Research On Landscape Sprinkler Irrigation System With Rainwater As A Supplement In Highway Service Area

With rapid economic and social development, people around the world grow greater demand for water resources. Many countries have been suffering from varying degrees of water resources shortage and even water crisis. Water resources shortage has also long been a big problem that keeps China from sustainable development. Besides, both temporally and spatially unbalanced distribution of rainwater in China has left water problem to be even more sever. To cope with worldwide water crisis and also ensure sustainable development, it is significant to develop various kinds of water-saving technologies including sprinkler irrigation. Rainwater, been wasted most, is one of the most economic water resources which is easy to access and also easy to ignore. So one way to develop water-saving technologies is to collect rainwater and utilize it for irrigation after proper treatment. Aiming at the greening in a highway service area in Tengchong County, Yunnan, the paper mainly researched the key technologies in the landscape sprinkler irrigation system, and the rainwater was collected from the impervious concrete roof of the service complex as a supplemental water source for irrigation system. Main research results and conclusions are follows:(1) Subjects including soil science, metrology, hydrology and engineering have been involved in the sprinkler irrigation greening system in service area, and research on these theories offers support and basis for the following designs such as daily water requirement, daily water application rate, and pipe network and so on.(2) Overall scheme of the landscape irrigation system with rainwater as a supplement has been settled, automated management of the landscape irrigation is realized by use of water sensors buried in the soil and automatic control system on the ground.(3) Two values of daily water application rate (namely water consumption rate of the plant in this paper) of the irrigation system were achieved through two methods: Penman’s’method and filed moisture capacity method. Daily water application rate is4.83mm/d using Penman’s’method while it’s3.51mm/d using filed moisture capacity method. To ensure greening effect in service area, the larger one was selected as final. Checking analysis of daily water application rate was also carried out on the basis of relevant technical codes and regulations including "Technical code for sprinkler engineering" and "Technical specification for landscape irrigation engineering". Water supply and requirement balance was analyzed according to daily water application rate and the conclusion was that annual collecting rainwater is able to satisfy annual water requirement for landscaping in the service area.(4) Research on water source engineering, power system and pipe network has been done, dimensions and shapes of the intake well and the reservoir have been settled and dredging design of the reservoir has been analyzed. Sprinkler system with permanent pipe was chosen according to landscape, water source, project scale and other conditions of service area.(5) Hydraulic calculation of the irrigation system was carried out so that model and specifications of the pump can be settled. R17-24series rotary nozzle manufactured by the U.S. Rainbird company was chosen as the sprinkler nozzle. It has three patterns: full-circle (F), half-circle (H), triple-circle (T) and quarter-circle (Q). All the nozzles are set in an irregular way.