基于实测数据及遥感图片的土壤采样方法

如何结合土壤特性和先进手段,制定具有代表性,同时又经济的土壤采样方案一直是土壤分析的难题。该文根据陕西省卤泊滩盐碱地改良区土壤含盐量的实测资料和相应的遥感图片数据,并结合土壤属性空间分布特性,提出一种新的土壤水盐含量采集方案。结果表明,用33个已知点的实测数据可以估算出101个未测点的含量并最终构成插值343个点的空间分布图,且水分与盐分含量预测结果相关的确定系数分别为0.869和0.817。在此基础上进而对工程改良措施下的卤泊滩盐渍土表层水盐空间变异性进行研究。分析结果表明,研究区土壤水盐含量具有中等较强的空间自相关性和较弱的变异性。通过对该地区水盐空间变异性的研究可以及时了解盐渍地试验区的改良效果及水资源管理情况。

蓄水条件下土壤-水体水盐运移的室内试验

土壤水盐运移规律的研究是目前土壤物理学、农田灌溉学研究的一个重要方面,也是防治盐碱化、改良盐渍土的核心问题。蓄水条件下水体与土壤界面之间必然存在着盐分的迁移。通过实验室模拟田间实际情况,观测水体—土壤界面之间的水盐运移动态,得出水体—土壤界面盐分迁移的基本规律。采用"不排而蓄"的方法,监测不同时段土壤含盐量和土壤不同层段的含盐量。分析结果表明:蓄水条件下土壤表层盐分降低,底层盐分增多,从而充分说明在蓄水条件下,水体—土壤界面间的循环压盐原理能够降低土壤表层的盐分,加速土壤耕作层脱盐,降低含盐量,保证作物的正常生长。

干旱区盐碱化土地整理工程实证研究——以陕西省蒲城县卤泊滩土地整理项目为例

盐碱化不仅降低了耕地的生产力,而且严重制约着耕地持续利用,直接影响着农业的可持续发展。结合土地整理,治理和改良盐碱地,提高盐碱地的土地利用率和产出率,是盐碱地治理的新思路。该文以陕西省蒲城县卤泊滩盐碱地土地开发整理项目为例,从土地整理工程的角度研究盐碱地治理。

渭南市卤泊滩盐碱地造林方法探讨

分析盐碱地对树木的危害,阐述通过物理、水利和化学土壤改良的措施;在造林树种选择中以耐盐能力强、抗旱耐涝能力强、易繁殖、生长快、经济价值高为原则,选择了国槐、刺槐等11种乔木和灌木树种,并提出进行高标准、长周期的后期养护.

盐渍土地区岩土工程勘察中水土腐蚀性评价探讨——以渭北东部卤阳湖(卤泊滩)地区为例

卤阳湖(俗称卤泊滩)地处关中平原东部,东西长约30 km,南北宽1.5～7 km,总面积124 km2。卤阳湖土壤盐碱化严重,不宜农作物生长,对其开发中遇到的主要问题是盐渍土勘察、腐蚀性评价和地基处理。卤泊滩地基土属于硫酸盐渍土。

Simulation and optimization of irrigation schedule for summer maize based on SWAP model in saline region

In order to explore the appropriate irrigation schedule for summer maize,a field experiment was conducted in 2013 in Lubotan of Shaanxi Province.Soil water content,soil salinity,soil hydraulic parameters,crop growth parameters and summer maize yield were measured in the experiment.The SWAP model was calibrated based on field experiment observation data in 2013.The SWAP model was used to simulate and optimize irrigation schedule for summer maize after calibration.The results showed that model simulation results of soil water content,soil salinity and summer maize yield agreed well with the measured values.The Root Mean Square Error(RMSE)and Mean Relative Error(MRE)were within the allowable error ranges.The RMSE values were all lower than 0.05 cm3/cm3 and the MRE values were lower than 15%in soil water content calibration.The RMSE values were all lower than 0.1 mg/cm3 and the MRE values were lower than 20%in soil salinity calibration.The RMSE and MRE values were 1299.6 kg/hm2 and 15.26%in summer maize yield calibration.The model parameters suitable for the study area were obtained in calibration.The SWAP model could be used to simulate and optimize irrigation schedule for summer maize after calibration.The SWAP model was used to simulate soil water-salt balance,summer maize yield and water use efficiency under different irrigation schedules.The model simulation results for different irrigation schedules indicated that the optimal irrigation schedules of summer maize were three times each for jointing stage(July 5),heading stage(August 5)and grain filling stage(August 30)with irrigation amount of 128 mm,128 mm and 96 mm,respectively.The optimal irrigation quota was 352.0 mm for summer maize in the study area.

陕西卤泊滩盐渍地生态环境遥感监测研究

针对土壤盐渍化地区难以进行信息有效提取和动态监测的问题,本研究构建了改进后的土壤盐渍化生态指数(MSSEI)。利用主成分分析方法,获取卤泊滩1994~2015年的生态环境状况指标。结果表明,在卤泊滩盐渍化区,湿度指数和植被指数对研究区生态环境起正面的贡献;而土壤盐度—建筑指数和地表反照率对卤泊滩生态环境起负面影响;卤泊滩土壤盐渍化生态指数MSSEI 1994~2003年均值从0.607下降到0.572;2003~2015年均值从0.572上升到0.673。因此,通过对卤泊滩土壤盐渍化的综合治理,其生态环境质量呈现逐渐好转的趋势。