Study On Rainwater Absorption Characteristics Of Landscape Organic Mulch And Its Effect On Soil Moisture

Worldwide climate change,rapid urbanization,and unreasonable urban pipe network design have caused serious rain problems in many cities,especially large and medium-sized cities,so it is imperative to strengthen urban rain management.The urban green space rainwater management is not only to solve the problem of rainwater discharge,but more importantly,it can realize the resource utilization of rainwater.In 2013,my country proposed to build a sponge city with rainwater �natural accumulation,natural penetration,and natural purification�.The rainwater utilization function of urban green space is getting more and more attention from all over the world.A large number of studies at home and abroad have shown that organic mulch has the function of absorbing rainwater and maintaining soil moisture,but the actual application lacks accurate data support.In this study,16 kinds of organic mulch for the study,16 kinds of organic mulch are: pine cone shells(PS),oak leaves(-OC),peanut shells(the PnS),pine bark color(1.5-3cm)(CP),Chinese fir bark(CFP),polished pine bark(3-6mm)(PPB1),polished pine bark(3-5cm)(PPB2),fermented pine bark(9-17mm)(FPB1),fermented pine bark(3-6mm)(FPB2),palm shreds(CF),earthworm feces(EC),walnut shells(WS),pine needles(PN),willow bark(WB),crushed maple(ANBM),sawdust(SD).Indicators organic mulch material density,the volume of water absorbency,water absorption rate of the volume,quality water absorbency,water absorption rate quality,soil and water content were measured.Supported by experimental data,methods and measures for rational application of organic mulch in urban green spaces are proposed.(1)Carry out research on various indicators of 16 kinds of organic mulch by water immersion method.Analyzing the maximum water holding capacity of different materials through the experimental data is helpful for the preliminary evaluation of the rainwater absorption performance of different materials and provides a reference for the next experiment.The results of the study indicate that all 16 materials have the ability to absorb water,but there are significant differences.In urban rainwater management measures,suitable materials can be selected according to specific needs.If you need to choose lightweight materials such as roof greening,you can choose sawdust(SD),peanut shell(PnS),oak leaf(OC),compound leaf maple crushed material(ANBM),palm coconut silk(CF),pine tower shell(PS)and other materials;when used as urban ground greening,sawdust(SD),earthworm droppings(EC),peanut shells(PnS),pine shells(PS),fir bark(CFP)and other materials are the preferred materials.(2)Analyze the rainwater infiltration capacity of 16 materials by artificial rainfall simulation method,the thickness of the material is 5cm.The simulated rain intensity is 16.2mm / h,48 mm / h,84 mm / h and 132.4mm / h.Through artificial rainfall simulation experiments,it was found that there are some differences in the rainwater absorption properties of 16 materials,including pine shell(PS),peanut shell(PnS),walnut shell(WS),pine needles(PN),willow bark(WB),compound leaves Maple crushed material(ANBM),sawdust(SD)and other materials perform well in rainwater absorption.Experiments show that 16 kinds of materials can effectively absorb rainwater in a short time.The commonality of the 16 materials is that they have the strongest water absorption capacity at the beginning of the rain,and can quickly absorb the rainfall,and then the water absorption capacity gradually decreases with the increase of time.(3)Study the influence of 16 materials covering the soil surface on the soil moisture content.The experimental materials are laid in two thicknesses of 5cm and 10 cm,and the soil measurement depths are: 0-10 cm,10-20 cm,20-30 cm and 30-40 cm.Through the measurement of soil water content in different soil depths with different materials,compared with the blank control,both laying thicknesses have an effect on different soil depths.The experiment showed that the average soil water content of the treatment with covered organic matter was higher than that of the blank control.After 13 days of measurement,the soil water content of the blank control was basically maintained at 18%,while the soil water content of the 16 materials covered by all was above 23%.The mulch shows a good effect of maintaining soil moisture.As the most important rain bearing part in the city,green space has a large elastic space.As an important part of green underground cushion surface,ground cover has important theoretical significance and application value for its research.Scientific analysis of the absorption characteristics of organic surface mulch on rainwater and its impact on soil moisture,etc.,provides a scientific basis for the selection of organic surface mulch in the use of urban green land rainwater resources.