land
use and biophysical changes in the area. However, the limited nature
and scope of the study cannot rule out inherent gaps and recommends
that further investigations on the matter should be undertaken to
conclusively determine the extent of the dynamics of population
change and the present situation in the area, where land sizes have
considerably declined in the absence of more new lands to absolve the
growing population and robust agricultural extension services.
Acknowledgement
e authors acknowledge all the respondents who actively and
willingly participated in providing the much needed information
during the study. We also thank Makueni County Government and
Non-Governmental organizations’ ocials who provided required
information especially as key informants during the study.
Authors’ Contribution
Author 1’ designed the study, performed the statistical analysis,
wrote the protocol, and wrote the rst dra of the manuscript and
managed the literature searches. ‘Author 2’ and ‘Author 3’ managed the
analyses of the study. All authors read and approved the nal
manuscript.
Citation: Kieti RN, Kauti MK, Kisangau DP (2016) Biophysical Conditions and Land Use Methods Contributing to Watershed Degradation in
Makueni County, Kenya. J Ecosys Ecograph 6: 216. doi:10.4172/2157-7625.1000216
Page 7 of 8
J Ecosys Ecograph, an open access journal
ISSN: 2157-7625
Volume 6 • Issue 4 • 1000216
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Citation: Kieti RN, Kauti MK, Kisangau DP (2016) Biophysical Conditions and Land Use Methods Contributing to Watershed Degradation in
Makueni County, Kenya. J Ecosys Ecograph 6: 216. doi:10.4172/2157-7625.1000216
Page 8 of 8
J Ecosys Ecograph, an open access journal
ISSN: 2157-7625
Volume 6 • Issue 4 • 1000216
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