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Fellow Mars-simmers,
The current leading cause of Martian settler fatalities in the simulation over a long (simulated) period of time is dehydration is settlements due to overcrowding and running out of water. I think we should try to resolve or reduce this problem before the 2.86 release if possible. There might be several ways of doing this, so I am hoping we can discuss ideas here.
Settlements have a population capacity determined by total living quarters capacity of its buildings. The configured settlement templates have population capacities of 4, 8, 12, and 25 inhabitants. It's also possible for the inhabitants to construct additional living quarters buildings to increase their settlement's population capacity.
When a settlement is overpopulated, the consumption of life-support resources such as food, oxygen and water exceed what the settlement was designed to produce. Normally settlements build up a surplus of these resources, but this can be quickly depleted if the settlement is heavily overcrowded. Water seems to be the life-support resource that runs out first, which leads to the inhabitants dying of dehydration.
Another contributing factor to the problem is that when a settlement is overcrowded, the inhabitants' stress increases considerably, which, in turn, reduces their effective performance at doing tasks. When a person has 100% stress for a period of time, he has a chance of having an anxiety attack, a medical illness that's basically a mental breakdown. When this happens, the person's performance goes down to 0% and he must rest for a period of time until his stress goes down a bit. In an overcrowded settlement filled with stressed out residents, the population will be constantly having anxiety attacks, which prevents any useful activities or missions that might alleviate the overcrowding problem.
When settlers are in an overcrowded settlement, they will tend to perform EVA tasks or go on rover missions to reduce the number of people in the settlement and the stress effect associated with that. This doesn't reduce the overall consumption of water, however, as they're still taking and consuming water when they leave the settlement.
Causes:
There are a number of situations that can lead to a settlement becoming overpopulated.
The Travel to Settlement rover mission is a primary cause for overpopulation. The mission allows people to immigrate from one settlement to another based on better work and social relationships. Reducing overcrowding is a factor in deciding to immigrate from one settlement to another, but it isn't an overriding concern for the settlers.
Rescuing stranded rovers contributes to overpopulation as the rescuing settlement may bring back a number of survivors that are beyond its capacity.
The Trade rover mission involves a crew driving a rover loaded with goods to another settlement and barter trading them for other goods, then loading those goods up and returning home. Sometimes there's a problem where goods they traded for are no longer available by the time they load up again, in which case the mission ends and the crew stays at the settlement they were trading with. I think this is a bug or at least should be handled more gracefully with the crew accepting the loss and continuing the mission.
Those are all the causes for settlement overpopulation that I can think of at the moment. Please let me know if I've missed any.
Solutions:
We should probably look for solutions to the causes of overpopulation, its effects, and the manner in which a settlement's inhabitants deal with it.
I think we should limit the Travel to Settlement mission to only pick destination settlements with more population capacity than residents, and to not allow more mission crew members than the destination settlement has capacity for. This will allow people at overcrowded settlements to emigrate to nearby settlements with space available. Once settlements construct new living quarters buildings and increase their population capacity, people will be able to move from settlement to settlement much more freely. This change should be fairly easy to implement, I think.
I'm thinking that the rescue stranded rover mission should probably stay as is. This is an emergency situation and the rescuing settlers should probably not worry about overpopulating their settlement with survivors, but rather deal with that after the rescue.
The trade mission should be changed so that it handles lack of goods at the destination trading settlement more gracefully, rather than causing the mission to fail and end as it does now, which leaves the crew members at the destination settlement. They should probably just log the missing goods as trade credit between the settlements and continue with the mission. I'm not sure how difficult this will be to implement, but I hope it will be relatively easy to do.
I think it's somewhat realistic that increased stress due to overcrowding would lead to arguments, frayed nerves, and anxiety attacks which effectively paralyze the settlement and prevent any useful activity. We may want to tweak the stress effects and chance of anxiety attack a bit, but I think the overall scenerio is reasonable. I think a doctor may be able to help alleviate this situation by providing stress reducing medication and treating patients suffering from anxiety attacks (perhaps with psychiatric therapy). I'm not sure how difficult it would be to add this to the medical system in the simulation. Let me know if anyone has other ideas for handling overcrowding stress problems.
Sebastien also brought up the idea of a pick up mission where a rover with a small crew would be sent from an underpopulated settlement to pick up immigrants from a nearby overpopulated settlement. This would be useful if the overpopulated settlement couldn't send a travel to settlement mission itself (lack of water, available rover, etc). This might require quite a bit of refactoring work since we don't have a rover mission that currently supports having a portion of the mission crew start and be joined by the other portion of the crew later.
Another idea is to have a rover mission to bring emergency supplies (such as water) to another settlement that is running dangerously low. This might be doable with the existing trade mission if it's modified to allow more of a trade-for-credit model. I'm planning on taking a look through the trading algorithm to see if this is reasonable to do.
Please let me know if you have any ideas or questions about the settlement overpopulation problem and solutions. I'm hoping we can implement a few simple solutions that will make things a lot better for the Martian settlers.
