Introduction: I hate to use averages but…

There are more than 200 nations on the globe. They represent an enormous variety in terms of water, environment and development. All these three, manysided entities can be measured with an innumerable amount of indicators. No single indicator tells too much about the actual situation within a geographic region, but there are a plenty of indicators, however, that reveal very interesting features, despite of their simplicity. For this representation, I chose the approach of using selected indicators of water, environment and development when relating and comparing the Mexican situation in these aspects to the rest of the world, as well as to the most critical regions on this planet.

None of the 200 and more nations of the world can be considered as an average one, that would represent the whole globe in a miniature scale. However, some countries, as described with commonly used development indicators, are closer to the average of the mankind than many others. Mexico belongs to such countries.

Fig. 1 presents a selection of development indicators for Mexico, as a proportion of the world total, and of the Latin America (including Caribbean) total. In order to allow direct comparison with the size of the human population, the diagrams have been scaled with the population shares of Mexico with respect to the two areas under concern.

As far as the population indicators are concerned, Mexico is very close to the Latin American average. It is also close to the world average, except in the urbanization rate, which is notably higher than the world average; in Mexico, over ¾ of the population lives in urban areas, whereas the global rate is just approaching 50%.

Mexico’s human development indicators show, that in these respects, the country is notably better off than the Latin America on average, and more so, when related to the rest of the world. Its indicators for infant mortality, illiteracy, and malnutrition all show the same direction.

What comes to the availability of natural resources, Mexico is subjected to substantial scarcity when compared to the Latin American average. Knowing that Latin America is exceptionally rich in most resources, the situation is different when comparing Mexico with the rest of the world. Surprisingly though, it is much better off with accessible water resources than the world average situation is. This is because a great proportion of world’s population live in water-scarce countries such as China, India, Pakistan, and Egypt, and on the other hand, a great deal of Mexican population lives in water-scarce areas.

Mexico already withdraws 22% of its total water supply, which is a very high proportion, and can be considered to be within critical limits for sustainable development, as will be discussed later. Besides water withdrawals, Mexico exploits very intensively its other basic natural resources as well.

Fig. 1. Mexico compared with the Latin American and the world averages using selected development indicators. Data: World Bank (1997), except human development indicators from UNICEF (1998) and IFPRI (1997), and water data from Postel et al. (1996) and SEI (1997).
 
 

The world average implies in many respects a situation which is far from good. The fact is that, for instance, in terms of water resources exploitation and management, the world situation is rapidly worsening (e.g. Kulshreshtha 1993, SEI 1997, Somlyódy et al. 1998, Vakkilainen & Varis 1998a, b, Varis 1998a). Mexico is a good example of that; taking the three main axes of water deterioration:

• surface water and ground water
• rural exploitation and urban exploitation
• water quality and water quantity

When analyzing the economic output at the national level, the indicators for Mexico imply a relatively low efficiency; it uses high quantities of energy and natural resources, produces high emissions to the environment, but its economic output is not in line with those, although the world averages again are far from a good situation. Some bias in the use of this indicator is due to the fact that Mexico is an important oil producer, and its industrial base is very much built on the use of this domestic resource as the energy source.

Although Mexico lies around the world average in terms of GNP per capita, the Mexicans belong to the wealthiest 1/5 of the mankind. This may seem contradictory, but it is not. It is due to the very uneven wealth distribution of the world’s population. This issue will be discussed in more detail later on.

Besides the issues discussed above, Mexico can—without a very big vulgarization—be considered as one of the best countries that represent the world "as an average" due to its natural, climatic, and cultural characteristics. In all these respects, it is one of the richest countries in terms of diversity.

The most stressed and critical regions of the world

As was shown above, Mexico belongs to the mid-range of world’s nations with respect to many of its development aspects. It is of interest to analyze, which regions are the most critical ones, and how do they differ from Mexico, and which directions are similar.

In a diagnostic analysis of the most critical and vulnerable regions of the world, Varis (1997, 1998a) and Vakkilainen & Varis (1998b) defined the 6 criteria shown in Table 1 for the selection of the regions that will be most probably be impacted to the most profound manner of global changes and developments concerning climate, water, food, poverty, population, and urbanization. The Table also shows how the world’s macro meet these criteria. On these grounds 5 regions were chosen for closer studies and comparison with each other.

Critical regions with respect to all criteria are the Nile Basin and the Sahel/W Africa, China and S Asia (Fig. 2). SE Asia was also included, despite the fact that there are states like Singapore, Malaysia and Thailand, which are rapidly becoming affluent. Population growth in the area, urbanization and shortage of water resources (for instance in Indonesia and the Philippines) is, however, massive even considering the global situation as a whole, and the stability in terms of economics and politics has not been strong over the last decades.

The Near East, from Turkey to Afghanistan, would have been the next region (Vakkilainen & Varis 1998b). Also the vulnerability of the area as far as constant conflicts are concerned would support a more careful analysis. On the other hand, its urbanization rate and income level are higher than in the areas chosen for study.
 
 

Table 1

The world’s macroregions with respect to the 6 critical factors. = does not fulfill, no mark = some risk, + = fulfills the criterion.
 
