2. RESULTS AND DISCUSSIONS
The population density computed for each sub-basin is listed in Table 3. Yenneholé sub-basin, which is a part of Sharavathi Wildlife Sanctuary, has low population density. Among all sub-basins, Haridravathiholé sub-basin on the eastern part has high population density (112.49 persons/sq. km). Trends in population change over six decades were analysed for eastern, central and western sub-basins and is depicted in Figures 4, 5 and 6 respectively. In the eastern part of the study area, apart from Haridravathiholé sub-basin, Nandiholé and Mavinaholé sub-basins have low rates of population increase. The Sharavathi sub-basin and central zone recorded rapid increase compared to the neighbouring Hilkunjiholé sub-basin. Similarly, population increase is comparatively higher in Hurliholé and Yenneholé (western part) than the Nagodiholé sub-basin.
From Table 4, it is evident that the majority of the households (92.17%) still depend on fuelwood for their cooking energy needs followed by biogas plants (10.06%) and LPG (3.80%). This higher dependence on fuelwood is due to the availability forest resources in the immediate vicinity at zero cost. Two types of fuelwood collection are observed in the region namely, daily collection and seasonal collection.
The daily fuelwood collection is the task performed by women who normally spend about 1–5 hours to collect dry and fallen trees from forest areas during non-rainy seasons. The seasonal fuelwood collection is usually performed by men (from nearby households in a group) during summer for usage in monsoon. It involves mainly lopping of trees and some times it is more harmful to the forests as full tree is removed. It was seen that the fuelwood extraction is not uniform over the entire forest patch. The forest areas nearer to human settlements tend to be more deteriorated. Also, normally people cut tree branches or trees, as collecting dead and fallen tree parts are a tedious and time-consuming task. Less dependence on LPG may be due to the lack in availability of resources, infrastructure and higher costs.
The study shows that there is enormous potential for the biogas technology over the study area to replace the usage of fuelwood in domestic energy for cooking. Biogas has a higher heating value than producer gas and coal gas, which implies increased services. As a cooking fuel, it is cheap and extremely convenient. Based on the effective heat produced, a 2m3 biogas plants could replace, in a month, fuel equivalent of 26 kg of LPGor 37 litres of kerosene or 88 kg of charcoal or 210 kg of fuelwood or 740 kg of animal dung cake. It is a clean fuel without any health hazards or offensive odour and burns with soot less, clean bluish flame thereby making cleaning of cooking utensils easier. Biogas technology has enhanced energy supply decentralization, thus enabling rural areas to meet their energy requirements especially when the commercial fuels are inaccessible. In terms of cost, biogas is cheaper than conventional biomass fuels (dung cakes, fuelwood, crop wastes, etc.) as well as LPG, and is only fractionally more expensive than kerosene. Biogas systems have attracted considerable attention for the potential of waste recycling, pollution control and improvement of sanitary conditions, in addition to providing fuel and manure free of pathogens.
All surveyed houses use twigs and horticultural residues (coconut wastes, etc.) for water heating. In Sagar taluk alone, out of 230 sampled houses, 141 areca land owners use green manure for the plantations. Green leaves required for this purpose, are obtained from the forestland. Each areca plantation owner is permitted by the government to use forests (in the ratio 1:9) for collection of leaves. Farmers lop trees in one-third of the allocated forest area and use green leaves for mulching, while twigs and branches are used for energy production. This method of collection results in canopy opening and degradation of forest patches. This necessitates the exploration of viable energy alternatives to conserve forests while meeting the growing energy demand.
Cooking and water heating are the major domestic end-uses of wood energy. Space heating during winter is met either along with water heating or in paddy fields while guarding the crops from wild animals.
Quantification of fuelwood requirement specifically for this activity is difficult. The per capita fuelwood consumption for cooking and water heating among landholding category is given in Table 5. Seasonal variation can be clearly seen for water heating as the region experiences extremes in temperature throughout the year. There is no significant variation in cooking fuelwood consumption. Average annual fuelwood consumption by an individual including all activities amounts to 1.2 tonnes. This value is double the national average of 0.7 tonnes/capita/year (Ramchandra et al., 2000a; Sinha et al, 1997). A similar trend of fuelwood consumption was observed in the neighbouring Uttara Kannada district, which showed a yearly per capita fuelwood consumption of 1.44 tonnes (Ramachandra et al, 2000b).
