Chapter II

2.2    Population and Land Use

    2.2.1   Population: Levels, Growth, Distribution and Movements

2.2.1.1   Levels and Growth Pattern

In 1995, Zamboanga City had a total population of 511,139. It had increased two and half times over a 25-year period. This enormous growth may be traced to the rapid growth experienced between 1970 and 1980, when the City’s population was increasing at a rate not lower than 5% per annum. The growth lost its momentum in the early 80s and plummeted to a rate of 2.55 percent per annum. However, the rate started to pick up again during the first half of the decade (1990-1995), registering an average of 2.74 percent annual growth. Assuming the persistence of the current rate of growth, the 1997 mid-year population of the city is projected at 536, 906.

To trace the source of growth of the City, the increase in population was broken into two components: natural increase and net migration. Natural increase is the difference between the number of births and the number of deaths during a specified period. Net migration, on the other hand, is the difference in-migrants of the city during the same period. Given the population levels and the natural increase between periods, the increase or decrease in population due to net migration can be calculated. The following table illustrates the decomposition of population growth of Zamboanga City in terms of absolute figures for the periods 1980-1990 and 1990-1995.

To summarize, between 1980 and 1990, 75 percent of the increase in population was accounted for by natural increase, and 25 percent by net migration. However between 1990 and 1995 the contribution of natural revenue to the population growth dropped to 70% while growth due to net migration went up to 30%.

To interpret the population growth decomposition in terms of growth rates, the rates of natural increase (RNI) and the net migration rate (NMR) were calculated. The results were as follows:

The above table indicates that the rate of growth of the city due to natural increase remained constant from 1980 to 1995. Net migration rate, on the other hand, increased by 0.2 percentage points. Clearly, the increase in the growth rate from 2.55 percent between 1980 and 1990 to 2.74 percent in 1990-1995 can be attributed to the increase in the net migration rate. 

While the country experienced a steady and consistent decline in the population growth rate, both Region IX as a whole and Zamboanga City posted an undulating and abrupt pattern of change in their growth rates. (See table II-4).

Note: Region IX’s estimates of growth from 1970 to 1990 included Sulu and Tawi-tawi.

However, it is important to note that as the country experienced a significant decline in the population growth during the period 1980-1990, the respective growths of the whole region and the city decelerated at a much faster rate. This significantly sharp descent coincided with the intensified population and family planning campaign program during the 80’s. Apparently, the program had created a significant impact on the natural increase of population in Zamboanga City and the entire region.

The City’s population as a percentage of the region’s population for various periods is presented in the table below.

  Note: Region IX’s population from 1970 to 1990 included Sulu and Tawi-tawi

The proportion of the population of Region IX residing in Zamboanga City rise steadily, consistently. However, while the population of the region decreased considerably during the 1990-1995 period the proportion of the region’s population accounted for by Zamboanga City, increased abruptly. Apparently, this was due to the region to form the ARMM with other Muslim provinces.

The growth pattern of Zamboanga City is compared to other cities of Mindanao in Table II-6. It is significant to note that while Zamboanga City had the fastest growing population between 1970 and 1975 among the four cities, it lagged behind in the recent years. While the other three cities were at their peaks of growth between 1975 and 1980. The peak growth of Zamboanga City slowed down slightly

Table II-6.   Population Growth Rates of Selected Cities: 1970-1995

The abrupt changes in the population growth patterns of the four cities could be responses to their rapidly changing economic and social structures. For instance, after suffering a very abrupt declivity in growth during the 1980-1990 period. General Santos City posted a high 5.14 percent annual growth in the next 5- year period. Apparently, the main reason for this was the increased volume of in-migration to the City, which in turn was influenced by the influx of investors attracted by the existence development inputs in the form of major infrastructure facilities (e.g., fishing port and wharf, airport facilities, roads, etc.)

