<p>Hydrologic Measurements Project</p><p>Project Goal: Construct a measurement system to monitor the one-dimensional water balance of a soil column under artificial irrigation. Can we close the water balance?</p><p>Objectives: -Design irrigation system -Design and construct measurement system -Install system and conduct experiment -Report </p><p>Expectations -Active participation in experimental design, sensor construction, and logger programming -Independent analysis of data, -Independent report in standard scientific format -Problem statement: Close the water balance with measurements within measurement uncertainty</p><p>Analysis and Report</p><p>You will write a report in standard scientific format assessing our ability to close the water balance within measurement uncertainty.</p><p>Components of the paper: 1. Abstract Summarize the goals and key conclusions in approximately 300 words.</p><p>2. Introduction -A few paragraphs setting up the importance of understanding the water balance and the problem of measurement uncertainty. End with a very clear problem statement or hypothesis followed by some specific objectives.</p><p>3. Background -Provide sufficient background so that the reader clearly understands the problem. You should begin with an explanation of the water balance, and then explain the theory behind each measurement principle. Include a list of potential errors for each measurement or calculation.</p><p>4. Methods -The methods section should outline a clear path of how you got from the objectives, through the results, to the conclusions. It does not have to be a chronology of events. How did you solve the problem? -You should include some site specific methods. There may be some redundancy with the background section. You’ll have to decide how to partition the methods and background.</p><p>-There should be a clear explanation of the uncertainty analysis (see results).</p><p>5. Results -Presents the relevant results in a logical order. Limit discussion to what is essential to understand the result being presented. The goal of the results section is to lay out the solution to the problem. </p><p>-Follow methods presented in Harmel et al for the error analysis</p><p>6. Discussion -Use your results to answer the question posed in the introduction. Are there interesting issues that arose during the experiment?</p><p>7. Conclusion -Restate your key conclusions, answer the question, avoid repeating methods, speculate on broader impacts. Soil Moisture Storage Error</p><p>When two or more measured quantities are transformed together through a mathematical operation, the uncertainties can be propagated using the root mean square error approach.</p><p> where i is a source of error, E, and n is the total number of sources of error. If the mathematical operation is additive, E can be reported in absolute units. If, however, the operation is multiplicative, relative errors must be used. </p><p>Soil moisture storage in a soil layer, Si (cm), is calculated as the product of the thickness, </p><p>Ti, and the volumetric water content, i, of the layer, i. Total soil moisture storage, S is calculated by summing Si for all layers </p><p>For n = 5 we have</p><p>S = 1T1 + 2T2 +3T3 +4T4 +5T5 </p><p>The absolute error in S, Es, is obtained by first calculated the error in each layer, Esi, and then calculating the total error.</p><p>Each Esi must be in units of cm. The relative error in each layer is</p><p> and the absolute error in each layer is</p><p>The total absolute error is therefore The values Ti and i are measured. The associate errors in absolute units are ETi = 0.5 cm and Ei = 0.03 m/m for all i.</p><p>The change in storage is calculated as the difference between storage before the experiment and at peak moisture content.</p><p>S = Spost - Spre</p><p>The absolute error in S is finally estimated by propagating the error in S at each time Project Tasks and Timeline</p><p>1. Compile all time series data 4/19/11 2. Identify experiment duration, calculate all water balance depths 4/21/11 3. Error analysis 4/26/11 4. Report due 5/3</p>