Update channels_hillslopes_notebook.ipynb

channels_hillslopes_notebook.ipynb

@@ -283,6 +283,25 @@
     "print(\"Maximum elevation is \", np.max(z1))"
    ]
   },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "# Code Block 8.5, added last minute :)\n",
+    "\n",
+    "imshow_grid(mg1,\n",
+    "            \"topographic__steepest_slope\",\n",
+    "            grid_units=(\"m\", \"m\"),\n",
+    "            var_name=\"topographic slope (m/m)\")\n",
+    "title_text = f\"$K_{{sp}}$={K_sp}; $D$={D}; $time$={total_time} yr; $dx$={dxy} m\"\n",
+    "plt.title(title_text)\n",
+    "\n",
+    "mean_slope = np.average(mg1.at_node[\"topographic__steepest_slope\"][mg1.core_nodes])\n",
+    "print(\"Mean slope is \", mean_slope)"
+   ]
+  },
   {
    "cell_type": "markdown",
    "metadata": {},
@@ -533,15 +552,15 @@
     "\n",
     "Please complete the following tasks. Make sure your write in full sentences and proofread the document that you hand in.\n",
     "\n",
-    "1. Using the parameters provided in the initial notebook, run the landscape to steady state. (Note that you can keep running the main evolution loop - Code Block 7 - and the different plotting blocks without running the code blocks above them.) [These landscapes may not reach a perfect steady state. Close is fine.] When the landscape reaches steady state, record the channel steepness, $k_{sn}$ (only applies for the channelized part of the landscape) and total relief (in this case the minimum elevation is zero, so the total relief is just the maximum elevation). Also note the approximate critical drainage area. (See the description at the top of this notebook if you don't know that term.) Save some illustrative plots. This example has a relatively small critical drainage area/large drainage density. (10 pts)\n",
+    "1. Using the parameters provided in the initial notebook, run the landscape to steady state. (Note that you can keep running the main evolution loop - Code Block 7 - and the different plotting blocks without running the code blocks above them.) [These landscapes may not reach a perfect steady state. Close is fine.] When the landscape reaches steady state, record the channel steepness, $k_{sn}$, (only applies for the channelized part of the landscape), the average slope of the entire watershed, and the total relief (in this case the minimum elevation is zero, so the total relief is just the maximum elevation). Also note the approximate critical drainage area. (See the description at the top of this notebook if you don't know that term.) Save some illustrative plots. This example has a relatively small critical drainage area/large drainage density. (10 pts)\n",
     "\n",
-    "2. Rerun the notebook with a new diffusivity value, but keep all other parameters the same (so do not change the fluvial erodibility or rock uplift value). You should find a scenario with a critical drainage area higher than the initial value, but less than 1e6 m$^2$. Run to steady state, and record the critical drainage area, channel steepness index, and total relief. Make sure you also record the diffusivity value used. Save some illustrative plots. (10 pts)\n",
+    "2. Rerun the notebook with a new diffusivity value, but keep all other parameters the same (so do not change the fluvial erodibility or rock uplift value). You should find a scenario with a critical drainage area higher than the initial value, but less than 1e6 m$^2$. Run to steady state, and record the critical drainage area, channel steepness index, average slope, and total relief. Make sure you also record the diffusivity value used. Save some illustrative plots. (10 pts)\n",
     "\n",
     "3. Repeat step 2. So same everything except use a third, different diffusivity value. This example should have a different critical drainage from the previous two landscapes, and the critical drainage area should be less than 1e6 m$^2$. (10 pts)\n",
     "\n",
-    "3. Now repeat steps 1, 2, and 3, two more times. I want you to choose two different fluvial erodibility values (both should be smaller than the original value of $K_{sp} = 1E-5$, i.e. they should produce larger $k_{sn}$ values). For each $K_{sp}$ value, you should produce three landscapes with three different diffusivity values. Try to keep all slope values (on hillslopes and channels) less than 1 m/m. Try to keep the critical drainage area less than 1e6 m$^2$. Record critical drainage area, channel steepness index, and total relief for all the landscapes. (20 pts)\n",
+    "3. Now repeat steps 1, 2, and 3, two more times. I want you to choose two different fluvial erodibility values (both should be smaller than the original value of $K_{sp} = 1E-5$, i.e. they should produce larger $k_{sn}$ values). For each $K_{sp}$ value, you should produce three landscapes with three different diffusivity values. Try to keep all slope values (on hillslopes and channels) less than 1 m/m. Try to keep the critical drainage area less than 1e6 m$^2$. Record critical drainage area, channel steepness index, average slope, and total relief for all the landscapes. (20 pts)\n",
     "\n",
-    "4. You should have produced a total of 9 steady-state landscapes, using three different fluvial erodibility values, and at least three different diffusivity values. In all cases, the uplift rate remained the same, so the erosion rate remained the same. What trends do you notice about controls on relief and channel steepness index? Is relief related to critical drainage area? Is it related to channel steepness index? Can you summarize (in 5 sentences or less) some things you have learned about rivers and fluvial erodbility, hillslopes and diffusivity, and topographic trends? (15 pts)\n",
+    "4. You should have produced a total of 9 steady-state landscapes, using three different fluvial erodibility values, and at least three different diffusivity values. In all cases, the uplift rate remained the same, so the erosion rate remained the same. What trends do you notice about controls on relief, average slope, and channel steepness index? Is relief related to critical drainage area? Is it related to channel steepness index? Average slope? Can you summarize (in 5 sentences or less) some things you have learned about rivers and fluvial erodbility, hillslopes and diffusivity, and topographic trends? (15 pts)\n",
     "\n",
     "5. Thought question ... If you had a larger watershed, do you think that would impact any of the trends (or lack of trends) that you observed? Please explain in 5 sentences or less. (5 pts)"
    ]