2.2.1.2   Population Age-Sex Structure

The age and sex composition of Zamboanga City’s population in 1995 is shown in Table II-7 and graphically illustrated in Figure II-1. The over-all sex ratio approaches 100, meaning, there is one male for every female in the city. In terms, of absolute number, the males slightly exceeded the females by 148. The sex ratio, however, is high among the infants with 107 males per 100 females, and even higher among elderly group (65 years and over) with 118 males per females.
 

Source: NSCB, 1995 Census of Population

          Figure II-.   Age-Sex Pyramid, Zamboanga City 

While it defines the volume of demand for various goods and services and supply of human resources, the age-sex structure of a population distribution presents important implications for future population growth, both in terms of immediate and long-term effects. For instance, the fact that 54 percent of the female population of Zamboanga City in 1995 are in their reproductive ages (15-49) years) and that 49 percent of the females 10 years old and over are currently married may indicate a rising birth rate at least in the near future. Moreover, the large number of females at ages 15-19 who are basically at the onst of their childbearing span implies that more births will occur in the next thirty years.

Another determinant, however, of fertility of births as the rate at which women of reproductive ages are marrying. The annual rates of increase in marital union among females 10 years old and over in Zamboanga City are around 3 percent or an additional

2, 370 married women in a year. This is particularly due to the changes in marital status among residents and to a lesser extent, the in-migration of married women. The age-sex structure can also be interpreted in terms of its implications on economic productivity. Basically, Zamboanga City has a young population with a mean age of 23.3 years in 1995.

Population growth, over a period of time, leads to an increase in the working age

population, a prime determinant of the labor force supply. The rapid growth experienced by the city during the period 1970-1980 resulted in significant proportion of the population who are at aged 15 to 25 years. Over all, 60 percent of the total household populations are in their economically productive years. This pool of human resources will be beneficial to the economic expansion of the city.

2.2.1.3  Number of Households and Household Size

Estimates and projections of the number of households are extremely useful in planning especially for mass housing and other specific types of utilities. Ideally, the number of households should grow in proportion to population. In the case of Zamboanga City, the number of households grew at a faster rate than its population – in fact, while, the number of households increased by around 2.5 times during the 20-year period the population grew by 1.9 times between 1975 and 1995. the gap can be attributed to the increased rates of household formation caused by the high marrying rate and household dissolution due to the tendency of inter-barangay or short-distance migration among the people of Zamboanga City.

Meanwhile household size was in a declining trend. From 6.56 members in 1975, the size shrunk down to an average of 5.06 in 1995. as far as planning for mass housing is concerned, information on the household size is an important input in determining the ideal size of dwelling units.

2.2.1.4 Spatial Distribution of Population

Population is heavily concentrated in the urban area and its vicinity leaving a relatively sparsely populated hinterland. Since 1970, the concentration of people has been in the city proper but it is currently showing evidences of spreading towards the northeast.

Data on population distribution and population densities by barangay are presented in Table II-10 (Annex). It indicates the unbalanced and skewed spatial distribution of the city’s population.

Figure II-2 further illustrates the concept of p[population concentration as a function of the distance from the city center – that is, those barangays located nearest to the center where the City Hall is likely to be the most densely populated. The urban barangays of Mariki, Campo Islam, Sta. Barbara, Sto. Niño, Sta. Catalina and Zone exhibited the highest population concentration in terms of inhabitants per hectare, ranging from 200 to as high as 10 thousand. The latter figure, which refers to Barangay Mariki, however, is exceptionally high although it has a very small land area. Its residents live in houses but on the coastal waters.

Except from Taluksangay, Arena Blanco, Tictabon and Recodo, barangays located beyond the 5-kilometer radius posted a density of not more than 20 people per hectare in 1995.

2.2.1.5  Population Movement

Unlike fertility and mortality, migration can respond quickly to social and economic changes. Thus, migration or mobility may be considered as a component of population change, which can be substantially influenced by medium or even short-term interventions.

Because of the scarcity or even lack of data on migration or population movements, interferences were made using the growth pattern of each barangay in the city. Table II-11 (Annex) presents an analysis of the migration status of the 98 barangays of Zamboanga City. The summary table below shows that even rural barangays are recipients of migrants; in fact 26 of the classified rural barangays are categorized as in-migration areas.

