Waters, Vol. 2, Issue 1, Dec  2019, Pages 1-24; DOI: 10.31058/j.water.2019.11001 10.31058/j.water.2019.11001

Assessment of Residential Water Demand and Spatial Distribution in Cities in the West African Sahel: Jalingo, Taraba State, Nigeria in Perspective

, Vol. 2, Issue 1, Dec  2019, Pages 1-24.

DOI: 10.31058/j.water.2019.11001

Joshua Ma’Aku Mark 1,2 , Ojeh Vincent Nduka 1* , Olajire Olabanji 2

1 Department of Geography, Taraba State University, Jalingo, Nigeria

2 African Regional Centre for Space Science and Technology-in-English and Centre for Space Research Applications, Federal University of Technology, Akure, Nigeria

Received: 21 October 2018; Accepted: 25 February 2019; Published: 4 April 2019

Abstract

In the face of a growing demand for portable water catalyzed by population and rapid urbanization, there exist a precarious imbalance between water availability and accessibility by the populace. This study seeks to assess residential water demand and distribution as it relates to urban population change in Jalingo, Taraba State Mapping of the existing water supply network was achieved through Geo-referencing and digitization of scanned map obtained from Jalingo Water Agency; Landsat image of 1986, 2001 and 2016 were used for land use land cover classification and change detection analysis adopted to provide insight into spatio-temporal variation in urban extent; population data obtained from National Population Commission was used to analyze population trend  and density analysis; using simple regression analysis, the relationship between urban population change and water demand was established; and weighted overlay analysis (WOA) which incorporated elevation and the various land use and cover classes was adopted to identify suitable areas for siting proposed buffer stations and new service areas for water supply facilities within the study area. The results reveal that the population of Jalingo stands 159,950 with a growth rate of 3.2% coupled with spatial variation in density ranging from 10-80 people per km2 both in the core and peripheral areas. Using built-up area as an indicator of urban change, the associated urban expansion rate from 1986 to 2016 stands at 23%. The increase in population also correlated strongly with water demand (p-value<0.05) and indicates that water demand may outweigh supply at the current coverage of water distribution facilities. Furthermore, demand was projected to be about 7.9 billion cubic meters by 2031.  These therefore creates the need for optimization which proposed more buffer stations and facility expansion with a view to enhancing sustainable planning and management of residential water consumption and distribution in the study area.

Keywords

Residential Water Demand, Spatial Distribution of Water, West African Sahel, Weighted overlay Analysis, Population, Jalingo, Nigeria

1. Introduction

Water is one of the most precious gifts of nature. It is very crucial for sustaining life and is required in almost all the activities of mankind. A few of the uses of water include;domestic and industrial use, irrigation to meet the growing food and fiber needs, power generation, navigation, recreation etc. and also required for animal consumption [1]. Water is essential for human existence requiring extensive management, particularly in urban areas where supplies and infrastructure must meet the needs of a heterogeneous and growing population. As population grows in urban areas, ensuring a long-term, safe and reliable source of potable water becomes essential [2].

In time past, predicting the intermediate- and long-term evolution of the demand for water was thus not a major concern for managers of drinking water utilities. Water was viewed as an inexpensive commodity, and developing excess capacity was considered a much better option than risking a shortage. This tactic worked well – as long as economic and population growth continued and water resources were readily available [3]. The scenario is different in recent times due to dynamism experienced in human population so much that total population in the planet is estimated to be more than 7 billion people [4].

Global water demand is largely influenced by population growth, urbanization, food and energy security policies, and macro-economic processes such as trade globalization and changing consumption patterns [5]. As reported by Population Action International [6], per capita water availability is projected to fall by half by 2050;the situation is likely to be dire in the coming years. Projections show that by 2035, 3.6 billion people will be living in areas with water stress or scarcity, as population growth causes more countries and regions to become water scarce. The path of future population growth will impact water stress and scarcity. This challenge is further compounded by the fact that the majority of the world’s population growth in the next 40 years will be absorbed by urban areas, particularly in less developed regions [7].

In explaining and rationalizing this global developmental issue, a World Bank Report in 2000 and another one from the International Monetary Fund in 2006, had indicated that about 66 percent of the world’s population lived in the countryside in the early 1950s;however, current estimate by the United Nations has put the world population at 6.572 billion people, of which 3 billion (about 50%) now live within the urban areas, and by 2030, about 61 percent of the world population is projected to live in the cities;and this growth is expected to occur mainly in developing countries [8];[9];[10];[11]. Following from the above argument, achieving the goal 6 of the SDGs for Africa by 2030 may be daunting in the face of a changing climate.

Furthermore, Jekinson [12] reported that water use has been growing at more than twice the rate of population increases in the last century. In many parts of the Globe, population growth and urbanization are increasingly becoming challenges to Governments. Currently, more than 80 countries, with 40% of the global population suffer from severe water shortages [10]. The gap between water demand and water supply is growing as global water demand will grow at an accelerated rate from 4,500 billion miters cubed to 6,900 billion cubes by 2030 [13]. Whereas water availability is shrinking due to competing demands from agriculture, mining, and industry and from deteriorating water quality and climate change (World Bank-IUWM) [14]. The recent water shortage in 2015-2017 occurred mainly because rainfall was low according to Wolski [15].

