On the arid island that had not seen rain for two months, it was evident how scarce the fresh water resources were.
Lu Zhe asked again, "By the way, how many coconuts have we used up these past couple days?"
Ning Shu said, "The coconuts we had picked earlier are basically all used up. There's probably still around one third left of the ones we picked later that we can't reach."
Lu Zhe nodded, "At this rate of usage, the coconuts around here will be exhausted by us in less than a week!"
Ning Shu asked, "Where else are there a lot of coconut trees?"
Lu Zhe shook his head, "Relying solely on coconuts is not a solution! Even if we had all the coconuts on the island to use, they wouldn't last a few months!"
Shen Bing also nodded, "There's too little water in each coconut. Some don't even have water inside or they've gone bad and are completely undrinkable."
Ning Shu said, "And drinking only coconut water all the time probably isn't good for our health right?"
Tang Xiaoguo strongly agreed, "Yes, yes! We've been drinking coconut water these past few days and I feel unwell. Just the smell of coconuts makes me want to vomit now."
Jiang Yao said, "Me too, I'm about to turn into a coconut fairy!"
Lu Zhe understood how the girls felt, because he felt the same way. No matter when, coconut water would never be a complete substitute for fresh water!
"Additionally, we need to clear land and open fields. We must find a sustainable source of fresh water in order to do so!"
Shen Bing asked, "Lu Zhe, what are your plans going forward?"
"To truly venture into the jungle and search for water sources!"
Ning Shu said, "You mean you guys didn't truly enter the jungle today?"
"No!"
Lu Zhe shook his head, "Today, Qianqian and I walked along the mountainside, searching for mountain streams. But from the current situation, it appears the mountain streams have already dried up. Continuing the search this way, we probably won't find any fresh water!"
Shen Bing asked, "Can you find some if you enter the jungle?"
Lu Zhe thought for a bit, "I can't say for sure we'll find any, but at least there will be more options! We can try climbing to the highest point of the island and look down at the whole island from above. If there are lakes or rivers, we'd be able to see them!
Additionally, we can search for groundwater deep inside the island!"
"Groundwater?" Shen Bing was a little puzzled, "Even if there's groundwater on an island, would it be fresh water?"
"Yes!"
Lu Zhe nodded firmly, "Haven't you heard of a term called a 'freshwater lens'?"
Shen Bing thought for a bit, "It sounds kind of familiar."
"A freshwater lens, also known as a Ghyben-Herzberg lens, is a special geological structure found on coral islands."
Jiang Yao said, "I think we learned about it in high school geography, but after going to college I returned most of my high school knowledge back to the teachers."
Ning Shu nodded, "Me too. Can you explain in more detail?"
"On coral islands, there are some places that are thick in the middle and thin around the edges. The tiny pores in the coral form a filter layer that stores rainwater and allows the fresh water to float above the seawater without mixing together!
Because this geological phenomenon looks like an underground convex lens buried there, it is also called a freshwater lens!"
Lin Qianqian said,
"Now I remember! When our country's artificial Yongshu Island was being developed, many wells were drilled, and over one third of them discovered fresh water! Scientists studied and found it was caused by this lens phenomenon!"
"That's right, this is it!"
Lu Zhe nodded, "The area of this volcanic island is even greater than that of Yongshu Island. There should be similar geological structures!"
Ning Shu marveled, "I really didn't expect your geography knowledge to be so extensive Lu Zhe!"
Jiang Yao was a little worried though, "But I heard from Qianqian that only one third of the wells discovered fresh water. So isn't finding it pretty much up to luck?"
"Of course, due to the prolonged drought, or the volcanic geology of the island, it's possible that even after digging very deep pits there's no gain." Lu Zhe frankly said,
"But if we don't try, the probability will be zero!"
Shen Bing nodded, "It does seem necessary to go into the jungle. When do you think we should set off?"
Lu Zhe thought for a bit, "At the very least, we have to wait for your leg injury and Qianqian's jellyfish stings to heal.
Ning Shu said, "So everyone should go into the jungle together? No need to stand guard at camp?"
Lu Zhe nodded, "In less than a week the coconuts here will be drank up by us. By then we'd have to move anyway, so we might as well all go into the jungle together. If we come across a steady freshwater source, we can build a camp right there and save having to come back here to notify whoever stayed behind."
Ning Shu smiled, "Exploring the jungle together sounds rather worth looking forward to huh?"
Lin Qianqian said, "If we camp in the jungle, it'll be less convenient for us to go to the beach."
Jiang Yao also said, "We won't be able to pick up sea treasures or pry open clam shells either."
Tang Xiaoguo was sad too, "Or the camp we spent a whole night prettifying..."
"There always has to be trade-offs. For us right now, nothing is more important than a steady supply of fresh water!"
The girls looked at each other. Although they all felt some regret in their hearts, they understood Lu Zhe's judgment was likely the most sensible.
Lu Zhe pondered some more, "But don't worry too much. After we find fresh water, the location may end up not being too far from the beach anyway, and everyone can still go to the sea to pick up treasures every day!"
Shen Bing asked, "If all six of us go into the jungle, won't we need to prepare a lot of supplies?"
Lu Zhe thought for a bit and nodded,
"Let me give a rough list!
First, everyone needs to prepare at least 5 bottles of fresh water!
We also need sufficient food, so we don't have to spend too much effort searching for food when we first enter the jungle!
Second, prepare protections! There will be far more mosquitos and insects in the jungle compared to the beach! Every two people should have a bottle of mosquito repellant!
Third, directly sleeping on the ground in a tropical jungle is asking for death. So we need a lot more rope to make hammocks for camping!"
Shen Bing nodded, "We can use coconut water to substitute fresh water! And our current food reserves should be adequate too. Looks like rope is the main thing. These past few days Ning Shu taught me how to weave rope from banana bark. Let's weave more ropes during our recovery over the next few days!"
The girls all voiced their agreement!
"Alright, let's lock down this plan for now! Over the next stretch we don't need to maintain the shelter! For those with time and energy, enrich our variety of freshwater and food in preparation for jungle exploration!"
Lu Zhe checked his watch again, "It's gotten late today. Everyone eat something and rest early. We'll start preparations for the expedition tomorrow morning!"
On this day they turned in early. Opening his eyes the next morning, Lu Zhe saw Tang Xiaoguo smiling at him.
He was so shocked he jumped.
"Sis, what are you doing?"
Tang Xiaoguo pouted, "Didn't the books say, what men most want to see when opening their eyes in the morning, is their cute girlfriend gently smiling at them? I'm your designated girlfriend of the day!"
Lu Zhe scratched his disheveled hair and bitterly chuckled, "But you don't have to shock me right?"
"Too unfanciful!"
Tang Xiaoguo was about to snap, but she suppressed the urge, "I'm determined to be the best, most considerate girlfriend today, so no matter what you say I won't get angry!"
Saying that, she handed the prepared breakfast to him.