STUDY OF RAINFALL, AND FLOW OF A CATCHMENT, REQUIRED FOR DETERMINATION OF ANNUAL RUN-OFF.

As for as study on the captioned rainfall is concerned the maximum rainfall of a year and the minimum rainfall of another year of a place has been found very variable, for which the study taken on the captioned subject matter deliberation, it has been concluded by the recording made that maximum rainfall (annual) of a place is 1.51 times the average annual rainfall, and the minimum annual rainfall is 0.60 of the average annual rainfall. Average rainfall is (annual) the mean of 35 years. For two consecutive years the maximum rainfall of the both years together will be 2×1.35 ×average annual rainfall and the minimum rainfall will be 2×0.69 × average annual rainfall. As for as the soil erosion is concerned, the washing away of top soil by the action of floods, rainfall or winds where by the soil loses its agricultural productive qualities is the erosion of natural soil occured and the method adopted for prevention of soil erosion is called soil. Conservation. The productive qualities of a soil may also be impaired by excessive use artificial intelligence and fertilizing manures. As for as the forest land is concerned the government is taking cognisance of the Soils Conservation Act -1980 for protecting the natural cover of grass and forests from the ground). Methods adopted for controlling soil erosion or for improving the soil are, Holding irrigation or rain water over the land for long periods or making it flow at a very slow velocity by constructing small bunds  or terraces, growing small plants on the fields at all seasons to hold water, making temporary dams, coffer dams of brush wood against streams and by making detention basins. The state government of Himachal pradesh has issued an instruction not to work on the construction projects till 16-9-2023 as the study of rainfall is found over and above the required variables and now the angle of repose has been gone unstable because of the maximum rainfall and water contents in the soil. As for as it's results on the captioned subject matter deliberation required to be maintained under the catchment area evaluation it is not similar for the other catchment areas, so it is better to use the rational method given under the chapter of drainage, and take use of the same for the flow off of a catchment, required for the determination of annual run -off.