 

Region	Water resources vulnerability & scarcity	Populated in global scale	Population growth is rapid	Urbanization and megacity growth is extensive	Low/middle income dominance	undernourishment / grain net  importers
N Europe	—	—	—	—	—
C & W Europe	+	+	—	—	—
E Europe			—	—
Ex-USSR/Europe	—		—	—		+
N America		+			—	—
C America	+		+	+
S America	—	+	+
N Africa, Egypt excl	+	—	+			+
Nile Basin	+	+	+	+	+	+
Sahel/W Africa	+	+	+	+	+	+
C Africa	—		+	+	+	+
S Africa	+		+	+
N Asia	—	—
C Asia, Kazakhstan	+	—	+			+
China	+	+	+	+	+	+
Middle East	+	+	+			+
S Asia	+	+	+	+	+	+
SE Asia	+	+	+	+		+
Japan	+		—	—	—
Australia & NZ		—		—	—	—
Oceania	—	—		—	—

Fig. 2. The world’s most critical regions.
 
 
 

Water use and vulnerability

Quantity

When talking about water scarcity and vulnerability, the available and accessible water resources are related with water demands. Mexico has 3,900 cubic meters of water resources per capita on an annual basis. The total water withdrawals amount to 22% of that, which is almost 80 cubic kilometers. 86% of that goes to agriculture. Mexico’s population is approaching 100 millions. Egypt has now 60 million people, and it consumes 56.4 cubic kilometers. These, and some other water scarce and crowded areas are compared in Table 2.
 
 

Table 2

Water resources and their use in selected water scarce regions, which account for ¼ of the world’s population (data: World Bank 1997).
 
 

	Mexico	Egypt	Northern China	India	Pakistan	Java, Indonesia
Population, millions	96	60	126	945	145	110
Water availability, annual
km3	369	58	45	2088	470	127
1000 m3 per person	3.8	1.0	0.35	2.2	3.2	1.2
Water withdrawal
km3	80	56.4	38.8	380	154
1000 m3 per person	0.8	0.9	0.3	0.4	1
% of all water	22	97	87	18	33

 

When difficulties in meeting the water demand are estimated, the rating can be based on the relation of water consumption to annual runoff (Falkenmark and Lindh 1976, SEI 1997). If water demand is less than 5% of the total runoff, it can be met without problems. When water demand is near 10% the risk caused by temporary disturbances increases and the meeting water requirement demands careful planning of water resources. If water demand is 10% to 20%, the situation becomes problematic and large investment is the only possible solution. At between 20% and 40% the situation requires massive investment and a large part of GNP has to be sacrificed for water management in developing countries in particular. A water demand above 40% is a serious water shortage that usually has to be met by desalination and using groundwater to the extent of groundwater depletion. According to Falkenmark and Lindh (1993) 1,000 m³ per annum is a critical water quantity, below this areas will suffer from serious water shortage.

The recent years have seen a series of global freshwater assessments (e.g. Kulshreshtha 1993, SEI 1997, Shiklomanov 1993, 1998). They try to highlight the critical regions, typically on a country-level, with respect to water resources and their vulnerability due to various human activities plus the potential changes in climatic conditions. Water quality tends to be ignored.

Kulshreshtha (1993) has estimated the change in water consumption in major areas until the year 2025 and described a set of scenarios: Effect of food self-sufficiency level on water use, effect of population growth, effect of industrial development, and effect of climate change. The country-specific results are presented with plots, in which countries can be compared with respect to their population and water availability, and are classified according to their water vulnerability.

This study unfortunately includes a plenty of inaccuracies, as can be seen from the results for Mexico. The plot shows that the country’s population should be around 350 millions by the year 2025, whereas the United Nations forecast, that the population should be around 130 millions. Therefore, the results should be not considered as quantitative, and should be approached with caution.

According to the overall results, only S America, N Europe, Central Africa, SE Asia and Oceania will be below the critical consumption level of 20%. There will be major problems in N Africa and Near East, where water requirement will exceed water supply manifold. Fig. 3 shows that the share and the number of the world population that will be suffering from the shortage of water is in an expanding phase.
 
 

Fig. 3. The number of people subjected to water scarcity is in rapid growth. Vulnerability of the global population to water supply deficits, and the use-availability classification used (Kulshreshtha 1993).

Shiklomanov (1993) has estimated the change in water consumption in the year 2000 and divided the world in 26 parts. His estimation has been extrapolated until the year 2050 based on the rates of population growth and water consumption.

The study clearly illustrates how difficult the situation will be in certain areas. When water management is conducted in accordance with the principle of sustainable development it cannot in any way be accepted that water consumption could be manifold in comparison with the annual runoff. This is the case, however, in certain states. Libya, for example, consumes almost 10 times more water than its renewable resources are.

This study is a part of a comprehensive assessment project: World Water Resources at the Beginning of the 21^st Century, that is carried out as a joint undertaking by UNESCO/IHP and the State Hydrological Institute of St. Petersburg. The work is still in progress, but some pre-results are already available. For instance, some main results are summarized by Shiklomanov (1998), and those for Central America are summarized by Izmailova and Moiseenkov (1998). Based on these reports, the final, extensive volumes, will be of great value.

Stockholm Environment Institute’s (SEI 1997) assessment first describes the availability, quantity, and variability of water resources, and their present use. Then, an analysis on current and future water needs and problems faced is presented. At the end, strategies and options for the sustainable development of global freshwater resources are reported.

