农业工程学报
農業工程學報
농업공정학보
2014年
24期
114-123
,共10页
曾为军%张云伟%陈岭%王大龙%董晓伟%王彦钧
曾為軍%張雲偉%陳嶺%王大龍%董曉偉%王彥鈞
증위군%장운위%진령%왕대룡%동효위%왕언균
径流%泥沙%侵蚀%径流量%含沙量%光照法%时间法%数据拟合
徑流%泥沙%侵蝕%徑流量%含沙量%光照法%時間法%數據擬閤
경류%니사%침식%경류량%함사량%광조법%시간법%수거의합
runoff%sediments%erosion%runoff volume%sediment concentration%light transmission method%time keeping method%data fitting
针对坡面径流及泥沙含量传统测量方法存在精度不高且难以在坡面现场在线同步测量的问题，该文提出了一种基于计时法和光照法的径流量与含沙量测量方法，设计了坡面径流量及泥沙含量同步在线检测的自动检测系统。阐述了该系统中机械装置和电子测控的设计方案和工作原理，并设计了光照法测量含沙量的辅助试验系统。通过试验，发现影响含沙量测量精确度的主要因素为光源与光敏传感器之间的距离及溶液中泥沙分布均匀度，揭示了A/D转换值随含沙量变化而单调变化的规律。通过试验获得了溶液搅拌最佳电机转速为428 r/min，并运用最小二乘法和统计学理论对数据进行分析，确定了当该系统的光源和光敏传感器之间的距离为30 mm时，光照法测量含沙量的精确度最高。最后，将试验结果与理论计算值进行对比，结果表明除了浓度为1～3 kg/m3的溶液所测得的泥沙含量误差率较大外，其余溶度的误差率均小于1%，论证了光照法测量含沙量的可行性。该研究可为推进水土保持动态监测理论方法及技术提供参考。
針對坡麵徑流及泥沙含量傳統測量方法存在精度不高且難以在坡麵現場在線同步測量的問題，該文提齣瞭一種基于計時法和光照法的徑流量與含沙量測量方法，設計瞭坡麵徑流量及泥沙含量同步在線檢測的自動檢測繫統。闡述瞭該繫統中機械裝置和電子測控的設計方案和工作原理，併設計瞭光照法測量含沙量的輔助試驗繫統。通過試驗，髮現影響含沙量測量精確度的主要因素為光源與光敏傳感器之間的距離及溶液中泥沙分佈均勻度，揭示瞭A/D轉換值隨含沙量變化而單調變化的規律。通過試驗穫得瞭溶液攪拌最佳電機轉速為428 r/min，併運用最小二乘法和統計學理論對數據進行分析，確定瞭噹該繫統的光源和光敏傳感器之間的距離為30 mm時，光照法測量含沙量的精確度最高。最後，將試驗結果與理論計算值進行對比，結果錶明除瞭濃度為1～3 kg/m3的溶液所測得的泥沙含量誤差率較大外，其餘溶度的誤差率均小于1%，論證瞭光照法測量含沙量的可行性。該研究可為推進水土保持動態鑑測理論方法及技術提供參攷。
침대파면경류급니사함량전통측량방법존재정도불고차난이재파면현장재선동보측량적문제，해문제출료일충기우계시법화광조법적경류량여함사량측량방법，설계료파면경류량급니사함량동보재선검측적자동검측계통。천술료해계통중궤계장치화전자측공적설계방안화공작원리，병설계료광조법측량함사량적보조시험계통。통과시험，발현영향함사량측량정학도적주요인소위광원여광민전감기지간적거리급용액중니사분포균균도，게시료A/D전환치수함사량변화이단조변화적규률。통과시험획득료용액교반최가전궤전속위428 r/min，병운용최소이승법화통계학이론대수거진행분석，학정료당해계통적광원화광민전감기지간적거리위30 mm시，광조법측량함사량적정학도최고。최후，장시험결과여이론계산치진행대비，결과표명제료농도위1～3 kg/m3적용액소측득적니사함량오차솔교대외，기여용도적오차솔균소우1%，론증료광조법측량함사량적가행성。해연구가위추진수토보지동태감측이론방법급기술제공삼고。
In the research of soil erosion and loss, slope runoff volume and sediment concentration are two important hydrodynamic parameters to forecast slope runoff variation, reveal soil erosion mechanism and find movement rule of soil on hill slope. There is still no special instrument which can be widely used to measure runoff rate and sediment concentration. In fact, slope runoff volume and sediment concentration should be obtained in one testing at the same time, and then the testing data can be valuable for scientific research. Therefore, it has significant meaning to develop on-line equipments to measure slope runoff and sediment concentration accurately and synchronously. In order to resolve this problem, an automatic testing device for detection of runoff rate and sediment concentration was designed based on time method and illumination method, which could overcome the shortage of traditional methods. Its working principles and electronic controlling section were described. The automatic testing device is composed of two parts, the mechanical device and the electronic testing component. The mechanical device consists of funnel-shaped device and sampling device. The electronic testing component includes three parts, i.e. runoff volume measure and control, sediment concentration measure and control, and digital display. Data acquisition and processing are performed by electronic testing component. The software design employed automatic cycle way to control SCM (single chip microcomputer) working. The testing data was saved in EEPROM of SCM. An additional experimental system was proposed for measuring sediment concentration by using above system. It is composed of measure device and testing circuit control. During the measurement of sediment concentration, keeping stirring solution is necessary to avoid silt sinking at bottom, and this is helpful to improve testing accuracy. Testing accuracy of sediment concentration is mainly affected by two factors:distance from light source to light sensor and sediment distribution uniformity in solution. A/D value output by light sensor changes along with sediment concentration. Through experiments of sediment concentration measurement, two conclusions were obtained by using least squares method and statistics theory. Firstly, the suitable rotation speed of electromotor is 428 r/min which can make sediment distribute uniformly in solution. Secondly, the best accuracy of sediment concentration measurement can be obtained when the distance from light source to light sensor is 30 mm. The variation trend between A/D value and sediment concentration can be expressed in fitted polynomial equation. At last, testing experiments were done to verify above theoretical analysis and equation by using proposed methods and parameters. The experiments included sediment concentration testing in fourteen groups of solution with different sediment concentrations. The deviation between actual value and measured value was obtained. The result shows the accuracy of sediment concentration is within 1% except the solution with 1-3 kg/m3 sediment concentration. This demonstrates the feasibility of sediment concentration measurement by light transmission method. Furthermore, experiments also indicate that the proposed automatic detection device system is able to get the values of runoff rate and sediment content synchronously, which overcomes the limitation of traditional measurement. The device can be used not only in laboratory studies of soil erosion, but also in field monitoring of runoff volume and sediment concentration. This study provides a reference to promote new method and technology improvement for soil and water conservation monitoring.
