Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany.
Center of Water Management and Climate Change, Institute for Environment and Resources, Vietnam National University - Ho Chi Minh City (VNU-HCM), Ho Chi Minh City 700000, Viet Nam.
Sci Total Environ. 2022 Mar 20;813:151918. doi: 10.1016/j.scitotenv.2021.151918. Epub 2021 Nov 24.
This paper presents the first attempt to capture a comprehensive spatial view of land use change in the Vietnamese Mekong Delta (VMD) for a long period, i.e., from 2000 to 2020. It is aimed at monitoring holistically the land use change and flooding situation in the region, addressing the reasons for land use change, and assessing the impacts of land use change on hydraulic aspects and farmer livelihoods during the last 21 years. MODIS products, in particular, are used to study the dynamics of land use and floods after demonstrating high validation with statistical data and radar satellites, with R = 0.96 and R ≥ 0.97 for land use and flood maps, respectively. The results show that rice cultivation is the most dominant land use type, accounting for 40% to 46% of the delta area, while aquaculture accounts for 10% to 22%, respectively. The total rice cultivation area increased from 3764 thousand hectares (thous. ha) in 2001 to 4343 thous. ha in 2015 based on the intensive development of triple rice cropping in the upper zone, then decreased to 3963 thous. ha in 2020. In contrast, aquaculture areas are farmed mainly in the coastal area and remained relatively steady, increasing slightly from 619 thous. ha in 2001 to 856 thous. ha in 2020. The massive construction of dikes for triple rice cropping in the upper zone appears to cause a significant impact on the annual flooding regime. Land use policies have influenced the changes in land use patterns, flooding situations, and the livelihoods of local farmers.
本文首次尝试对越南湄公河三角洲（VMD）在较长时期（即 2000 年至 2020 年）的土地利用变化进行全面的空间观测。其目的是综合监测该地区的土地利用变化和洪水情况，探讨土地利用变化的原因，并评估过去 21 年来土地利用变化对水力方面和农民生计的影响。本文特别使用 MODIS 产品来研究土地利用和洪水的动态变化，这些产品经过验证，与统计数据和雷达卫星高度吻合，土地利用和洪水图的 R 值分别为 0.96 和 R≥0.97。研究结果表明，水稻种植是最主要的土地利用类型，占三角洲面积的 40%至 46%，而水产养殖分别占 10%至 22%。基于上区三季稻的集约化发展，总水稻种植面积从 2001 年的 376.4 千公顷（thous.ha）增加到 2015 年的 434.3 千公顷，然后在 2020 年减少到 396.3 千公顷。相比之下，水产养殖主要集中在沿海地区，面积相对稳定，从 2001 年的 61.9 千公顷增加到 2020 年的 85.6 千公顷。上区三季稻大规模修筑堤坝似乎对年度洪水状况产生了重大影响。土地利用政策影响了土地利用模式的变化、洪水情况以及当地农民的生计。
