Greenwood small agricultural catchment study - soil management (Queensland) 1978-1984

This study was established to examine the influence of soil surface conditions on runoff and soil erosion, on a site representative of one of the major soil types of the eastern Darling Downs. This dataset containa 7 years of daily record of rainfall, runoff, suspended sediment and soil movement, along with periodic soil sampling for soil water, soil surface cover and roughness. This project examined the influence of rainfall intensity, runoff rate and ground cover on suspended sediment moving through a flume at the exit from a contour bay and the effects of contour banks on sediment delivery to streams were evaluated. Several methods of sampling and calculating suspended soil loss were evaluated. Key findings: Surface cover was effective in reducing soil movement and runoff from contour bay catchments. Runoff and sediment concentration were both inversely related to surface cover and total soil movement was greatly reduced by surface cover. Greater than 75% of the variance in soil movement from single events was explained by surface cover and peak runoff rate. This dataset provides a sound basis for developing and testing water balance/water quality models for cropping and pastures in southern Queensland.本研究旨在探究土壤表面状况（soil surface conditions）对径流（runoff）与土壤侵蚀（soil erosion）的影响，试验场地代表了达令唐斯（Darling Downs）东部主要土壤类型之一。 本数据集包含7年的日度降雨、径流、悬移质泥沙（suspended sediment）与土壤移动量记录，同时附带定期采集的土壤水分（soil water）、地表覆盖度（surface cover）及地表粗糙度（roughness）相关土壤样品数据。 本项目探究了降雨强度（rainfall intensity）、径流速率（runoff rate）与地表覆盖度对等高小区（contour bay）出口处水槽（flume）内悬移质泥沙运移的影响，并评估了等高埂（contour banks）对泥沙向溪流输移的作用。研究同时对多种悬移土壤侵蚀量的采样与计算方法进行了对比验证。 核心研究结果表明：地表覆盖度可有效降低等高小区集水区的土壤移动量与径流量。径流与泥沙浓度均与地表覆盖度呈负相关关系，地表覆盖可显著减少总土壤移动量。单次降雨事件中，土壤移动量75%以上的变异可由地表覆盖度与峰值径流速率解释。 本数据集可为昆士兰州南部（southern Queensland）耕地与牧场的水量平衡（water balance）/水质模型的开发与测试提供可靠依据。