The field survey for the elucidation of the mechanism and the control of the drought that occurs frequently in the agricultural zone of the yellow river basin in recent years

在中国的黄河流域农业区，1972年频繁出现缺水现象，并一直持续到1999年。阐明了这一机制，提出了适合黄河流域的农业生产模式。用GMS建立的地表温度和反照率模式，通过多元线性回归分析，假定14个点的降水。利用卫星资料建立了黄河流域的太阳辐射和净辐射模型，并应用于2000年6月至2002年12月的神木和禹城。通过观测，太阳辐射的分布与气候图相似。我们还建立了蒸散模型，并应用于安塞地区。模型显示，农作物缺水151天。为了保持充足的水分，需灌溉239 mm。下游流域的用水量受到上中游出流的影响，尽管努力实现了有效用水，但情况仍不可预测。利用1981-2000年的卫星资料和观测资料，对黄河下游干旱期的植被变化进行了研究，发现了黄河下游流量与NDVI之间的相关关系。它来自于从黄河取水灌溉秋天。

In the agricultural area in the Yellow River basin in China, a water shortage occurred frequently in 1972 and continued until 1999. We clarified this mechanism and proposed a suitable agricultural form.Evaluation of water resources of the Yellow River basin was performed. The model with surface temperature and albedo by GMS presumes the precipitation of 14 points by multiple linear regression analysis. From this model, we concluded that the precipitation of the Yellow River basin does not have a downward tendency.We developed a model for the solar and net radiation by satellite data and applied to Shenmu and Yucheng form June 2000 to December 2002. The distribution of solar radiation is similar to the climate map by observation. We also developed a model for evapo-transpiration and applied to Ansai. The model showed there were 151 days of water shortage for crops. To keep sufficient water content, irrigation with 239mm of water was needed.The water use in the lower basin is affected the outflow from the upper and the middle basin and although the effort to effective water use was made, the situation is still unpredictable. We also investigated the change of the vegetation in the lower basin of Yellow River during the periods of dry-up of the river by satellite data and observational data in 1981-2000 and found the correlation between the water flow rate and NDVI. It came from the uptake of water from the Yellow River to irrigate the autumn.