|
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
 |
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
State of water environmental issues
2.2.5. Detailed survey of surface water in the Tonle Sap Great Lake catchment2.2.5.1 Potential groundwater in studied areas Table 9: Potential groundwater resources by province
Table 10: Estimated potential groundwater per capita and by province in 1997
Despite this rough estimation, figures obtained reflect the under-exploitation of groundwater in the majority of provinces of the Tonle Sap Sub-area (There is no data available for Pursat, Banteay Meanchey, Oddar Meanchey and Krong Pailin.) Kompong Thom Province, with only an average volume of 2.2 litres per capita of groundwater is dominates other provinces. The situation in Battambang was critical in 1997 because potential available groundwater is non-existent for the population (only three productive wells were found with an extremely low average yield of 25 litres/m). 2.2.5.2.Water uses by sectors in Kampong Chhnang, Battanbang, Pursat, Kampong Thom, Siem Reap, Banteay Meanchey, Preah Vihear, Otdor Meanchey and Pailin Dmestic and other purposes: The use of water is the part of consumptive demand that is actually served at a given time. Many such uses generate a return flow, for example as sewage, or as irrigation tail water. The return flow can occur at a different time or place than the withdrawal, for example in the case of a storage reservoir retaining water during part of the year and releasing it in a different part of the year. The use of water can be increased by infrastructural development and reduced by demand management. An important part of water resources analysis is the examination of the scope for balancing the availability and demand of water under different assumptions about availability. During this analysis, a clear distinction should be made between water availability (water resources generated), water demand, and actual water usage. This is in order to prevent ends and means becoming mixed up. Water consumption by industrial sector: Water is necessary for all industrial activities, including cooling processing or manufacturing operations, power generation, cleanup and other sanitary purposes, and fire protection. The quality and quantity of industrial water demand varies significantly by country, industry and particularly uses, ranging from high water quality for the beverage industry to brackish water or treated municipal effluent for cooling purposes. Urban water usage is estimated at about 100 litres per person per day, for a total average annual supply of 36 million m³ for other urban centres in Cambodia. The total water usage represents about 0.01 percent of the flow in the Mekong River (Water Utilization Program, 2001). It is assumed that most Phnom Penh wastewater transported to the Delta will travel via the Bassac River. However, with the distance from Phnom Penh to the Vietnam border (about 110 km) and high water temperatures (about 29 degrees Celsius) in the Bassac River, the rate of decomposition of any organic matter discharged from Phnom Penh will be rapidly broken down and organic types of pollution are not likely to reach the border of Vietnam (Hart, 2001).
2.2.5.3. Intensification of fisheries Unsustainable fishing is taking place, notably on the Tonle Sap River. Although total catch may not be decreasing, the catch per fisher is. In addition, the share of large and medium-size, higher-value fish has declined. Mangrove forests are being degraded for charcoal extraction and aquaculture. Illegal fishing is increasing. Development of intensive aquaculture may generate destructive environmental effects. 2.2.5.4. Threats to water resources Water environment in general: A major environmental assumption outside the control of the project is that works in the Upper Mekong Basin have no substantial negative impacts on the hydrology and water quality of the Tonle Sap. It is currently unclear what the nature of the impacts might be. 2.2.5.4.1. Water pollution There has been an increase in domestic waste, untreated industrial effluent, the use of agrochemicals, and discharges and spillage of oil and fuel. A number of literature has indicated that the general level of pollution is still low, although some problems exist locally, for instance in and around floating villages. Despite this, some studies express concern about the results of human activity. In 2000, an estimated 1.3 million litres of pesticide were used in the catchment areas of the lake, including many highly hazardous chemicals such as DDT, methyl parathion and monocrotophos imported from neighbouring countries. It was recently reported that ten tons of DDT and Folidol (methyl parathion) used on 2,000 hectares of mange bean crops had run off into the Tonle Sap Great Lake. The impacts of pesticide use on ecological security have yet to be assessed, but are potentially acute. Toxic chemicals in high doses can cause acute sickness and death. In 2001, the media broke a story on a case where people died from eating poisonous fish in Siem Reap province. Although there is no proof that the cause of death was because a direct result of fish consumption, it gives an indication that monocroptophos is a cholinesterase inhibitor that disrupts the nervous system, causing acute effects including weakness, pain, vomiting, and blurred vision. The ingestion of less than one tablespoon of liquid can kill an adult. Other chemicals, particularly persistent organic pollutants, are concentrated in the food chain and display long term detrimental effects such as DDT. DDT can cause changes in avian courtship behaviour, delays in egg laying, eggshell thinning and embryo death. The fish samples taken from the Lower Mekong Basin indicate that pesticide residue is ubiquitous with the highest concentration in catch fish species. The widespread uses of fertilisers in the dry season can also affect the ecology of the lake, causing localised temporary eutrophication and even death in fish. In early 2002, many fish died. Some experts concluded a link with the death of many fish in the lake to the eutrophication phenomena and the low level of water to a shortage of oxygen. As the river had less water than normal and the river floor contains mud, the movement of motorboats in the lake increased the turbidity in the water, which caused the fish to die. Fish have varying sensitivities to pollutants in the aquatic environment. In many cases the pollutant itself may not be lethal, but it acts to reduce the fish’s ability to cope with disease or reduces its ability to produce viable offspring, thereby significantly impacting species reproduction. Cambodia's population is mostly concentrated around the lowlands and near inland freshwater. Freshwater bodies are becoming more polluted where people are living in or near water. There