Method for measuring soil moisture characteristic curve and unsaturated hydraulic conductivity

Abstract

The invention discloses a method for measuring a soil moisture characteristic curve and an unsaturated hydraulic conductivity. Relevant data, such as a soil profile matrix potential, in a soil evaporation process is used, and with the help of a repeated iteration correction technology, the soil moisture characteristic and the unsaturated hydraulic conductivity are simultaneously obtained. The method comprises the following steps: loading and taking undisturbed soil, sealing the bottom after adequately saturating a soil column, and ensuring that water leakage and water penetration phenomena donot happen; according to a condition of soil column moisture consumption and a change situation of reading of a tensometer, observing for 1-2 times every day, wherein content comprises a soil column weight and the reading of each tensometer; while a matrix potential value of a soil column measure point exceeds a working range of the tensometer, ending a test; sampling the soil in a laid point of each tensometer and measuring soil moisture content by using a weighing method, and measuring a soil column dry soil weight for calculating the soil column water content and time interval evaporation capacity. The method is simple in operation, and clear, and capable of more accurately forecasting unsaturated soil moisture movement, realizing agricultural production and providing support for ecological accurate measurement.

Description

technical field [0001] The invention belongs to the technical field of agricultural soil characteristic measurement, in particular to a method for measuring soil moisture characteristic curve and unsaturated hydraulic conductivity. Background technique [0002] With the increasingly prominent problems of water resources and environment, the research on water movement in soil has become an important topic. Soil moisture movement is a complex process, which is closely related to many factors such as irrigation methods, soil conditions and external environment. Soil moisture status directly or indirectly affects the status of soil gas and Jehol fat, and is related to crop harvesting and soil fertility. As well as the physical, chemical and biological processes inside the soil, it is of great significance to the accurate measurement and research of agricultural production and ecology. [0003] Solving the soil moisture characteristic curve and the corresponding saturated hydrau...

AI Technical Summary

Problems solved by technology

The Van Genuchten model has been widely used in solving the problem of soil moisture characteristic curve because of its good fit between the line shape and the measured data curve. Although these methods have obtained good fitting results, these methods either rely on dry soil column infiltration tests, or the algorithms need to be programmed, or rely on Matlab software, which are time-consuming, laborious and inefficient. question

Images