Tiêu đề Soil and Water Conservation Engineering1.pdf ✅

Practical Manual On Soil and Water Conservation Engineering 2019 Jharkhand Rai University Ranchi
50 Preface Out of the173.5 m ha of the total degraded land of our country, nearly 95 m ha suffer from soil erosion, which constitutes 82.6 m ha erosion through water and 12.4 m ha erosion through wind. Annually 16.35 t soil/ha is lost through water erosion and in this process 5.4-8.4 t/ha nutrients are lost. The loss of valuable fertile soil and nutrients causes 5-50% decline in crop yield, siltation of water reservoirs and thus reducing their capacity and useful life, raising the beds of streams and rivers thus reducing their capacity and consequently spilling of the floodwater into the adjoining areas. So there is a need to understand the mechanisms involved in soil erosion and developing techniques to measure the loss of water through runoff and loss of soil through erosion. This will help to develop technologies to minimize these losses so that the soil health and productivity can be maintained for a long run. The present practical manual on “Soil and water Conservation Engineering (13A.153)” is intended for use by post Graduate students of the Indian Agricultural Research Institute and other State Agricultural Universities. In this manual an attempt has been made to discuss complex experimental protocols in an easy and step-by-step manner, which will be very useful for the beginners. At the end of each chapter, exercises have been given with solved examples. The manual consists of twelve chapters viz., Computation of kinetic energy of falling rain drops, Estimation of runoff, Calculation of rainfall erosivity (R) factor from recording rain gauge, Determination of various Indices of soil erodibility (k), Measurement of land slope (s) by hand level and Abney level, Calculation of soil loss using universal soil loss equation (USLE) & MUSLE, Calculation of sediment discharge from different location of a river basin, Land capability classification, Prioritization of Watershed Using Remote Sensing and GIS and Delineation and Codification of Watersheds in India. In order to limit the volume of the manual, detailed theoretical aspects have been avoided and instead presented in a short and simple manner.
It is believed that the manual will prove useful for the student communities for whom it is intended. Authors look forward to receive suggestions for improvement of the manual. July, 2019 JRU,Ranchi Dr. A. Kumar
56 Contents 1. Study different types and forms of water erosion. 1 2. Exercises on computation of rainfall erosivity index. 4 3. Computation of soil Erodibility index in soil loss estimation. 12 4. Determination of length of slope (LS) and cropping practice (CP) factors for soil loss 14 estimation by USLE and MUSLE. 5. Exercises on soil loss estimation / measuring techniques. 17 6. Study of Rain fall simulator for erosion assessment. 20 7. Estimation of sediment rate using Coshocton wheel sampler and multi-slot devisor. 33