are two major causes of water pollution: industrial waste, including waste from small industries and the agricultural sector, and domestic waste. Cambodia's urban areas have limited domestic waste management infrastructure and most domestic waste goes directly into waterways as a point-source (pipe) discharge without treatment. This not only pollutes the waterways with toxic and disease-laden septic water but also adds nutrients which foster low oxygen concentrations through localised eutrophication. Such pollution will harm more fragile fish than hardy fish species, and will simplify the species diversity. Health issues for humans that eat fish from these waterways may also develop. Small industries are becoming established as Cambodia's economy is starting to grow, but there is no effective management for their waste. Most small industrial waste is directly or indirectly discharged into local waterways. Pollution from agricultural run-off is becoming more common due to an increasing use of chemicals, such as fertilisers, herbicides and pesticides. 2.2.5.4.2. Water settlements In Cambodia, water settlements mostly occur along the Mekong River, Bassac River, and areas surrounding the Tonle Sap Great Lake. Besides settlements, floating restaurants are also present. In Phnom Penh Municipality, floating restaurants are growing more rapidly along the Mekong and Bassac rivers in response to customer demands for fresh air and natural aesthetics. Competition among owners of floating restaurants can put more pressure on the natural and aquatic environments. Most people who live in floating communities in Phnom Penh Municipality are Vietnamese, but floating communities surrounding Tonle Sap Lake are composed of different nationalities such as Khmer, Chinese, Cham, and Vietnamese who have different careers. Floating communities in the Tonle Sap Lake areas seasonally move from place to place. 2.2.5.5.Population pressure Migration towards the Tonle Sap Sub-area is of concern due to anarchic resource exploitation and serious environmental degradation. If the provinces of Oddar Meanchey, Banteay Meanchey and Pailin City have been preferred destinations for migrants for the past five years, Battambang, Pursat, Kompong Chhnang and Preah Vihear Provinces are now under pressure. Development of tourism, infrastructure improvement and foreign investment are major factors encouraging migration towards urban areas where employment opportunities are created. 2.2.5.6. Inundated forestry degradation Over the last 40 years, forest cover has declined from about 75 percent to about 55 percent of total area. Success of the government’s effort to control forest exploitation is limited. Rapid degradation of flooded forests will inexorably result in irreversible harm on the fish and wildlife ecosystems due to the disappearance of forest cover and degradation of water quality. 2.2.5.7.Booming Tourism Governmental policies aiming to encourage the development of tourism in Cambodia, e.g. Open Sky Policy and modernisation of the airport, resulted in a boom in tourism. The presence of numerous archaeological sites in the provinces of Siem Reap, Kampong Thom, and Preah Vihear, etc., contributes to the local and national economy with the use of foreign currencies. But a number of side effects are also generated from increased water use, archaic waste elimination and rapid social mutation. Development of ecotourism remains embryonic despite unique and valuable biota in the Tonle Sap basin. 2.2.5.8. Impoverishment of the vulnerable Despite the abundance of its natural resources, the Tonle Sap provides an inadequate lifestyle for most of the inhabitants of the provinces that adjoin it (Battambang, Kampong Chhnang, Kampong Thom, Pursat and Siem Reap). Half of the villages have between 40 to 60 percent of households below the poverty line with a peak of 80 percent in some areas. Many households have no land holdings and are entirely dependant on fishing and foraging, with access to fishing areas often under dispute. If conflict and instability are major causes of poverty, impoverishment originates from poor access to health and education services, lack of land ownership, women’s social deprivation and increasing vulnerability to natural calamities. Demographic pressure on the environment resulting in degradation is also a mechanism of impoverishment of the vulnerable in terms of limited access to resources. This trend is aggravated by the inadequacies of the governance system. 2.2.5.9. Navigation and road development Maximization of natural assets consisting of abundant water bodies implies development of navigation serving tourism, transportation, fishery and agricultural trade. Despite serious competition from inland transport via almost rehabilitated National Routes No. 5 and No. 6, navigation remains crucial for shipment between Phnom Penh Municipality and the Tonle Sap region for fish, crop production, agricultural inputs, gasoline and heavy equipment. Tourism in Siem Reap is an economic catalyst for navigation in the Tonle Sap region. Despite its poor network, navigation remains an important opportunity of mobility for the majority of poor rural people in the Tonle Sap Sub-area. The rehabilitation of National Routes No. 5 and No. 6 has already reduced travel times to the major towns in the Tonle Sap Sub-area by several hours. With the expected completion of the route between Ho Chi Minh City in Vietnam and Bangkok in Thailand and ASEAN plans to liberalise cross-border traffic flows, enormous changes will occur in terms of the flow of people and goods, access to markets, knowledge and technology and the economy. This will completely recast all activities and mindsets in the Sub-area, both opening up large opportunities and bringing with it many potential threats and dangers. Coping with this change will be a key trend for the foreseeable future. 2.2.5.10. Ongoing decentralisation process The success of the decentralisation process is strongly conditioned by the effective participation of grass-roots communities in planning, decision-making and monitoring-evaluation. Resource management in the Tonle Sap basin is a national and regional challenge for the government in the context of economic and political liberalisation, with its unavoidable conflicts of interest among local actors. Capacity building and good governance tend to be key pre-requisites for accountable and equitable resource management to alleviate poverty in the Tonle Sap Sub-area. Increased awareness is rising in local communities and authorities about the potential and fragility of the ecosystem as another enhancing factor for sustainable and pro-poor exploitation of natural resources. References
|
| pagetop |
| POLICIES | TECHNOLOGIES | NGOs & CBOs | SOURCES |
| Home | About WEPA | What's new | Activities | Definitions | Link | Sitemap | Contact Us |
|