International Archives of Photograrametiy and Remote Sensing. Voi. XXXII Part 7C2, UNISPACE III, Vienna. 1999 
30 
ISPR5 
UNISPACE HI - ISPRS Workshop on 
“Resource Mapping from Space” 
9:00 am -12:00 pm, 22 July 1999, VIC Room B 
Vienna, Austria 
ISPRS 
utilized lands. Globally, key problems threatening natural 
resources and sustainability of life support systems are: (i) soil 
degradation (ii) the availability of water and (iii) the loss of 
biodiversity'(Humi, 1997). 
For sustainable development of natural resources Humi (1997) 
has advocated an approach viz. sustainable land management 
(SLM) and is of the view' that the natural resources can 
potentially be used in a sustainable w ; ay if appropriate land 
management teclmology, regional planning and the policy 
framework complement one another in a purposeful way in 
accordance with the principles and concepts of SLM. 
Sustainable land management (SLM) lias been defined as “a 
system of technologies and/planning that aims to integrate 
ecological with socioeconomic and political principles in the 
management of land for agricultural and other purposes to 
achieve intra- and inter-generational equity (Dumanski. 1994; 
Hurni, 1996). SLM , thus, comprises of three development 
components, namely technology, policy and land use planning. 
3. SUSTAINABILITY 
Sustainability refers to qualitative and quantitative continuity in 
the use of a resource. It implies a state of equilibrium between 
human activities as influenced by social beliavior, acquired 
knowledge and applied technology, on one hand and the food 
production on the other (Farshad and Zinck, 1993). 
Sustainability attempts not only to address global issues, such as 
resource degradation, deforestation and ozone layer depletion, 
but also local issues, such as maintenance of eco-and socio-eco 
systems or a combination of these. Sustainability of natural 
resources depends on their resilience and carrying capacity. 
Resilience refers to how easily a soil can recover lost fimctions or 
restore the balance among functions (Warkentin, 1995). Further, 
resilience of land when under stress due to inadequate 
management is. in fact, central to sustainability. In agro 
ecosystems resilience lias been defined as “The ability of a 
disturbed system to return after new disturbance to a new 
equilibrium (Blum and Santelises, 1994). Central to the concept 
of resilience in agricultural system is the soil architecture and its 
recovery- after damage. Carrying capacity refers to the maximum 
number of a population that can continue to live at a pre-defined 
level of well-being and in a limited area without causing 
irreversible changes in the envirorunent, so that its living 
conditions deteriorates and its growth declines (Farshad and 
Zinck, 1993). There are several perspectives of sustainability, 
namely economic, ecological, social and an optimum mix of 
ecological and economic perspective. From ecological view 
point, sustainability may be defined as "an increasing trend in 
production over time per unit consumption of the non-renewable 
or limiting resources or per unit degradation of soil and 
environmental characteristic. The dominantly economically 
oriented perspective puts more emphasis on economic aspects. 
Natural resources are either disregarded or only marginally taken 
into account (Ikerd, 1990). The role of such factors of 
production as the availability of natural resources and 
environmental services, but also that of environmental impacts as 
products of economic activity are neglected. In the eco-friendly 
economic development perspective, the ecological equilibrium is 
taken as norm and the focus is mainly on building up a pattern 
and a rate of resource use which the environment can sustain 
indefinitely (Wilkinsoa 1973). Lastly, the social perspective 
lays more emphasis on continued welfare of the society'. The role 
of economic - demographic interrelationship is either explicitly or 
implicitly referred to. 
4. ACHIEVING SUSTAINABILITY 
Over exploitation of natural resources, as pointed out earlier, lias 
led to land degradation of varying degrees. In order to achieve 
sustainability' of our natural resources, efforts need to made to 
prevent further deterioration of degraded lands, to employ 
appropriate soil and water conservation measures to arrest soil 
loss and conserve soil moisture for vegetation growth, to restore 
and improve soil fertility, followed by adoption of suitable soil 
and water management practices to maintain soil fertility in the 
long mu 
For preventing soil degradation alley cropping - raising fast 
growing trees between broad beds of field crops to develop 
conditions similar to the recycling system of the original forest 
ecosystem need to be practiced. Arresting soil loss from severely 
eroded lands under cultivation, on the other hand, could be 
achieved by switcliing over to fallowing for at least 10 years 
period from existing annually tilled crops. Such a practice allows 
regeneration of the resource base. 
Managing the non-crop period especially before onset of 
monsoon w'here soil erosion is very severe, is a key to sustainable 
development. Such a practice aims at minimizing undesirable 
material flows from agro-ecosvstems. The noncrop period is to 
be used to increase the diversity and complexity of agro 
ecosystems . Cover crops could be seeded during the life cycle of 
existing crop to serve ecologically important functions including 
erosion control, suppression of pests, alteration of pest cycle, and 
fixation and bio cycling of nutrients. 
These are. however, several constraints, namely agro-ecologic, 
agronomic, technologic, social, economic, institutional and 
political on achieving sustainable development. Constraints 
occur mostly at two levels i.e. the farm level, where application 
takes place, and the policy-making level, where many of the 
application conditions are set in. At the farm level for example, 
sustainability is controlled by the limited resources of the 
production unit but also by national and international policies 
(e.g. the General Agreement on Tariff and Trade). Policy making, 
in turn, is conditioned by global programs (e.g. Agenda 21 and 
birth control programs). 
5. SUSTAINABILITY INDICATORS