7 research outputs found
Spatio-seasonal variation of water quality influenced by land use and land cover in Lake Muhazi.
peer reviewedUnderstanding the influence of land use/land cover (LULC) on water quality is pertinent to sustainable water management. This study aimed at assessing the spatio-seasonal variation of water quality in relation to land use types in Lake Muhazi, Rwanda. The National Sanitation Foundation Water Quality Index (NSF-WQI) was used to evaluate the anthropogenically-induced water quality changes. In addition to Principal Components Analysis (PCA), a Cluster Analysis (CA) was applied on 12-clustered sampling sites and the obtained NSF-WQI. Lastly, the Partial Least Squares Path Modelling (PLS-PM) was used to estimate the nexus between LULC, water quality parameters, and the obtained NSF-WQI. The results revealed a poor water quality status at the Mugorore and Butimba sites in the rainy season, then at Mugorore and Bwimiyange sites in the dry season. Furthermore, PCA displayed a sample dispersion based on seasonality while NSF-WQI's CA hierarchy grouped the samples corresponding to LULC types. Finally, the PLS-PM returned a strong positive correlation (+ 0.831) between LULCs and water quality parameters in the rainy season but a negative correlation coefficient (- 0.542) in the dry season, with great influences of cropland on the water quality parameters. Overall, this study concludes that the lake is seasonally influenced by anthropogenic activities, suggesting sustainable land-use management decisions, such as the establishment and safeguarding protection belts in the lake vicinity
Spatial analysis of water supply network dispersion and its impact on community livelihood in Rwanda - - a case study of Nyanza district
在全球范围内,水资源是每个家庭生存的基本需求。如果全球水资源在空间和时间上都得到很好的分配和利用,那么就不会遇到水资源短缺的问题。水在人类生活是必不可少的, 在饮水,食品制备和卫生健康等行业更为突出。当今的水资源危机并不是由于水量减少造成的,而是由水资源管理不善造成的。即使现在,世界上仍然有数量众多的人口正遭受着供水不足以及水资源的不可持续使用的困扰。在发展中国家,导致水源供应服务问题的因素是众多的、复杂的、相互关联的,有时还受到政治决策、 社会不稳定、贫穷和内战的影响,人们获取水资源的方式差异很大,对于卢旺达也是如此。卢旺达是一个拥有 30 个地区的山区国家,其中 Nyanza 地区水资源严重短缺,其原因包括气候变化, 自然景观,水资源管理投资少以及可用供水网络的空间分布不均等,饮用水的供应需要投入大量资金来建设管道供水设施。一直以来,气候变化的加剧,当局的管理不善和腐败,水资源管理机构的缺失,官僚主义的惯性以及人力资源建设和物质基础设施投资的缺乏被认为是限制人们获得水资源的主要原因。。在卢旺达,水管是目前的主要发展的供水设施,由于众多原因无法向每个家庭输送自来水管, 分配足够的水,结果导致水资源供给短缺。 本文的研究地区 Nyanza 具有多种可利用的饮用水资源,包括河流和地下水,但是,它们大部分尚未开发,该地区居民无法获得足够的生活用水。因此,在水资源的获取和分配方面存在诸多差距。 本文通过查阅文献资料以及实地考察, 发现供水系统分配不均的主要原因是空间数据的不足和缺乏社区水资源管理技术的支持。Nyanza 地区需要建立与供水网络有关的水资源可达性优化系统,这将有助于水资源供给网络的合理分布,并且考虑到不同水源的储存水源的定位。 一项对该地区水资源文献的批判性研究表明,在界定研究区域所观察到的水资源短缺问题时,存在一些关键的概念困境。 在 Nyanza 地区观察到的水资源短缺问题已经影响到当地居民的家庭生活和农业发展。该地区可以利用的水资源可以从井或河中获得,但无法将水资源输送分配到每家每户,由于集水设施的限制,只有少部分家庭可以使用自来水。这项研究旨在分析 Nyanza 地区家庭供水网络的空间分布,并评估其对社区生计的影响。 本研究的是使用不同的数据集和方法来实现的;采用的数据集类型包括遥感数据和社会经济数据。使用地理信息系统(GIS)对收集的遥感数据进行了分析; 使用数字高程模型(DEM)生成等高线和坡度图;形成研究区域的地形信息用来设计供水网络线路,供水管沿着该地区的道路分布。此外,通过应用空间分析工具的欧几里德距离生成与河流的距离。此外,该研究使用主要和次要数据源。第一阶段, 进行调查问卷,以收集与社会经济特征和供水网络的空间分布对 Nyanza 地区社区的影响以及社区对水服务和状况的总体看法有关的数据。次要数据源包括期刊文章,政策文件,不同年份的遥感影像,自来水公司(WASAC)的数据,书籍和互联网资源。多次对 WASAC 总部进行了个人访问,以搜索文档,档案记录,文献和出版物。综上所述,本研究的主要数据来自与受访者(WASAC代表和用水者)的深入问卷调查,通过使用社会科学统计软件包(Statistical Package forSocial Sciences, SPSS 23.0) 对从调查中获得的数据进行描述性和分析性统计。最后,通过观察和家庭启示;确定了公共自来水,井水, 电井水和河水等水源,并使用 GPS 对这些水源和住户在研究区域中的位置进行了定位。通过调查得到主要结论, 如下:(1)参加问卷调查的居民中,男性占 44%,女性占 56%。这意味着女性比男性参与度更高;与之前的研究一致,即从传统渠道获取水源的影响对女性的生活造成了损害,她们对水的需求高于男子。(2)研究揭示了该地区可用的各种水源,包括公共水龙头,室内水龙头,井眼,雨水,挖井,河流/溪流。