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Pankaj Kumar Roy , Amlanjyoti Kar , Chandan Ray , Asis Mazumdar

Abstract

Shifting cultivation provided a way of life for most of the ethnic groups of north eastern states. Policy approach to deal with shifting cultivation in Arunachal Pradesh aims to replacing it with permanent forms ofland use by cultivation of oil palm as per availability and suitability of land. In Jhum land area oil palm plantation may be promising in the state. However, as per the requirement of climatic factors and availability of irrigation water, the oil palm cultivation could be practiced in areas where a compact area between 450-500 hectares of land and sufficient rainfall and SUlllly days are available. Since, the minimum land requirement for oil palm plantation, advocated by NRCOp, is 500 ha, a total number of nearly 60,000 nos. plant may be grown in such a composite oil palm garden. In view of non availability of a considerable land area of 500 hectares under single holding and cost involvement, community participation should be encouraged. Since irrigation water requirement of each plant is 200 litres per day, total quantity of 12 million litres or 0.012 MCM of water per day would be required for sustainable growth of such oil palm plantation. Various practices of watershed development can also be applied in the sloping terrain. In the foothill areas of Arunachal Pradesh, with optimum minimum temperature of 6-10°C, shallow aquifers may be tapped with shallow tube wells or dug wells/collector wells with infiltration galleries. Surface water/rain water resources could be developed in and around Jhum cultivation areas through construction of check dams in series with sub surface dams and through construction of ponds.

Keywords

Hydrological Parameters, Shifting Cultivation, Jhum Land, Oil Palm

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Subhasish Das ¹, Pankaj Kumar Roy ¹, Asis Mazumdar ¹

Affiliations
1 School of Water Resources Engineering, Jadavpur University, Kolkata, West Bengal, IN

Abstract

Management measure for Irrigation water by tidal back-water influx is an important issue for the sustainable living of rural communities in the areas where the rainfall is insufficient for rabi crop cultivation. Tidal back-water influx is one of the sources of irrigation water in the lower gangetic planes of West Bengal, India. Based on that concept, a plan is provided for the Magrahat basin of South 24 Parganas district in West Bengal for the augmentation of irrigation facilities through excess amount of tidal back-water entry during the post-monsoon period when the salinity of water is considerably low. In the present study, twenty major canals or khals of Magarahat basin are considered. Volume of available tidal water for irrigation of rabi crops was determined from the gauge data of tidal rivers. Here an attempt has been made to delineate not only the enhancement of the economic return of the people of the Magrahat basin but also to create provision for multi-cropping (rabi crops) pattern of agriculture/horticulture facilities during the dry season for sustaining of their livelihood. Also the tidal backwater surface profiles have been suggested for all the major canals of Magrahat basin using standard step method of gradually varied flow.

Keywords

Water Availability, Tidal Back-Water Influx, Gradually Varied Flow, Water Requirement of Crop, Water Distribution Management.

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