Land use and land cover changes in sub-catchments of Zimbabwe and their implications on wetland and catchment soil water conditions

IF 4.1 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Physics and Chemistry of the Earth Pub Date : 2025-08-26 DOI:10.1016/j.pce.2025.104081

Oshneck Mupepi , Thomas Marambanyika , Mark Makomborero Matsa , Timothy Dube

{"title":"Land use and land cover changes in sub-catchments of Zimbabwe and their implications on wetland and catchment soil water conditions","authors":"Oshneck Mupepi , Thomas Marambanyika , Mark Makomborero Matsa , Timothy Dube","doi":"10.1016/j.pce.2025.104081","DOIUrl":null,"url":null,"abstract":"<div><div>This study evaluated land use and land cover changes in the Shashe and Tugwi and Zibagwe sub-catchments from 2017 to 2023, with a focus on their impacts on dry season wetland extent and condition. Utilizing the Google Earth Engine Cloud Computing platform, Sentinel-2 Level 1C data were processed using Support Vector Machine (SVM) classification algorithm to analyse these changes. The Soil Moisture Active Passive level 4 (SMAP L4) soil moisture and the Normalised Difference Vegetation Index (NDVI) were computed to determine the influence of catchment level land cover change on soil moisture conditions. This study considered the influence of land cover on wetland conditions and catchment level soil moisture levels which got minimum attention in previous wetland studies. The study highlights that bare land in Tugwi and Zibagwe increased more rapidly (601.1 %) than in the drier Shashe sub-catchment. However, the wetland area decreased more in Shashe, indicating greater wetland degradation despite the slight difference (0.4 %). The analysis revealed that wetlands experienced an overall 11.8 % loss in Shashe and 11.4 % loss in Tugwi-Zibagwe. Results indicate that 5.2 %, 3.4 % and 2.3 % of the wetland area was replaced by grassland, shrubland and bare land respectively in Tugwi and Zibagwe combined whilst 4.8 %, 3.6 % and 2.32 % of the wetland area were replaced by bare land, grassland and shrubland respectively in Shashe. Statistically significant weak positive correlations were confirmed between soil moisture and NDVI in Tugwi and Zibagwe combined (<em>r = 0.28; p = 0.04</em>) and Shashe (<em>r = 0.43; p = 0.02</em>). Rainfall had stronger correlation with soil moisture in Tugwi and Zibagwe (<em>r = 0.43; p = 0.19</em>) and Shashe (<em>r = 0.62; p = 0.38</em>) which were not statistically significant indicating more influence of land cover on soil moisture than rainfall. The findings accentuate the critical need for sustainable land use practices to mitigate the adverse effects on natural land cover and wetland ecosystems. The rapid expansion of bare land and reduction in wetlands underscore the pressing challenges posed by land cover changes, particularly in regions experiencing increasing aridity.</div></div>","PeriodicalId":54616,"journal":{"name":"Physics and Chemistry of the Earth","volume":"141 ","pages":"Article 104081"},"PeriodicalIF":4.1000,"publicationDate":"2025-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Physics and Chemistry of the Earth","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1474706525002311","RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"GEOSCIENCES, MULTIDISCIPLINARY","Score":null,"Total":0}

引用次数: 0

Abstract

This study evaluated land use and land cover changes in the Shashe and Tugwi and Zibagwe sub-catchments from 2017 to 2023, with a focus on their impacts on dry season wetland extent and condition. Utilizing the Google Earth Engine Cloud Computing platform, Sentinel-2 Level 1C data were processed using Support Vector Machine (SVM) classification algorithm to analyse these changes. The Soil Moisture Active Passive level 4 (SMAP L4) soil moisture and the Normalised Difference Vegetation Index (NDVI) were computed to determine the influence of catchment level land cover change on soil moisture conditions. This study considered the influence of land cover on wetland conditions and catchment level soil moisture levels which got minimum attention in previous wetland studies. The study highlights that bare land in Tugwi and Zibagwe increased more rapidly (601.1 %) than in the drier Shashe sub-catchment. However, the wetland area decreased more in Shashe, indicating greater wetland degradation despite the slight difference (0.4 %). The analysis revealed that wetlands experienced an overall 11.8 % loss in Shashe and 11.4 % loss in Tugwi-Zibagwe. Results indicate that 5.2 %, 3.4 % and 2.3 % of the wetland area was replaced by grassland, shrubland and bare land respectively in Tugwi and Zibagwe combined whilst 4.8 %, 3.6 % and 2.32 % of the wetland area were replaced by bare land, grassland and shrubland respectively in Shashe. Statistically significant weak positive correlations were confirmed between soil moisture and NDVI in Tugwi and Zibagwe combined (r = 0.28; p = 0.04) and Shashe (r = 0.43; p = 0.02). Rainfall had stronger correlation with soil moisture in Tugwi and Zibagwe (r = 0.43; p = 0.19) and Shashe (r = 0.62; p = 0.38) which were not statistically significant indicating more influence of land cover on soil moisture than rainfall. The findings accentuate the critical need for sustainable land use practices to mitigate the adverse effects on natural land cover and wetland ecosystems. The rapid expansion of bare land and reduction in wetlands underscore the pressing challenges posed by land cover changes, particularly in regions experiencing increasing aridity.

