Application of GIS for Water Harvesting in Tea Planted on Hillocks in...

Application of GIS for Water Harvesting in Tea Planted on Hillocks in Assam

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Er. P.K. Bordoloi Scientist Gr IV (4)
Tocklai Experimental Station, Tea Research Association,
India
Email: [email protected]

In Assam tea is largely planted on flat alluvial terrains of the Brahmaputra and the Barak valley as well as hillocks and plateaus of the Barak valley. Highly uneven rainfall distribution in the north eastern region of India give rise to two fold water management problem for tea plantation in the region – (a) flooding and water logging due to excessive summer rainfall, and (b) moisture stress due to lack of rainfall in cold winter months. In case of tea plantation on the hillocks another dimension of the problem is added – soil loss and land slide in summer monsoon season and aggravation of moisture stress particularly on south and western aspect of the tea plantation on hill slopes. The Barak valley owes its origin to tectonic activity of this seismically active region. Tea is planted on small hillocks, locally known as teelah, which consists of 35% of the total plantation area of 38270.50 ha, plateau and high flats consists of 60% and the low peat area occupies 5%. These low lying areas are intervening low flat lands between two hillocks, very rich in organic matter content but are subjected to severe waterlogging and flooding in summer due to low relief. Tea planted in such areas is prone to flooding and waterlogging. Tea plant is very sensitive to waterlogging which impair the growth and productivity of the plantation, give rise to secondary root disease – violet root rot under prolong waterlogging which culminates in crop failure if ameliorative measures are not undertaken timely. In winter tea plants undergo dormancy as the weather condition favourable for growth like day length, photoperiod, minimum temperature etc are not met. In the dry cold winter the plant experiences moisture stress that continued till April. It affects the productivity of the first flush tea, which usually fetch higher price for better quality. At the backdrop of these problems and climatic and topographic condition of the tea plantation Tea Research Association had taken up an investigation with satellite borne Remote Sensing and GIS as diagnostic tool and came out with a solution for water harvesting in low valley fill waterlogged areas between the plateaus, hillocks and high flats and is presented in this paper.