Ch 10 pt 1
3. Describe the hydrologic cycle, including each of its three loops—evaporation, runoff, and groundwater.
The hydrologic cycle is the continuous movement of water between the atmosphere, land, and oceans. Evaporation loop: Water evaporates from oceans and land, forms clouds, and returns as precipitation. Runoff loop: Water flows over the surface into rivers, lakes, and eventually the ocean. Groundwater loop: Water soaks into the ground, is stored in aquifers, and slowly moves back to the surface or oceans.
14. What is the average amount of water consumed in a USA household for direct and indirect usage?
a typical house-hold in the United States consumes an average of 380 liters (100 gal.) per person per day. If all indirect uses are added (especially irrigation), this figure increases to 4,200 liters (1,100 gal.) per person per day.
9. What is the difference between consumptive and nonconsumptive water use?
Consumptive - The use of water for such things as irrigation, wherein the water does not remain available for potential purification and reuse.
Non consumptive - Uses for water in which the water remains available for further uses.
1. What is detritus? What is humus? Where are the found in the soil profile, and why?
Detritus is dead plant and animal matter and humus is surface litter or decomposing plant matter. Detritus is found in the O horizon which is the topmost layer and it is found here because it consists of dead organic matter from plants, leaves, stems, fruits, and seeds. Humus is found as well in the O horizon and is more at the bottom than the top.
6. What is the impact of water and wind on bare soil? What is meant by desertification?
Water erosion → washes away topsoil, wind erosion → blows away dry soil, desertification: fertile land becomes desert due to overuse, drought, farming.
7. How do dams facilitate the control of surface waters? What kinds of impacts do they have?
Dams control surface water by storing it in reservoirs and regulating river flow for uses like irrigation, drinking water, flood control, and hydroelectric power. However, they can harm ecosystems, block fish migration, trap sediment, and displace communities.
6. Be familiar with the Aral Sea and Manupali River case studies. What can we learn from them?
The Aral Sea was drained for farming, causing it to shrink drastically. It destroyed ecosystems, hurt community health, and collapsed. Manupali River was farmed and deforestation caused erosion, leading
11. What are the main problems with how groundwater is being mined from aquifers?
The main problems with how groundwater is being mined from aquifers is it is causing a lot of water to become nonrenewable making it unavailable for the future. It is leading to severe groundwater depletion which is extremely bad for the future and the amount of water availability that will be had.
2. Why is soil considered to be a detritus-based ecosystem? Describe how the aboveground portion and the belowground portion of an ecosystem act as two interrelated, interdependent communities.
Soil is considered to be a detritus based ecosystem because organisms feed on it and burrow through the soil which then leads to a humus-rich topsoil. The aboveground and belowground portions of the soil work together because animals feed on the detritus which is a part of the topsoil and as you get closer to the bottom you reach the humus.
7. What is meant by salinization? How does salinization result from irrigation?
A build-up of salts in soil, caused by irrigation water evaporating and leaving salts behind causing soil to be unfit for crops.
2. What are the three major human uses of water? What are the major sources of water for human use?
Agriculture use (Crops, livestock, Takes up about 75% of water usage)
Industrial use (Manufacturing, electric cooldown)
Domestic Consumption (Drinking, etc.)
5. How will climate change affect the hydrologic cycle?
Climate change speeds up the hydrologic cycle by increasing evaporation and atmospheric moisture, leading to heavier rainfall, more flooding, and more severe droughts as water is distributed unevenly.
13. How can water demands be reduced in agriculture, industry, and households?
Water demand can be reduced by using efficient irrigation methods in agriculture (like drip irrigation), recycling and reusing water in industry, and conserving water at home through fixing leaks, using low-flow fixtures, and reducing unnecessary use.
3. What are the different layers, or horizons, that compose the soil profile? What makes each one distinct?
The 5 soil horizons are O horizon, A horizon, E horizon, B horizon, and C horizon. Starting with the O horizon, this is the topmost layer that consists of detritus and is high in organic content. It is the primary source of energy for the soil community and decomposition advances the lower you go. Next, the A horizon is a mixture of mineral soil and humus. It is very important for plant growth and can be called topsoil. The E horizon is the next layer and stands for eluviation. This layer dissolves minerals creating a downward movement of water. The B horizon is characterized by deposition of minerals leached from the A and E horizons. It is referred to as subsoil and is typically high in clay and minerals. Finally the C horizon is represented by weathered rock, glacial deposits, volcanic ash and is the parent material that originally occupied the spot.