查看原文本刊更多论文

津巴布韦子流域土地利用和土地覆盖变化及其对湿地和流域土壤水分条件的影响

本研究评估了2017 - 2023年沙舍、图格维和齐巴圭子流域土地利用和土地覆盖的变化，重点研究了其对旱季湿地范围和状况的影响。利用谷歌Earth Engine云计算平台，利用支持向量机（SVM）分类算法对Sentinel-2 Level 1C数据进行处理，分析这些变化。通过计算土壤水分主动被动4级（SMAP L4）和归一化植被指数（NDVI）来确定流域土地覆盖变化对土壤水分状况的影响。本研究考虑了以往湿地研究中较少关注的土地覆被对湿地条件和集水区土壤湿度的影响。该研究强调，Tugwi和Zibagwe的裸地面积比干旱的Shashe子集水区增加得更快（601.1%）。而沙社湿地面积减少幅度较大，虽然差异不大（0.4%），但湿地退化程度较大。分析显示，沙舍的湿地总体损失了11.8%，图圭-齐巴韦的湿地损失了11.4%。结果表明：吐格维-孜巴格组合湿地面积分别为5.2%、3.4%和2.3%为草地、灌丛和裸地，沙舍湿地面积分别为4.8%、3.6%和2.32%为裸地、草地和灌丛。土格维、孜巴格韦两地土壤湿度与NDVI呈显著的弱正相关（r = 0.28, p = 0.04），沙舍两地土壤湿度与NDVI呈显著的弱正相关（r = 0.43, p = 0.02）。在图格维、孜巴格韦和沙舍地区，降雨与土壤湿度的相关性较强（r = 0.43, p = 0.19），但差异无统计学意义（r = 0.62, p = 0.38），说明土地覆被对土壤湿度的影响大于降雨。研究结果强调了可持续土地利用实践的迫切需要，以减轻对自然土地覆盖和湿地生态系统的不利影响。裸地的迅速扩大和湿地的减少凸显了土地覆盖变化带来的紧迫挑战，特别是在日益干旱的地区。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Physics and Chemistry of the Earth 地学-地球科学综合

CiteScore

5.40

自引率

2.70%

发文量

176

审稿时长

31.6 weeks

期刊介绍： Physics and Chemistry of the Earth is an international interdisciplinary journal for the rapid publication of collections of refereed communications in separate thematic issues, either stemming from scientific meetings, or, especially compiled for the occasion. There is no restriction on the length of articles published in the journal. Physics and Chemistry of the Earth incorporates the separate Parts A, B and C which existed until the end of 2001. Please note: the Editors are unable to consider submissions that are not invited or linked to a thematic issue. Please do not submit unsolicited papers. The journal covers the following subject areas: -Solid Earth and Geodesy: (geology, geochemistry, tectonophysics, seismology, volcanology, palaeomagnetism and rock magnetism, electromagnetism and potential fields, marine and environmental geosciences as well as geodesy). -Hydrology, Oceans and Atmosphere: (hydrology and water resources research, engineering and management, oceanography and oceanic chemistry, shelf, sea, lake and river sciences, meteorology and atmospheric sciences incl. chemistry as well as climatology and glaciology). -Solar-Terrestrial and Planetary Science: (solar, heliospheric and solar-planetary sciences, geology, geophysics and atmospheric sciences of planets, satellites and small bodies as well as cosmochemistry and exobiology).