The analysis on future water demands is based on a set of scenarios. On the supply side, 3 different scenarios are driven. One is based on the assumption that the climate will remain as it has been in the recent decades, and the 2 others assume the climate be changed due to human influence. On the demand side, the range of water withdrawals are projected using 3 scenarios: low, middle, and high. The time frame used is to 2025, and the analysis is made on a country level.

The results of the scenarios are presented as a set of vulnerability index values for each country. The 5 indices used, and the results of the middle conventional scenario are shown in Fig. 4. Among these indices, which all describe a specific view to the water resources issue, the Composite Water Resources Vulnerability Index I appear to be the most useful to studies such as this, due to their interdisciplinary character. It shows, that the most critical regions in Latin America are Mexico, Peru, and most of the Caribbean Islands.

These analyses, as well as the other ones available, only include water quantity based on national, aggregate values and it is likely that including quality information or disaggregating spatially and temporally could drastically change the results. Incorporation of water quality problems would reveal that the water scarcity issue still an essentially more severe problem than shown in the Figures of this Chapter. The possible climate changes are likely to add to these problems. The two last mentioned issues will be discussed in more detail below.
 
 

Quality

Groundwater contaminants can be clustered into following categories:

• Physical: temperature, changed viscosity, color, etc.

• Inorganic chemical: salts (K⁺, Na⁺, Ca⁺⁺, Mg⁺⁺, SO₄⁼, Cl^-, etc.), acidity (pH), hardness, plant nutrients (nitrogen compounds etc.), etc.

• Trace elements such as heavy metals and radioactive compounds.

• Organic chemical: a variety of substances such as hydrocarbons and halogenated hydrocarbons.
 
 

• Bacteriological: pathogenic bacteria for humans or animals.

In Latin America, groundwater is typically used more than in most other parts of the world. According to Reboucas (1998), more than 50% of Latin American people and around 90% of its industries depend on ground water supply. In precipitation-scarce heavily populated areas of Mexico, around Mexico City in particular, the combined effects of groundwater overdraft and rapid degradation of its quality due to insufficient pollution abatement practices are among the most problematic groundwater management cases in Latin America, and evidently in the whole world.

Surface water quality problems cover several issues. This is due to the great diversity of lakes, reservoirs and rivers, the wide range of needs and preferences in society for the use of surface water, and the complexity of aquatic ecosystems. These changes are caused either by point-source polluters such as industries and settlements that have a sewerage system; non-point polluters such as agriculture, or through the atmosphere. The most common water quality problems are:

• Eutrophication caused by the abundance of nutrients and other agents of enhanced primary production.
• Oxygen depletion due to degradation of organic matter in water.
• Hygienic problems due to pathogenic organisms such as viruses, bacteria or protozoa.
• Salinization: high concentrations of ions such as calcium, sodium, chloride and sulphate.
• Acidification due to atmospheric deposition of SO₂ and NOx or by industrial, mining or natural emissions.
• Toxic or cumulative compounds such as heavy metals or other trace elements, radioactive compounds, halogenated hydrocarbons or water-borne toxins.
• Suspended material and turbidity (inorganic or organic).
• Changed thermal conditions due to thermal pollution, flow control or changed climate.

It is fairly complicated to draw any global comparisons on water quality issues and problems, due to the manysidedness of the question. Water quality consists of a number of criteria, and their relation to the very varied water uses, differ greatly. Within this report, I will restrict to refer to the useful global databases such as the GEMS/WATER and WHO systems for surface waters (GEMS/WATER 1991, Kraemer 1994), and the more specific ILEC (1994) system for lakes, and the UNESCO/IHP (Takeuchi et al. 1995) database for rivers.

These systems may not be as accurate as many national systems, but still they allow regional comparisons. In the case of Mexico, they reveal, that the rivers of the country suffer from all the classes of water quality problems. As an example, water quality indicators for the river Balsas are related to the the data of 78 other rivers in the world, as given in the GEMS/WATER database (Fig. 5).

Water quality deterioration has been almost neglected in global water assessments. This is a severe handicap of those assessments. Water may be abundant, but the deteriorated quality is often a major obstacle for human uses as well as to the ecological balance in a watershed. No amount of water is sufficient, if its quality is deteriorated.
 
 

Table 3

Water uses and water quality: From surface water quality to uses. Typical influences of water quality problems on most frequent uses. + = low or occasional impact, and ++ = high impact. - = low or occasional influence, -- = marked influence (Varis & Somlyódy 1996).
 
 

Use	Eu-trophic-ation	Oxygen depletion	Hygiene	Salinity	Acidity	Toxic/ cumu-lative	Turbidity & suspen-ded matter	Thermal pollution
Conservation	--	--	--	--	--	--	--	--
Recreation	--	--	--	-	-	--	--	-
Fisheries	--	--		-	-	--	-	-
Aquaculture	-	--		-	-	--	-	-
Withdrawal:
- Households	--	--	--	-	-	--	-
- Municipalities	--	-	-	-	-	--	-
- Irrigation, etc.	-	-	--	--	-	--	-
- Industry	-	-	-	-	-	-	-
Transport	-						-
Flood control							-
Hydropower							-
Cooling basin								-
Waste transport & disposal	-

 

Table 4

Water uses and water quality: From uses to surface water quality. Typical impacts of most frequent water uses on water quality. Symbols as in Table 3 (Varis & Somlyódy 1996).
 
