谁改变了四川?
岷江 是蜀郡最大河流,它的冲积扇成就了古代的成都平原,同时也带来较为严重的旱涝灾害,所以成为治理工作的重点。https://cdn.wenzhu.net/public/attachments/2022/10/08/Z80c1LexQjJ3oPLM1DuLEdoFPDg0UfFdDHF0mvK1.jpeg?sign=q-sign-algorithm%3Dsha1%26q-ak%3DAKIDymOkwsV5IgphCeqplXAajdKlv2xz2XBa%26q-sign-time%3D1767282774%3B1767369234%26q-key-time%3D1767282774%3B1767369234%26q-header-list%3Dhost%26q-url-param-list%3D%26q-signature%3D0f3eb1d0af31474c8574d837f69e53b5452fcad3&&imageMogr2/format/webp/quality/20/interlace/1/ignore-error/1都江堰修筑后成都平原的灌溉水源得到保证,对水灾的防控能力也随之提升,天府之国自此奠基。(图:图虫创意)▼岷江,成都平原的母亲河冲出西部山地后进入地势相对低平的成都平原,河道变宽流速放缓。河水中裹挟的泥沙沉降形成冲积扇,为成都平原提供了肥沃的土地。(图:图虫创意)▼岷江对于成都平原地形的塑造能力源于它的水文条件——岷山从发源地到成都平原之间要经过341公里的群山峡谷,水汽在群山中自汶川至紫坪铺的区域里易形成暴雨,降雨与春夏季融化的高山雪水一起,形成了具有138条支流的岷江水系 。这些支流汇聚形成的岷江水量丰富,到都江堰处,年流量可达150.8亿m³,平均径流量478m³/s。岷江水系并不是最大的一个https://cdn.wenzhu.net/public/attachments/2022/10/08/qaBd6mDzpSy9NHLyLVT6RSSosuDKkkdnvUr3VWdV.jpeg?sign=q-sign-algorithm%3Dsha1%26q-ak%3DAKIDymOkwsV5IgphCeqplXAajdKlv2xz2XBa%26q-sign-time%3D1767282774%3B1767369234%26q-key-time%3D1767282774%3B1767369234%26q-header-list%3Dhost%26q-url-param-list%3D%26q-signature%3D5e507271184df0171fbe668dd9a3831d8b2f49ab&&imageMogr2/format/webp/quality/20/interlace/1/ignore-error/1https://cdn.wenzhu.net/public/attachments/2022/10/08/zZjmFx8VcVTzko9OXX0MlgrWV1rzvbRJ9Cuprc6f.jpeg?sign=q-sign-algorithm%3Dsha1%26q-ak%3DAKIDymOkwsV5IgphCeqplXAajdKlv2xz2XBa%26q-sign-time%3D1767282774%3B1767369234%26q-key-time%3D1767282774%3B1767369234%26q-header-list%3Dhost%26q-url-param-list%3D%26q-signature%3Dee5b76d7cfc55b0abed81e992363a1c247495a21&&imageMogr2/format/webp/quality/20/interlace/1/ignore-error/1每年夏天,岷江中下游的水常常会浑浊不堪将上游泥浆冲刷带入了河流导致的https://cdn.wenzhu.net/public/attachments/2022/10/08/36flCCOnuyW2kkL6liwvFmPFzD5d41Az70O8kzPm.jpeg?sign=q-sign-algorithm%3Dsha1%26q-ak%3DAKIDymOkwsV5IgphCeqplXAajdKlv2xz2XBa%26q-sign-time%3D1767282774%3B1767369234%26q-key-time%3D1767282774%3B1767369234%26q-header-list%3Dhost%26q-url-param-list%3D%26q-signature%3D544471ec080285432d1b0ec3dc72092d7028aacf&&imageMogr2/format/webp/quality/20/interlace/1/ignore-error/1在没有水利设施的状态下,一旦洪水爆发漫过河岸,成都平原就是天然的泄洪区。洪涝灾害三五年就可能爆发一次,已经见多不怪https://cdn.wenzhu.net/public/attachments/2022/10/08/utxM3tA45Xt2gEwYWhnFMDmtqCqXYj2TNhAGhP5X.jpeg?sign=q-sign-algorithm%3Dsha1%26q-ak%3DAKIDymOkwsV5IgphCeqplXAajdKlv2xz2XBa%26q-sign-time%3D1767282774%3B1767369234%26q-key-time%3D1767282774%3B1767369234%26q-header-list%3Dhost%26q-url-param-list%3D%26q-signature%3Dd4d9f00d25fa279adeac27f924ea8b10bbbf92db&&imageMogr2/format/webp/quality/20/interlace/1/ignore-error/1旱灾发生时没有灌溉水源的农田就会遭遇减产甚至绝收,灌溉水源就成为了保障粮食安全的保险。