CAJ | 학술논문

针对1960—2010年径流量显著减少的中国主要流域, 包括松花江、辽河、海河、黄河和汉江等, 选择其上游地区受人类直接取用水影响较少的山区小流域, 分析径流变化及其原因. 采用基于Budyko假设的流域水热耦合平衡方程, 估计了流域年径流量变化的气候弹性系数和下垫面弹性系数, 并对各流域径流变化进行了归因分析.结果表明, 在气候较为湿润的地区, 径流对气候和下垫面变化均不敏感; 在气候较为干燥的地区, 径流对气候和下垫面变化都更为敏感, 且区域差异性明显. 潜在蒸散发的变化对径流减少的影响微弱, 降水减少和下垫面变化是径流减少的主导因素, 其中人类活动导致的下垫面变化对径流减少的影响尤为显著. 对比两个阶段的径流变化归因分析结果, 近10年间流域下垫面变化对年径流量的影响程度较前20年有显著增加. 通过分析近30年的归一化植被指数( NDVI)数据发现, 植被覆盖改善是下垫面变化的重要原因, 说明中国水土保持工程发挥了显著生态效益的同时也导致了流域径流减小.
침대1960—2010년경류량현저감소적중국주요류역, 포괄송화강、 료하、 해하、 황하화한강등, 선택기상유지구수인류직접취용수영향교소적산구소류역, 분석경류변화급기원인. 채용기우Budyko가설적류역수열우합평형방정, 고계료류역년경류량변화적기후탄성계수화하점면탄성계수, 병대각류역경류변화진행료귀인분석.결과표명, 재기후교위습윤적지구, 경류대기후화하점면변화균불민감; 재기후교위간조적지구, 경류대기후화하점면변화도경위민감, 차구역차이성명현. 잠재증산발적변화대경류감소적영향미약, 강수감소화하점면변화시경류감소적주도인소, 기중인류활동도치적하점면변화대경류감소적영향우위현저. 대비량개계단적경류변화귀인분석결과, 근10년간류역하점면변화대년경류량적영향정도교전20년유현저증가. 통과분석근30년적귀일화식피지수( NDVI)수거발현, 식피복개개선시하점면변화적중요원인, 설명중국수토보지공정발휘료현저생태효익적동시야도치료류역경류감소.
A sharp reduction of annual runoff has been observed during the past 50 years in five major river basins of China, namely Songhuajiang River, Liaohe River, Haihe River, Yellow River and Hanjiang River. In this study, changes of catchment runoff and their causes were investigated in 107 small catchments with relatively small artificial water uses from the 5 basins. The coupled energy-water balance equation based on the Budyko hypothesis is employed to estimate climate elasticity and landscape elasticity of runoff, which were then used for attribution analysis of runoff decrease in these 107 catchments. The results show that the catchment annual runoff is relatively less sensitive to cli-mate and landscape changes in relatively humid regions while it is more sensitive to climate and landscape changes in relatively arid regions. By the attribution analysis, it is found that the change in potential evapotranspiration has little impact on runoff in most of the 107 catchments while the dominant factors leading to runoff reduction are the changes in precipitation and catchment landscape. It is also seen that the landscape change induced catchment runoff reductions have significantly intensified in the recent 10 years. Based on the analysis of NDVI ( Normalized Difference Vegetation Index) during the recent 30 years, vegetation increase appears to be the dominant change in landscape. This implies that the soil and water conservation project carried out in China has achieved a notable ecological effect although it is also one of the major causes of runoff reduction.