|Sourcebook of Alternative Technologies for Freshwater Augmentation in some Asian Countries (UNEP-IETC, 1998)|
|Part A - Introduction|
The approach used in this study is based upon literature reviews, field surveys, and discussions with concerned individuals and professionals. An extensive review of the available literature was made by a group of water experts from the Asian Institute of Technology (AIT), Bangkok, Thailand. In addition to the literature available at the AIT library, information was collected from individuals from within the region. Much of the literature reviewed did not contain complete or quantitative information on the various technologies identified, and a significant portion of the available literature was only available in specific countries or from local sources (e.g., unpublished documents, internal papers, etc.), not readily accessible by the study team. Only references to freely available documents have been included.
Field surveys were carried out in Bangladesh, India, Nepal, and Thailand to supplement the results of the literature survey. The four countries were identified, during the initial phase of the study, as countries within Asia that were leading the region in the development and implementation of freshwater augmentation technologies. Within these four countries, various hydrological regions were identified that represent typical hydrological and social areas of Asia, excluding oil-rich west Asia. For example, the rainwater harvesting technologies used in northern and northeastern Thailand represent technologies that could be applied in the southern China and Indo-China regions. Similar climatic conditions also prevail in Laos, Cambodia and Vietnam. Likewise, the conditions in southern Thailand are similar to those in Malaysia, Myanmar, Singapore, and parts of Indonesia. Nepalese conditions represent those in the mountainous areas of the region (e.g., Afghanistan, Bhutan, China (Tibet), and northern areas of Pakistan and India), while the socio-economic conditions in Nepal are representative of those in the smaller, poorer countries of the region, with large rural populations. Conditions in India, a sub-continent with a wide range of physical, social, cultural and climatic characteristics, have relevance throughout Asia and outside. Likewise, the physical and tropical climatic conditions in Bangladesh are representative of many regions in Asia including Sri Lanka, Myanmar, Cambodia, and Vietnam. Local consultants carried out the field surveys and prepared the case studies in the different countries. The Danish Hydraulic Institute, Bangladesh Regional Office, in association with the Water Expert Group of AIT, coordinated the field survey and compiled the Source Book using information drawn from the country reports. These detailed country reports are available from the UNEP Water Branch, Nairobi, Kenya, together with additional information, photographs and illustrations of the various technologies.
The field surveys were carried out in three stages by survey/reconnaissance teams within each of the four representative countries in the region. In the first stage, information on the use, place of use, and characteristics of use of freshwater augmentation technologies was obtained from discussions with resource persons belonging to universities, research organizations, government departments and NGOs. The available literature on freshwater augmentation technologies was also reviewed. In the second stage, informed persons from government departments, research organizations, universities, and international organizations were consulted for more detailed information on the places and types of use of freshwater augmentation technologies. Finally, site-specific, detailed information was collected through a questionnaire survey and focussed group discussions. Questionnaire surveys of heads of households were conducted in randomly-selected individual households chosen from the total number of households within a specific settlement or village. Individuals included in the focussed group discussions included school teachers; members of the local councils; well known farmers, fishermen and industrialists; and representatives of farmers organisations, etc., as well as officials from organizations such as UNICEF and NGOs directly or indirectly connected with freshwater augmentation technologies.
At the conclusion of the field investigations, a Workshop and Expert Group meeting was organised in Kathmandu, Nepal, between 5 and 9 November 1995. In addition to the local consultants who conducted the field surveys, experts and others involved in water resources management and development from throughout Asia were invited to discuss the findings of the study. The Draft Source Book was reviewed and new ideas were received in four focal areas; namely, rainwater harvesting, water conservation and recycling, water quality improvement, and groundwater recharge. It should be noted that rainwater harvesting has been defined in its broadest sense as any process whereby (i) crops or plants are grown by exploiting runoff or directly impounded waters, (ii) human water needs are satisfied by waters drawn from catchments either within or outside an individual household, (iii) fish and other aquatic livestock are cultured using waters drawn from individual catchments or runoff, and (iv) processing and manufacturing water requirements are satisfied by utilizing rainwater in whatever form it is available.
Field surveys in Bangladesh were carried out by the Intermediate Technology Development Group, a non-governmental organization (NGO). Survey teams were sent to each of the five ecological and water planning zones exist within Bangladesh (e.g., the North-Central, North-East, North-West, South-Central-West, and South-East zones). Information on the various technologies was obtained from literature surveys, field visits, questionnaire-based interviews, and focussed group discussions with agency officials and project beneficiaries. Rainwater harvesting was identified as the main, and perhaps only, freshwater augmentation technology being practised regularly in Bangladesh.
Field surveys in Nepal were carried out by D&M Associates, a consulting company specialising in water, environment and sanitation issues in Nepal. Information on the various technologies was obtained from literature surveys, field visits, and interviews and discussions with agency officials and project beneficiaries. Five technologies for freshwater augmentation were identified as being in common use in Nepal; namely, the use of stone spouts and pokharis, spring development and protection measures, rainwater harvesting, bamboo-piped water supply systems, and hydraulic rams.
Field surveys in India were carried out by Prasad Modak and Associates of Bombay, a consulting organisation specialising in water and environmental issues. A literature survey, and interviews and discussions with concerned personnel, were used to prepare sixteen case studies of various freshwater augmentation technologies commonly used within India. The technologies identified included the adoption of industrial water conservation practices, use of reclaimed wastewater, recycling of process water, water harvesting for drinking water supply, traditional soil and water conservation practices, roof-top water harvesting, conjunctive use of surface and ground waters for irrigation, use of evaporation retardants, artificial recharge of groundwater, and use of water sprinkler and drip irrigation technologies.
Field surveys in Thailand were conducted by the Water Experts Group of the Asian Institute of Technology, Bangkok, and by Dr. Sacha Sethputra of the Khon Khaen University. Technologies surveyed in Thailand includes rainwater harvesting for agriculture and domestic use, particularly in the northern and northeastern portions of Thailand, and desalination. A detailed case study of the Thai Rainwater Jar, which has become popular in the Indo-China region, was prepared.