权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

A physiographical study on the secular fluctuations and regional characteristics of rainfall-runoff processes

降雨径流过程长期波动及区域特征的地理学研究

基本信息

批准号：
17500706
负责人：
MORI Kazuki
金额：
$ 1.28万
依托单位：
Nihon University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2005
资助国家：
日本
起止时间：
2005 至 2006
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-17500706/
关键词：
water balance climate change precipitation evapotranspiration runoff ratio river water quality 蒸発散量流出量

项目摘要

Changes in the components of rainfall-runoff characteristics including precipitation, evapotranspiration, and runoff ratio over the last 100 years were comparatively investigated in two river basins as a case study. Annual precipitation in the study area has tended to decrease since the first half of the 1970s. On the other hand, the smooth trend curve indicates that annual evapotranspiration has increased over the long term, especially since the 1980s. Smoothed long-term changes in the difference between annual values of precipitation and potential evapotranspiration are analogous to those of annual precipitation. The average annual runoff ratio for each year has also shown a tendency to decrease during the last few decades. It is pointed out that the notable characteristics of current frequency-magnitude distributions in annual precipitation are both a reduction of intervals of hydrological extremes and an increase of range in each year. Under conditions of extreme meteorological events that increased air temperature in the summer of 1994, river water quality showed a remarkable change compared to its average value in a normal year. The most striking feature due to high temperature and small discharge was a very low value for the concentration of dissolved oxygen, especially in July and August. The facts identified in the present study provide a meaningful perspective of the possible consequences of global warming for rainfall-runoff processes, and are also useful basic data for evaluating the effects of future climate change on the aquatic environment.

以两个流域为例，对比研究了近100年来两个流域降雨径流特征成分的变化，包括降水、蒸散量和径流比。自20世纪70年代上半期以来，研究区年降水量呈下降趋势。另一方面，平滑的趋势曲线表明，从长期来看，年蒸散量有所增加，特别是自20世纪80年代以来。年降水量与潜在蒸散量之差的平滑长期变化与年降水量的变化类似。在过去的几十年里，每年的平均年径流比也显示出下降的趋势。指出了当前年降水量频级分布的显著特征是水文极值间隔减小，年内极差增大。在1994年夏季气温升高的极端气象事件条件下，河流水质与常年平均值相比有显著变化。由于温度高和流量小，最显著的特征是溶解氧浓度很低，特别是在7、8月份。本研究确定的事实为全球变暖对降雨-径流过程可能产生的后果提供了有意义的视角，也是评估未来气候变化对水环境影响的有用基础数据。