Survey & Reclamation of soil Prepared by M. U Survey & Reclamation of soil Prepared by M .U. Kale Assistant professor Irrigation & Drainage Engineering Dr. P.D.K.V. Akola

Survey :- Surveying is the art of measuring distances, angles and positions on or near the surface of the earth.

Types of Surveying There are two types of surveying: Plane surveying: Earth surface is considered a plan of x-y dimensions. - Z-dimension (height) referenced to the mass spherical surface of the earth (MSL). - Most engineering and property survey are plane survey correction to curvature is made for long strips (Higher).

Geodetic surveying: Earth surface is considered spherical in resolution (actually ellipsoid) x-y. for - Z is referenced to MSL (surface of earth) - Very precise surveys (boundaries and coastal networks).

1.5 Surveying Instrument 1- Transit and theodolite: Establish straight or curved lines, horizontal and vertical angles. 2- The level and rod: measure difference in elevations. 3- Steel tape: measure horizontal and slope distances. 4- Total station. 5- GPS (global positioning system) receivers.

Steel tape Level ( stadia principle ) Total station Thedilite GPS

Classes of surveys Preliminary survey: (data gathering ) is the gathering of data (distances, position and angles) to locate physical features (rivers, roads, structures) so that data can be plotted to scale (map or plan), also include diff. in elevation so that contour could be plotted.

Layout survey: Marking on the ground using sticks iron bar or concrete monuments. The features shown on a design plan features: - Property lines (subdivision survey). - Engineering work (construction survey). - Z-dimensions are given for x-y directions. Control survey: used to reference prelim and layout surveys.

Horizontal Layout survey: Marking on the ground using sticks iron bar or concrete monuments. The features shown on a design plan features: - Property lines (subdivision survey). - Engineering work (construction survey). - Z-dimensions are given for x-y directions. control: arbitrary line tied to prop line or HWY center or coordinated control stations. Vertical control: Benchmarks: points whose elev. above sea level is carefully determined. - In Control survey more care to accuracy. - Control lines should be easy to re-establish.

1- Topographic survey: preliminary surveys used to tie earth surface features. 2- Hydrographic survey: preliminary surveys tie underwater feature to surface control line 3- Route surveys: preliminary, layout and control surveys that range over a narrow but long strip of land (highways, railroads, electricity transmission lines and channels).

4- Property surveys: preliminary, layout and control surveys determine boundary locations for a new map. 5- Aerial survey: preliminary and final surveys convert aerial photograph into scale map using photogram metric tech.

6- Construction survey: layout of engineering work. 7- Final (as built) survey: preliminary surveys tie in features that just have been constructed

Objectives of Reclamation: To increase crop yield per unit area To increase WUE To improve farmers’ living standard

Methods of Land Reclamation: 1: Physical Methods Sub soiling Deep ploughing Sanding Horizon mixing Profile inversion

2: Biological Methods Growing of crops on problem soils and/or their incorporation at the stage of maximum biomass productivity.

3:Chemical Methods It includes the application of Gypsum Sulphur Sulphuric acid Hydrochloric acid etc

Prerequisites for Land Reclamation: Good surface drainage Leveled soils Availability good quality water Chemical amendments

Reclamation of Saline Soils: Reclamation of saline soil is done by applying excess water to the soil surface. The removal of salts may be accomplished either by continuous ponding of water on soil surface or by intermittent leaching.

Reclamation Requirement: It is amount of water required for reclamation, usually depends upon Salts concentration Soil texture Soil structure Trenching

Sources of calcium for replacing exchangeable sodium: Irrigation water Gypsum and lime present in soil Chemical and biological amendments High-salt water

Reclamation of sodic and saline-sodic soil: Reclamation of sodic and saline-sodic soil is more difficult, time consuming and expensive than that of saline soil. It involves not only leaching a soluble salts but also the replacement of exchangeable sodium with calcium and the improvement of physical properties of soil. The two most difficult aspects of the reclamation process are Provision of source for replacement of sodium with calcium Water for leaching

Replacing exchangeable sodium: CaCO3 is insoluble in water. However, the presence of lime is important in sodic and saline-sodic soil, if it is treated with acids or sulphur, it provides calcium. when vegetation is established, CO2 released and converts the CaCO3 into relatively soluble Ca(HCO3)2.

Crop During Reclamation: Some kind of vegetation should be grown during reclamation, as they help reclamation and also provide some income to farmers. Growth of crop helps reclamation in two ways The development of roots improve the permeability and infiltration capacity of soil. CO2 released into the soil by roots increase solubility of CaCO3.

Thank you !