1.1 水利水电工程对气候的影响
区域性气候是由大气环境和水体分布决定的,大气环境和水体分布在自然状态下是平衡的,然而,在人类修建水库和灌溉工程后,或多或少地会对水体的分布造成影响。水是构成大气环境的重要因素,正是因为水循环过程才有了气候的千变万化,水体分布的改变打破了原有的平衡,造成了气候的无法调控甚至灾难气候。
1.2 水利水电工程对降雨的影响
水利水电工程的不断建造会使水库不断增多。经过阳光的照射,降雨量会大大增加,大量的降雨对于部分区域是“甘露”,对于部分区域却会引起洪涝灾害。据调查发现,地势高的迎风面降雨会增加,反之降雨会减少,即在距离水库比较近的地方,降水量反而会下降。水利水电工程的建立原本是为推动当地经济发展,现在看来,似乎有些顾此失彼。长此以往,降雨时间分布也发生了变化,比如南方的大型水库的夏季降雨量就会减少,冬季降雨量就会增多。综上所述,水利水电工程的建造对降雨量、降雨分布、降雨时间分布等方面都产生了影响。无形中的变化却造成有形的破坏。
1.3 水利水电工程对水体的影响
当水库建成以后,大量的水容纳于一个地方,库内的水无法及时流出,造成“死水”的堆积,水库储存较久的水会让被淹没的植物腐烂更快,大量腐烂的植物会消耗水中的氧气,水中形成大量的二氧化碳和沼气甚至毒物质和难降解的重金属,形成次生污染源。
1.4 水利水电工程对物种的影响
在大坝开闸时,水流速度过快,产生了大量的氮氧,幼鱼会因此死亡。鱼的大量死亡会对土壤造成恶劣影响,土壤的污染又会破坏植物。水库蓄水会造成水库周围土地大量被浸没,长久以来,周围的土地不再适合植物生长,不充足的氧气、土壤浓度的改变将会造成难以逆转的生态危机。库区周围的土壤过于湿润,导致养分不足,植物无法扎根立足于此,造成大量的植物失去了赖以生存的家园。
1.5 水利水电工程对人们生活的影响
水利水电工程在施工过程中难免会产生并没有处理完全的废水,废水直接通过排放管道进入河道,造成河水的污染。水污染的严重化给人们的日常生活带来了不方便,比如,施工过程中会产生一些难闻的气味,含化学物质的气体进入人体内,潜移默化地伤害着呼吸系统;河道水污染造成周围的居民饮用水质得不到保障,长期住在附近的居民无法享受良好的水源,对生活质量有所影响;施工期间,难免会产生噪声,影响了周围居民的生活。综上所诉,水利水电工程的建立对人们造成了许多影响,空气质量的下降也使得生病率大大提升。
1.6 社会及人文资产破坏
为了经济的发展,各地政府都争先恐后地要求在本地建立水利水电工程。然而,水利工程建设对社会与人文资产的\'影响巨大。如果一个地方确定要建设水利工程,则当地就要为此准备,人们世世代代居住的地方选为建筑地后,当地百姓不得不背井离乡,曾经无数的记忆却成为现代化器械工作的场所。同时,如果水库恰好选中有大量文物古迹的地方,则为了大力开发水利水电,人文资产必定受到损坏,得不到保护的文化只能在经济发展中消失殆尽,唯一残存的可能只能来源于老一辈的记忆。因此,在进行水利水电工程设计和选址时需要慎重决策,尽量不迁移群众和破坏人文资产。
Elephant is the largest animal on land today. It weights some ninety kilograms and is about one metre high when born. When it is 12 years old, it studs over three meters and does not grow any more. Elephant is usually grey in color, having a long trunk with large ivory tusks protruding from each side of its mouth. Usually moving in groups and caring for each other, Elephant is know to be a very and gentle creamre. For many years people have used the strength of these poweful animals to move trees and heavy logs. Elephant has been and is a vital tool for people to do many things that would normally be imposs-ible. Elephant is and will continue to be one of the greatest creatures man has ever come into contact with. Its size. beauty, and power willforever be useful to man.
Elephants are the biggest animals on the land.They are big and srong.They have big ears and trunks.They can walk quietly and help people move heavy things. They are very friendly,kind and always live together.But the number of elephants reduces.People kill elephants for their ivories.We must take action to protect them or else they will extinct from the world.
Children's finally here, it is our holiday, but imagine the children also accompanied by together, everybody is more excited.