Water distribution system, hydraulic infrastructure consisting of elements such as pipes, tanks, reservoirs, pumps and valves etc. is crucial to provide water to the consumers. Elements of a distribution system include distribution mains, arterial mains, storage reservoirs and system accessories (valves, hydrants, mainline meters, service connections, and backflow preventers). Distribution mains are the pipelines that make up the distribution system. Their function is to carry water from the water source or treatment works to users [16];[1]. However, it has been observed that ineffective water supply and demand management, operational inadequacies improperly weaken and physical infrastructure in many urban areas compounds the water demand/supply debacle. As the pressure to fill the gap in water and sanitation access grows, emphasis is beyond simply planning for basic water access but focuses on continuous water supply. Thus, the municipal water sector in recent years has been subjected to a process of constant changes [17].

The ability to accurately forecast water demand is an integral part of water utility planning for water production levels and the associated finances [18]. The factors influencing water consumption is complex, making demand forecasting challenging. This will likely entail some degree of demand-side policy interventions and changes to current consumption patterns. While such changes can be crucial for the long-term sustainability of the water sector and the welfare of the society depending on it, they can also temporarily impose undesirable burdens on some parts of society [19].All human beings require at least 3 - 6 liters of water per day to survive [20] but in order to sustain a minimum acceptable standard of living, 20 - 25 liters of safe water are required each day for cooking, drinking, personal hygiene, laundering, cleaning and other domestic activities [21]. The WHO minimum requirement is 40 liters per capita per day for all rural areas [22]. Forty liters of water is therefore a basic need for all households;but greater quantities of water are normal goods and eventually become luxury goods. It is pertinent to note that at least 1.8 million children less than five years old die every year due to water related disease, accounting for around 17 per cent of deaths in this age group. Worldwide, some 2.2 million people die each year from diarrheal disease. Poor hygiene and unsafe water are responsible for around 88 per cent of all diarrheal incidents [23].

Globally, more people live in urban areas than in rural areas, with 54 percent of the world population residing in urban areas in 2014, and by 2050, 66% of the world’s population is projected to be urban. The world is undergoing the largest wave of urban growth in history. More than half of the world’s population now lives in towns and cities [24]. Growth in population is a major contributor to water scarcity [6]. Water resources in many parts of the world are pushed to their natural limits because of population growth and economic development.

Water is the finite resource that enables life and fuels all human activities. The volume of water used by individuals is directly related to various human attributes such as age, education, cultural background, religious beliefs, and financial status [25]. Today, one third of the world population is currently leaving in countries with medium to high water stress;by 2025 because of the rapid growth in population, two out of three of the world population will live in countries with same condition of medium to high water stress [6]. A recent report by Koop [26] warns that within two decades, water demand will exceed supply by 40 percent. Population growth is a major contributor to water scarcity. Growth in populations is mounting demand and competition for water for domestic, industrial, and municipal uses [9].

Jalingo the Taraba State capital since creation in 1991, has witnessed population growth as a result of migration to the urban area for a drive towards obtaining meaningful and comfortable leaving which also come with its positive and negative impact on the environment. in a bid to draw relationships and analyze trends of urban water consumption, several variables such as population growth, volumetric pricing and changes in consumption patterns have been considered by the works of Dalhuisen [27] and Grafton [28] as key determinants of water utilization and consumption in cities whereas less focus has been on the role of urban density changes as predictors of water consumption and utilization in cities.

Although, several studies have focused on water distribution and demand in isolation but little has been done in the areas of forecasting water consumption taking into cognizance joint parameters of distribution, demand and urban density. This study tends to assess the residential water demand and distribution in Jalingo city as relates to population density. The Taraba State water agency is facing the challenge of finding ways to use its increasingly scarce resources in a sustainable manner with the increasing population in Jalingo the State Capital. It is on this basis that the following questions come to mind as:what is the nature of pipe used for water distribution in Jalingo? What is the rate of urban population change and water demand/supply in Jalingo? Is there any risk of water shortage in the near future?The introduction of your article is organized as a funnel that begins with a definition of why the experiment is being performed and ends with a specific statement of your research approach. And it highlights controversial and diverging hypotheses when necessary.

The study is hinged on the Urban Water Cycle Model. One of the most fundamental concepts of hydrology and indeed in the water resource management is the hydrologic cycle which has been speculated on since ancient times [29]. There is some diversity of definitions of hydrologic cycle, but generally it is defined as a conceptual model describing the storage and circulation of water between the different spheres of the environment [30]. Water can be stored between oceans, lakes, rivers, streams, soil, glacier, ground water aquifers and atmosphere. The flux of water among this storage compartments is orchestrated by processes such as evapo-transpiration, condensation, precipitation, infiltration, percolation, snow melt run off which are also referred to as water cycle components.

The combined effects of urbanization, industrialization and population growth affects natural landscapes and hydrological response of watersheds. Though the key components remain intact, hydrologic cycle becomes more complex in urban areas as it is modified by urbanization impacts on the environment and the need to provide water services to the urban population including water supply, waste water management, drainage and beneficial uses of receiving waters. Hence, the resulting urban hydrological cycle is then referred to as urban water cycle [31];[32]. Sowby [33] simplifies the various components that comprise the ever-complex urban water cycle as shown in ( Figure 1 ).

Figure 1. Showing Urban Water Cycle [33].

Sowby (2014) explains the key components illustrated in Figure 2 as follows:

Source:Many freshwater sources in the environment can be traced to geological and meteorological processes. The choice of a water source depends on several factors, including quality, usability, availability, proximity, socio-economic and legal issues.

Water Treatment:To enhance usability and quality of water for distribution and human use, raw water must be passed through treatment process to remove contaminants and pathogens. The water treatment process may vary due to various factors such as locations, technology of the plant, the water it needs to process and the end usage but the basic principles are largely the same.