Analyses of fuelwood requirement with respect to income show a linear declining trend as shown in Figure 7. The low-income groups depend on fuelwood as a source of cooking energy. Increase in income promotes the people to afford alternative energy sources like biogas, etc. This transition in the energy ladder has considerably reduced the dependence on fuelwood. The household survey shows that out of 43 biogas owners in the sampled households, 33 households have an annual income of Rs. 30,000. Further, out of the 17 LPG owning households, 16 households have an annual income above Rs. 30,000. However, most of the households in this region belong to low-income category and cannot afford LPG, etc.; there is a scope for energy interventions in the form of improved energy-efficient fuelwood cook stoves or biogas with appropriate financial incentives, service back up, etc.
Due to the changes in socio-cultural practices, livelihood aspects and accessibility to resources, the energy consumption pattern in landless category shown in Table 6, seems to vary from that of landholding category. This category is solely dependent on fuelwood for cooking and water heating activities. Based on this, the annual consumption of fuelwood works out to be 1.16 tonnes/capita. Seasonal variation is seen in fuelwood consumption for cooking as well as water heating. During field survey, it was observed that all households depend on traditional devices for cooking, which are energy inefficient. Use of biogas, LPG and kerosene is absent for cooking.
To assess energy in industry sector, sample survey was conducted for 32 industries out of 112 industries, which depend on biomass. Totally about 112 natural resource based industries were surveyed for analysing the composition and employment abilities of the small-scale industries of the region and results are given in Table 7. These industries being situated in the sub-urban areas of the region, serve as the source of employment to many local people. Wood based industries such as carpentry, manufacture of cane products, etc., constitute 64.29% of the total due to the cheap and easily available wood in the region. This is followed by agriculture-based industries like rice and flourmills with 18.75%.
Sub-basin wise bioenergy status was computed to evolve specific management strategies based on the local conditions, which is given in Table 8. This shows that the
eastern and southern sub-basins have percentage utilisation greater than 30. The subbasin wise area and bioresidues available for areca (Areca catechu) and coconut (Cocos nucifera) are given in Tables 9 and 10 respectively. These residues (and bagasse during seasons) are most commonly used as a source of fuel for water heating. Bagasse is the fibrous residue left after extracting the juice from sugarcane (Saccharum officinarum). The quantity of bagasse depends on the fibrous content of the sugarcane and is in the range of 30–32%, which is a rich energy source. The area under sugarcane in the river basin is 281.82 ha with a production of 17,094 tonnes. The bagasse available is about 5470.08 tonnes, which has an energy equivalent of 19145.28 million kcal/year. One tonne of bagasse can generate 2.5 tonne of steam in steam generators. Bagasse is used as a fuel in improved jaggery making stoves in Baniga village of Hosanagara Taluk. With this, the plant has attained self-sufficiency in terms of fuel requirement. This technology has not reached all places in the river basin, which is evident from the survey that most households still use, huge wooden logs in traditional stoves (with efficiency of 5–8%).
Agricultural households own 5–6 animals (considerably high number) for manure, tilling and transportation purposes. Free fodder availability due to vast grazing areas in the region has contributed to higher number of livestock per household. Table 11 show sub-basin wise livestock population and dung yield, while Table 12 gives the biogas availability with potential for cooking energy. The dung yield by livestock depends on various factors and differs from place to place. Usually the effective dung available from stall-fed animals is more than that of grazing animals. Similarly, dung available during monsoon and winter is more due to the availability of sufficient green fodder compared to summer. It is estimated from the survey that, the average dung yield by various livestock is 7.82 kg/cattle/day, 12.64 kg/buffalo/day, 10.3 kg/bullock/day, 1.95 kg/sheep/day and 1.95 kg/goat/day. Table 13 shows the extent of stall-feeding and open grazing by different livestock. Grazing in forests reduces the effective dung available and also harms forest regeneration.
