Developing DRAINMOD-Geostatistical Technology to Predict Nitrate Leaching

Abstract

In Egypt, the government has initiated large-scale projects to reuse drainage water to face the great challenges due to its limited water resources. Taking into consideration the environmental aspects of drainage water reuse, the diffuse pollution of water resources from agricultural sources (fertilizers) is a major environmental issue. A high percentage of applied fertilizers is lost because of poor management, which leads to nutrients leaching through different crop rotations. An integrated precise tool to predict nitrate leaching is needed for the adoption of management policies to address water quality problems and to establish limits for sustainable drainage water reuse. To quantify and analyze subsurface nitrate leaching, a combination model of the system was made in DRAINMOD-N software. The study was applied to the Mashtul Pilot Area, Egypt, as a case study. In addition to analyzing subsurface nitrate leaching, the model calculated nitrate leaching for the year 2020 for the area. The modeling system combination was applied to the study site to model nitrate leaching predictions after ten years. The system combination consisted of DRAINMOD-N and Geostatistical Analyst. The study revealed that the modeling system performed well and was reliable and accurate in predicting nitrate leaching. Therefore, this system can be used to develop guidelines for drainage design and water management to control nitrate pollution. The system can potentially be used by policymakers in the long-term strategic management of large-scale irrigation development projects.