Water Distribution:Water distribution systems include pumping stations, distribution storage and distribution piping. The hydraulic performance of each component depends upon the performance of the others. The bridge between water supply and demand by consumers is the distribution system. While much of this infrastructure is buried and invisible, it is of great importance that the distribution network enhances accessibility to water resources when and where it is needed for consumption.

Use:This represents the need for water from the consumer’s standpoint. Water customers use the supplied water for various purposes. Industries use water for manufacturing and cleaning whereas homes utilize water for drinking and domestic purposes.

Wastewater Collection:While urban water distribution has its origin from the suppliers with destination point being the customers, conversely, waste water collection entails processes for channeling waste water from customers to treatment plants which is achieved usually by gravity, to a wastewater treatment facility through a network of increasingly large pipes.

Wastewater Treatment:After use, water quality has been degraded and requires treatment before it can be reintroduced into the environment. The wastewater generated by residences, businesses and industries in a community consists largely of water. It often contains less than 10% dissolved and suspended solid material [34]. Hence, waste water treatment is a critical phase towards achieving environmental sustainability in urban water management processes.

While this provides a good conceptual and unifying basis for studying water balance and conducting water inventories of urban areas, each component in the urban water cycle brings its own benefits and challenges, and understanding them is the first step to developing sustainable water solutions for our growing population.

2. Materials and Methods

2.1. Study Area

Jalingo lies between latitude 08° 43′N and 09° 07′N of the Equator and longitude 10° 50′E and 11° 25′E of the Greenwich meridian, covering an approximate land mass of 59,400 square kilometers ( Figure 2 ). The study area is bounded by three Local Government Areas, namely Lau to the North, Yorro to the East and Ardo-Kola to the South. The population of Jalingo as released by the National Population Commission (NPC) census exercise 2006 has the figure of 140,318 people with a projected growth rate of 3.2% annually.

Figure 2. Study Area.

Geologically, Jalingo Local Government Area (LGA) consists of sandstones of the Yolde formations which mark the transition from marine to continental sedimentation. In some areas there is an alternating sequence of shales, mudstones with minor sandstones. Jalingo LGA is located in the undifferentiated basement complex rock system. The outcrop of this rock could be seen in the heart of Jalingo town popularly referred to as the Jalingo hill. Quartz, mica and feldspar crystals (in fairly equal proportion) are some of the constituent minerals that make up this rock. This rock is overlain by sandy-loam soil characterized by hydromorphic and ferruginous soils derived from the parent materials [35].

The relief of Jalingo LGA consists of an undulating plain interspersed with mountain ranges. Between Kwaji-Mika to the east and Kona to the west, stretching to Kassa-Gongon to the south exist this compact mass of rock outcrops. The mountain ranges run from Kona area through the border between Jalingo and Lau LGAs down to Yorro and Ardo Kola LGAs in a circular form to Gongon area, thus given a periscopic semi-circle shape that is almost like a shield to Jalingo town. From any vantage point in Jalingo town, one can have a glimpse of these beautiful ranges looming in the background (Oruonye and Ahmed, 2016). Jalingo metropolis is drained by two rivers ( Figure 2 ), Mayogwoi and Lamurde which emptied their content into the Benue River system at Tau village which is dotted with ox-bow lakes. These were formed as a result of depositional activities of rivers Lamurde and Mayogwoi. The major fishing ponds in Jalingo LGA are Vendu-Nange, Vendu-Ginnaji, Jeka-Dafari, Wuro-Sembe, Vendu Jodi and Vendu-Lamurde. These ponds are rich in fish and other aquatic lives [36].

Jalingo LGA has tropical continental type of climate characterized by well-marked wet and dry season. The wet season usually begins around April and ends in October. The dry seasons begins in November and ends in March. The dry season is characterized by the prevalence of the northeast trade winds popularly known as the harmattan wind which is usually dry and dusty. Jalingo has a mean rainfall of about 1,200mm and annual mean temperature of about 29°C. Relative humidity ranges between 60 – 70 per cent during the wet season to about 35 – 45 per cent in the dry season. Jalingo is located within the northern guinea savanna zone characterized by grasses interspersed with tall trees and shrubs. Some of the trees include locust bean, shea-butter, eucalyptus, baobab and silk cotton tree.

Agriculture is the dominant economic activity practiced by the vast majority of the people in the area especially those settling along river Lamurde. Along the river plain, dry season farming is being practiced on annual basis. During the wet season, the plain is used for the cultivation of food crops such as maize, rice and guinea corn. Thus, the plain has been put into intensive use yearly. In addition to the cultivation of crops, the plain is being used as a grazing land since fresh grasses and harvested crop materials are available [37].

2.2. Methods of Data Collection

The data type used in this work was primary and secondary data. Table 1 provides details on the data used for the study.

Table 1. Data Characteristics and Sources.

