Irrigation Delivery And Distribution Pipe Network Optimization Research Based On GIS

Compared with other water-saving irrigation technology, delivery and distribution pipe network systems have great superiority and developmental potential in improving the utilization of irrigation water, saving farmland, expanding irrigated area and tractor-plowing. Pipeline networks will be an important trend for water-saving irrigation in the development of irrigation. Meanwhile, pipeline network systems are complex to design, need much more materials and equipment; its first-time investment is much higher. Seeking the optimum plan of pipe network with the higher irrigation quality, less investment and lower consumption of energy can produce great economy benefits using the optimal design theory, methods and tools.This paper takes irrigation pipe network optimization as research object, based on the summarization of the domestic and foreign pipe network optimization and the optimized technology achievement, using modern mathematics optimization method, discussed several type of pipe network. The mainly research achievements of this paper are as flowers:1) Build the optimal layout model for tree pipe network. The objective function of this model only has parameters of pipe length and flow, not only take flow change into consideration but also exclude the influence from pipe price, pipe type, etc, that get the optimal calculation directly and easy. Use the graph theory and LCA (Line-up Competition Algorithm) in the process of modeling and computer, LCA with the f two means competition that between families and inside a family and little controls parameter was introduced in optimal design. It was testified by case study that this model can obtain the optimal result, and is better in search efficiency and stability compared with other algorithm.2) Previous irrigation pipe network model take pipe cost as objective function in pipe network optimization which ignored the other fee for network build and run, can't guarantee that the optimal design calculated by that objective function can provides a satisfactory performance practically. This paper proposed take the utilization degree of gravity head to evaluate the design's utilization rate of pressure drop created by hypsography, using two different expressions namely utilization rate of pipe gravity head and utilization rate of path gravity head as network optimization objective functions. The result testified by case study and compared with the model based on minimization of cost showed that the method this paper proposed is more suitable for tree pipe network with more elevation difference and can obtain the optimal result and is superior in search efficiency.3) The existed water distribution pipe net work deterministic optimal design model simplified the influence factor for model development, but many parameters is uncertain in practical, the existed model doesn't consider the influence on optimal result of uncertain parameter. This paper took pipe flow, node required minimal water head and pipe roughness coefficient as stochastic, established pipe network chance-constrained programming models for optimal design of water distribution network by gravity pressure and pump station. Based on the technical of stochastic simulation, line-up competition algorithm was applied for model solving. The result testified by case study showed that the uncertain parameter had obvious influence to optimal result, and with the wider variable range, the larger pump and cost.4) For evenly pressure distribution, flexible flow dispatch and high rate of pipe utilization, the loop network is widely used, but the research about it is less. The core of loop pipe network optimization is hydraulic balance calculate, to get pipe pressure, flow, pump head etc. This paper use LCA to optimal calculation, and graph theory to hydraulic balance calculation, make the complicated hydraulic calculation become simple matrix transform, needn't initial flow distribution.5) One of the main factors that restrict the development of pipe network optimization is that the optimal design isn't take the terrain into account. In some extent, the pipe network optimal is still remains at theoretical research. This paper takes GIS and Access Database into irrigation pipe network optimization, uses spatial analysis and network analysis function of GIS, data store and data processing function of database, achieve seamless link of map, optimal model and data's read-write and store, the result can be showed by three approach, such as map, program and database.6) All optimal models build are for practical application. The program using Visual Basic language, MapX COM (Component Object Model) and Access database have been designed for irrigation delivery and distribution pipe network optimization. The models and the program tested by case study showed that the program have great practicality and universality.