Regime of groundwater level is a comprehensive reflection of the hydrogeological environment from the perspective of groundwater. Based on the analysis of the water-level change of 65 groundwater monitoring points fro...Regime of groundwater level is a comprehensive reflection of the hydrogeological environment from the perspective of groundwater. Based on the analysis of the water-level change of 65 groundwater monitoring points from 1987 to 1990, it is found that intermittent cones of depression came into being due to groundwater exploitation in Guilin during the observation period. The buried depth of groundwater in the drawdown cones, the annual variation of water level and specific yield have higher values. Improvement has been made to the formula of infiltration coefficient of precipitation. By using the precipitation response data recorded at every 15 minutes for water level of No. 9 borehole which is near Zengpiyan Cave, the specific yield of phreatic variation zone is indirectly calculated by using the modified formula. The results are range from 0.012 to 0.462 and the spatial distribution of specific yield is ascertained. These make up the deficiency that empirical values cannot be categorized based on the actual conditions. What’s more, the widely used Aviriyanover’s empirical formula is poorly applicable to karst area. This is due to its strict requirement for outside conditions, such as shallow buried depth, homogeneous aquifer medium and small hydraulic gradient.展开更多
利用随机样法构建种-面积曲线,对每一取样面积下的物种数进行999次随机抽样后计算均值,得到不同取样面积下的植物物种数,由此绘制实际种-面积曲线,并采用8种曲线模型拟合桂林岩溶石山常绿落叶阔叶混交林的种-面积关系,结合赤池信息量准...利用随机样法构建种-面积曲线,对每一取样面积下的物种数进行999次随机抽样后计算均值,得到不同取样面积下的植物物种数,由此绘制实际种-面积曲线,并采用8种曲线模型拟合桂林岩溶石山常绿落叶阔叶混交林的种-面积关系,结合赤池信息量准则AIC值及生物学意义确定最优拟合模型,通过对比群落总种数比例法、二阶导数法与实际种-面积曲线结果,最终确定桂林岩溶石山常绿落叶阔叶混交林的最小面积。结果表明,桂林岩溶石山常绿落叶阔叶混交林种-面积关系的最优拟合模型为累积韦伯分布模型(cumulative Weibull),拟合方程为S=73.8017(1-exp(-0.0138A ^(0.6685)))。二阶导数法比群落总种数比例法更具科学性和准确性,最终确定桂林岩溶石山常绿落叶阔叶混交林的最小面积为2500 m ^(2)。所以,最小面积的确定应根据实际区域的物种特征来确定。展开更多
基金supported by National Natural Science Foundation of China(No.41172231)
文摘Regime of groundwater level is a comprehensive reflection of the hydrogeological environment from the perspective of groundwater. Based on the analysis of the water-level change of 65 groundwater monitoring points from 1987 to 1990, it is found that intermittent cones of depression came into being due to groundwater exploitation in Guilin during the observation period. The buried depth of groundwater in the drawdown cones, the annual variation of water level and specific yield have higher values. Improvement has been made to the formula of infiltration coefficient of precipitation. By using the precipitation response data recorded at every 15 minutes for water level of No. 9 borehole which is near Zengpiyan Cave, the specific yield of phreatic variation zone is indirectly calculated by using the modified formula. The results are range from 0.012 to 0.462 and the spatial distribution of specific yield is ascertained. These make up the deficiency that empirical values cannot be categorized based on the actual conditions. What’s more, the widely used Aviriyanover’s empirical formula is poorly applicable to karst area. This is due to its strict requirement for outside conditions, such as shallow buried depth, homogeneous aquifer medium and small hydraulic gradient.
文摘利用随机样法构建种-面积曲线,对每一取样面积下的物种数进行999次随机抽样后计算均值,得到不同取样面积下的植物物种数,由此绘制实际种-面积曲线,并采用8种曲线模型拟合桂林岩溶石山常绿落叶阔叶混交林的种-面积关系,结合赤池信息量准则AIC值及生物学意义确定最优拟合模型,通过对比群落总种数比例法、二阶导数法与实际种-面积曲线结果,最终确定桂林岩溶石山常绿落叶阔叶混交林的最小面积。结果表明,桂林岩溶石山常绿落叶阔叶混交林种-面积关系的最优拟合模型为累积韦伯分布模型(cumulative Weibull),拟合方程为S=73.8017(1-exp(-0.0138A ^(0.6685)))。二阶导数法比群落总种数比例法更具科学性和准确性,最终确定桂林岩溶石山常绿落叶阔叶混交林的最小面积为2500 m ^(2)。所以,最小面积的确定应根据实际区域的物种特征来确定。