S/N

Data Type

Source

Acquisition Year

Relevance

1

Landsat TM 30m resolution

Earthexplorerhttp://earthexplorer.usgs.gov

1986

For LULC classification and estimating the rate of urban expansion

2

Landsat ETM 30m resolution

Earthexplorerhttp://earthexplorer.usgs.gov

2000

For LULC classification and estimating the rate of urban expansion

3

Landsat OLI 30m resolution

Earthexplorerhttp://earthexplorer.usgs.gov

2016

For LULC classification and estimating the rate of urban expansion

4

GPS Coordinate

Fieldwork

2017

For spatial distribution of water buffer station

5

Administrative map of Taraba State

Office of the Surveyor General, Bureau for Land and Survey Jalingo

N/A

To delineate study Area

6

Population data

National population commission, Jalingo

1991 &2006

For population figure and projected rate of growth

7

Water distribution data &its network designed

Taraba water Agency, Jalingo

2006 to 2016

To ascertain the volume of water been distributed

8

Nigeria population density raster/DEM

www.diva-gis.org/gdata access on 10/04/2017

2016

For population density/elevation

Source:Authors’ Compilation

C:\Users\wujin\Desktop\3.png

Figure 3. Methodological Workflow chart of Water Demand and Distribution Analysis.

2.3. Methods of Data Analysis

The data analysis involved the mapping of the existing water supply network which was achieved the through scanning of the hard copy obtained from the Jalingo water Agency, Georeferencing and digitization. Landsat image of 1986, 2001 and 2016 were classified using maximum likelihood with a supervise classification approach to achieve land use land cover output of the study area. Population data of 2006 of the study area obtained from National population commission Jalingo was used to project population up to 2016. Water demand in the study area (i.e. the total consumption rate of the population) is given as a product of population per capital consumption and safety factor of 1.5. Digital elevation model was use to obtained the elevation of the study area and raster density map of the study area was used to obtained population density map of the study area. Simple regression analysis was used to obtain the relationship between population growth and water demand and in turn fit in for prediction and optimization. Figure 3 shows details of the workflow.

2.3.1. Image Classification

Employing bands 4 3 2 and 5 4 3, a Color composite was done on the acquired images which was further subjected to supervised classification using maximum likelihood approach. In order to gain insights into the land use and land cover dynamics as well as gains and losses over the study period, a supervised image classification using maximum likelihood approach was adopted. The classifier was adopted because of its effectiveness in land use and land cover classification which has been tested in many researches Mullerova, [38]; Guo et al., [39]. The classifier makes use of mean and covariance which helps to narrow the class values to close to accurate and precise values. The classification algorithm was used in conjunction with a pixel-based sample training technique on the image. This increased the functionality of the classifier by distinctively identifying each land use and cover class. A similar approach was adopted by Adepoju in 2007 [40];Ade and Afolabi in 2013 [41] to delineate land use land cover classes for rate of urban expansion in Benin and Ibadan respectively. However, three land use/cover classes were identified for the purpose of this study;namely built up area, vegetation and water body which was also cross examined through ground-truthing.

2.3.2. Change Detection Analysis

Changes in the rate of urban expansion that have occurred over the study period of 1986-2016 were analyzed through map comparison of coverage area of the different LULC classes. The extent of land use land cover over the study period was calculated as this gave insights to built-up area dynamics over time. Map differencing was also used in visualizing built up area dynamics over the study period. The built-up area extent served as a proxy for urban expansion. The results were presented in maps, charts and tables.

2.3.3. Relationship between Urban Population Change and Water Demand

Simple regression analysis was applied to ascertain the relationship between population change and water supply. This was chosen as the appropriate statistical tool on the grounds that the underlying assumptions fit the variables considered for the analysis. Moreover, apart from its correlation function and direction of relationship, the regression model also has predictive functionalities. This was necessary for forecasting demand depending on the strength of the relationship. Here, population changes represent the independent variable whereas water demands represent the dependent variable. The formula for simple regression is stated as follows:[42].

         (1)

         (2)

         (3)

Where

N=number of observations, of years;

X= annual urban Population change;

Y= Residential water demand per annum;

b = Slope

a = Intercept

2.4. Prediction of Future Population Growth and Optimize Water Supply

The regression model derived from the third objective computation is then adopted for forecasting demand by substituting with the appropriate parameters of population growth and change of demand. This was used for predicting water demand for Jalingo in the phase of growing population and urban growth. (i.e Y = a + bx, with Y = demand, b = slope of the line, a = Y intercept and x = population).

2.5. Weighted Overlay Analysis

Taking into cognizance the need to expand the water utility system to accommodate future population growth, Site suitability of the reservoirs was considered using Weighted Overlay Analysis (WOA). Weighted overlay is a type of suitability analysis that analyses site conditions based on multiple criteria. Weighted overlay analysis allows combination;weight and rank of several different types of information which when visualized can evaluate multiple factors at once. By identifying and rating areas based on criteria, opportunities, risks, and constraints in an area can be identified [43].

Weighted overlay analysis approach was adopted to produce suitability map for new suitable service areas for sitting water buffer stations.

In accomplishing this, first step was choice and ranking of criteria selected for this study were, elevation and Land use. The choice of elevation as key criteria was informed by interaction with the authorities who agreed that the mode of distribution is by gravity from elevated reservoirs. The choice of the criteria was however consistent with the works of Ibitoye [44] which adopted a similar approach for water supply optimization in Osogbo, Nigeria. The selected criteria were ranked as follows:

Table 2. Criteria for Weighted Overlay Analysis.

Criteria

Range/land use

Rank assigned

Elevation

168–215

1

215-289

2

289-497

3

Land Use/Land Cover Classes

Vegetation

3

Water body

1

Built-up

1

Percentage Ranking of Criteria

Elevation

70%

LULC

30%

3. Results and Discussion

This section show and discusses the results of the study.