由于季节变化,这些来源的使用也相应变化。 56%的居民表示,雨水是雨季的主要来源,在干旱季节, 居民从公共水龙头取水。(3)由于政府无法整合与水有关的资源,从而无法确保公民获得充足和廉价的水源供应。 居民根据当地的地形条件定居导致水源分配和可及性方面的差异。有些人居住在规划外的定居点中, 有些人居住在较高的山坡上,给负责机构安装水相关基础设施(例如管道和其他供水设施)带来困难。由于供水网络的分布不均匀, 部分地区的自然地理位置不佳,该地区并非每个人都可以充分获得充足的水资源供应。此外,人口增长和城市化也是挑战性因素。根据定居点类别的土地覆被/土地利用(LCLU)的变化趋势, Nyanza 地区从 1990年到 2018年发生了很大变化。例如,从 1990年到 2000年,定居点扩大到 2公顷,占总面积的 0.3%;而从 2000 年到 2010 年,定居点持续扩大,从 2010 年到 2018 年,从 2公顷扩大到 1600.7 公顷,占总面积的 0.75%。(4)调查结果还表明,供水不足对社区居民生活有负面影响。该地区的水资源短缺尤其对日常家庭活动产生重大影响。女性是 Nyanza 的主要取水者,因此承担着水资源稀缺和可及性的大部分负担。这清楚地证实了她们是大多数经历和了解得更多并且遭受负面影响最大的人。社区从经济影响,健康问题,卫生状况,社会冲突和移民的角度揭示了缺水的影响。(5) Nyanza 地区的 317 个供水源在空间上的分布不均。在供水系统(WSS) 中,确定了公共水龙头,水井和;其中,有些没有发挥应有的功能。与住户相比,还绘制了 10个扇区中的 1017 个地理参考住户,以根据可用住户供水系统(WSS)根据计算得出的住户到所用 WSS 的距离,确定真正造成缺水的扇区。调查结果表明,供水系统(WSS)在50 米以内的人等于 15.8%,而 7.5%的家庭在 50 至 500 米之间。此外,取水距离在 500 至1000 米之间的家庭占 8.5%,而取水距离在 1000 至 1500 米之间的家庭占 65.9%。 最终,其余 2.3%的人在 1500 多米处取水。这一发现与伦敦卫生学院(London School of Hygiene)(2009)完全不同,该观点指出,每个家庭的取水点最大不应超过 500 米。通过欧几里得距离的平均值,邻近分析表明,供水系统(WSS)到最近家庭的距离。 据统计,许多住户到最近的供水系统(WSS)的距离在 0 到 1000m 之内,但是我们还观察到丘陵地区的许多住户面临着水的问题,这使得他们在长途跋涉中取水。有住户距离最近的供水系统(WSS)很远,这意味着距离超过 1000 m,但是问题是许多最近的供水系统(WSS)无法正常工作。(6)当前社区的水供应和可及性与各种挑战有关。人们发现这些挑战是由于各种因素造成的,这些因素造成了这种资源向社区的传播差异。绝大多数 32%的受访者提到供水基础设施已经老化导致他们的用水量很低且利用率很低。此外,有 29%的人表示人口增长和城市化在很大程度上造成了供水不足,而有 24%的人认为自己的地理位置。此外,还有其他受访者认为,水分配和可及性方面的不平等问题是由供水机构(WASAC)的失败造成的。不仅在 Nyanza 地区,而且在整个卢旺达,不可靠的电力供应也被认为是公共供水不足的原因。总之,决策者需要做出更多努力来应对 Nyanza 地区的水资源短缺问题,因为据描述,他们没有基础设施的空间状况,尤其是在供水领域,这导致他们做出的决策不会解决当前和实际的问题。因此, 需要提高水资源的公平分配。从这项研究中获得的信息非常重要,因为它们可以在制定有关公平性和充分水扩散的新政策时用作基准。建议政府不仅通过放置达到需求点的额外管道来促进网络的合理扩展,而且应通过加强,修复或更换网络水管来保卫这一过程,此外还要投资于雨水 收集技术和社区水基础设施,并制定控制人口增长的机制和政策
A CA–Markov-Based Simulation and Prediction of LULC Changes over the Nyabarongo River Basin, Rwanda
Over the past few decades, the growth of population and the development of the economy have had a significant impact on the way land is used and covered (LULC) in the Nile Nyabarongo River basin. However, there is limited knowledge about the patterns of land use and the mechanisms that drive changes in these patterns because of human activities. Therefore, it is crucial to examine how land use and cover are shifting in this area, identify the factors responsible for these changes, and forecast future patterns. This study sought (1) to evaluate the changes in LULC from 1990 to 2020 and (2) to predict future fluctuations until 2060. By analyzing the LULC data for the years 1990, 2000, 2010, and 2020, this study simulated the future LULC patterns of the area for the next 30 years using the LULC transition matrix and the Markov chain model. The study classified the LULC into five categories: forestland, grassland, cropland, settlement, and water. The results revealed that there will be significant changes in the LULC of the study area from 2030 to 2060. The forest area is projected to decrease by 801.7 km, 771.6 km, and 508.2 km, while the cropland area will expand by 6307.2 km, 6249.2 km, and 6420.6 km during this period. The grassland area will experience a small increase of 761.1 km, 802.4 km, and 859.1 km, and the settlement area will also grow by 355.2 km, 407.4 km, and 453.2 km. In contrast, the water area will decrease by 55.9 km, 50.5 km, and 40 km. The ongoing pattern of LULCC is expected to persist over the next three decades, with an increase in cropland area and grassland. This study’s findings can provide valuable insights for land use planners and water resource managers in developing fair land use and water resource management policies for the entire region, enabling them to make well-informed decisions