Table 14 illustrates the role of family income in energy transition as biogas plants are found more in high-income households. However, there are several nonoperational biogas plants due to technical snags. This necessitates proper training and awareness among the villagers as well as local service units with trained technicians to handle energy efficient devices. Among the 91 surveyed landless, lowincome category households, none of them had biogas plants mainly due to high installation cost, space limitation and lack of service support in post installation period.
Table 15 shows the relative share of various fuel types in the river basin. In all the sub-basins, nearly 90% of energy potential is of forest resources. This also accounts for energy used in the commercial sectors such as hotels, and fuelwood used during festivals, etc., which is about 30% of the total energy consumption. To understand the sub-basin wise bioenergy status, percentage share of energy demand to the availability is computed and is listed in Table 16. This reveals that Hilkunjiholé (61.8%) and Haridravathiholé (57.2%) sub-basins need immediate intervention to prevent further degradation of natural resources.Central zone, Nandiholé, Sharavathi and Mavinaholé sub-basins are having moderate availability of resources.
The participatory approach in forest management with 23VFCs was initiated in the study area in 1996. The data of 10VFCs illustrates that about 286 ha of land was brought under plantations, within which, 215 ha was of Non-Timber Forest Produce (NTFP) type and remaining 71 ha was of Acacia plantation to cater the fuelwood requirement.
The data collected on the plantation activities in sampledVFCs show that the scheme formulated from ecological and energy point of view has lost its significance due to the improper selection of species and plantation area. The vital objective of the JFPM scheme to fulfil the daily fuel, fodder and food requirement of the local population is deprived due to monoculture plantations. Apart from this, VFCs failure in protecting the degraded land and forest patches is leading to considerable decrease in regeneration.
Land use analysis (Table 17) shows that Haridravathiholé has about 34.7% barren area. Similarly, in all the sub-basins, the percentage barren lands available ranges between 10 and 35%. Thus, there is greater scope for initiating energy plantations in the eastern clusters where there is urgent requirement for energy planning. The selection of the species considering the local needs in terms of fuel, food and fodder, through active public participation will ensure the success of the programme.
Analysis at the sub-basin level illustrated that the energy situation varies within various sub-basins and correspondingly the management strategies need to be designed. Decentralized approach can be considered for planning the energy interventions. By introducing the improved fuelwood cook stoves, fuelwood consumption can be reduced considerably. Because, the most commonly used traditional cook stoves have very less efficiency of 10%. Fuel efficiency studies (Ramchandra et al, 2000) conducted in 82 households showed that for cooking, there is a fuel saving of 42% in improved stoves compared to traditional stoves, whereas, for water heating, the fuel saving is 19–24% with improved stoves. Use of improved stoves for cooking activity and water heating can save annually about 38,600 tonnes and 16,507 tonnes of fuel wood respectively.
Along with this, restriction on open grazing in the forestlands and promotion of stall-feeding allows regeneration and increases the effective dung availability. Thus, appropriate livestock rearing with the introduction of improved varieties along with natives would enhance the dung yield for biogas as well as manure. According to the data, about 88% of the total households have the potential to install biogas plants. At least 60% utilization of this resource can lead to fuelwood saving of 8839.8 tonnes annually. The estimation shows that about 119 villages have the potential to supplement the cooking energy for more than 60% of the total population.
Monsoon paddy cultivation is practiced in the study area. After the crop is harvested, the fields are kept unused until the next season. In this regard, farmers need to be properly guided to suitably select the cropping system depending on water availability such as cultivating horse gram in areas where moisture content is less. Fodder cultivation can supplement fodder requirement for the livestock, which can be stall-fed considerably, there by increasing the dung yield.
The Gram Panchayath (at village level), Revenue and Forest Departments should take active participation in energy planning and development. With proper training to the village people as well as departmental staffs, it is possible to manage their own ecosystem with effective scientific guidance. JFPMoffers an opportunity to increase the forest wealth of the region. If sufficient protection is provided, the forests in the study area, though under extensive population pressure, can retain self-regenerating capacity due to highly favourable environmental conditions. If this protection is extended to other degraded areas of the river basin with complete protection from destructive wood collection, grazing by animals, etc., there is tremendous scope for re-establishing the healthy forests in most of the study area.