3.1. Distribution of the existing Water Supply Pipe Network

Figure 4 show the digitized water distribution pipe network map of the study area. The digitized map shows the existing water pipelines in the study area. The map also shows the facilities attributed to the pipelines which include gate valves, fire hydrants, washout valves, junctions, air valves and tanks designed to enhance water distribution in the area. Also, the map shows the natural attributes of the study area which include the elevation of the area, depicted with contours and the river channels crisscrossing through the study area.

Figure 4. Showing the Water Distribution Pipe Network.

3.2. Water Supply and Network

Figure 5 shows the pipeline network used for water distribution in the study area with their distances covered and their diameters. It can be deduced that pipes with DN 90/75 covers a distance of about 10667m which makes them to have the second highest coverage in the area. Pipes of DN 100 and DN 200 covers distances of approximately 1853m and 9956m respectively;while pipes of DN 150 covers an approximate distance of 19090m making it to have the highest coverage in the study area.

Figure 5. Showing the Water Supply and Network.

3.3. Population Change and Associated Urban Expansion in the Study Area

Figure 6 and Figure 7 show the population growth per five years’ interval and the population density of the study area respectively. The chart shows that there exists a temporal change in population as it records significant increase considering the time interval, with 2016 having the highest number of human populations. From the density map, it could be deduced that areas between 0-10 (Pkantinapo, Kona Garu) have the lowest population, while the areas between 10-20 (Jauro and voto), 20-30 (Nasarawo), 30-40 (Lasandi, Abuja) and 40-50 (Sabon gari, Jeka-dafari, Sintali, Mile six, Nukkai, and Ungwan gadi) show different levels of population density within the study area respectively. The highest population agglomeration is recorded within Magami and Mayogwoi localities which possess a density of 50-60. Apparently, the recorded increase in population will however impinge on the demand for water resources at residential level and therefore spells the need for water supply enhancement and distribution network optimization to meet the need of the teeming urban population.

Table 3. Population and Water Demand.

Years

Population

Demand (m3)

1991

17772

2666400

1996

46207

6931050

2001

76642

11496300

2006

103078

15461700

2011

131513

19726950

2016

159950

23992500

A trend analysis ( Figure 6 ) was ran to observe water demand in the study area in relation to population change and was plotted to provide an insight into the temporal trend between population growth and water demand. Table 3 is the product of the population trend and water demand in the study area for the period of 1991 to 2016. The result agrees with the recent findings of Oumar and Tewari [45] which warned that within two decades, water demand will exceed supply by 40 percent. Also, the United State Geological Survey (USGS) circulars, 1980 to 2005 which stated that an Increased in population and Urban growth will give rise to growing water demand. The said reports can be seen to be already taking place in the study area, whereby, the figure review that water demand is growing at an average of 41.3% above population growth in the study area.

Figure 6. Showing the Trend Analysis of Population and Water Demand.

Figure 7. Showing the Population Density.

Figure 6 shows the trend of water demand and population growth. As at 1991, due to low population in the study area, water demand was relatively low as it stood at 25000m3. Within a span of five years, in 1996 as population figures approached 50,000 people, water demand rose to above 80000m3. As clearly seen in the chart, this trend is continuously on the increase. In year 2016, the rise in urban population to about 159978 was in accompanied by a rise in water demand which recorded over 249000m3. This is in tandem with United Nations report of 1996 in assessing freshwater of the world which revealed that water use has been growing at more than twice the rate of population increases during this century [24].

Consistent upon the findings of several studies, the migration of people from rural to urban areas in the search of “greener pasture” and “cleaner jobs” has become a double edge sword to developing economies. The rural-urban migration inflicts serious demographic, social and economic consequences to both the exit and destination points of migrants. On their destination spot, it creates congestion and amplifies the need for extension and creation of more drinking water supply coverage [45];[46].

3.4. Determining the Relationship between Urban Population and Water Demand

Table 4. statistical regression analysis.

REGRESSION STATISTICS

Multiple R

1

R Square

1

Adjusted R Square

1

Standard Error

205.9909

Observations

6

Deducing from the Table 4 the results reflect that R2 (correlation coefficient) = 1.

This implies a strong positive correlation between the population (predictor variable) and the demand for water (predicted variable). At a confidence level of 95%, the p-value = 0.00 <0.05. This affirms the significance of the relationship between population growth and water demand in Jalingo. After substituting the values of the intercept, slope and population projection for the year 2031 water demand was forecasted as 7,909,559,677m3.

Table 5. ANOVA.

Df

SS

MS

F

Significance F

Regression

1

3.17E+14

3.17E+14

7.47E+09

1.07E-19

Residual

4

169729

42432.25

Total

5

3.17E+14

Coefficients

Standard Error

t Stat

P-value

Lower 95%

Upper 95%

Lower 95.0%

Upper 95.0%

Intercept

371.1443

176.122

2.107314

0.102801

-117.849

860.1373

-117.849

860.1373

Population

149.997

0.001735

86455.33

1.07E-19

149.9921

150.0018

149.9921

150.0018

The results obtained therein gives in-depth clarification of the earlier discussed findings as it shows a positive relationship between the two variables. In concurrence with Malthusian theory, it supports the view point that population increase impacts on the rate of water resource utilization. This also points to the fact that though the present supply may be sufficient, demand may outweigh supply in the nearest future. This will be catalyzed by determinants of rapid population change and urban dynamism.