Children on this day, white clouds float over the blue sky, the children also have made a hot air balloon, they sit together on yourself a hot-air balloon, extremely happy! Balloon flying high, and finally flew to the sky, the children are in the sky holiday, the children sit on clouds, umpa jump, like a frisky little monkey.
Playing children, suddenly to rain cats and dogs, the children of the balloon has stalled, baiyun sister swept away by the wind, the children fell into despair. Is a time of crisis, a group of dragonflies sister and sister flew caught the children, and the safety of the children to the ground.
On the ground, only butterflies woven into a rainbow "lei", the children wear a wreath, some like a fairy, some like a warrior.
Play tired, the children fell asleep between full of fragrance of flowers.
Children's good play my imagination, to one day be able to live in such a children's day.
记得在我上二年级的时候,发生过这样一件事。
那天中午,我正在房间里抱着爸爸给我新买的那本《十万个为什么》,翻来覆去地看个不停。妈妈正在厨房里为了做菜忙得火热朝天。
忽然,听到妈妈喊一句:“儿子啊,没有味精了!你帮我到公园门口的小超市买一包味精回来好不?”我在看书,正看的起劲,想也没想就脱口而出:“好。妈妈塞了20元钱到我手里。我还沉浸在书里,一手拿住书,另一手拿住钱,穿好鞋子就边看书边走到了小卖部门口。”
我照妈妈的话,用极高的童音对着小卖部里面的阿姨说:“阿姨,要一条围巾。”
里面的那位阿姨很是奇怪:“现在大热天的买什么围巾啊?”
我说:“我也不知道,我妈妈要我买的。”
那位阿姨就拿了一条便宜的17元的围巾给我,找回我3元钱后,我看着书回到了家里。
刚进家门,妈妈就高兴地欢呼:“噢,味精来了,味精来了。”
我说:“妈啊,你大热天的买围巾干什么?”
妈妈说:“做菜要用啊!做菜不给味精味道就差很多!”
我心里暗暗默念:以后如果我会做菜了,一定每次都要给一条围巾。就把那条围巾递给了妈妈。
妈妈拿到围巾,顿时傻了眼:“我要你买的味精,你买围巾回来干什么?”
我大惑不解:“就是你要我买围巾回来的啊!”
这时我忽然想起妈妈吩咐我的时候我的脑袋里全是书,当然会听错。便说:“。不好意思。我看书太认真。听错了。”脸涨得通红。
妈妈开心地笑了,把我搂进怀里。
这件事再回想起来,还能让我开怀大笑。
每当看到那部剃须刀,七彩的童年生活犹如放电影般呈现在了我的脑海中,久久挥之不去。
那年我才四岁,有一天我去姥爷家,看着家中柜上面各种各样的摆设品,强烈的好奇心驱使我不住地摸摸这儿,玩玩那儿。忽然老爷手中的一个黑盒子”吸引了我的注意力,他长得并不好看。却能发出嗡嗡的声音。姥爷拿着它在嘴边蹭来蹭去,一副悠闲自得的样子,那感觉简直像腾云驾雾的活神仙。而站在一旁的我早就看得心痒痒了,眼睛直直地盯着黑盒子,恨不得马上就体验一下那感觉。好不容易等到姥爷出去,我立刻一个箭步冲上去。拿起黑盒子”,随手按了一个按钮,那玩意儿立刻不停的震动起来,犹如蜜蜂采蜜般嗡嗡地叫起来,真好听。我尝试着慢慢用它在脸上蹭来蹭去,啊!那感觉仿佛把整个脸都埋进了棉花里,皮肤都跟着不停颤动,舒服极了。这时姥爷回来了,他神情怪异地盯着我看,忽然缓缓地问:你的眉毛哪儿去了?”我闻声大惊,急忙拿起镜子一瞧,嘿,果真我的眉毛竟不翼而飞啦!我吓得哇哇大哭起来,姥爷却忍不住哈哈大笑。这时我又瞅见了镜中那个狼狈不堪的我,又不禁破涕而笑。
冰心曾说过,童年是梦中的真,是真中的梦,是回忆时含泪的微笑,这句话是多么贴切啊。
I like elephants. They are very gentle and they can walk quietly and help people move heavy things.
Elephants are the biggest animals on the land.They are big and strong.They have big ears and trunks. It weights some ninety kilograms and is about one metre high when born. When it is 12 years old, it is over three meters high and does not grow any more. Elephants are usually grey in color. They usually live in groups and care for each other.
We should protect elephants . They are the friends of ours.
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