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Table 4 Hierarchy and weights for obtaining the state-level global water security index in our study

From: State level water security indices in Mexico

Global water security index

Availability

45%

Accessibility

20%

Safety and quality 20%

Management

15%

a) WSI (70%).

\( \boldsymbol{WSI}=\frac{{\boldsymbol{W}}_{\boldsymbol{w}}}{{\boldsymbol{A}}_{\boldsymbol{w}}-{\boldsymbol{E}}_{\boldsymbol{w}}} \)

where:

Ww: water withdrawal

Aw: water availability (renewable) and

Ew: environmental flow requirements; in %Rw, as determined by Mexican standard NMX-AA-159-SCFI-2012, which establishes the procedure for environmental flow determination in hydrological basins.

b) Drought index (15%).

As percentages of the municipalities with drought and of the state surface experiencing a drought, according to the Mexico Drought Monitor.

c) Groundwater depletion (15%).

Ratio of groundwater extraction to natural recharge plus return flows from irrigation.

a) Access to drinking water (60%).

Percentage of the population with access to sources of improved drinking water, i.e., installation of delivery points that protect water from external contamination, particularly fecal contamination. Includes piped water to homes, public hydrants, wells, protected springs, and rainwater collection systems.

b) Access to sanitation (40%).

Percentage of the population with access to improved sanitation (whereby human excretions are hygienically separated and is not public, either private or shared). Includes discharge to sewers, septic systems, discharge latrines, simple pit latrines or ventilated pit latrines.

a) Water quality index (50%).

Includes the following four water-quality parameters monitored by CONAGUA at 4999 sites around Mexico: BOD5, COD, TSS, and TDS

b) Flood index (50%).

Relative flooding frequency for a given period, whereby the information is available in public reports on hydrometeorological phenomena per municipality published by CONAGUA.

Expresses social and institutional management issues such as water planning and management, economic policies, and others.

a) World governance index (70%).

Includes voice and accountability, political stability and absence of violence, government effectiveness, regulatory quality, rule of law, and control of corruption

b) Transboundary legal framework (15%).

Expresses the range of treaties per transboundary basin and their associated risks of conflict.

c) Transboundary hydropolitical tension (15%).

Expresses the level of tension in transboundary basins and the associated risk levels.