 

Use	Eu-trophic-ation	Oxygen depletion	Hygiene	Salinity	Acidity	Toxic/ cumu-lative	Turbidity & suspen-ded matter	Thermal pollution
Conservation
Recreation			+
Fisheries
Aquaculture	++	+					+
Withdrawal:
- Households
- Municipalities
- Irrigation, etc.	+			+
- Industry
Transport			+			++	+
Flood control	+	+					+	+
Hydropower	+	+		+			++	+
Cooling basin	+	+				+		++
Waste transport & disposal	++	++	++		+	++	++

 

Many Asian metropolises such as Bangkok, Calcutta, and Dhaka that are practically floating on water, but where the water contamination in almost all conceivable ways makes the water use a very difficult issue. Water transfer systems even from distances of hundreds of kilometers are being constructed to meet the urban needs. Large-scale water scarcity problems are created in the regions from which water is conveyed away. In Thailand’s central plain, which is one of the rice baskets of the world, large irrigation systems must these days stay dry in dry seasons, because their water is drawn away to meet Bangkok’s boosting demands (Varis 1998a). The city itself, is sinking just like Mexico City, due to overdraft of groundwater, and its ample surface waters are too heavily polluted for any other use but navigation.

Fig. 5. Water quality indicators of Río Balsas, compared with the averages of 10 rivers of North and Central America, 7 rivers from South America, and 79 rivers in the world. Data from the GEMS/WATER database. The unit on the horizontal axis is (Balsas value minus data average) / standard deviation of the data. TDS = total dissolve solids.
 
 

In general terms, a sustainable, and often, in long term, the most economic solution should be based on the principle of closing the material and energy cycles (Fig. 6). This can be made in many ways (Varis & Somlyódy 1996, 1997), but should not be overlooked in any case. This requirement is in fundamental contradiction with the present type of urbanization process, in developing countries in particular. Instead, the high population densities should be avoided, unless the waste produced in cities can be recycled to the production of food or other mass products. The wastes, if discharged to water courses and aquifers, contribute essentially to the water scarcity through pollution.

Pollution prevention is one of the leading contemporary paradigms in water management. It addresses the observation from innumerable cases that remediation of damaged watersheds, rivers, etc., tends to be exceedingly more expensive than prevention of the damage beforehand. The dilemma is the political pressure needed to take the actions: often it is not there before the problems turn visible to the society.

Fig. 6. Pollution problems are expanding. Among the most difficult causes is the uncontrolled urbanization development which, among many other things, opens material and energy cycles. This is an unsustainable tendency, that should be combated with capacity building and all other conceivable means.
 
 

Climate and its changes

The recent years have seen a boom in assessments of global climatic changes and variations, as well as their future forecasts and prognoses. Human activities have changed the concentrations of many components of the atmosphere, particularly during the last one hundred years. The concentrations of the so-called greenhouse gases have increased; CO₂ by 30%, NH₄ by 145% and NOx by 15%. This has been due to burning of fossil fuels, land-use changes, and agriculture. Greenhouse gases have a warming effect on the globe’s surface temperatures.

Burning results also in the increase of aerosols. These aerosols, in contrary, have a cooling effect on climate. It is believed to be smaller than the warming effect of the greenhouse gases. Present-day scenarios suggest warming of the world’s climate by 1 to 4 °C in average, relative to 1990 (FAO 1996), in the time frame of one Century ahead.

Such changes are anticipated to vary much with respect to local and regional weather conditions. Some evidence suggests that the changes in variations are much more significant than those in the mean behavior of the climate (Katz & Brown 1992). In fact, extremes such as floods, droughts, storms and their frequency, are often critical to water resources management, and changes in their pattern or frequency can be very influential to the economy and society.

The equatorial belt is the globe’s most critical area

A recent analysis of the world’s vulnerability to climate changes and variations (Varis 1998b) revealed, that the regions selected on the basis of the 6 criteria defined above, coincide with the area called the equatorial belt (Fig. 7). It covers the range of the seasonal movement of the intertropical convergence zone (ITCZ). In this zone, the trade winds from the both hemispheres confront, causing rainfall. Its location varies seasonally, being in extreme N during the northern hemisphere summer, and in extreme S in the southern hemisphere summer.

This equatorial belt is subjected to highest uncertainties in the climate change projections (IPCC 1996), and few decades ahead, it will be affected more by other global changes—population growth, urbanization, industrialization, and political-economic transitions—than other parts of the world. This makes the economies particularly sensitive; they are prone to social unrests, dislocations of people, disease outbreaks, uncontrolled urbanization, malnutrition and famines, ecological disasters, and environmental degradation.

Fig. 7. The map showing the tropical, monsoon zone (intertropical convergence zone, particularly vulnerable to climate change and variation) in January and in June (Varis 1998b).

Trade winds and monsoons

The trade winds are driven by the earth’s rotation; the N hemisphere winds are turned to SW, and those of the S hemisphere NW. These easterly winds tend to be strongest in the E Pacific. The trade winds convey relatively cool air, and together with the rainy summer seasons related to the geographical movement of the ITCZ make the climate exceptionally comfortable to humans. Consequently, many regions of the belt have been development sites of ancient civilizations, e.g., the river valleys of the Nile, the Indus, the Ganga-Brahmaputra, the Huang He, the Yangtze, and the Niger. Today, around 3/5 of humans dwell within the belt, and the population densities are high in large areas.

