I am having difficulty analyzing my lab data. I don't know whether to analyze a chart or use calculations to define the data. I am trying to use the Cooper-Jacob method. I also need to calculate transmissivity and storativity, but am having difficulty choosing the information required to complete this.

Analyzing lab data can be a complex task, but I'll try to guide you through it. For the Cooper-Jacob method, you'll need to determine the transmissivity and storativity. Here's how you can approach it:

1. Understand the Cooper-Jacob method: The Cooper-Jacob method is commonly used to analyze pumping test data to determine the properties of aquifers. It involves analyzing the drawdown (change in groundwater levels) data from pumping tests to calculate transmissivity and storativity.

2. Collect necessary data: To analyze your lab data using the Cooper-Jacob method, you'll require the following information:
- Pumping rate: The rate at which water is pumped from the aquifer during the test.
- Drawdown data: The change in groundwater level at various time intervals during the pumping test.
- Aquifer characteristics: This could include information such as aquifer thickness, well radius, and specific storage.

3. Plot drawdown data: Once you have the drawdown data, create a graph with time on the x-axis and drawdown on the y-axis. This will help visualize the drawdown over different time intervals during the pumping test.

4. Identify applicable well function: By analyzing the shape of the drawdown curve, you can identify the appropriate well function to use in the Cooper-Jacob method. Common well functions include Theis, Hantush, and Neuman.

5. Fit the well function: Using the appropriate well function, fit it to your drawdown data. This involves adjusting the parameters of the well function to best match the observed drawdown curve. This is typically done using software programs like AQTESOLV or Excel.

6. Calculate transmissivity and storativity: Once the well function is fitted to the drawdown data, you can use the Cooper-Jacob method equations to calculate transmissivity (T) and storativity (S). The equations can vary depending on the well function used, so be sure to refer to the specific equations for the well function you selected.

7. Validate the results: Finally, it's important to validate your results by comparing them with other available data or known values for similar aquifers. This will help ensure the accuracy of your calculated transmissivity and storativity.

Remember, analyzing lab data requires careful attention to detail and knowledge of specific methods like the Cooper-Jacob method. It may also be helpful to consult your lab manual, research papers, or seek guidance from your instructor or colleagues with expertise in hydrogeology.