Analysis And Simulation Of Rural Road System's Impact In Hydrology

Due to the intricate interlacing of natural surface and construction areas,the rural area's spatial heterogeneity significantly increases the complexity of natural processes of confluence transmission and hydrological simulation.The settlement of the road system in the village has changed the direction of production and confluence in some areas,and has also had a certain impact on the overall hydrological process of the area.In the existing hydrological process simulation,the performance of the surface hydrological process is currently based on the digital elevation model to divide the sub-basin and extract the confluence and drainage paths.It cannot be accurately expressed,and the influence of the rural road system on the water cycle process in the river basin is often ignored during the hydrological modeling process.Therefore,it is particularly important to accurately analyze and simulate the hydrological process under the influence of the rural road system.This article firstly clarifies the composition of the rural road system and its spatial structure through fieldwork and literature analysis,analyzes the composition of different types of road systems in cross section,and analyzes the corresponding hydrological functions of roads,ditches and culverts.Then,combined with their respective hydrological characteristics,extract their characteristic attribute information,through the way of terrain correction or watershed matrix modification,use Arcgis Model Builder visual programming module to build a rural road system geoprocessing tool,and add it to hydrological modeling To construct a treatment method that reasonably reflects its hydrological impact.Finally,the watershed hydrological model is used for simulation and comparative analysis to scientifically quantify the impact of the rural road system on the regional hydrological process.The main contents and results of this article include the following three aspects:(1)The rural road system is mainly composed of roads,ditches and culverts.The lifting effect of the road is more obvious,and its hydrological function is manifested as an artificial watershed in the local area;ditches are usually built on both sides of the road,changing the way of slope confluence and water gathering time;culverts are usually built under the road,through the road On both sides,the hydrological continuity of the watershed is guaranteed,resulting in rapid migration of slope flow areas.Based on the respective hydrological characteristics of roads and other artificial structures,the paper proposes a modeling method for terrain correction and flow direction correction that takes into account the hydrological impact of roads and other artificial structures,calculates the uplift correction value of the road through the formula,and obtains the trench excavation by looking up the table Correct the value and modify the flow matrix through the culvert connecting line.Based on Arcgis Model Builder visual programming platform,the construction of hydrological modeling tool for rural road system is completed.(2)The rural road system has a significant impact on river basin discretization and river basin hydrological structure.Due to the impact of road uplift,the river basin terrain is more complicated,the shape of the river basin is narrower and narrower,the watershed area is reduced,the sub-basin division is more fragmented,and the number of sub-basins is significantly increased,thus forming the hydrological fragmentation of the watershed;Impact,which makes the structure of the river network more complicated,the branch ratio of the river increases significantly,and the fractal dimension of the watershed does not increase but decreases,reflecting the instability of the overall development of the watershed;at the same time,the culvert completes the connection between the ditches in the form of underdrain A true reflection of the regional hydrological process.(3)Using the SWAT watershed hydrological model and a scenario simulation method,a comparative study on the impact of rural roads and other artificial buildings on the watershed hydrological process was conducted.In the annual runoff simulation,the model's determination coefficient R~2 before the improvement is 0.960,the Nash coefficientis 0.678,the R~2 after the improvement is 0.972,and theis0.821;in the monthly runoff simulation,the previous model R~2 is 0.826,is0.734,and the improved model R~2 is 0.813,andis 0.764.In the annual-scale sediment simulation,the R~2 before the improvement is 0.555,theis 0.418,the R~2 after the improvement is 0.602,theis 0.600.In the monthly sediment simulation,the model R~2 before the improvement is 0.397,theis 0.367,the model R~2 after the improvement is 0.468,and theis 0.468.The simulation results indicate that the accuracy and quality of distributed hydrological simulation in the study area can be improved under the premise of considering the influence of artificial structures such as rural roads.