近35年长江流域土地利用时空变化特征及其径流效应

发布时间：2018-01-13 20:27

本文关键词：近35年长江流域土地利用时空变化特征及其径流效应　出处：《郑州大学》2017年硕士论文　论文类型：学位论文

更多相关文章： 长江流域 土地利用变化 径流 HEQM模型

【摘要】：土地利用/覆被变化是当前全球变化研究的重点内容,土地利用发生变化后会影响水文过程并最终导致径流发生变化,因此是水文学者重点关注的领域。本文以长江流域作为研究对象,对流域内近35年的土地利用时空变化特征进行了详细分析,并建立流域水文模型,对土地利用变化后径流影响进行定量计算,分析流域土地利用的径流效应,研究结果表明:(1)长江流域近35年土地利用变化特征如下:1980~1990年和2000~2005年期间土地利用变化速度要比1990~1995和1995~2000年期间要快,研究期内第一(1980~1990年)和第四时期(2000~2005年)的平均交换变量值分别为0.61和0.45,远远大于中间两个时期的平均值0.09和0.08。在空间分布上流域上游中部的四川一带的交换变量值比较大,是流域内土地转移最活跃的地区,其次是上游源头地区,流域中下游地区的转移活跃程度相对较小。不同类型的土地利用变化方面也有不同的特征,耕地、水域、建设用地和未利用地的面积先减后增,林地和草地的面积在前两个时期增加,后两个时期内减少。人类毁林和过度放牧等使上游林地、草地等面积减少明显,这些土地类型多转为未利用地,中下游的在林地、耕地之间的转换相对较多,下游的水域面积在前期转为未利用地和水田的较多,后期水域面积增加则主要来源于未利用地和水田的转化,建设用地是流域内增加最明显的用地类型,特别是经济发达的下游地区。(2)模型计算结果表明土地利用变化后对径流产生了明显的影响。在不同的土地利用条件下多年日平均径流量、枯水期和丰水期径流平均值及洪、枯水值都发生变化,研究中的11个站点径流变化如下:上游干流的直门达、屏山;雅江小得石站和鄱阳湖水系的径流量减少。屏山站年径流量减少了840623.62万m3,减幅5.03%,是所有站点中径流减少最多的站点;剩余的7个站点:高场站、北碚站、武隆站、皇庄站、城陵矶站和干流宜昌站和大通站年径流量都呈增加变化。径流增加幅度最大的在嘉陵江的北碚站,年径流值增加了520060.18万m3,增幅为9.32%;增加相对较小的是泯沱江的高场站,年径流量只增加3784.32万m3,增幅仅为0.05%;位于下游干流的大通站年径流量增加了78209.28万m3,增加0.08%。枯水期和丰水期平均值的变化趋势多数跟年径流总量变化一致,或同时增加,或同时减少,但是宜昌、城陵矶和大通站的变化不一致。10%频率洪水在屏山以上的站点、宜昌和湖口站减少,其中屏山站的减少最多,减幅为2.67%,其余都减少1.00%;北碚、皇庄等站洪水值增加,最大增幅3.48%。枯水值只在北碚、宜昌、皇庄和大通站增加;多数站点的枯水径流减少,最大减幅68.70%,土地利用变化后对枯水径流影响较大。流域径流量在土地利用变化后,上游屏山站以上和鄱阳湖水系的流量减少,中下游地区朝着增加的趋势变化。
[Abstract]:Land use / cover change is the focus of current global change research. Land use change will affect hydrological process and eventually lead to runoff change. Therefore, it is the focus of hydrologists. This paper takes the Yangtze River Basin as the research object, analyzes the temporal and spatial changes of land use in the basin in detail, and establishes the hydrological model of the basin. The runoff effect after land use change was calculated quantitatively and the runoff effect of land use in watershed was analyzed. The results show that: 1). The characteristics of land use change in the Yangtze River Basin in the past 35 years are as follows:. The rate of land use change in the period from 1980 to 1990 and from 2000 to 2005 was faster than that between 1990 and 1995 and from 1995 to 2000. The mean exchange variables of the first period (from 1980 to 1990) and the period of 4th (from 2000 to 2005) were 0. 61 and 0. 45, respectively. It is far larger than the average values of 0.09 and 0.08 in the middle of the two periods. The exchange variable values in the middle part of the upper reaches of the basin are relatively large, which is the most active area of land transfer in the basin. Secondly, the upstream source area, the middle and lower reaches of the river basin transfer activity is relatively small. Different types of land use change also have different characteristics, arable land, water. The area of construction land and unused land decreased first and then increased, the area of forestland and grassland increased in the first two periods, and decreased in the latter two periods. Most of these land types are converted into unused land, the middle and lower reaches of the forest land, the conversion between arable land is relatively more, the lower reaches of the water area in the early period to unused land and paddy fields more. In the later period, the increase of water area mainly comes from the transformation of unused land and paddy field, and the construction land is the most obvious type of land increase in the basin. Especially in the economically developed downstream area, the results of the model show that the land use change has a significant impact on runoff, and the average daily runoff under different land use conditions. The mean value of runoff, flood and low water value changed in dry and high water periods. The changes of runoff at 11 stations in the study were as follows: Zhimenda, Pingshan of upstream main stream; The annual runoff of Pingshan Station was reduced by eight billion four hundred and six million two hundred and thirty-six thousand and two hundred m3, which was the largest of all the stations. The remaining 7 stations: Gaochang Station, Beibei Station, Wulong Station, Huangzhuang Station, Chenglingji Station and main Stream Yichang Station and Datong Station have increased annual runoff. The largest increase range of runoff is in Beibei Station of Jialing River. The annual runoff value increased by five billion two hundred million six hundred and one thousand and eight hundred m3, the increase was 9.32%; The increase is relatively small in the Mintuo River, the annual runoff increase only thirty-seven million eight hundred and forty-three thousand and two hundred m3, the increase is only 0.05; The annual runoff of Datong Station located in the main stream of the lower reaches increased by seven hundred and eighty-two million ninety-two thousand and eight hundred m3 and 0.08%. The variation trend of the average value in dry and high water periods is mostly consistent with the total annual runoff. Either increase or decrease at the same time, but Yichang, Chenglingji and Datong stations do not change in the same frequency. 10% flood frequency in the stations above Pingshan, Yichang and Hukou stations decreased, among which Pingshan station decreased the most. The decrease was 2.67 and the rest was 1.00; The flood value of Beibei, Huangzhuang and other stations increased, the maximum increase was 3.48. The low water value only increased in Beibei, Yichang, Huangzhuang and Datong stations. The dry water runoff of most stations was reduced, the maximum reduction was 68.70, and the land use change had a great influence on the dry water runoff, and the runoff of the watershed was changed after the land use change. The flow above Pingshan station and Poyang Lake decreases, and the middle and lower reaches tend to increase.
【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P333

【相似文献】