3.5. Change in Urban Expansion of Jalingo

It can be deduced from the maps that in 1986, built-up areas occupied an area of about 2%, water body occupied about 1%, while vegetation occupied 97% ( Figure 8 . (a)). In 2000, the built-up increased and covered an area of about 8%;water body remained at 1%, while vegetation decreased to about 91% ( Figure 8 . (b)). The pressure on water distribution has been increased due to increase in built-up areas. This will increasingly make the addition of new pipelines a paramount necessity. In 2016, built-up areas increased to cover an approximately 15% of the study area, while water body increased to 2% and vegetation decreased to about 83% ( Figure 8 . (c)). Here, addition of new water pipelines has become paramount because built-up areas have increased and will continue increasing at a tremendous rate.

C:\Users\user\Desktop\FOLDERS\thesis results\1986.png

C:\Users\user\Desktop\FOLDERS\thesis results\2000.png

a

b

C:\Users\user\Desktop\FOLDERS\thesis results\2016.png

c

d

e

f

Figure 8. (a), (b), (c), Showing the LULC of 1986, 2000, 2016 and (d), (e), (f) showing LULC Pie Chart of 1986, 2000, 2016 respectively.

Figure 9. Showing LULC Buildup Changes from 1986-2016.

Figure 9 shows the built-up locations and the areas they cover from 1986-2016;while Figure 10 and Figure 11 show the rate of changes overtime experienced by the three features of interest:built-up, vegetation and water body from 1986 to 2016.

Figure 10. LULC Changes from 1986-2000.

Figure 11. LULC Changes from 2000-2016.

Table 6. Area and amount of change in different land use/cover categories in the study area during the period of 1986 to 2016.

Land use/cover categories

1986 Km2 %

2000 Km2 %

2016 Km2 %

Change1986-2000Km2

Change

2000-2016

Km2

Build – up

3.144

2

13.745

8

28.288

15

10.61

10

14.53

23

Water body

1.694

1

1.965

1

2.898

2

0.27

2

0.93

3

Vegetation

176.837

97

165.955

91

150.489

83

-10.88

6

-15.47

13

Total

181.675

100

181.665

100

181.675

100

0.00

0.00

Table 6 depicts the spatio-temporal pattern of land use/cover of Jalingo for the years 1986, 2000 and 2016. These data reveal that in 1986, 2% (3.144 km2) area of Jalingo was build-up, similarly, water body constitute 1% (1.694 km2) while about 97% (176.837 km2) was under vegetation cover. In the year 2000, 8% (13.745km2) was build-up;water body maintained 1% (1.965km2) and a vegetation cover of 91% (165.955km2). The year 2016 experience a rapid expansion as build-up rose to 15% (28.288km2), water body at 2% (2.898km2) and vegetation decreased to 83% (150.489km2). From the perspective of gains and losses, the results reveal that other land cover has been transitioning to built-up area where urban expansion is the major contributor to land change in the area.

It can be deduced from this trend of urban expansion that between 1986 and year 2000, Jalingo experience 10% (10.61km2) urban growth, and 23% (14.53km2) between 2000 and 2016. This trend indicates there is a high demand for water as stated by United Nations World Water Development report [47] which reveals that Global water demand is largely influenced by population growth and urbanization.

A similar study by Grafton et al, [48] points to the alarming rates of urban expansion as a major determinant of volumetric consumption and pressure on existing distribution network. This further unfolds the pertinence of expansion in water distribution facilities coverage taking into cognizance the parameter of urban expansion.

3.6. Water Distribution Optimization

In other to accommodate change in population and water demand, Site suitability of the reservoirs was considered using Weighted Overlay Analysis (WOA). This in turn review possible site for new buffer stations based on elevation as can be seen in Figure 12 .

C:\Users\user\Desktop\FOLDERS\thesis results\dem.png

Figure 12. Showing the Elevation.

Figure 13. Showing the site suitability for buffer stations.

Figure 12 shows the elevation characteristics of the study area which is a very important criterion for selecting suitable sites to place the proposed new buffer stations, while Figure 13 shows the best suitable sites for the siting of the proposed buffer stations. It is noticed that the areas that are most suitable are areas of lowland, bringing to bear the importance of gravitation as water is distributed from a central station. This will not only help in a faster distribution of water to the populace in the study area, it will also be less difficult to trace and repair any damage on the pipelines.

Moreover, it can be observed that some residential areas are beyond the reach of the existing pipelines. With the growth in population and rates of urban areas gain earlier discussed, visualizing and pinpointing these areas is of great importance as planning efforts intensify for sustainable water management in the area. This can serve as decision support for proposing new service areas by concerned authorities.

overlay work

Figure 14. Showing the Overlay analysis of buffer station.

4. Conclusions

This study has shown that Jalingo city is fast growing in population and in the phase of raid urban dynamism. Consequent upon this, the pressure of population and demand mounted on existing water distribution facilities and supply efficiency is of great concern to planners and concerned authorities. Population densities indicate high population in the city core of above 50-80 per Km2 whereas density in the peripheral areas of the city such as Pkantinapo, Kona Garu stands at 0-10 persons per Km2.

Furthermore, the rate of urban expansion from 1986-2016 which stood at 23% implies that though the existing distribution network may prove sufficient presently, there may be challenges of distribution network coverage in the nearest future. This may lead to water scarcity and lack of accessibility to the basic need of water for residential utility. Coupled with the growing demand for water for residential use which is projected to be 7,909,559,677m3 the study therefore pinpoints the need to optimize water supply systems taking into cognizance the spatio-temporal aspects of urban population change consequent urban expansion.

Adopting elevation and land use pattern as criteria, the findings propose new service areas as well as suitable areas for siting more buffer stations so as to accommodate the need of the growing population, incessant urban expansion and peripheral settlement of Jalingo city.