Mexico lies somewhat outside the belt, but is not very far from it. It is close enough to be influenced by it in a profound manner. The North-East trade winds blow through the country throughout the year, and if any changes happens with the equatorial belt, Mexico’s winds and rains are also affected. But to Mexico’s fortune, it does not seem to lie in the most critical zone, which unfortunately appears to be the most difficult zone to forecast as well.

Observed trends

Changes in the atmosphere’s composition have various influences in its heat budget, and consequently in transfer processes such as winds.

The belt has witnessed some clear trends in measured temperatures and precipitations in the 20^th Century. The changes have been most remarkable in W Africa where the temperatures have grown with around 1^oC, and the precipitation has decreased markedly. The other trends in Africa are much smaller, except the temperature increase in the Sudan, and the precipitation growth in Egypt. Almost all the study countries in Asia have become warmer. S Asia and China have become wetter, while SE Asia has turned somewhat dryer. It has not been shown unambiguously that the observed trends are consequences of human-enhanced greenhouse effect, but it is highly possible.

In Mexico, temperature has grown with 2^oC, but trends in precipitation have been very small. Such trends impose an important factor that augments water scarcity problems of the country, and establish growing risks to agriculture as well as urban water supply.
 
 

El Niño—Southern Oscillation (ENSO)

The ITCZ system, in particular the trade winds, are subjected to many factors that cause large weather variations. One of the crucial determinants of the year-to-year variation is ENSO, which has been followed over centuries as a natural feature of the regional climate patterns.

It has been recognized as the most important determinant in this respect globally(Whetton & Rutherford 1994, IPCC 1996), and as the primary factor causing interannual fluctuations in the whole Latin America (IPCC 1998). There is evidence based on sand ridges of Peru that ENSO has been active at least for 6000 years (Sandweiss (1986). For the last 500 years, there are various, relatively accurate data sets that can be used for the analysis of ENSO. It occurs at irregular intervals of 2-10 years, consisting of a consequence of phenomena.

The strong trade winds of the E Pacific transport warm, solar-heated surface waters of the equatorial Pacific, and induce a vast warm water accumulation to the W Pacific, around Indonesia. This warm water causes a plenty of evaporation and consequently much precipitation, keeping most SE Asia very humid; throughout the year close to the equator, and elsewhere during the rainy monsoons. On the ocean’s eastern end, the warm water moved westwards by winds is replaced by nutrient-rich, cool water from deeper water layers. This causes a dry climate to western S American coast, and feeds the world’s commercially most important fish stocks along the Peruvian coast.

The El Niño—the warm phase of the ENSO—starts with weakening trade winds. The warm surface waters start to return to the east. The coasts of Peru experience increased water temperatures, reduced fish catches, and growing precipitation with heavy storms that can be devastating. The rainfall that usually benefits SE Asia, precipitates earlier on its way to the west, falling mostly to the ocean. Therefore, Indonesia and several other countries (Fig. 8) experience droughts.
 
 

Teleconnections of ENSO

There are some interesting and important connections of regional climates around the equator. The monsoon patterns and, consequently, the wetness of rainy seasons are affected also else-
 
 

where, not just in SE Asia. For instance, the rainfall anomalies in the source area of the Nile—the Ethiopia-Sudan region—are very closely related to the Indian summer monsoon, i.e. the rainy season (Camberlin 1997). The Asian summer monsoons in different regions have similar, high correlations. Another example is the effect of the strength of trade winds to the jet streams that transfer the air back to mid-latitudes: they are also weakened along with trade winds. This causes changes even in N America and Europe. Therefore, a drought in Chihuahua may be due to the same phase of Southern Oscillation than a flood in Indonesia.
 
 

Greenhouse warming and Southern Oscillation

Although ENSO seems to be known today well enough to be used in seasonal weather forecasts several months ahead (Stockdale 1998), the relation between the enhanced greenhouse effect and ENSO are highly unclear. There is a heavy debate going on around this question (IPCC 1996, Trenberth & Hoar 1996, 1997, Harrison & Larkin 1997, Rajagopalan 1997). The hypotheses under argumentation are:

• Greenhouse warming and El Niño have no relation.
• El Niño will become more frequent with greenhouse warming.
• El Niño will last longer with greenhouse warming.
• El Niño will even become a permanent condition in future.

The recent El Niño events have been exceptionally strong and long-lasting, and more frequent than before (Cole et al. 1993). There is a wide concern that the oscillation pattern has already changed, and will continue to change in the future. According to Trenberth & Hoar (1996), the recent events represent such extremity that could statistically occur only once in a few thousand years.
 
 

Social development

I will now discuss the following aspects of social development, both in a philosophical perspective, and on a concrete basis with some illustrative data and statistics: Economy, Poverty, sustainability, human resources, food, urbanization, and institutional development.
 
 

Economy

I mentioned in the Introduction, that Mexico’s GNP per capita is around the world average. However, Mexicans belong to the wealthiest 20% of the humankind. This is because of the very uneven distribution of world’s wealth (Fig. 9); the high-income countries that have around 15% of the world population enjoy over 80% of world’s GNP. When taking into account the different domestic price levels in different countries, the Purchasing Power Parity comparison shows somewhat less uneven and distorted view of the global economic situation.
 
 

Fig. 9. World’s population vs. GNP per capita and Purchasing Power Parity. Data: World Bank (1996).
 