Building warehouses that store spare supplies in case of overcroweding this would give time for emergency or usual relocaton of populations
Settleres building emergency water collection - generation plants that are offline but can be onilned in emerg situation therefore allowing time for relocation
The rover rescue mission impact if another empty or underpopulated base is within range rover will head for 2nd destination ( thats where building new settlements would be useful we could build a small outpost with emerg supplies that could act as a connecting pont between established settlements) in caretaker mode for issues that arise.
As for the stress perhaps some form of treatment may be factored in later on if medical bays recieve goods produced into the manfuacturing line
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Storage of supplies really hasn't been a problem with over population, as the settlements normally produce excess life support supplies under normal population and have considerable storage for them already. Usually when an over population situation happens, the settlement storage is nowhere near filled to capacity. In an over populated settlement, particularly a small one, the demand for the resources exceeds the production and the supplies slowly dwindle down to the point where the population is in danger.
There actually are automated processes in settlements that can be toggled on or off, and some of these generate water from other resources. The sabatier processes in ERV bases and the atmospheric processor building can generate water and methane from hydrogen (and CO2 pumped in from outside). This requires hydrogen, which may need to be manufactured or produced from other processes. The water recycling process is able to convert waste water into drinkable water, and green house crops can do this as well over time. All of these processes require electrical energy to run and can be toggled on or off based on the value and availability of the input resources and power. As water levels get low, the value of water at the settlement should increase compared to other resources.
Having a rescue mission take the survivors to a different, underpopulated settlement is certainly a possible solution. It would add some additional complexity to the mission. Currently the nearest settlement with a capacity to rescue the rover does so and brings the survivors back. If there is an underpopulated settlement nearby, the rescuing settlement should start a travel to settlement mission to send as much of the over capacity population to the destination settlement as it will comfortably hold. If overpopulation due to rescues continues to be a problem in the future, we might look into separate rescue destinations as a possible solution.
I'm looking into adding doctor-prescribed medication to help reduce stress. As a part of a future medical system improvement, I would like to add a large set of medications that could be supplied from Earth or manufactured at settlements from greenhouse-grown crops. These medications could have different effects (and side effects), and could be traded among settlements. I need to flesh out the idea on the project wiki a bit more. What I'm thinking of adding for this version should be pretty simple and will need to be revamped for a larger medication system.
Thanks for your ideas. I'm hoping settlement over population will be less of a problem with our fixes in the 2.86 release.
Copied from developer mailing list
----------------------
Fellow Mars-simmers,
The current leading cause of Martian settler fatalities in the simulation over a long (simulated) period of time is dehydration is settlements due to overcrowding and running out of water. I think we should try to resolve or reduce this problem before the 2.86 release if possible. There might be several ways of doing this, so I am hoping we can discuss ideas here.
Settlements have a population capacity determined by total living quarters capacity of its buildings. The configured settlement templates have population capacities of 4, 8, 12, and 25 inhabitants. It's also possible for the inhabitants to construct additional living quarters buildings to increase their settlement's population capacity.
When a settlement is overpopulated, the consumption of life-support resources such as food, oxygen and water exceed what the settlement was designed to produce. Normally settlements build up a surplus of these resources, but this can be quickly depleted if the settlement is heavily overcrowded. Water seems to be the life-support resource that runs out first, which leads to the inhabitants dying of dehydration.
Another contributing factor to the problem is that when a settlement is overcrowded, the inhabitants' stress increases considerably, which, in turn, reduces their effective performance at doing tasks. When a person has 100% stress for a period of time, he has a chance of having an anxiety attack, a medical illness that's basically a mental breakdown. When this happens, the person's performance goes down to 0% and he must rest for a period of time until his stress goes down a bit. In an overcrowded settlement filled with stressed out residents, the population will be constantly having anxiety attacks, which prevents any useful activities or missions that might alleviate the overcrowding problem.
When settlers are in an overcrowded settlement, they will tend to perform EVA tasks or go on rover missions to reduce the number of people in the settlement and the stress effect associated with that. This doesn't reduce the overall consumption of water, however, as they're still taking and consuming water when they leave the settlement.
Causes:
There are a number of situations that can lead to a settlement becoming overpopulated.
The Travel to Settlement rover mission is a primary cause for overpopulation. The mission allows people to immigrate from one settlement to another based on better work and social relationships. Reducing overcrowding is a factor in deciding to immigrate from one settlement to another, but it isn't an overriding concern for the settlers.
Rescuing stranded rovers contributes to overpopulation as the rescuing settlement may bring back a number of survivors that are beyond its capacity.
The Trade rover mission involves a crew driving a rover loaded with goods to another settlement and barter trading them for other goods, then loading those goods up and returning home. Sometimes there's a problem where goods they traded for are no longer available by the time they load up again, in which case the mission ends and the crew stays at the settlement they were trading with. I think this is a bug or at least should be handled more gracefully with the crew accepting the loss and continuing the mission.
Those are all the causes for settlement overpopulation that I can think of at the moment. Please let me know if I've missed any.
Solutions:
We should probably look for solutions to the causes of overpopulation, its effects, and the manner in which a settlement's inhabitants deal with it.
