气候与土地利用变化对流域水资源的影响--以美国北卡罗莱纳州Trent流域为例

Impacts of climate and land-use change on water resources in a watershed:A case study on the Trent River basin in North Carolina,USA

分布式水文模型PRMS可为气候与土地利用变化对流域水资源影响的研究提供技术和理论支撑。对Trent流域产流过程采用PRMS模型进行模拟检验，结果表明，Nash模型确定性系数达到0．8以上。水文响应单元（HRU）划分尺度减小，可以有效地提高PRMS模拟精度达7％左右，划分尺度缩小到71个HRU时，模拟精度不再提高。流域蒸散量和产流量对土地利用和气候变化的敏感程度为：降水量变化〉城市土地利用变化〉气温变化〉农作物和草地（林地）变化；土地利用变化和气候变化对流域产流量的影响大于蒸散量。利用PRMS模型预测Trent流域在未来气候和土地利用同时变化条件下，多年平均蒸散量将增加5．64～201．29mm，产流量有可能增加160mm左右或减少180mm左右。

The distributed precipitation-runoff modeling system （PRMS） will support the study on the impacts of cli- mate change and land-use change on water resources in a watershed. Modeling results show that the PRMS model performs satisfactorily for simulating water yield, as indicated by an overall Nash-Sutcliffe simulation efficiency over 0.8. The reduced scales of HRU （ Hydrological Response Units） delineation show a better model-fit efficiency to some extend about 7%. The 71 HRUs delineation can result in the best overall performance of the modeling system. The order of land-use and climate change sensitivity to evapotranspiration and water yield is given as follows： precipitation 〉 urban land-use 〉 temperature 〉 crop and grasses. The water yield has greatly larger changes than the evapotranspira- tion under land-use and climate changes. It is predicted that the annual evapotranspiration will increase 5.64-201.29 mm, and the water yield will increase about 160 mm or decrease about 180 mm under the scenarios of land-use change corresponding with the climate change.