 

Poverty vs. sustainability

Again, the averages do not tell the whole story of country’s wealth and poverty. The wealth is unevenly distributed in all countries. In Mexico, 30% of the population have been estimated to live in absolute poverty by Nafziger (1997). In all developing countries, excluding the countries of the former Soviet Union, the percentage of people in absolute poverty (having less than around US$ 1 a day) is also 30%. In terms of poverty alleviation, Mexico is around the third world average.

It appears typical to middle-income economies, that their income inequality is much broader than in high or low-income countries. This is true for Mexico as well. As the poorest 40% of its population earn only 11.9% of all earnings, while the richest 20% earn 56%, Mexico is classified as a high-inequality country (Nafziger 1997).

Both poverty and wealth are related to environmental degradation, but in a different way (Fig. 10). This should be realized. It appears, that the share of developing countries of the world’s economic output is decreasing, while their share of emissions is growing rapidly (Fig. 11). As related to the world total, the countries within the 5 critical regions defined earlier pollute the double than one generation ago, but their economic share of the world total has reduced to one half.

In 1970-1992, Mexico’s proportion of world’s GNP has remained around 1.3% of the world total, while its CO₂ emissions have grown from 0.7% to 1.6%. In 1992, Mexico emitted 2.0 kg of CO₂ to produce one US$ of GNP, whereas Brazil released 0.8 kg, Indonesia 1.7 kg, USA 1.0 kg, Spain 0.6 kg, Finland 0.5 kg, and France 0.4 kg. Many countries, though, are less efficient; the corresponding figures for India are 2.3 kg, China 6.6 kg, and Kazakhstan 12.6 kg (World Bank 1997), but apparently Mexico’s efficiency could and should be increased to work towards both ecological and economic sustainability.

Fig. 10. Sustainable development is challenged by both poverty and affluence (Jalal 1993).
 
 

Fig. 11. The share of developing countries of the world’s GNP is going down, while their share of emissions is growing. Data: World Bank (1997).
 
 
 

Human resources

Mexico has prerequisites to balanced development, also in environmental sense. Perhaps the most important of them, education, is in a shape that is one of the best in the developing world. Consequently, the illiteracy rates are lower than in most developing countries (Fig. 12). Most of them still suffer from social problems such as illiteracy and gender disparity in a much more severe way than Mexico does.

Fig. 12. Adult illiteracy rates (population over 15 years) in different parts of the world. Data: World Bank (1997).
 
 
 

United Nations Development Programme (UNDP) has developed an index that attempts to measure human development in a balanced way. This human development index, updated annually, consists of life expectancy, illiteracy, education and wealth. After UNDP (1995), Mexico was on the position 53 among the 174 countries included in the analysis. Its indicators of human development were much closer to the industrialized country averages than those of developing countries.
 
 

Food

Over 2/3 of all water withdrawals go for food production. Around 16% of all arable land is under irrigation, and those fields produce 1/3 of agricultural output (Postel 1993). The crucial role of water as an agricultural input, and as a major factor in the rapidly grown food production in 1970-1990, is unarguable. The arable land area did not grow in that period, but the irrigated area went up 40%. In conjunction with the developments in the application of other inputs, the world’s grain production grew 72%. This yielded a notable improvement in the global food situation, because the population growth did not exceed 40%. This positive development trend has been replaced by a more stagnant one in this decade. Both the arable land area and the fertilizer application rate have decreased. The irrigated area grows still, but much more slowly than before. As a consequence, food production has not grown, whereas population has with 14%, with 720 millions. This trend has evoked wide concern in various directions recently, because much of the achievements of the past decades has already been lost; the per capita grain production has returned to the mid 1970 level.

There must be several reasons to this shift. One (both ways) is the rapid urbanization; roughly 80% of all population growth ends to urban areas. Many developing countries witness a strong political priority to urban development over rural one. Accordingly, it has been estimated, that whereas today roughly 1/2 of the global population is still rural, in 2025 that share will only be 1/3. Yet, it is mainly the rural population that feeds also the urban dwellers. One reason is the collapse of centrally planned economies, with highly input-intensive agriculture. Partly as a consequence of the collapse, the free trade paradigm has been prevalent, forcing agricultural investments to compete more with other investments (manufacturing industry, urban services, tourism), on the basis of revenues per invested sum of money.

Malnutrition and food insecurity are huge problems in the world. According to IFPRI (1997), in the world, there are 180 million undernourished children, and 800 million food insecure people (Fig. 13). Almost all of them are now, and will also be on the five regions defined in Fig. 2 in the coming few decades.

Latin America suffers only marginally of these problems, in comparison to many other parts of the world. In contrary, it merely belongs to food exporters, and therefore the food insecurity problem is by far not as relevant an issue for Mexico as it is for many other, even middle-income countries, particularly in Asia. However, Mexico’s food self sufficiency rate has been going rapidly down from 100 in 1969/71 to only 74 in 1988/90 (Alexandratos 1995). Mexico is increasingly dependent on food imports; According to Brown (1996): Rising food prices in grain-importing countries, such as China, Egypt, and Mexico, could create unmanageable problems. Mexico’s food production is increasingly water-constrained; it currently uses 86% of all water withdrawals for agriculture, but the pressing urban and industrial needs are bringing this rate gradually down.

