A Comparative Study Of Water-saving Irrigation Technologies For Urban Greening And Their Applicability To Recycled Water

In 2020,China’s per capita park green area is only 14.8 m~2,which is still far behind the international advanced level.With the continuous development of China’s urbanization in the future,the area of urban green space is bound to continue to increase,and the contradiction between water consumption and water shortage is becoming increasingly obvious.Under the triple constraints of urban ecological civilization construction,water shortage and water environmental pollution,it is the trend to promote the application of water-saving irrigation technology in cities.In addition to the well-known traditional water-saving irrigation technologies such as sprinkler irrigation,micro sprinkler irrigation and drip irrigation,there are also emerging new water-saving irrigation technologies such as moistube irrigation and trace irrigation in recent years.To explore the applicability of different green space water-saving irrigation systems to reclaimed water and the irrigation water volume of different green space irrigation systems is the basis for accelerating the construction of urban ecological civilization and alleviating the crisis of urban water resources.Based on this,this paper systematically compares different water-saving irrigation technologies such as sprinkler irrigation,micro-sprinkler irrigation,drip irrigation,moistube irrigation and trace irrigation,selects moistube irrigation and trace irrigation,carries out research on the clogging characteristics and mechanism of moistube and trace irrigation pipes under the conditions of reclaimed water sources,and finally,based on the results of the previous study,makes suggestions on the reclaimed water utilization countermeasures and water-saving irrigation system for urban green space irrigation technology in China,in order to provide a reference for the The main findings of this study are as follows:The water-saving irrigation technology in China’s urban greenery is used to promote and apply the water-saving irrigation system,to develop reasonable water consumption standards for urban greenery irrigation,and to maintain the stable operation of the greenery irrigation system.The main conclusions of this study are as follows.(1)Based on the scenario assumption,the water consumption and total investment of new water-saving irrigation systems such as moistube irrigation,trace irrigation and traditional water-saving irrigation systems such as sprinkler irrigation,micro sprinkler irrigation and drip irrigation were compared.The results show that the annual water consumption per unit area of moistube irrigation and trace irrigation is the lowest among the five types of irrigation systems,but the investment per unit area of moistube irrigation and trace irrigation is the highest among the five types of irrigation systems,mainly due to the high cost of pipes and accessories.(2)The experimental study on the clogging characteristics and mechanism of moistube pipe and trace irrigation pipe was carried out under the condition of reclaimed water source.The results showed that the time points of flow sudden drop of moistube pipe and trace irrigation pipe were 312 h and 216 h respectively.Compared with the time of flow sudden drop of other irrigation systems,the sprinkler irrigation system and micro sprinkler irrigation system had the strongest applicability for reclaimed water,followed by moistube irrigation system and trace irrigation system,The applicability of drip irrigation system to reclaimed water is the worst.(3)Under the condition of reclaimed water as the water source,the greater the diversity and abundance of biofilm microorganisms in the pipe wall,the greater the influence on the flow rate of the pipe and the higher the content of each component of the plugging material,and the different pipes also have a greater influence on the structural composition of the microbial community in the pipe wall,and the percentage of microbial communities in the moistube pipe and the trace irrigation pipe will change significantly over time.(4)The cleaning cycle of different types of irrigation device is proposed under the condition of reclaimed water as water source,among which the cleaning period of drip head varies from 184 h to 368 h;The cleaning periods of moistube pipe and trace irrigation pipe were312 h and 216 h respectively;When the system is blocked,the blocking problem of irrigation system can be alleviated by means of"front control,middle row and rear cleaning";Combined with the meteorological data of 19 provinces and cities in China,the standard of irrigation water quantity per season in different regions of China is calculated and put forward.It is applied to xiong’an new area.The total investment of irrigation system,green space irrigation system and irrigation system applicable to different green space types in the New Area is proposed.