Wetlands are highly productive ecosystems that regulate hydrological processes, store carbon, and support rich biodiversity, yet they remain highly vulnerable to hydro-climatic variability and anthropogenic pressures. This study examines long-term eco-hydrological dynamics influencing wetland systems in the Madhubani district of North Bihar during 2002–2024 using an integrated framework of climatic, hydrological, and ecological indicators. Rainfall trends were analyzed alongside Actual and Potential Evapotranspiration (ET, PET), Standardised Water Deficit (SWD), Wetness Index (WI), Gross and Net Primary Productivity (GPP, NPP), and remote sensing indices, including the Modified Normalized Difference Water Index (MNDWI) and Soil-Adjusted Vegetation Index (SAVI) derived from Terra MODIS and Landsat datasets. Trend analysis indicates a non-significant but persistent decline in annual rainfall (Z = − 1.33; Sen’s slope = − 7.53 mm year−1), with stronger decreases during the monsoon season (− 8.65 mm year−1). ET (320–720 mm yr−1) remained substantially lower than PET (2030–2520 mm yr−1), indicating persistent atmospheric water demand and increasing moisture stress, as reflected in Standardised Water Deficit variability and relatively low Wetness Index values. Vegetation productivity exhibited considerable interannual variability, with GPP ranging from ~ 770 to 1530 g C m−2 yr−1 and NPP from ~ 100 to 430 g C m−2 yr−1. Both productivity metrics declined sharply during 2012–2015, suggesting sensitivity to monsoon rainfall variability. Spatial analysis reveals significant hydrological and ecological changes. Post-monsoon moderately wet areas declined from 75.10% (2002) to 55.27% (2024), while dry zones expanded from 17.24 to 39.55%, indicating progressive wetland contraction. Vegetation dynamics derived from SAVI show spatial redistribution of vegetation cover, with dense vegetation increasing from 21.32 to 26.18%, particularly in northern areas associated with irrigation supported agriculture. Correlation analysis further demonstrates strong eco-hydrological coupling, with rainfall positively correlated with the wetness index and negatively associated with water deficit. Overall, the findings indicate a shifting eco-hydrological regime in Madhubani characterized by declining rainfall reliability, increasing moisture stress, wetland shrinkage, and changing vegetation patterns. These trends highlight the need for integrated wetland management and climate-resilient water resource strategies to sustain ecological stability in the floodplain landscapes of North Bihar.

Integrated eco-hydrological and vegetation productivity analysis of wetland landscapes in Madhubani, Bihar (2002–2024)

期刊论文
出版模式：

开放获取
发表日期：

2026年7月9日

查看全文

Manu Raj Sharma,
Sonu Kumar Das

摘要

Wetlands are highly productive ecosystems that regulate hydrological processes, store carbon, and support rich biodiversity, yet they remain highly vulnerable to hydro-climatic variability and anthropogenic pressures. This study examines long-term eco-hydrological dynamics influencing wetland systems in the Madhubani district of North Bihar during 2002–2024 using an integrated framework of climatic, hydrological, and ecological indicators. Rainfall trends were analyzed alongside Actual and Potential Evapotranspiration (ET, PET), Standardised Water Deficit (SWD), Wetness Index (WI), Gross and Net Primary Productivity (GPP, NPP), and remote sensing indices, including the Modified Normalized Difference Water Index (MNDWI) and Soil-Adjusted Vegetation Index (SAVI) derived from Terra MODIS and Landsat datasets. Trend analysis indicates a non-significant but persistent decline in annual rainfall (Z = − 1.33; Sen’s slope = − 7.53 mm year⁻¹), with stronger decreases during the monsoon season (− 8.65 mm year⁻¹). ET (320–720 mm yr⁻¹) remained substantially lower than PET (2030–2520 mm yr⁻¹), indicating persistent atmospheric water demand and increasing moisture stress, as reflected in Standardised Water Deficit variability and relatively low Wetness Index values. Vegetation productivity exhibited considerable interannual variability, with GPP ranging from ~ 770 to 1530 g C m⁻² yr⁻¹ and NPP from ~ 100 to 430 g C m⁻² yr⁻¹. Both productivity metrics declined sharply during 2012–2015, suggesting sensitivity to monsoon rainfall variability. Spatial analysis reveals significant hydrological and ecological changes. Post-monsoon moderately wet areas declined from 75.10% (2002) to 55.27% (2024), while dry zones expanded from 17.24 to 39.55%, indicating progressive wetland contraction. Vegetation dynamics derived from SAVI show spatial redistribution of vegetation cover, with dense vegetation increasing from 21.32 to 26.18%, particularly in northern areas associated with irrigation supported agriculture. Correlation analysis further demonstrates strong eco-hydrological coupling, with rainfall positively correlated with the wetness index and negatively associated with water deficit. Overall, the findings indicate a shifting eco-hydrological regime in Madhubani characterized by declining rainfall reliability, increasing moisture stress, wetland shrinkage, and changing vegetation patterns. These trends highlight the need for integrated wetland management and climate-resilient water resource strategies to sustain ecological stability in the floodplain landscapes of North Bihar.