Use of distributed hydrological model and field investigation for efficient water management decision making in the Mekong Basin.

最初，利用现有的空间分布的信息，湄公河流域的水文模拟使用分布式水文模型。将模型预测与观测到的河流流量数据进行了比较，结果表明，需要大大改进现有数据，以便对替代发展方案进行可靠的影响评估。该项目其余部分的大部分重点是收集水文气象和集水区物理数据。结果，整个湄公河流域的数据集得到了改善，并从90个流量计和99个雨量器，可用于数值模拟的数据汇编。土地覆被、海拔、土壤数据已经汇编和检验。特别是对高程数据集进行了检验，通过计算和比较不同排水密度的排水网的Horton参数，分析了水流的流态和变化，特别是分析了20年来水流特性的变化。研究发现，流域内水利基础设施的发展对河流流量有着深刻的影响。河流的枯水流量总体上在增加，而洪水流量在减少。尽管总体特征如此，但在极端天气条件下，可以看到非常低的河流基流和超过历史记录的极端高流量。此外，流量随时间的变化甚至不沿着主要河流。该流域的某些地区的水消耗量增加，对主流流量的总体贡献为负。除了数据汇编外，还开发了研究方法，以改进洪水淹没建模和损失估计。评估未来水需求的主要障碍之一是缺乏关于水基础设施的充分信息。开发了一个基于电子邮件的数据收集系统，用于收集水基础设施数据，以解决这一问题。

Initially, using the available spatially distributed information, hydrology of the Mekong basin was modeled using a distributed hydrological model. The model predictions were compared with the observed stream flow data which showed the need to vastly improve existing data to make reliable impact assessment for alternative development scenarios. The bulk of the remaining part of the project focused on the collection of hydro meteorological and catchment physical data. As a result, the whole Mekong basin data set was improved and data were compiled from 90 discharge gauges and 99 rain gauges that can be used in the numerical simulations. The land cover, elevation, soil data has been compiled and tested. Especially the elevation data set was tested by computing and comparing Horton parameters for the drainage network for various drainage density networks.The flow regime and changes were analyzed, especially the flow characteristic changes over a period of two decades were analyzed. It was found that the river flows are affected profoundly by the water infrastructure development in the basin. River low flows in general have been increasing while the flood flows are decreasing. Even though the general characteristics are such, in extreme weather conditions, very low river base flows and extreme high flows that exceed historical records can be seen. Further more, the flow variation over time are not even along the main river. Some parts of the basin has shown increased water consumption, making a negative overall contribution to the mainstream flow.In addition to data compilation research methodologies have been developed to improve flood inundation modeling and loss estimates. One of the major obstacles in assessing future water demand is the lack of adequate information on water infrastructure. An email based data collection system was developed for collecting water infrastructure data to address this issue.