Current assessments of food security and food production rely very much on the growth of exports from developed countries to developing countries. Malnourishment and meat import data (Fig. 12; IFPRI 1997) are based on an optimistic economic scenario allowing food import food and consequent reduction of malnutrition, although the history of economic development has not been very promising.
 
 

Fig. 13. Malnourishment and food insecurity (data: IFPRI 1997)
 
 
 

Urbanization

Many voices say that urbanization will even be a more problematic and momentous issue than the population growth itself. Such general statements are often overly simplistic, however, the trend is clear: almost all population growth ends to cities. It is a big issue to a big proportion of all the individuals in coming decades, as well as when considered as a driving force in any development of the societies, whether nature, environment, social issues or economics are in focus.

The growth rate of the global human population is approximately 1.6%, while in Africa it is close to 3%. The rate of third world cities with over 1 million inhabitants was approximately 5.6% during the period 1980-1990 (Drakakis-Smith 1987). This growth rate implies a 72% growth within a decade. Some cities, Africa in particular, have more than doubled their population within the last decade. In Africa and Asia, the proportion of urban population is around 1/3 while in all the other continents it is over 2/3. Therefore, the most massive urbanization development is to be expected in Asia and in Africa (Fig. 14).

Considering the wealth of different countries, it seems that urbanization will touch most drastically the low-income countries, in most of which urbanization is very fast and will continue long (cf. Fig. 15). In terms of population share, India and China are in the key position; they have roughly 2/3 of the low-income category population.

Fig. 14. Rural and urban population. Data: United Nations (1994).

Fig. 15. The regions’ share of the world’s rural population remains high, around 4/5, but the urban population share grows dramatically (data: United Nations 1994).

Latin America differs markedly from other developing regions in this respect. Its urbanization rate was 74% in 1995, and Mexico’s was 75%. These rates are almost equal to those in high-income countries (78%). Urban environmental and water problems are still in growth in Latin America, but not at the rate comparable with Asia and Africa.
 
 

Institutions

According to Reboucas (1998), the basic problem with Latin American water is not the absolute scarcity—although some parts of Mexico are definitely an exception of this—but …one of instituting more rational and better management practices. He continues: …urbanization and industrialization have been growing explosively, political, institutional, and administrative methods remain undeveloped. I will make a few notes on institutional development below.
 
 

Classification of institutions

Douglass C. North (1990), one of the leading figures in new institutional economics, divides institutions in the following 5 classes:

• Legislative and executive institutions provide the formal rules for selecting the decision-makers and for decision-making, including making, revising, and implementing laws and regulations.
• Juridical ones are responsible of selecting and motivating judges, implementing laws and other formal rules, and other juridical tasks.
• Administrative institutions govern the conduct of bureaucratic activities including relations such as dealings with the public, contracting with the private sector, and responsibility allocation within the bureaucracy.
• Informal institutions cover custom, cultural values, religions, and broadly accepted norms of behavior that constrain the behavior of individuals and groups of people.
• The structure and character of social interests: Group identities and their interrelations defined by ideology, culture, kinship, ethnicity.

Table 5

Examples of formal and informal institutions. The various roles of informal institutions are often overlooked (cf. North 1997)

Typically, the informal institutions have very manifold roles in societies, and their understanding can be a highly complicated and difficult process for an outsider. In S Asia, the mixed, highly important roles of the cast system, ethnic hierarchies and religious issues may easily appear as a sort of fatalism that hinders the development. Yet, ignoring these issues tends to make formal institutions invalid (cf. Bista 1991).
 
 

Top-down vs. bottom-up approaches

In the strata of social units in a society (Fig. 16), 2 opposite directions of information flow can be distinguished. They are from government to individuals (top-down), and from individuals to the government (bottom-up). The top-down approach is characterized by such terms as central planning, command and control, big government, regulations, etc. Terms such as public participation, grass-root initiatives, non-governmental organizations (NGOs), public awareness, participatory approach, etc., are frequently associated to the bottom-up approach.

Fig. 16. Left: Social units: Levels of decision making in the water sector (According to Serageldin 1994). Right: Top-down vs. bottom-up approaches: Selected characteristics

Recent years have seen a shift towards the emphasis of the latter in many agendas. The World Bank (Serageldin 1994) suggests that water decisions should be made at the lowest appropriate level in the society. NGOs have increasingly been recognized as justified partners in decision making, even in UN Summits such as HABITAT II in 1996.

A challenging scheme is to develop solutions that allow the integration of the top-down (governmental) and bottom-up (localized markets, public awareness) implementation and control of water decisions. The decision units concerning water at different vertical levels of the society (Fig. 17) should be closely linked, not only from government level down to households but also to the opposite direction. The participatory approach, based on public awareness, boosting the transfer of decision making to the lowest appropriate level appears to be high in many agendas, in comparison to sectoral, central planning model that has dominated a few past decades. This is a great challenge to institutional building, especially in many third world countries; informal institutions such as NGOs, neighborhood associations, private enterprises and even households should make commitments and be incorporated in the decision-making processes.

The mainstream discussion, however, tends to forget the horizontal direction of the society: there should be enough "social glue" that will keep the society together. Wit this I mean, that the social units that are in the same level with each other should also be working together and fit to one another.

Fig. 17. Positive interconnections between public, private, and informal sectors. The public and private sectors should be able to work in partnership, and the informal sector should support the public sector.
 
