It is becoming acknowledged that water is likely to be the most pressing environmental concern of the next century. Difficulties in river basin management are only exacerbated when the resource crosses international boundaries. One critical aid in the assessment of international waters has been the Register of International Rivers a compendium which listed 214 international waterways that cover 47% of the earth's continental land surface. The Register, though, was last updated in 1978 by the now defunct United Nations Department of Economic and Social Affairs. The purpose of this paper is to update the Register in order to reflect the quantum changes that have taken place over the last 22 years, both in global geopolitics and in map coverage and technology. By accessing digital elevation models at spatial resolutions of 30 arc seconds, corroborating at a unified global map coverage of at least 1:1 000 000, and superimposing the results over complete coverage of current political boundaries, we are able to...

International River Basins of the World

https://www.eawag.ch/fileadmin/Domain1/Abteilungen/siam/software/modawec/development__gepic.pdf

GEPIC – modelling wheat yield and crop water productivity with high resolution on a global scale

Boundary conditions for displacement experiments through short laboratory soil columns [Dispersion coefficients]

Suspended sediment load prediction of river systems: An artificial neural network approach

/pdf/meta-analysis-of-strategies-to-control-nitrate-leaching-in-2taxsv4ck4.pdf

Meta-analysis of strategies to control nitrate leaching in irrigated agricultural systems and their effects on crop yield.

Impacts of fertigation via sprinkler irrigation on nitrate leaching and corn yield in an acid–sulphate soil in Thailand

https://academiccommons.columbia.edu/doi/10.7916/D8SX6PTS/download

Application of GIS and crop growth models in estimating water productivity

Advances in the traditional method of subsurface porous clay pipe irrigation rely on knowledge of the distribution of water in the soil. Knowing the relationships among the hydraulic and physical parameters in the system is important for both the design and management of the system. To simulate the infiltration from the porous clay pipe and predict the wetted zone geometry in the soil, a computer model is developed herein. Laboratory experiments were conducted on soil samples representing two different soil textures in a specially designed bin to understand the flow phenomenon and to validate the developed model. In a given soil texture, the installation depth of the pipe and the volume of water applied in the soil are the major factors affecting the wetted zone. The relationships among various parameters, namely lateral spacing, installation depth, irrigation run time, hydraulic conductivity of the body of the pipe, and hydraulic head in the system, were established using the developed model.

Simulation of infiltration from porous clay pipe in subsurface irrigation

A linear programming (LP) based optimization model and a simulation model are developed and applied in a typical diversion type irrigation system for land and water allocation during the dry season. Optimum cropping patterns for different management strategies are obtained by the LP model for different irrigation efficiencies and water availability scenarios. The simulation model yields the risk-related irrigation system performance measures (i.e. reliability, resiliency and vulnerability) for the management policies defined by the optimization model. The alternative strategies are evaluated in terms of all performance criteria (i.e. net economic benefit, equity and reliability) simultaneously through a trade-off analysis using a multi-criteria decision making method (compromise programming). For the case study of the Kankai irrigation system in Nepal, with equal preference to the objectives, a management strategy with equal share of water among the project subareas appears to be the most satisfactory alternative under water shortage conditions. The existing water allocation policy is not economically efficient. Deficit irrigation in Early paddy appears attractive under favorable hydrologic scenario, particularly if accompanied by measures to improve existing irrigation system efficiency.

Performance based irrigation planning under water shortage

The occurrence of fingered preferential flow depends on both flow and porous media characteristics. The boundary condition of unsaturated infiltration has been investigated to assess whether it produces unstable wetting in homogeneous coarse sands. Laboratory tracer experiments were conducted in two coarse sand materials; for each sand material two initial conditions of air dry and field capacity were considered. Results indicate that the commonly occurring process of nonponding rainfall can provoke fingered preferential flow in homogeneous sandy soils. This phenomenon is very predominant in dry as compared to wet initial conditions. Models of water flow and solute transport in uniform coarse soils should incorporate the effects of such fingered flow phenomenon.

http://hydrologie.org/hsj/400/hysj_40_01_0001.pdf

Rainer Loof

Papers

Impacts of fertigation via sprinkler irrigation on nitrate leaching and corn yield in an acid–sulphate soil in Thailand

Application of GIS and crop growth models in estimating water productivity

Simulation of infiltration from porous clay pipe in subsurface irrigation

Performance based irrigation planning under water shortage

Fingered preferential flow in unsaturated homogeneous coarse sands