8. Why are fertilizers needed for agriculture? What kinds of organic and inorganic fertilizers can be used?
Fertilizers are needed for agriculture because they replenish nutrients in topsoil. Organic fertilizers include plant or animal wastes, manure, and compost. Inorganic fertilizers are chemical formulations of nutrients with organic components. They don’t have the organic matter to support soil organisms leading to loss of nutrients.
8. Distinguish between renewable and nonrenewable groundwater resources and their consequences.
Renewable groundwater is naturally replenished by precipitation and recharge, so it can be used sustainably if not overdrawn. Nonrenewable groundwater (such as fossil water) is not replenished on human timescales, so its use leads to depletion, land subsidence, and long-term water shortages.
12. What are the five options for meeting growing water demands, and what are their problems and benefits?
There are 5 five options for meeting growing water demands and these include 1. Capturing more runoff water, 2. Gaining better access to existing groundwater aquifers, 3. Desalting seawater, 4. Conserving present supplies by using less water, and 5. Making food production more efficient. Capturing runoff can be beneficial because it can be beneficial as a source of water however there are many disadvantages that dams can create which is one of the main ways to capture runoff. Tapping more groundwater can be beneficial but it can also be difficult because the water is being increasingly polluted. Removing salt from seawater can be beneficial to plants and agriculture but is extremely expensive making it not a very reasonable solution. Conserving present supplies and using less water can be a great option but is very unrealistic for most people.
4. How does deforestation or urbanization change the pathway of water? How does it affect Humans?
Changes to the Earth's surface include the loss of vegetation, the taming of rivers and wetlands, and the construction of structures and dams.
4. What are the major properties of the most widespread soil orders: Mollisols, Oxisols, Alfisols, & Aridisols?
Mollisols are fertile dark soils found in temperate grasslands and are said to be the world’s best agricultural soils in the Midwestern United States. Alfisols are widespread, moderately weathered forest soils that are mostly found in the temperate forest biome and are suitable for agriculture when supplemented with organic matter. Oxisols are the soils that are found in tropical and subtropical rain forests and have layers of iron and aluminum oxides in the B horizon. Ardisols are found in dry lands including deserts and seasonally dry areas.
3. What are the different layers, or horizons, that compose the soil profile? What makes each one distinct?
The 5 soil horizons are O horizon, A horizon, E horizon, B horizon, and C horizon. Starting with the O horizon, this is the topmost layer that consists of detritus and is high in organic content. It is the primary source of energy for the soil community and decomposition advances the lower you go. Next, the A horizon is a mixture of mineral soil and humus. It is very important for plant growth and can be called topsoil. The E horizon is the next layer and stands for eluviation. This layer dissolves minerals creating a downward movement of water. The B horizon is characterized by deposition of minerals leached from the A and E horizons. It is referred to as subsoil and is typically high in clay and minerals. Finally the C horizon is represented by weathered rock, glacial deposits, volcanic ash and is the parent material that originally occupied the spot.
11. What are the main problems with how groundwater is being mined from aquifers?
The main problems with how groundwater is being mined from aquifers is it is causing a lot of water to become nonrenewable making it unavailable for the future. It is leading to severe groundwater depletion which is extremely bad for the future and the amount of water availability that will be had.
15. What are water subsidies and why are they a big issue?
Water subsidies are when the government lowers the cost of water for certain groups of people which can become a big issue because of things like waste, environmental damage, and issues with the economy due to water being underpriced.
1. Of the water on planet Earth, how much is freshwater that is available for human use?
About 0.77% of freshwater is available for human use.
5. Why are tropical soils so poor, and what is the impact of slash-and-burn farming on tropical soils?
Nutrients are stored in vegetation not the soil. Heavy rainfall takes away nutrients. Slash-and-burn temporarily adds nutrients, but soil quickly becomes infertile leading to deforestation and land degradation.
4. What are the major properties of the most widespread soil orders: Mollisols, Oxisols, Alfisols, & Aridisols?
Mollisols are fertile dark soils found in temperate grasslands and are said to be the world’s best agricultural soils in the Midwestern United States. Alfisols are widespread, moderately weathered forest soils that are mostly found in the temperate forest biome and are suitable for agriculture when supplemented with organic matter. Oxisols are the soils that are found in tropical and subtropical rain forests and have layers of iron and aluminum oxides in the B horizon. Ardisols are found in dry lands including deserts and seasonally dry areas.