 

Conclusions

I have presented an overview of the present situation of water, environment, and development in a global framework, and related Mexico in this context. The task is a huge one, and one cannot avoid many simplifications. I have based this presentation largely on a review of selected statistics and development indicators, which despite of their often very aggregated and simplistic nature, reveal many interesting features for comparative analyses. In addition, I have used results from global assessments of water resources scarcity and vulnerability.
 
 

Mexico’s water development

In terms of economy, Mexico belongs to the so-called middle-income economies. Its GNP per capita is around the world average, but Mexicans belong to the wealthiest 20% of the mankind. This is just an averaged statistic, based on country-level data. Mexico faces a severe poverty problem; its rate of people in absolute poverty, 30%, equals the average rate in all developing countries, among which most countries are markedly poorer than Mexico.

Poverty and unequal income distribution are important obstacles to sustainable development. Although both wealth—in the form of increased resource consumption—and poverty create environmental problems, the former tends to be far more capable of solving or even preventing those.

One of the important cornerstones in solving environmental and social problems is human development, which includes issues such as education, illiteracy, health, and wealth. Whereas the UNDP statistics reveal steady and rather rapid development in human development indicators almost throughout the world, the situation is still very far from good in many parts of the world. Mexico appears to have taken enough steps towards high human development to place the country among the best 1/3 of the world’s nations.

Mexico’s pressures to natural resources are much higher than in most Latin American countries. This is because its dense and rapidly growing population and scarcity of basic resources—water above all. Yet, its water resources availability when related to the population size is above world average; very many countries are much worse off in these respects. The same applies to economical capacity, as well as human resources. Moreover, it already has gone through most of the urbanization development, which most countries in Asia and Africa are just confronting.

Mexico’s challenges for solving its growing difficulties concerning balanced development with water and environment are tough. I started with an anecdote that Mexico lies in many respects around the world’s average. In fact, in several respects, it is well above world average. This means that in the global level, the challenges are equally tough or harder. I used 5 study regions in order to demonstrate the situation in those critical areas, and how they do differ from the Mexican situation. Those regions were China, South Asia, Southeast Asia, the Nile basin, and Sahel/West Africa. The request for sustainable development should not be overlooked in any conditions. The problems grow with an alarming rate in the world. The worse the situation evolves, the more demanding is the solution. Mexico is relatively well off with most of the essential capabilities.
 
 

Global assessments: we must continue to break borders

My personal feeling is that there is still a plenty of room for development of the present global assessments, such as those by Kulshreshtha (1993), Shiklomanov (1993), and SEI (1997). I argue that they generally suffer from higher inaccuracies and uncertainties than the reports themselves reveal, and do not pay enough attention to the various interconnections within the many factors driving the development. This can simply be seen when comparing assessments with one another. Moreover, there is still much of room for increasing their interdisciplinarity. Such features are mandatory in order to increase their applicability in policy advice and analysis. The importance of global studies is unarguable, but there are still major challenges, which partly are related to approaches and methodologies used.

Our ongoing study analyzes the various interconnections of water, food, poverty, and urbanization as a global phenomenon. 45 variables—including development theories, driving forces, impacts on water and land and on socioeconomy, and policy tools —were selected to allow an itemized analysis of interdisciplinary connections.

The above-mentioned 5 key regions are in a closer scrutiny. The time horizon is from 1970 to present, and from the present to 2025. This horizon gives a framework for the analysis of sustainable development and its policy implications, one generation in retrospect and another one to the future.

A computerized technique is used which is based on a network of interconnected probability distributions to analyze the situation in various regions in a more analytical way. The approach is based on a Bayesian expert judgment elicitation scheme (Kuikka and Varis 1997, Varis and Kuikka 1997), which has its roots in Artificial Intelligence.

More details of this study and its background can be found from Varis (1997, 1998a, b), Varis and Somlyódy (1997), Vakkilainen and Varis (1998a, b).
 
 

More interdisciplinarity is needed

It will be more and more difficult and demanding to meet the growing demand from deteriorating supply of water. Decisions and attitudes concerning solutions on capacity such as human development, institutional set-up, water constructions and other technological issues, given the economic and social constraints constitute a challenging entity with no simple answers.

The water issue is not only irrigation, hydropower, water supply, sanitation, but all these and much more. Besides science and engineering, it largely is a political, social and economic entity. The water sector has traditionally been split into narrow, competing branches, but last 10 years have shown a rising concern of interdisciplinary, holistic, and integrated water management. The challenge to water professionals is the enormous growth in the complexity of problem solving, given these new requirements.

This presentation underlines the importance of various uncertainties in the global assessments of water, food, population, economy, and social development. There exists very diverse views on their present, and their future projections are subject to notable mismatches. Political instability and unpredictability, hydrologic and climatic variations and their likely shifts from the observed behavior, economic development, ecological and environmental threats including land and watershed degradation being the foremost issues. The basic message is though clear: there is a rapidly growing pressure to natural resources, and the time constraint to tackle these problems is tough.

There should be more focus on real interdisciplinarity and integration in global assessments. Water should be considered in closer connection with social, economic, financial, environmental, political, and institutional issues to bring the analyses closer to policy making. Comparative, cross-sectorial works are needed. A methodological challenge to cope with interdisciplinarities and extreme uncertainties and complexities is evident.
 
 

References