I think we should limit the Travel to Settlement mission to only pick destination settlements with more population capacity than residents, and to not allow more mission crew members than the destination settlement has capacity for. This will allow people at overcrowded settlements to emigrate to nearby settlements with space available. Once settlements construct new living quarters buildings and increase their population capacity, people will be able to move from settlement to settlement much more freely. This change should be fairly easy to implement, I think.
I'm thinking that the rescue stranded rover mission should probably stay as is. This is an emergency situation and the rescuing settlers should probably not worry about overpopulating their settlement with survivors, but rather deal with that after the rescue.
The trade mission should be changed so that it handles lack of goods at the destination trading settlement more gracefully, rather than causing the mission to fail and end as it does now, which leaves the crew members at the destination settlement. They should probably just log the missing goods as trade credit between the settlements and continue with the mission. I'm not sure how difficult this will be to implement, but I hope it will be relatively easy to do.
I think it's somewhat realistic that increased stress due to overcrowding would lead to arguments, frayed nerves, and anxiety attacks which effectively paralyze the settlement and prevent any useful activity. We may want to tweak the stress effects and chance of anxiety attack a bit, but I think the overall scenerio is reasonable. I think a doctor may be able to help alleviate this situation by providing stress reducing medication and treating patients suffering from anxiety attacks (perhaps with psychiatric therapy). I'm not sure how difficult it would be to add this to the medical system in the simulation. Let me know if anyone has other ideas for handling overcrowding stress problems.
Sebastien also brought up the idea of a pick up mission where a rover with a small crew would be sent from an underpopulated settlement to pick up immigrants from a nearby overpopulated settlement. This would be useful if the overpopulated settlement couldn't send a travel to settlement mission itself (lack of water, available rover, etc). This might require quite a bit of refactoring work since we don't have a rover mission that currently supports having a portion of the mission crew start and be joined by the other portion of the crew later.
Another idea is to have a rover mission to bring emergency supplies (such as water) to another settlement that is running dangerously low. This might be doable with the existing trade mission if it's modified to allow more of a trade-for-credit model. I'm planning on taking a look through the trading algorithm to see if this is reasonable to do.
Please let me know if you have any ideas or questions about the settlement overpopulation problem and solutions. I'm hoping we can implement a few simple solutions that will make things a lot better for the Martian settlers.
Take care,
Scott Davis
Mars Simulation Project
http://mars-sim.sourceforge.net
scud1@users.sourceforge.net
Building warehouses that store spare supplies in case of overcroweding this would give time for emergency or usual relocaton of populations
Settleres building emergency water collection - generation plants that are offline but can be onilned in emerg situation therefore allowing time for relocation
The rover rescue mission impact if another empty or underpopulated base is within range rover will head for 2nd destination ( thats where building new settlements would be useful we could build a small outpost with emerg supplies that could act as a connecting pont between established settlements) in caretaker mode for issues that arise.
As for the stress perhaps some form of treatment may be factored in later on if medical bays recieve goods produced into the manfuacturing line
Thanks for the suggestions, Paul.
Storage of supplies really hasn't been a problem with over population, as the settlements normally produce excess life support supplies under normal population and have considerable storage for them already. Usually when an over population situation happens, the settlement storage is nowhere near filled to capacity. In an over populated settlement, particularly a small one, the demand for the resources exceeds the production and the supplies slowly dwindle down to the point where the population is in danger.
There actually are automated processes in settlements that can be toggled on or off, and some of these generate water from other resources. The sabatier processes in ERV bases and the atmospheric processor building can generate water and methane from hydrogen (and CO2 pumped in from outside). This requires hydrogen, which may need to be manufactured or produced from other processes. The water recycling process is able to convert waste water into drinkable water, and green house crops can do this as well over time. All of these processes require electrical energy to run and can be toggled on or off based on the value and availability of the input resources and power. As water levels get low, the value of water at the settlement should increase compared to other resources.
Having a rescue mission take the survivors to a different, underpopulated settlement is certainly a possible solution. It would add some additional complexity to the mission. Currently the nearest settlement with a capacity to rescue the rover does so and brings the survivors back. If there is an underpopulated settlement nearby, the rescuing settlement should start a travel to settlement mission to send as much of the over capacity population to the destination settlement as it will comfortably hold. If overpopulation due to rescues continues to be a problem in the future, we might look into separate rescue destinations as a possible solution.
I'm looking into adding doctor-prescribed medication to help reduce stress. As a part of a future medical system improvement, I would like to add a large set of medications that could be supplied from Earth or manufactured at settlements from greenhouse-grown crops. These medications could have different effects (and side effects), and could be traded among settlements. I need to flesh out the idea on the project wiki a bit more. What I'm thinking of adding for this version should be pretty simple and will need to be revamped for a larger medication system.
Thanks for your ideas. I'm hoping settlement over population will be less of a problem with our fixes in the 2.86 release.
Scott Davis
Mars Simulation Project
http://mars-sim.sourceforge.net
scud1@users.sourceforge.net