西南岩溶山区地下水资源评价方法对比研究——以寨底地下河流域为例

西南岩溶山区地下水资源丰富，查清地下水资源量是科学管理水资源的基础，岩溶山区地下水资源量的评价方法多样，计算过程不同，进而评价结果也存在差异。本文选择寨底地下河流域为研究对象，采用四种不同的评价方法（总排泄量法、基流分割法、径流模数法、数值模型法）对流域地下水资源量进行评价，分析各方法的评价机理和流程，研究其主要影响因素，并对其适用性进行讨论。结果显示:针对西南岩溶石山地区，基流分割法简单快捷，适用于枯季地下水资源量评价，在雨季地下水资源量评价中存在一定不足；总排泄量法的评价结果较为准确，但资料获取难度大，且成本较高；数值模拟法运算高效，但需要大量的前期调查研究数据资料；径流模数法操作性较强，对岩溶山区具有较强的适用性，但参数的选择存在一定的不确定性，对评价结果影响较大。确定计算参数是水资源评价中的关键步骤，通过实测流量反推和灰色聚类法，可提高参数精度和计算效率。 

Comparative study on evaluation methods of groundwater resources in karst area of Southwest China: Taking Zhaidi underground river basin as an example

The karst mountainous area in Southwest China is rich in groundwater resources. Finding out the amount of groundwater resources is the basis of scientific management of water resources. The evaluation methods of groundwater resources in karst mountainous areas are diverse with different the calculation processes， and hence the evaluation results are also different. At present， there is no comparative analysis of specific case for different evaluation methods， so it is impossible to horizontally compare the calculation accuracy and adaptability of these methods. Taking the Zhaidi underground river basin as the research object， and four different evaluation methods （total discharge， base flow segmentation， runoff modulus and numerical model） were used to evaluate the groundwater resources in the basin. The evaluation mechanism and process of each method were analyzed. Besides， the main influencing factors of these methods and their applicability were discussed. Zhaidi underground river system， located in Lingchuan county， Guilin City， is a typical karst underground river basin in the karst area of Southwest China. The underground water in this region generally flows from north to south， receives the supply of atmospheric precipitation， flows along karst fissures and pipelines， exposes itself in Shuiniue， Dongjiao， Xiaofu and other places. And then it converges with surface streams and ditches， turns underground again in Konglianshan and Xiangshuiyan， and is finally discharged in the outlet of Zhaidi underground river. The evaluation data come from the test site of "Guangxi Haiyang-Zhaidi test base" hosted by Karst Institute of China Geological Survey. The automatic monitor was used to monitor the changes of groundwater level and flow. The data were selected from the long-term observation data of groundwater from 2009 to 2019， including those from the observation points of karst spring and outlet flow of underground river. The year of 2018 was taken as the normal year for groundwater resources calculation. The evaluation results show that for the karst mountainous area in Southwest China， the base flow segmentation method is simple and fast， but the calculation results are smaller than those of other algorithms. The main influencing factors of this method are the segmentation algorithm and the dynamic change of groundwater. This algorithm is limited by the conditions of hydrological stations and the rapid rise and fall of groundwater in karst mountainous area. It can be applied to the evaluation of groundwater resources in dry season due to its deficiencies of the evaluation in rainy season. The evaluation result of the total discharge method is relatively accurate， but this method needs a heavy workload with high investigation accuracy and large consumption of time and manpower. Therefore， a total discharge method is mainly applied to the evaluation of water resources in a specific period of time or in small-scale investigation and research. In this method， it is also necessary to find out the groundwater runoff and discharge path， and master the hydraulic connection of each discharge point. The numerical model method is efficient， but needs a lot of preliminary investigation and research data. According to the hydraulic characteristics of frequent conversion between surface water and groundwater in karst area， the model algorithm needs to be improved. The runoff modulus method is highly applicable to karst areas， but there is a certain uncertainty in the selection of parameters， which has a great impact on the evaluation results. For the area lacking monitoring stations， the analogy method needs to be used to calculate the runoff modulus in combination with the measured data， but showing certain subjectivity. Determining the calculation parameters is a key step in water resources evaluation. The parameter accuracy and calculation efficiency can be improved through the measured flow regression and grey clustering method.