Figure II-2   Population Density vs. Distance from Center:

Zamboanga City, 1995

The most prominent receiving barangays include Divisoria, Calarian, Lunzuran, Talon-talon, Rio Hondo, Putik and Tugbungan among the urban classified barangays; and Malagutay, Arena Blanco, Lapakan, Licomo, Dulian (Upper Bunguiao), Recodo and Tictabon among the rural barangays. The out-migration barangays, on the other hand, include the urban barangays of Cabatangan and Zones I, II and III; and the rural barangays of Busay, Pangapuyan, Latuan, Baluno, Dita, Landang Laum, and Pamucatan.

The mobility of population across these barangays takes the following forms: the migration of farmers to new arable land another rural area; movement of landless farmers from depressed barangays to join the urban informal sector, and transfer of residence due to peace and order problem in area of origin.

If current trend in population growth persist, Zamboanga City is projected to have the following population levels:
 

Moreover, at the rate population is increasing (2.74 percent annually), the present population level of Zamboanga City is expected to double in 25 years. With the infusion of more infrastructure facilities and economic opportunities, there is a tendency for the rate of population growth population to accelerate. This acceleration is due primarily to immigration in short-term and improved income and health leading to increased fertility in the long-term. Given such a situation, population may eventually double in less than the expected doubling time of 25 years.

Therefore, addressing the city’s rate of natural increase through regulation of fertility or births is important in order to balance “demands of population” and “supply of resources” without sacrificing the environment. Tables II-14 to 16 (Annex) shows single-year interval projections of population for each barangay.

              2.2.2   Land Use

Land use classification is based on data for 1972 and 1993. It is evident that the coverage of forest and wetlands is declining even as agricultural and built-up areas continue to expand. Tables II-17 and II-18 show land classification for 1972 and 1993 respectively.
 

Source: Framework Plan, 1975: OCPDC               

Note: 1. Total excludes Islands 

            Source: Master Development Plan of Zamboanga City (1993-2003):OCPDC

                Notes:

1.        Total excludes Islands

Built-Up/Urban includes Industrial (834.21 has.), Commercial (56.76 has.), Residential (2.046.44 has.),

Religious (202.24 has) and Government (2.284.39 has.)        

The built-up/urban areas are heavily concentrated in the city proper and its environs. The city center has an unchallenged primacy over the rest of the city’s areas as almost all urban facilities are concentrated therein. Schools, universities, religious institutions, government institutions, commercial establishments, industries, the seaport, the airport, etc. are packed into this area accounting for the readily apparent congestion in the city center but commercial developments are making headway along major arteries.

The urban area has a tendency to expand in a linear manner in finger-like extensions following the alignment of the roads radiating out of the city center8: Expansion, however, is seen to occur more rapidly along the Zamboanga City-Pagadian National Road, the main northeastern corridor.

The hinterland is still largely agricultural. Wide tracts of ricelands, coconut and fruit plantations characterize the East Coast. There are also three hubs of activities in this area. First is Singali where the Zamboanga City Fish Port Complex and 100-MW Power Plant are located. The two other hubs are Curuan and Vitali, which are located in road convergence point’s sub-centers of trade in the rural area. The West Coast, on the other hand, also hosts rice lands and fruit plantations although not on the same sclae as those on the East Coast. It is an Emergent trading and Industrial area with the Regional Agro-Industrial Center in Ayala and the Zamboanga Ecozone in San Ramon.

           2.2.3   Land Supply and Demand Analysis

The supply and demand situation will be analyzed for urban and agricultural uses particularly for rice production. Land supply is determined through the traditional models of Eco-Engineering and Sieve Analysis. Urban land will be determined using the Aggregate Model while agricultural land demand shall be ascertained using the Food Balance Model.

After considering the supply and demand situation for urban and agricultural lands, the water carrying capacity of the City will be looked into. This shall serve as a benchmark in

determining the minimum population levels that the aquifers can handle without segmentation. This shall also be a critical guide in determining permissible intensity of the City’s socio-economic activities considering the available groundwater.

