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

Conference ·
OSTI ID:140042
;  [1];  [2];  [3]
  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; TRN: 93:024760
Resource Relation:
Conference: International symposium on growth and water use of forest plantations, Bangalore (India), 4-7 Feb 1991; Other Information: PBD: 1992; Related Information: Is Part Of Growth and water use of forest plantations; Calder, I.R.; Hall, R.L. [eds.] [Inst. of Hydrology, Wallingford (United Kingdom)]; Adlard, P.G. [ed.] [Oxford Forestry Inst. (United Kingdom)]; PB: 395 p.
Country of Publication:
United States
Language:
English