Agricultural watershed modeling: a review for hydrology and soil erosion processes

Abstract

Models have been used by man for thousands of years to control his environment in a favorable way to better human living conditions. The use of hydrologic models has been a widely effective tool in order to support decision makers dealing with watersheds related to several economic and social activities, like public water supply, energy generation, and water availability for agriculture, among others. The purpose of this review is to briefly discuss some models on soil and water movement on landscapes (RUSLE, WEPP, GeoWEPP, LASH, DHSVM and AnnAGNPS) to provide information about them to help and serve in a proper manner in order to discuss particular problems related to hydrology and soil erosion processes. Models have been changed and evaluated significantly in recent years, highlighting the use of remote sense, GIS and automatic calibration process, allowing them capable of simulating watersheds under a given land-use and climate change effects. However, hydrology models have almost the same physical structure, which is not enough for simulating problems related to the long-term effects of different land-uses. That has been our challenge for next future: to understand entirely the hydrology cycle, having as reference the critical zone, in which the hydrological processes act together from canopy to the bottom of aquifers.Index terms: RUSLE; WEPP; GeoWEPP; LASH; DHSVM; AnnAGNPS. RESUMOModelos têm sido usados pelo homem há milhares de anos para controlar seu ambiente de uma maneira favorável para melhores condições de vida para os humanos. O uso de modelos hidrológicos tem sido uma ferramenta muito eficaz para apoiar os decisores que lidam com as bacias hidrográficas para subsidiar diversas atividades econômicas e sociais, como o abastecimento público de água, geração de energia, e a disponibilidade de água para a agricultura, entre outros. Objetivou-se, nesta revisão, discutir brevemente alguns modelos muito aplicados ao estudo do movimento da água e solos em paisagens (RUSLE, WEPP, GeoWEPP, LASH, DHSVM and AnnAGNPS), para fornecer informações sobre os mesmos, para auxiliar no entendimento adequado de problemas específicos relacionados com os processos de hidrologia e erosão do solo. Modelos têm sido alterados e avaliados de forma significativa nos últimos anos, com destaque para o uso de sensoriamento remoto, GIS e processo de calibração automática, permitindo aos mesmos que sejam capazes de simular bacias hidrográficas nas suas condições atuais de uso do solo e mudanças climáticas. No entanto, os modelos hidrológicos têm quase a mesma estrutura física, o que não é suficiente para simular problemas relacionados com os efeitos a longo prazo de diferentes usos do solo. Esse tem sido um dos principais desafios para o futuro: compreender inteiramente o ciclo hidrológico, tendo como referência a zona crítica, na qual os processos hidrológicos agem em conjunto a partir do dossel até a base dos aquíferos.

A review of the (Revised) Universal Soil Loss Equation (R/USLE): with a view to increasing its global applicability and improving soil loss estimates

“…Since the USLE was originally designed at the plot scale, its use causes issues when used at larger scales with more complex topography. R/USLE compensates for this by using a Geographic Information System (GIS) method of determining runoff contribution from upstream areas to downstream locations (de Mello et al, 2016). A common criticism of R/USLE is the exclusion of sediment yields from gully, streambank, and streambed erosion.…”

“…A review by de Vente & Posen (2005) differs by focusing on semi-quantitative models that include different types of soil erosion in order to estimate basin 10 sediment yield. Other reviews have focused on the use of different types of soil erosion models in particular places, such as Brazilian watersheds for de Mello et al (2016). These papers reviewed soil erosion models in terms of their complexity and input requirements (Aksoy & Kavvas, 2005;Merritt et al, 2003).…”

How pixel size affects a sediment connectivity index in central Belgium

“…Modeling is a necessary tool for estimating and quantifying stream flows and other watershed responses to rainfall (Singh et al, 2011). The challenge is to use hydrological processes, properties and state variables correctly in order to quantify the watershed response (Sogbedji and Mclsaac, 2002;Fenicia et al, 2008;von Gunten et al, 2014;Boll et al, 2015;Mello et al, 2016). The model, therefore, has to rely on spatially distributed information in order to include watershed processes linked to hydrological connectivity (Pechlivanidis et al, 2010).…”

Hydrological responses to climate changes in a headwater watershed

“…Thus, the use of hydrological models has been a very effective tool to support decisions about the future of water resources (Mello et al, 2016). The Distributed Hydrology Soil Vegetation Model (DHSVM) is a physical-distributed model tested and validated in mountainous areas in the state of Montana, USA, notably in the Middle Fork Flathead watershed Vail;Lettenmaier, 1994).…”