The focal point of the study was to derive empirical insights into the complex interactions that exist between human population, urban landscape dynamics, demand for residential water and efficacy of water distribution networks in Jalingo city. The results however points to the fact water is a finite resource but insatiable demand and alarming growth in urban population may pose serious challenges in the nearest future. This may hamper on the achievement of millennium development goals of access to water and sanitation services.

Moreover, though adequate pipe network has been put emplace with the current intervention by the state Government, there is need for more buffer station with high capacity in other to match the high demand for water and the ever-increasing population in the study area. Also, in planning to site new reservoirs and buffer stations, elevation parameter should be given due attention considering the role of gravitational force to water supply. This is necessary to avoid stoppage at certain points of the piping network and to enhance the longevity of the facility.

Recommendations

The advent of modern technology such as GIS in our today’s world has solved and is still solving many problems encountered by man and his environment. Therefore, GIS technology should be wholly embraced in the management of our water utility for optimal utilization.

However, the scope of this study was limited to residential water consumption. Further research is thereby recommended in other sector of water demand in the study area such as commercial, industrial, agricultural and so on. This will enhance a holistic view of the phenomenon. Also, further research is recommended to incorporate other sources of water supply and economic determinants such as volumetric pricing, as this research focused more on piped born water supply and urban population change as the main determinant. This will give insight to development of alternatives to tackling the problem of water availability and accessibility within the study area.

Conflicts of Interest

The authors declare that there is no conflict of interest regarding the publication of this article.

Acknowledgments

We acknowledge the information provided by Taraba State Rural Water Agency. All cited works were duly acknowledged by way of references.

Copyright

© 2017 by the authors. Licensee International Technology and Science Press Limited. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

References

[1] Vipinkumar, G.Y.; Darshan, M.; Sahita I.W. To assess the prevailing Water Distribution Network using EPANET. International Research Journal of Engineering and Technology, 2015, 2(8), 777-781.

[2] Wafula, P.; Ngigi, T.; Dave, S.; Khan, A.; Kamble, Y.; Dabholkar, V.; Damle, S.; Dayana, P.M.; Adline, S.D.; Abdullah, M.; Othman, M. GIS-based analysis of supply and forecasting piped water demand in Nairobi. Int. J. Eng. Sci. Invent, 2015, 4, 1-11.

[3] Grafton, Q., Daniell, K.A., Nauges, C., Rinaudo, J.-D., Chan, N.W.W. (Eds.). Understanding and Managing Urban Water in Transition. Global Issues in Water Policy, Springer Netherlands, 2015, 15, DOI: 10.1007/978-94-017-9801-3. ISBN 978-94-017-9801-3

[4] Corey, J. A. B.; Barry W. B. Human population reduction is not a quick fix for environmental problems. Proceedings of the National Academy of Sciences of the United States of America. Current Issue. 2014, 111(46), 1-9.

[5] United Nations World Water Assessment Programme. Water for A Sustainable World Report: UNESCO. Paris: 2015, The United Nations World Water Development.

[6] Population Action International (PAI). Why Population Matters to water resources. Washington, DC: Population Action International, 2015

[7] United Nations Population Division. World Urbanization Prospect: The 2009 Revision. UN Population Division. United Nations Conference on Human Settlements (UNCHS). 2010, New York.

[8] United Nations Center for Human settlements. Cities in globalizing world: Global report on human settlement 2001. Routlede, 2001

[9] UN Water and FAO. Coping with water scarcity: challenge of the 21st Century United Nations Populations Fund, State of The World’s Population. 2007, UNFPA Annual Report.

[10] Shadananan, N. Challenges in Urban Water Management in A Changing Environment : Case Study From A Growing Tropical City Nansen Environmental Research Centre India. 2010, Environmental Research, 1-2.

[11] Daramola, A.; Ibem, E. O. Urban Environmental Problems in Nigeria; Implications for Sustainable Development. Journal of Sustainable Development in Africa, 2010, 12(1), 124-145.

[12] Cordon, C.P. System Theories: An Overview of Various System Theories and Its Application in Healthcare. American Journal of Systems Science, 2013, 2(1), 13-22, DOI: 10.5923/j.ajss.20130201.03.

[13] Hart, A. Water Demand-Supply Gap Rise. Water News, 2009, Policy and Politics Circle of Blue.

[14] Closas, A.; Schuring, M.; Rodriguez, D. Integrated urban water management: lessons and recommendations from regional experiences in Latin America, Central Asia, and Africa. Water partnership program case profile. 2013, no. WPP 1.Washington, DC: The World Bank Group

[15] Wolski, P. Was the water shortage caused by farmers, city dwellers or drought. SABI Magazine-Tydskrif, 2018, 10(6), 38-39

[16] Chung, G. Water Supply System Management Design and Optimization Under Uncertainty. Phd Dissertation department of civil engineering and engineering mechanics. University of Arizona Repository, 2007, 50-62.

[17] Brinda, H. D.; Gargi, R.; Ajay, P; Manik, H. K. Continuous Water Distribution Network Analysis Using Geo-Informatics Technology and EPANET in Gandhinagar City, Gujarat State, India. International Journal of Scientific & Engineering Research, 2015, 6 (4), 1557-1560.

[18] Gwendo, G.; Rhea, G.; Nadia, B.; Qing, Z. Water distribution systems demand forecasting with pattern recognition. In Water Distribution Systems Analysis Symposium 2008, 1-16.

