The soil moisture regimes beneath forest and an agricultural crop in southern India--Measurement and modelling

Conference · Thu Dec 31 04:00:00 EST 1992

OSTI ID:140042

Harding, R J; Hall, R L ^[1]; Swaminath, M H ^[2]; Murthy, K V ^[3]

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1. Inst. of Hydrology, Wallingford (United Kingdom)
2. Karnataka Forest Dept., Bangalore (India)
3. Mysore Paper Mills, Shimoga (India)

The environmental effects of plantations of fast growing tree species has been a subject of some controversy in recent years. Extensive soil moisture measurements were made at three sites in Karnataka, southern India. At each site measurements were made beneath a number of vegetation types. These included fast growing tree species (Eucalyptus, Casuarina and Leucaena), degraded natural forest and an agricultural crop (ragi). The measurements indicate that beneath mature forest the available soil water is exhausted towards the end of the dry season, usually by March. The soil only becomes completely wetted if the subsequent monsoon has above average rainfall; during the weak monsoon of 1989 the soil remained approximately 150 mm below field capacity. After the monsoon (and during breaks in the monsoon) soil moisture depletion is between three and five mm per day. This rate decreases as the soil drys out. All the mature forest types show a similar soil water regime. This contrasts strongly with that of the agricultural crop, which shows much smaller changes. A range of soil water accounting models was applied to these data. The most successful are those which use the Penman formulation to estimate the potential evaporation and include a two-layer soil water depletion model. The more general Penman-Monteith formulation was also tested.

• OSTI ID: 140042
• Report Number(s): CONF-9102202--; ISBN 0-471-93561-1
• Country of Publication: United States
• Language: English

Related Subjects

09 BIOMASS FUELS
AGRICULTURE
BIOMASS PLANTATIONS
ENVIRONMENTAL EFFECTS
FORESTRY
INDIA
MATHEMATICAL MODELS
MOISTURE
RAIN
SILVICULTURE
SOILS
WATER USE