Due to its versatility, the Soil and Water Assessment Tool (SWAT) has been widely applied to investigate the effects of management activities and climate change on water availability and quality. However, the use of high spatial resolution data and the advantages of SWAT itself have significantly increased the input/output (I/O) demand and thus the runtime of modeling routines that require a large number of iterative simulations. In this study, we proposed a generic scheme to reduce the SWAT runtime by caching the model inputs using the in-memory NoSQL database Redis. Then the SWAT source codes (rev 488) was modified according to this proposed scheme to develop the MA-SWAT (memory accelerated SWAT) model by incorporating a new subroutine known as Fortran_calls_c to retrieve the cached inputs. We then evaluated MA-SWAT with four synthetic hydrological models and five different parallel schemes in a quad-core commodity laptop. The test results showed that when applied with a parallel simulation program, MA-SWAT could achieve a speedup by a factor of 8.4 ~ 10.9 depending on model complexity. Compared with the original SWAT, MA-SWAT significantly improved the computation speed, indicating that the proposed scheme is a desirable method for solving high computational demand problems such as calibration, sensitivity and uncertainty analysis. Moreover, the proposed concept of linking the SWAT model with Redis via the minimalistic C client driver of Redis is a generic method, and it is possible to apply this method to other Fortran-implemented environmental model to alleviate I/O demands.

中文翻译：

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使用内存中 NoSQL 数据库加速 SWAT 模拟

由于其多功能性，土壤和水评估工具 (SWAT) 已被广泛应用于调查管理活动和气候变化对水资源可用性和质量的影响。然而，高空间分辨率数据的使用和 SWAT 本身的优势显着增加了输入/输出 (I/O) 需求，从而增加了需要大量迭代模拟的建模例程的运行时间。在这项研究中，我们提出了一种通用方案，通过使用内存中的 NoSQL 数据库 Redis 缓存模型输​​入来减少 SWAT 运行时间。然后根据这个提议的方案修改 SWAT 源代码（修订版 488），通过合并一个名为 Fortran_calls_c 的新子程序来开发 MA-SWAT（内存加速 SWAT）模型来检索缓存的输入。然后，我们在四核商用笔记本电脑中使用四个合成水文模型和五个不同的并行方案评估了 MA-SWAT。测试结果表明，当应用并行仿真程序时，MA-SWAT 可以根据模型复杂程度实现 8.4~10.9 倍的加速。与原始 SWAT 相比，MA-SWAT 显着提高了计算速度，表明该方案是解决校准、灵敏度和不确定性分析等高计算需求问题的理想方法。此外，提出的通过 Redis 的简约 C 客户端驱动程序将 SWAT 模型与 Redis 链接的概念是一种通用方法，可以将此方法应用于其他 Fortran 实现的环境模型以减轻 I/O 需求。