Review on water resources management and key threats in Rwanda, East Africa
Water is important for human health, industry, agriculture and ensuring the integrity and sustainability of the ecosystem. The water resources are the top affected by climate variability and population growth. The current population of Rwanda is about 12 million heading to about 25 million in 2050 under the changing climate, where since 1970 temperature rose by 1.4°C and is predicted that in 2050 to be about 2.5°C with severe effects on water resources in Rwanda. Thereby, this study reviewed the status and causes of water quality problems and suggested appropriate options to undertake for sustainable water resources access, employ and management in Rwanda. It was noticed that among others, the key threats to water quality in Rwanda, include not limited to climate change causing rainfall patterns which generated flooding, landslides and periodic droughts, which loaded pollutants into water. In addition, water quality is jeopardized by the rapid population growth, agrochemicals, industrialization, urbanization, soil steepness and land mismanagement. Accordingly, the reviewed water quality indicate that the water quality pollution likelihood is increasing over time. These facts reveal that the water quality soon or late will be highly polluted and calls for further adaptation and management measures
Analysis of fluctuations in vegetation dynamic over Africa using satellite data of solar-induced chlorophyll fluorescence
In Africa, vegetation is important for the protection of species habitats, maintaining local livelihoods, and the existence of wildlife. A comprehensive evaluation of vegetation dynamics using solar-induced fluorescence (SIF) is needed to acquire important information to understand the current situation of how ecosystems react to human activities and climate change, as well as for conservation planning. The research’s purpose was to detect vegetation dynamics in Africa from 2000 to 2017 using global, OCO-2-based SIF (GOSIF) and various datasets, as well as to analyze the factors influencing vegetation changes. The main findings revealed that: (1) The patterns for various vegetation in this study showed that forests experienced more vegetation expansions than croplands, grasslands, shrubland, and sparse vegetation, based on the Land Use Cover Change (LUCC) per vegetation type. (2) According to SIF, the decreasing area accounts for 29.4% of the total vegetation region while expanding area accounts for 70.6%. (3) The Hurst exponent summary exhibited that the majority of studied vegetation variations are consistent and accounted for 79.7%. (4) Based on the residual, we discovered that climatic patterns might be responsible for the greening trend of sparse vegetation and grassland. (5) The Boosted Regression Trees (BRT) showed that during the study period, Vapor pressure deficit (VPD) and the temperature had a greater impact on SIF vegetation dynamics than other factors. Our findings can aid in the development of appropriate vegetation management concepts or strategies to help in vegetation restoration in Africa