HYDROLOGICAL BEHAVIOUR OF SMALL WATERSHEDS UNDER DIFFERENT LANDUSES IN CHAMBAL RAVIES

Abstract

AN INVESTIGATION WAS CARRIED OUT FOR SEVEN YEARS (1979-85) TO COMPARE HYDROLOGICAL BEHAVIOUR OF (I) 0.4 ha AGRICULTURAL WATERSHED UNDER SORGHUM + PIGEONPEA (1:1) RATIO WITH (II) 0.85 ha RAVINE WATERSHED PLANTED WITH ACACIA NILOTICA ALONG WITH DICHANTHIUM ANNULATUM IN BETWEEN ROWS AND (III) 1.45 ha RAVINE WATERSHED UNDER DICHANTHIUM ANNULATUM ALONE. SEVEN YEARS AVERAGE ANNUAL RAINFALL (653 mm ) WAS 17.3% LESS THAN 25 YEARS AVERAGE ANNUAL RAINFALL (790mm) . RESULTS OF SEVEN YEARS STUDY REVEALED THAT AVERAGE MAXIMUM RUNOFF AND SOIL LOSS (14.2% AND 2.79 t/ha) WERE FROM AGRICULTURAL WATERSHED HAVING MILD SLOPE (1.1%) WHILE MINIMUM (2.25 % AND 6.54 t/ha) FROM WATERSHED HAVING STEEP SLOPE (24.5%) . RUNOFF AND SOIL LOSS FROM WATERSHED HAVING STEEP SLOPE (37.5%) WERE 4.9% AND 1.06 t/ha , RESPECTIVELY. THIS INDICATES THAT DICHANTHIUM ANNULATUM IS MOST EFFECTIVE IN REDUCING RUNOFF AND SOIL LOSS.