            2.2.3.1    Urban Land Supply and Demand Analysis

Lands that are available for urban expansion are those not included in the Protected Areas for Agriculture, the Environmentally Constrained Areas and the Existing Built-Up Areas.

Two supply situations exist. They differ mainly because off slope limitations and the stipulations of the Revised Forestry Code. The first situation determines the Gross Supply, which implies the absolute limits of urban expansion or the “Boundary Threshold”. Beyond which no urban development shall be allowed. This is primarily defined by the 50% and above slope line along with the other limiting factors indicated in Table II-19. Zamboanga City’s Gross Supply is estimated to be 51, 676 has.

The second situation determines the Net Supply or the “First Threshold”. The 18% to 50% slope range marks this, which are “conditional” restricted for urban use. Assuming that the Net Supply can cope up with the projected demand, then it may not be advisable to allow extensive urban development to cross the “First Threshold”. The City’s Net Supply is estimated to be at 36, 005 has.

            Note:

                 1. Built-up area size based on 1993 data.

 2. Protected Agricultural areas include irrigated and identified potentially irrigable lands as reported by NIA    Region IX

In order to estimate how large a population can be supported by the remaining urbanizable land, the net land carrying capacity is determined. If the first threshold is considered, the net carrying capacity ranges from over 100,000 to over four million people. Should the boundary threshold be considered, the maximum population might be around six million people. From these estimates, the additional projected population of 322,100 by the year 2012 may still be accommodated, considering land supply alone.

Map II-7 the Environmentally Critical areas.
 

Note:

1.        Population figures based on 1993 estimates.

2.        Net land carrying capacity pertains to the estimated number of people that can be accommodated in the areas identified for urban expansion.

FAO Standards specify 8 hectares per 1, 000 population.

In estimating the projected demand for urban land by the year 2012, an Aggregate Model was used based on current density or the space utilization factor per capita. For an additional population of 322, 100, the demand for urban land may range from 2, 577 to nearly 100, 000 has.
 

Supply for urban land is still ample if densities will not be based upon the very low value of 3, 24 persons per hectare, which is the Gross City Density. Further, the First Threshold is still capable of absorbing population growth.

2.2.3.2  Agricultural Land Demand and Supply Analysis

Since the demand for urban land normally conflicts with agricultural areas, the demand for agricultural land in order to fully support the population shall be ascertained. Demand will be estimated using a Food Balance Model where the nutritional requirements of the population are assumed to be fully met.

Looking particularly at the staple crops, the City requires a total of 61, 331 MT of rice and 26,285 MT of corn, to fully feed the population projected for the year 2012 population (Table II-24). Assuming that the City will internally produce all these, it would need 12, 315 has. of rice and 14,603 has corn lands cropped at an estimated intensity of 1.5 times per year (Table II-25). With the hectarage of planted area in 1993, there will be a land deficit of 7, 056 has. for rice and 9, 990 has. for corn. With the City’s prime agricultural lands estimated to be at 5, 168 has, becomes apparent that food self-sufficiency for staple crops cannot be attained (Table II-26).

Table II-24.   Estimated Food Requirements

Note:

1.        Assume 70% and 30% of population utilize rice and corn as staple food, respectively. Ration based on Zamboanga City’s 1998 SEPP.

2.        Vegetable Include Leafy, Fruit and Legumes

3.        Fruits were not included since no data was available.

Demand based on population divided by FNRI requirement.

Table II-25.   Estimated Yield and land Area Requirements

            Note;

1.        Effective estimated yield based on 1992 data from DA.

2.        Gross land area requirement (GLAR) equals demand over effective estimated yield per ha.

3.        Net land area requirement obtained during the GLAR by an assumed value of 1.5 representing cropping intensity.

TABLE II-26.   Land Requirement and Surplus/Deficit
 

Population Density Map 1970

Population Density Map 1975

Population Density Map 1980

Population Density Map 1985

Population Density Map 1990

Population Density Map 1995

Activity Centers Map

Environmentally Critical Areas Map