Study On Water-Saving Irrigation Model In Guangzhou Public Green Space

At present,the water resources situation is very serious in China.Two-third of the nation's urban is in water shortage.With the development of urbanization,the urban public park green area is growing very fast,the amount of water used for greening is also increasing,and the urban water shortage will be more permanent.The landscape irrigation is one of major water in the urban,so,the research on methods of water-saving irrigation in urban green space has became one of the important research subject to water conservation.Guangzhou is the third largest city in China,and it is in water quality-induced water shortage.To promote the construction water-saving landscape will become more important in Guangzhou.Four kinds of public green space in Guangzhou?park green space,dividing stripe greening,attached green space of road,overpass greening?had been selected as the research objects in this study.They were Guangzhou Exhibition park,Modiesha park Xingangdonglu dividing stripe greening,Yizhoulu dividing stripe greening,Xinjiaozhonglu attached green space,the south of Guangzhoudaqiao attached green space,Kecun overpass greening,Jianghaidadao overpass greening.The paper had summarized the characteristics of the irrigation technology of public green space in Guangzhou.Using the Analytic Hierarchy Process?AHP?method,we analyesed the weight of each evaluation factor affecting water-saving irrigation for the objects,and ranked the objects.The main conclusions are following:1.Setting up the index sytem of evaluation to Guangzhou public green spaces water-saving benefit.It has two hiberarchies.The first hiberarchy and indices are Economy?0.644?,Technoloy?0.085?,Social effect?0.271?.The second hiberarchy and indices are Unit area investment?0.218?,Water cost?0.691?,Maintenance cost?0.091?;Irrigation intensity?0.054?,Utilization of irrigation water?0.633?,Irrigation evenness?0.086?,Quality requirements for water?0.227?;Adaptability of Plants?0.561?,Landform adaptability?0.051?,Easy to use?0.126?,Safe?0.262?.2.The evaluation value of comprehensive benefit of water-saving irrigation for eight public green spaces are:Kecun overpass greening?0.783?>Xinjiaozhonglu attached green space?0.763?>Xingangdong dividing stripe greening?0.745?>Modiesha park?0.724?>Guangzhou Exhibition park?0.586?>Jianghaidadao overpass greening?0.575?>Yizhoulu dividing stripe greening?0.542?>the south of Guangzhoudaqiao attached green space?0.494?.The highest comprehensive water saving benefit is Kecun overpass greening.3.The index of E₂?Water cost?that the direct factor of water saving is:Drip irrigation?0.691?>intelligentautomationmicro-sprinklerirrigation?0.680?>micro-sprinkler irrigation?0.639?>sprinkling irrigation?0.481?>artificial hose irrigation?0.243?>average value of sprinkler truck irrigation?0.221?.In public green space,drip irrigation,intelligent automatic micro sprinkler irrigation and micro sprinkler irrigation are better than other irrigation techniques in water saving.