今年四川大旱,都江堰上游的紫坪铺水库(图:图虫创意)▼成都平原土壤肥沃、地势平坦,配合雨热同期的季风气候是理想的农业用地,古人并不会因为存在水旱灾害的可能性放弃这片宝地。随着文明的发展,一代代蜀人开始治理都江堰,古蜀国留下了巴人鳖灵成功治水而望帝禅位的传说。公元前316年 ,作为秦灭六国前扩充实力的准备工作,秦军南下吞并蜀国 。成都平原作为巴蜀开发程度最高的鱼米之乡,经营好它是为秦国提供粮草兵源的基础,治理时常受到水旱灾害影响的岷江就成为了重点工作。https://cdn.wenzhu.net/public/attachments/2022/10/08/VPDvCs1u9hzQYVOJ0bv8nnboEAWY4FqpVnLYttVv.jpeg?sign=q-sign-algorithm%3Dsha1%26q-ak%3DAKIDymOkwsV5IgphCeqplXAajdKlv2xz2XBa%26q-sign-time%3D1767282774%3B1767369234%26q-key-time%3D1767282774%3B1767369234%26q-header-list%3Dhost%26q-url-param-list%3D%26q-signature%3D207e81c06beed16b72eba437205b2c4857dc744e&&imageMogr2/format/webp/quality/20/interlace/1/ignore-error/1都江堰工程平面示意图都江堰适合务农的平坦地带集中在岷江东岸,岷江流向本为西北—东南向,但被玉垒山阻挡,在此处转向沿西岸山谷向南流,很难直接引水灌溉东部的小平原。李冰决定挖开阻挡江水与平原的前山,因为制造了一个如同瓶口的河道,被命名为宝瓶口,一部分水流得以沿宝瓶口进入东部平原作为灌溉水源。将岷江水资源更好地利用了起来https://cdn.wenzhu.net/public/attachments/2022/10/08/HkVIx951WXhka4BhH46ldAz3EnOiwwD8lzeWomXF.jpeg?sign=q-sign-algorithm%3Dsha1%26q-ak%3DAKIDymOkwsV5IgphCeqplXAajdKlv2xz2XBa%26q-sign-time%3D1767282774%3B1767369234%26q-key-time%3D1767282774%3B1767369234%26q-header-list%3Dhost%26q-url-param-list%3D%26q-signature%3D4735922b70ab03c5c61f7f802303f0233dc502b9&&imageMogr2/format/webp/quality/20/interlace/1/ignore-error/1为了解决引流问题,岷江主河道上又修建了一个堰起分水作用。其前端流线型的形态有利于分流岷江水,因酷似鱼嘴 因此得名,主体部名为金刚堤 ,高出水面,起到将岷江分为内外江两个部分的作用。其西侧为外江,主要作用为排洪疏沙,东侧为内江,在金刚堤的引导下向宝瓶口输水。在江面宽阔处形成一个人工岛,把江水分开岷江在都江堰处的河道西部为凸岸(沉积岸),河道较为平缓,东部坡度较大位于凹岸(侵蚀岸),河道较窄而深。这又影响了不同水量情况的主流线:丰水期底面积较大的外江分担水量显著增加,成为主流,起到泄洪作用;而枯水期时河道相对深、淤积情况较轻的内江成为主流,保证灌溉。为了提高泄洪能力、进一步排沙、输水,李冰还在内外江交汇处修筑了飞沙堰 。枯水期它能够起到类似堤坝的作用,阻挡内江水流入外江,搭配金刚堤将内江水引入宝瓶口为农田提供珍贵的灌溉水源。而汛期时,因飞沙堰较为低矮,内江水可以漫过它流入外江主河道,减轻宝瓶口泄洪压力。河道更低的宝瓶口后的渠能分得更多水https://cdn.wenzhu.net/public/attachments/2022/10/08/0XPLinwWn7T01khTiCv9Z6ltsnFxHjdxZnKJ0o98.jpeg?sign=q-sign-algorithm%3Dsha1%26q-ak%3DAKIDymOkwsV5IgphCeqplXAajdKlv2xz2XBa%26q-sign-time%3D1767282774%3B1767369234%26q-key-time%3D1767282774%3B1767369234%26q-header-list%3Dhost%26q-url-param-list%3D%26q-signature%3Df7e3f448987963d82ba95c0fbacbd39d63c9fdac&&imageMogr2/format/webp/quality/20/interlace/1/ignore-error/1当这一套工程起到综合作用时,就成就了包含整个成都平原与周边丘陵的都江堰灌溉区。该区凭借肥沃的土地,充足的光照,形成了一年两到三熟的粮油产区,成为成都平原蜕变为天府之国的地理基础。