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The measurements of solar radiation in the IR spectral region is of great significance in understanding physics, chemistry and the radiation budget of the atmosphere. The occurrence of a total solar eclipse on Octo ber 24, 1995 at New Delhi provided a unique opportunity to take some special solar radiation measurements in an infrared spectral region with the use of an IR photometer, the experiments were conducted during, after and before the total eclipse at Neem Ka Thana ( 75°47'E, 27°47'N ) and New Delhi ( 77° 13'E, 28° 39'N ) in the spectral ranges of 0.75 to 1.6 µm and 2.5 to 14.5 µm respectively. The measurements were used to estimate the water vapour ( 0.94 µm and 1.14µm), Ozone ( 9.6 µm ) etc. A significant variation in IR solar irradiance at various window wave lengths during the solar eclipse was observed. Also measurements of tem perature and humidity were made. In the present paper, the experimental set-up and results are discussed in detail.

The present study was conducted to test the efficiency and applicability of the EROSION-3D (Jürgen Schmidt, Berlin,Germany) model in the lower Shivaliks of Northwest India. Two similar micro-watersheds in terms of soil characteristics and land use were selected for calibration and validation of the model. The model was calibrated using the data from seven rainstorms of micro-watershed A and validated using data from 11 rainstorms in micro-watershed B. After calibration, the overall statistical parameters, namely RMSE (0.44 mm), percent error (4.92), correlation coefficient (0.94) and model efficiency (88%), clearly indicate that the model simulated runoff quite well in conditions prevalent in Shivaliks. For sediment yield, the overall statistical parameters, namely RMSE (0.365 Mg ha−1), percent error (12.71), correlation coefficient (0.97) and model efficiency (88.32%), clearly indicate that the model simulated sediment yield also quite well. During the validation process, for runoff, RMSE (1.72 mm), percent error (19.19), correlation coefficient (0.94), and model efficiency (81.25%) and, for sediment yield, RMSE (0.19 Mg ha−1), percent error (17.16), correlation coefficient (0.97), and model efficiency (74.48%) clearly demonstrate the reasonable accuracy of the EROSION-3D model to predict runoff and soil loss from micro-watersheds located in Shivaliks of Northwest India. Therefore, the EROSION-3D may be used as decision support system for soil conservation management decisions in the lower Shivaliks of India.