[19] Christian, K.; Katja, S.; Erik, G.; Bernd, K. Modeling Residential Water Consumption in Amman: The Role of Intermittency, Storage, and Pricing for Piped and Tanker Water. Water 7, 2015, no. 7, 3643-3670.

[20] Klümper, S. A. Analysis of Water Supply Projects in Practice, in Cost-Benefit Analysis and Project Appraisal in Developing Countries Colin Kirkpatrick and John Weiss (ed.). 1996 U.K: Edward Elgar Publishing Limited.

[21] Mensah, K. Restructuring the Delivery of Clean Water to Rural Communities in Ghana: The Institutional and Regulatory Issues. Water Policy 1998, Vol. 1, 383-395.

[22] Reddy, V. R. Quenching the Thirst: the cost of water in fragile environments. Development and Change, 1999, 30(1), 79-113.

[23] Habitat, U. N. Solid waste management in the world’s cities. Water and Sanitation in the Worlds Cities, 2010

[24] United Nations. Comprehensive Assessment of the Freshwater Resources of the World. The United Nations, New York Publication, 1996.

[25] koop, S. H.; van Leeuwen, C.J. Assessment of the sustainability of water resources management: A critical review of the city Blueprint approach. Water Resources management, 2015, 29(15), 5649-5670.

[26] Dalhuisen, J.M.; Florax, R.J.G.M.; De Groot, H.L.F.; Nijkamp, P. Price and income Elasticities of Residential Water Demand: A Meta-Analysis. Land Economics 2003, 79(2), 292-308.

[27] Grafton, R. Q.; Ward, M. B.; To, H.; Kompas, T. Determinants of Residential Water Consumption: Evidence and Analysis From A 10-Country Household Survey. Water Research Journal, 2011, 47(8), 1-12.

[28] Maidment, D. R. Developing a spatially distributed unit hydrograph by using GIS. IAHS publication, 1993, 181-181.

[29] Pidwirny, M. The Hydrologic Cycle: Fundamentals of physical Geography. Physical Geography, 2nd Edition, 2006, 50-62.

[30] McPherson, M. B. Need for metropolitan water balance inventories. Journal of the Hydraulics Division, 1973, 99(10), 1837-1848.

[31] McPherson, M.B.; Schneider, W.J. Problems in modeling urban watersheds. Water Resources Research, 1974, 10(3), 400- 434.

[32] Sowby, R.B. The Urban Water Cycle: Sustaining our modern Cities. National Geographic Water Currents, Available online: http://voices.nationalgeographic.com/2014/03/19/the-urban-water-cyclesustaining-our-modern-cities/2014 (accessed on 14 March 2016).

[33] Loucks, D. P.; Van Beek, E.; Stedinger, J. R.; Dijkman, J. P.; Villars, M. T. Water Resources Systems Planning and Management: an Introduction to Methods, Models and Applications, 2005. Paris: Unesco.

[34] Oruonye, E. D.; Abbas, B. The Geography of Taraba State, Nigeria. 2011 LAP Lambert Academic Publishing, Germany.

[35] Oruonye, E.D; Ahmed, Y.M. An Appraisal of the Challenges of Taraba State Agricultural Development Programme (TADP) in Nigeria. Agricultural Science Research Journal, 2016, 6(10), 263-268.

[36] TADP. Taraba State Agricultural Development programme, 2004-2005 Cropped Area and Yield Survey (CAYS) Report. Jalingo: 2006, Taraba State Agricultural Development programme.

[37] Müllerová, J. Use of digital aerial photography for sub-alpine vegetation mapping: A case study from the Krkonoše Mts., Czech Republic. Plant Ecology, 2005, 175(2), 259-272.

[38] Guo, L.; Chehata, N.; Mallet, C.; Boukir, S. Relevance of airborne lidar and multispectral image data for urban scene classification using Random Forests. ISPRS Journal of Photogrammetry and Remote Sensing, 2015, 66(1), 56-66.

[39] Adepoju, M. O. Land use and land cover change detection with remote sensing and GIS at metropolitan Lagos, Nigeria (1984-2002). 2007, Doctoral dissertation, University of Leicester (United Kingdom).

[40] Ade, M. A.; Afolabi, Y. D. Monitoring urban sprawl in the federal capital territory of Nigeria using remote sensing and GIS techniques. Ethiopian Journal of Environmental Studies and Management, 2013, 6(1), 82-95.

[41] Chatterjee, S.; Hadi, A. S. Regression analysis by example. 2015, John Wiley & Sons.

[42] Allen, D.W. GIS tutorial 2: spatial analysis workbook. 2016, Esri press.

[43] Ibitoye, M. O. A GIS-Based Assessment of Potable Water Network Distribution in Osogbo, Nigeria. Ife Research Publications in Geography, 2017, 14(1), 17-29.

[44] Oumar, S.B.; Tewari, D.D. The Evolution of Access to Drinking Water and Sanitation Coverage in Urban Centers of Selected African Countries. Mediterranean Journal of Social Sciences, 2013, 4(6), 747-757.

[45] Akkoyunlu, S. The potential of rural urban linkages for sustainable development and trade. International journal of sustainable development & world policy, 2015, 4(2), 20-40.

[46] United Nations World Water Assessment Programme. Water for a Sustainable World Report: UNESCO. Paris: 2015, The United Nations World Water Development.

[47] Grafton, R. Q.; Ward, M. B.; To, H.; Kompas, T. Determinants of Residential Water Consumption: Evidence and Analysis from a 10-Country Household Survey. Water Research Journal, 2011, 47(8), 1-12.