Desiccation of the Transboundary Hamun Lakes: Natural or Anthropogenic?

This paper investigates the hydrologic and water management reasons behind the desiccation of the Hamun Lakes in the Iran-Afghanistan border region. We analysed changes in Hirmand (or Helmand) River flow, the main tributary providing 70% of the lakes’ total inflow, and precipitation during 1960-2016 by calculating standardized indices for precipitation (SPI) and discharge (SDI). Also, we applied Normalized Difference Spectral Indices (NDSIs) using satellite images from 1987 to present to observe monthly areal change of the lakes. The transboundary water body is responding to changes in regional water management, which has severely reduced the lakes’ inflow. Upstream water regulation in Afghanistan coupled with reservoir construction on the Iranian side has caused nearly full desiccation of major parts of the lake system. There is a discernible shift in the relation between the Hirmand River flow at the international border and upstream precipitation over the lakes’ basin before and after 2004. From 1960 to 2003, high river flows were expected to feed the lakes due to high precipitation over the basin. However, the Hirmand River flow at the border declined after 2004 despite large amounts of upstream precipitation, including the largest recorded amounts, especially in the Hindu Kush mountains. Further, environmental water stress caused by anthropocentric water management in Iran by reservoir construction has impacted the area of the lakes. Although a long period of drought from 1998-2004, i.e. climatic driver, decreased the lakes’ area, the lake system is primarily falling victim to anthropogenic flow alterations in the transboundary river basin. The lakes’ shrinkage places socio-economic stress on an already-vulnerable region with important public health implications as the exposed lake beds turn into major sources of sand and dust storms.

Change point detection and Trend analysis of observed streamflow in the Upper Mekong Basin during the period 1960--2020

The Langcang-Mekong River Basin is the most important transboundary river basin in Asia. However, over the recent decades, dam construction has been increasingly recognized as having profound effects on hydrological processes, aquatic and riparian ecosystems. Understanding these impacts is critical for the foundation of sustainable runoff surface management. In this study, different methods based on both graphical and numerical techniques were applied to assess the effects of the dams on annual, seasonal, and monthly runoff and to detect hydroclimatic trends in the Upper Mekong Basin during the period 1960–2020. The results reveal two change points with respect to seasonal and annual flow regimes; that is 2003 for the flood season and annual flows, and 2013 for the dry season flow. The duration of the flood season and the volume of annual discharges have both significantly decreased since 2003 and the dry season discharge has significantly increased since 2013 (with both p-values < 0.05). The quantitative assessment suggests that, due to the effect of dams, the monthly discharges increased around 10–450 m3/s during the dry season (December to May), while the flood season’s monthly flows decreased significantly, approximately 1028–2150 m3/s from July to October at Chiang Saen station. The study of hydrological changes in the Mekong watershed is expected to be a significant contribution towards a better understanding of large watersheds in which the hydrological responses are influenced not only by climate change at large spatial and temporal scales but also by changes in the physical environment due to the construction of dams.

Hidroextractivismo en la cuenca del Usumacinta: entre dinámicas transfronterizas y diferenciaciones fronterizas / Hydroextractivism in the Usumacinta river basin: among transboundary dynamics and border differentation

Partiendo de una reflexión teórica sobre el extractivismo, el artículo desarrolla una tipología que evidencia a la vez las características del hidroextractivismo y su profunda diversidad. ¿Qué entendemos por hidroextractivismo y cuáles son sus componentes? ¿Cuáles son las expresiones del hidroextractivismo en la cuenca transfronteriza del río Usumacinta? ¿Cuál es la relación con lo fronterizo y transfronterizo en este escenario? Para contestar a estas tres interrogaciones, el trabajo aborda, en primer lugar, la noción de hidroextractivismo como fenómeno sociopolítico y sus diversas expresiones. En segundo lugar, presenta las formas que adopta en la cuenca del Usumacinta a partir de hallazgos del trabajo de campo. Finalmente, profundiza en torno a sus relaciones con las dimensiones transfronterizas del fenómeno y al papel de la frontera en la existencia de diferenciaciones asociadas a este fenómeno. Abstract: Starting from a theoretical reflection on extractivism, the paper proposes a typology that evidences the characteristics of hydroextractivism and its deep diversity. What is hydroextractivism and what is it compounded by? How is hydroextractivism stated in the Usumacinta transboundary river basin? How does it relate with transboundary and border issues in this context? To attend these questions, the text first evokes the notion of hydroextractivism as a socio-political phenomenon and its diverse expressions. Then it focuses on its manifestations in the Usumacinta basin according to fieldwork findings. It eventually deepens on the links between hydroextractivism, transboundary and border issues that deal with observed differentiations.Keywords: extractivism; hydroextractivism; Usumacinta; transfronterity; border.Résumé : A partir d’une réflexion théorique sur l’extractivisme, l’article développe une typologie qui met à la fois en évidence les caractéristiques de l’hydroextractivisme et sa grande diversité. Qu’est-ce que l’hydroextractivisme et quels en sont ses composantes ? Quelles sont ses expressions dans le bassin transfrontalier de l’Usumacinta ? Quelles sont les relations avec le frontalier et le transfrontalier dans ce contexte ? Pour répondre à ces trois questions, le texte aborde en premier lieu la notion d’hydroextractivisme en tant que phénomène socio-politique et ses diverses expressions. Il présente ensuite les formes qu’il adopte dans le bassin de l’Usumacinta à partir de données de terrain. Enfin, il approfondit les relations que ce phénomène entretient avec les dimensions transfrontalières et le rôle de la frontière dans l’existence d’éléments de différentiation.Mot-clés : extractivisme ; hydroextractivisme ; Usumacinta ; transfrontérité ; frontière.

Transboundary River Basin Governance: A Case of the Mekong River Basin

Conflict and cooperation are key governance challenges in transboundary river basin governance, especially in the Mekong River Basin. Hydropower dams have been at the center of such a conflict and cooperation that are useful metrics to assess the level and intensity of conflict and cooperation in transboundary river basin governance. This study examines transboundary river basin cooperation in the Mekong through the lens of hydropower dam projects. It uses a literature review and a case study of the Lower Sasan 2 (LS2) Dam to analyze the conflict and cooperation in the Mekong region, from the era of the US influence in the Cold War, the post-Cold War period, and the present-day with the rise of China. It concludes that Mekong river basin cooperation has evolved as a result of external influences and internal competition by riparian states over Mekong resources. The LS2 was identified in 1961 by US-supported hydropower studies and then by the GMS/ADB in 1998, but left unattended until 2007 when Vietnam signed an agreement with Cambodia to undertake a feasibility study in 2008. It took 16 years to get the LS2 built by a Chinese company in 2014 and completed it in 2017. Through the process, the states, powerful external actors, financial institutions, and private sector actors have politicized the LS2 studies, design, and construction. Cambodia, as a weak downstream state, has had to and must continue to position itself strategically in its relationships with these hydro-hegemons to compete for hydropower dam projects and protect its interests. The rise of China has induced the changing relationship between riparian states. Many hydropower dams were built with Chinese funding. Cambodia has also enjoyed its close ties with China, and the building of the LS2 dam by a Chinese company contributes to changing its positions in the Mekong cooperation but suffers environmental and social impacts.