是前人留给后世的无上至宝https://cdn.wenzhu.net/public/attachments/2022/10/08/Z7V3xrMkEsxnXp22ndhmqnITME48xxlDGlju0B23.jpeg?sign=q-sign-algorithm%3Dsha1%26q-ak%3DAKIDymOkwsV5IgphCeqplXAajdKlv2xz2XBa%26q-sign-time%3D1767282774%3B1767369234%26q-key-time%3D1767282774%3B1767369234%26q-header-list%3Dhost%26q-url-param-list%3D%26q-signature%3D6aec3357ff345abbfcc63c00b6dc583e8a18057e&&imageMogr2/format/webp/quality/20/interlace/1/ignore-error/1都江堰成就了天府之国,但是一条流量巨大、汛期明显的河流并不会仅仅因为一个单一的水利工程就变得水旱随人。正在对堤坝进行加固的工人(上,图源:壹图网)https://cdn.wenzhu.net/public/attachments/2022/10/08/bZKjxgD6OUDu2h215VOxxiZHXWS981zB3axkN0GL.jpeg?sign=q-sign-algorithm%3Dsha1%26q-ak%3DAKIDymOkwsV5IgphCeqplXAajdKlv2xz2XBa%26q-sign-time%3D1767282774%3B1767369234%26q-key-time%3D1767282774%3B1767369234%26q-header-list%3Dhost%26q-url-param-list%3D%26q-signature%3D78023689fac27682d2c0125992151cca8a63d638&&imageMogr2/format/webp/quality/20/interlace/1/ignore-error/1即使经过修缮,面对特大洪水都江堰依旧会遭受毁损,灌溉区还是会受到洪水影响,轻则冲垮田地,重则屋毁人亡。国民时期定例每年都要修缮一次,不时还会进行大修,但是依旧在1933年地震、1936、1943、1949年洪水中被冲毁数百米,严重的年份出现农田毁坏数万亩,灾民数十万的惨状。(图:图虫创意)▼这与岷江洪水的特点息息相关。前面提到,由于岷江上游同时受东南与西南季风影响,降水集中且不稳定,而都江堰作为从群山向平原过渡的关键点,自然会成为来势凶猛的洪水泄洪区域,当流量超过500m³/s就会引发涝灾,外江流量超过870m³/s就会冲毁设施。当堰体被冲毁,宝瓶口就无法有效收集灌溉水源,洪灾后抗旱能力也会大大降低 ,以至于水渠无水。1890-1990的一百年中都江堰灌溉区发生了7次这类旱灾,以及14次因久不降雨导致的旱灾。一代君主先是有了江山、而后便要追求“社”和“稷”https://cdn.wenzhu.net/public/attachments/2022/10/08/fP1VwYErENsyWfqS5u6Yu5d5OmkMkVLVOrTWZMcv.jpeg?sign=q-sign-algorithm%3Dsha1%26q-ak%3DAKIDymOkwsV5IgphCeqplXAajdKlv2xz2XBa%26q-sign-time%3D1767282774%3B1767369234%26q-key-time%3D1767282774%3B1767369234%26q-header-list%3Dhost%26q-url-param-list%3D%26q-signature%3Da5fab4be8947f741eb41497ed4d5805c65cd4ffd&&imageMogr2/format/webp/quality/20/interlace/1/ignore-error/1河流治理是一个系统工程,无法依靠一个点的经营一劳永逸。回顾两千年前古人留下的治水杰作,我们足可以看清自身的渺小,却又对古人改造生存环境和利用自然的智慧怀有敬意。如何与自然和谐相处,是人类的必修课https://cdn.wenzhu.net/public/attachments/2022/10/08/HFYg0vpJtB8OAKfnntf4TmIIYYtDMiL5NVwNa5Oh.jpeg?sign=q-sign-algorithm%3Dsha1%26q-ak%3DAKIDymOkwsV5IgphCeqplXAajdKlv2xz2XBa%26q-sign-time%3D1767282774%3B1767369234%26q-key-time%3D1767282774%3B1767369234%26q-header-list%3Dhost%26q-url-param-list%3D%26q-signature%3D23d1add1d74a6958d733cd2f9ea35dc120ef78f8&&imageMogr2/format/webp/quality/20/interlace/1/ignore-error/1王芳芳 吴时强 都江堰工程思考及其启示李映发 岷江与都江堰对成都平原生存环境的影响——从历史考察的角度
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